Patent Publication Number: US-2020288743-A1

Title: Chocolate-like food containing polyunsaturated fatty acid

Description:
TECHNICAL FIELD 
     The present invention relates to a chocolate-like food product containing polyunsaturated-fatty-acid-containing oil and fat. 
     BACKGROUND ART 
     Chocolate-like food products, typically chocolate, are also a favorite of children. Thus, incorporation of a specific nutrient component into a chocolate-like food product can allow children to effortlessly intake the nutrient component. 
     Materials whose physiological effects are gathering attention include polyunsaturated fatty acids, typified by DHA and EPA. However, it is often difficult to incorporate polyunsaturated fatty acids, which are susceptible to oxidative deterioration, into regular food products. 
     Patent Literature (PTL) 1 discloses a chocolate composition comprising non-hydrogenated oil-and-fat containing eicosapentaenoic acid and/or docosahexaenoic acid, and at least one type of catechin. 
     PTL 2 discloses a polyunsaturated-fatty-acid-containing food product comprising a film of oil and fat obtained by coating polyunsaturated-fatty-acid-containing oil and fat with an edible film-forming substance comprising a protein or a salt thereof, a lipid, or a combination thereof such that the oil and fat are substantially insulated from the outside air, the film of oil and fat being in the form of particles having a diameter of 2 mm or less. 
     PTL 3 discloses using proline as an anti-oxidant. 
     PTL 4 discloses using proline to adjust the flavor of chocolate. 
     CITATION LIST 
     Patent Literature 
     
         
         PTL 1: JPH05-292885A 
         PTL 2: JPS59-17949A 
         PTL 3: JP2004-331724A 
         PTL 4: JP2005-506847A 
       
    
     SUMMARY OF INVENTION 
     Technical Problem 
     The present invention relates to a chocolate-like food product containing polyunsaturated-fatty-acid-containing oil and fat, and an object of the present invention is to provide a chocolate-like food product with reduced flavor change that occurs with time. 
     Solution to Problem 
     The present inventors conducted extensive research to achieve the object. 
     The method disclosed in PTL 1 is considered to achieve, to some extent, an effect of reducing changes that occur with time; however, chocolate-like food products having a relatively long best-before period require a stronger effect. 
     The method disclosed in PTL 2 involves the addition of a polyunsaturated fatty acid in a capsule form; thus, its application to chocolate-like food products, which are valued for melting texture in the mouth, was difficult. 
     PTL 3 discloses using proline as an anti-oxidant. PTL 3 also discloses use in chocolates. However, this is only disclosed in a list of various food products, and their specific effects are nowhere disclosed. PTL 3 also nowhere discloses an effect on polyunsaturated-fatty-acid-containing chocolate-like food products. 
     PTL 4 only discloses using proline as a flavor precursor for chocolate flavor, and PTL 4 nowhere discloses an effect on polyunsaturated-fatty-acid-containing chocolate-like food products. 
     The present inventors conducted further research and found that incorporation of amino acid into a chocolate-like food product containing polyunsaturated-fatty-acid-containing oil and fat significantly reduces the unpleasant odor that occurs with time. The present invention has thus been accomplished. 
     Specifically, the present invention relates to the following: 
     (1) A chocolate-like food product containing EPA and DHA in a total amount of 0.02 to 10 wt %, and further containing an amino acid in an amount of 0.002 to 0.5 wt %. 
     (2) The chocolate-like food product according to Item (1), wherein the amino acid is at least one amino acid selected from glycine, glutamic acid, alanine, proline, lysine, tryptophan, methionine, valine, serine, histidine, isoleucine, leucine, phenylalanine, arginine, threonine, cysteine, aspartic acid, glutamine, or asparagine. 
     (3) The chocolate-like food product according to Item (1), containing catechin in an amount of 0.005 to 0.4 wt %. 
     (4) The chocolate-like food product according to Item (2), containing catechin in an amount of 0.005 to 0.4 wt %. 
     (5) The chocolate-like food product according to Item (1), containing 0.02 to 2 wt % of an aqueous phase in a dispersed state, the aqueous phase containing the amino acid in an amount of 1 to 50 wt % and having a total water-soluble solids content of 30 to 70 wt %. 
     (6) The chocolate-like food product according to Item (2), containing 0.02 to 2 wt % of an aqueous phase in a dispersed state, the aqueous phase containing the amino acid in an amount of 1 to 50 wt % and having a total water-soluble solids content of 30 to 70 wt %. 
     (7) The chocolate-like food product according to Item (3), containing 0.02 to 2 wt % of an aqueous phase in a dispersed state, the aqueous phase containing the amino acid in an amount of 1 to 50 wt % and having a total water-soluble solids content of 30 to 70 wt %. 
     (8) The chocolate-like food product according to Item (4), containing 0.02 to 2 wt % of an aqueous phase in a dispersed state, the aqueous phase containing the amino acid in an amount of 1 to 50 wt % and having a total water-soluble solids content of 30 to 70 wt %. 
     (9) The chocolate-like food product according to Item (5), wherein the aqueous phase contains catechin in an amount of 2 to 50 wt %. 
     (10) The chocolate-like food product according to Item (6), wherein the aqueous phase contains catechin in an amount of 2 to 50 wt %. 
     (11) The chocolate-like food product according to Item (7), wherein the aqueous phase contains the catechin in an amount of 2 to 50 wt %. 
     (12) The chocolate-like food product according to Item (8), wherein the aqueous phase contains the catechin in an amount of 2 to 50 wt %. 
     (13) The chocolate-like food product according to any one of Items (5) to (12), wherein the aqueous phase contains, as the water-soluble solids content, at least one member selected from sugar alcohols, glucose, sucrose, dextrins, or oligosaccharides. 
     (14) A method for producing a chocolate-like food product, the method comprising the steps of: 
     dispersing an aqueous phase containing an amino acid in an amount of 1 to 50 wt % and having a total water-soluble solids content of 30 to 70 wt % in polyunsaturated-fatty-acid-containing oil and fat; and 
     blending the polyunsaturated-fatty-acid-containing oil and fat to obtain a chocolate-like food product containing EPA and DHA in a total amount of 0.02 to 10 wt %, and further containing the amino acid in an amount of 0.002 to 0.5 wt %. 
     (15) The method for producing a chocolate-like food product according to Item (14), the method comprising the step of adding 2 to 50 wt % of catechin to the aqueous phase. 
     (16) The method for producing a chocolate-like food product according to Item (14) or (15), the method comprising the step of adding, as the water-soluble solids content, at least one member selected from sugar alcohols, glucose, sucrose, dextrins, or oligosaccharides to the aqueous phase. 
     In other words, the invention includes the following. 
     (21) A chocolate-like food product containing EPA and DHA in a total amount of 0.02 to 10 wt %, and further containing an amino acid in an amount of 0.002 to 0.5 wt %. 
     (22) The chocolate-like food product according to Item (21), wherein the amino acid is at least one amino acid selected from glycine, alanine, threonine, phenylalanine, serine, valine, proline, glutamic acid, lysine, or aspartic acid. 
     (23) The chocolate-like food product according to Item (21) or (22), containing catechin in an amount of 0.005 to 0.4 wt %. 
     (24) The chocolate-like food product according to Item (21) or (22), containing 0.02 to 2 wt % of an aqueous phase in a dispersed state, the aqueous phase containing the amino acid in an amount of 1 to 50 wt % and having a total water-soluble solids content of 30 to 70 wt %. 
     (25) The chocolate-like food product according to Item (24), wherein the aqueous phase contains catechin in an amount of 2 to 50 wt %. 
     (26) A method for producing a chocolate-like food product, the method comprising the steps of: 
     dispersing an aqueous phase containing an amino acid in an amount of 1 to 50 wt % and having a total water-soluble solids content of 30 to 70 wt % in polyunsaturated-fatty-acid-containing oil and fat; and 
     blending the polyunsaturated-fatty-acid-containing oil and fat to obtain a chocolate-like food product containing EPA and DHA in a total amount of 0.02 to 10 wt %, and further containing the amino acid in an amount of 0.002 to 0.5 wt %. 
     Advantageous Effects of Invention 
     The present invention can reduce the flavor change that occurs with time of a chocolate-like food product containing polyunsaturated-fatty-acid-containing oil and fat. 
    
    
     DESCRIPTION OF EMBODIMENTS 
     An example of a “chocolate-like food product” as used in the present invention is chocolates. “Chocolates” as used herein refers not only to chocolate, quasi-chocolate, and chocolate-using food products as defined by the Japan Fair Trade Council of Chocolate Industry or the Fair Trade Council of Chocolate-Using Products, but also to those containing oil and fat as essential components, optionally with adjuncts, such as sugar, milk powder, cacao starting materials (e.g., cacao mass, cocoa, and cocoa butter), fruit-juice powder, fruit powder, taste improvers, emulsifiers, flavoring, and color additives in any amounts. 
     Typical examples of chocolates include sweet chocolates, milk chocolates, and white chocolates. Examples also include strawberry chocolates and the like that contain a fruit component. 
     The polyunsaturated-fatty-acid-containing oil and fat as used in the present invention contain at least one polyunsaturated fatty acid as the constituent fatty acid. The polyunsaturated fatty acids as used herein refer to fatty acids with many double bonds and may also be called “PUFAs.” Specific examples include DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid). The polyunsaturated-fatty-acid-containing oil and fat may be also referred to as “PUFA oil.” 
     It is essential for the chocolate-like food product according to the present invention to contain polyunsaturated-fatty-acid-containing oil and fat such that the total amount of DHA and EPA is 0.02 to 10 wt %, preferably 0.2 to 8 wt %, and more preferably 1 to 6 wt %. Incorporation of an appropriate amount of polyunsaturated-fatty-acid-containing oil and fat is expected to achieve its effect. 
     It is essential for the chocolate-like food product according to the present invention to contain an amino acid in an amount of 0.002 to 0.5 wt %, preferably 0.006 to 0.2 wt %, and more preferably 0.01 to 0.15 wt %. Incorporating an appropriate amount of amino acid makes it possible to reduce the unpleasant odor that occurs with time in the chocolate-like food product that contains DHA and EPA in a total amount of 0.02 to 10 wt %. 
     The amino acid can also be added as a salt. For example, sodium glutamate may be added instead of glutamic acid, and sodium aspartate may be added instead of aspartic acid. In the present invention, even when the term “amino acid” is simply used, the scope of this term also encompasses salts thereof. 
     Various amino acids may be used as the amino acid. It is preferable to use at least one amino acid selected from glycine, glutamic acid, alanine, proline, lysine, tryptophan, methionine, valine, serine, histidine, isoleucine, leucine, phenylalanine, arginine, threonine, cysteine, aspartic acid, glutamine, or asparagine; it is more preferable to use at least one amino acid selected from glycine, glutamic acid, alanine, proline, lysine, tryptophan, methionine, valine, serine, histidine, isoleucine, leucine, or phenylalanine; it is still more preferable to use at least one amino acid selected from glycine, glutamic acid, alanine, proline, lysine, tryptophan, or methionine. 
     Some amino acids are less soluble, and such amino acids may be used in combination with other amino acids. 
     The use of an appropriate amino acid makes it possible to reduce the unpleasant odor that occurs with time in the chocolate-like food product that contains DHA and EPA in a total amount of 0.02 to 10 wt %. 
     The present invention is characterized in that the amino acid is present in a dissolved state in water in the chocolate-like food product. In the present invention, an aqueous solution in which the amino acid is dissolved is referred to as an “aqueous phase.” The concentration of the amino acid in the aqueous phase is preferably 1 to 50 wt %, more preferably 1.5 to 40 wt %, and still more preferably 2 to 26 wt %. 
     If the amino acid concentration in the aqueous phase is appropriate, it is possible to reduce the unpleasant odor that occurs with time in the chocolate-like food product that contains DHA and EPA in a total amount of 0.02 to 10 wt %. 
     In the present invention, a carbohydrate is preferably dissolved in the aqueous phase. The carbohydrate is preferably at least one member selected from sugar alcohols, oligosaccharides, various monosaccharides, such as glucose, various disaccharides, such as sucrose, or dextrins, more preferably a sugar alcohol, sucrose, or a dextrin, and even more preferably sucrose or a sugar alcohol. 
     Of sugar alcohols, preferred are glycerol, maltitol, sorbitol, and erythritol; more preferred is erythritol. 
     The carbohydrate is used in the aqueous phase in a total amount with other water-soluble solids including the amino acid, of preferably 30 to 70 wt %, more preferably 32 to 65 wt %, and still more preferably 34 to 61 wt %. 
     If an appropriate amount of an appropriate carbohydrate is used to adjust the solids content to an appropriate value, it is possible to reduce the unpleasant odor that occurs with time in the chocolate-like food product that contains DHA and EPA in a total amount of 0.02 to 10 wt %. 
     In the present invention, the aqueous phase in an amount of preferably 0.02 to 2 wt %, more preferably 0.04 to 1.8 wt %, and still more preferably 0.06 to 1.6 wt %, is present in a dispersed state in the chocolate-like food product that contains DHA and EPA in a total amount of 0.02 to 10 wt %. 
     If an appropriate amount of the aqueous phase is dispersed, it is possible to reduce the unpleasant odor that occurs with time in the chocolate-like food product that contains DHA and EPA in a total amount of 0.02 to 10 wt %. 
     It is also possible to use vitamin C or catechin as an anti-oxidant. If contained, the amount of catechin in the aqueous phase is preferably 2 to 50 wt %, more preferably 10 to 45 wt %, and still more preferably 12 to 43 wt %. 
     In the chocolate-like food product that contains DHA and EPA in a total amount of 0.02 to 10 wt %, catechin is preferably contained in an amount of 0.005 to 0.4 wt %, and more preferably 0.04 to 0.3 wt %. 
     The use of catechin in an appropriate amount makes it possible to reduce the unpleasant odor that occurs with time in the chocolate-like food product that contains DHA and EPA in a total amount of 0.02 to 10 wt %. 
     The use of vitamin C, however, in the chocolate-like food product that contains DHA and EPA in a total amount of 0.02 to 10 wt % may cause a specific unpleasant taste. 
     The present invention is characterized in that an amino acid is used as an anti-oxidant, and this makes it possible to obtain a chocolate-like food product that contains PUFA oil such that DHA and EPA are present in a total amount of 0.02 to 10 wt %, without impairing the fundamental flavor of chocolate. 
     The following describes the method for preparing a chocolate-like food product according to the present invention. 
     First, an aqueous phase is prepared. The aqueous phase as used herein is prepared for the purpose of imparting antioxidative activity to a chocolate-like food product that contains DHA and EPA in a total amount of 0.02 to 10 wt % and essentially consists of water, an amino acid, and a carbohydrate. 
     Although the chocolate-like food product contains in itself a carbohydrate to achieve sweetness, this carbohydrate is distinguished from the carbohydrate in the aqueous phase since the carbohydrate in the aqueous phase is present in a dissolved state in the aqueous phase. 
     The amounts of the amino acid and carbohydrate in the aqueous phase are as stated above. 
     In the present invention, the water-soluble solids content in the aqueous phase must be present in a substantially dissolved state. The determination of whether the water-soluble solids are substantially dissolved is made by introducing 5 ml of the aqueous phase into a 20-ml centrifugal tube, followed by centrifugal separation (3000×g, 1 minute) at 20° C. If no precipitate is visually observed even after this process, a substantially dissolved state is considered to be achieved. 
     In the present invention, expressions such as “contained in the aqueous phase” mean being present in the dissolved state in the aqueous phase, as described above. 
     When the water-soluble solids content is dissolved in the aqueous phase, it is possible to reduce the unpleasant odor that occurs with time in the chocolate-like food product that contains DHA and EPA in a total amount of 0.02 to 10 wt %. 
     The prepared aqueous phase is dispersed in oil and fat. There is no limitation on the oil and fat used here. It is possible to use oils and fats such as soybean oil and rapeseed oil, which are commonly used as edible fats and oils. It is also possible to use polyunsaturated-fatty-acid-containing oil and fat from this stage. 
     An oil-soluble emulsifier is preferably dissolved in advance in the oil and fat to be used. Examples of the oil-soluble emulsifier used include a polyglycerol condensed ricinoleates, sugar esters, glycerol fatty acid esters, and lecithins, with a polyglycerol condensed ricinoleate being preferable. The polyglycerol condensed ricinoleate (polyglycerol polyricinoleate) may be abbreviated as “PGPR.” 
     The use of an appropriate oil-soluble emulsifier makes it possible to reduce the unpleasant odor that occurs with time in the chocolate-like food product that contains DHA and EPA in a total amount of 0.02 to 10 wt %. The phase obtained by dissolving the oil-soluble emulsifier in oil and fat is called an “oil phase.” 
     Next, the aqueous phase is mixed with the oil phase to obtain an oil-and-fat composition in the form of a water-in-oil emulsion. Here, various devices can be used as an emulsifying device, as typified by a high-pressure homogenizer. The obtained oil-and-fat composition in the form of a water-in-oil emulsion is used as one of the starting materials of the chocolate-like food product that contains DHA and EPA in a total amount of 0.02 to 10 wt %. 
     The chocolate base itself of the chocolate-like food product that contains DHA and EPA in a total amount of 0.02 to 10 wt % according to the present invention can be prepared by commonly used methods. Existing chocolates may be used by melting. 
     The following describes the simplest preparation method that involves melting of existing chocolate. 
     As the chocolate, a commercially available chocolate product can be used. For example, “Couverture Sweet” produced by Fuji Oil Co., Ltd., may be used. 
     The chocolate is melted in hot water at 50 to 60° C. Then, the oil-and-fat composition in the form of a water-in-oil emulsion and polyunsaturated-fatty-acid-containing oil-and-fat are added thereto. If the oil-and-fat composition in the form of water-in-oil emulsion is prepared using polyunsaturated-fatty-acid-containing oil and fat, then a further addition of a polyunsaturated fatty acid is not essential here. 
     Additionally, to adjust the hardness, hard butter that is melted in advance is suitably added. After homogenization, tempering is suitably performed, and then, the resulting product is put into a mold. 
     Subsequently, cooling is performed at 3 to 10° C. to obtain a final product. 
     The Examples are described below. 
     EXAMPLES 
     Study 1 
     Samples of formulations shown in Table 1 were prepared in accordance with the “Method for preparing a polyunsaturated-fatty-acid-containing chocolate-like food product” section. 
     The obtained samples were evaluated by the “Method of evaluation of polyunsaturated-fatty-acid-containing chocolate-like food product” section. Table 2 shows the results. 
     
       
         
           
               
             
               
                 TABLE 1 
               
               
                   
               
               
                 Formulations 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
               
            
               
                   
                 Ex. 1 
                 Ex. 2 
                 Ex. 3 
                 Ex. 4 
                 Ex. 5 
                 Ex. 6 
                 Ex. 7 
                 Ex. 8 
                 Ex. 9 
                 Ex. 10 
                 Ex. 11 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
               
               
            
               
                 Aqueous 
                 Maltitol 
                 0.04 
                 0.07 
                 0.23 
                 0.14 
                 0.02 
                 0.14 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 phase 
                 Erythritol 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 0.06 
                 0.02 
               
               
                   
                 Sugar 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 0.04 
                 0.16 
                 0.09 
                 — 
                 0.03 
               
               
                   
                 Catechin 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 0.075 
                 0.150 
                 0.200 
                 — 
               
               
                   
                 Gly 
                 0.020 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 0.010 
                 — 
               
               
                   
                 Ala 
                 — 
                 0.020 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                   
                 Phe 
                 — 
                 — 
                 0.020 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                   
                 Thr 
                 — 
                 — 
                 — 
                 0.020 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                   
                 Ser 
                 — 
                 — 
                 — 
                 — 
                 0.020 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                   
                 Val 
                 — 
                 — 
                 — 
                 — 
                 — 
                 0.020 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                   
                 Pro 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 0.019 
                 0.020 
                 0.020 
                 — 
                 — 
               
               
                   
                 Glutamic acid 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 0.020 
               
               
                   
                 Water 
                 0.08 
                 0.14 
                 0.47 
                 0.28 
                 0.05 
                 0.28 
                 0.04 
                 0.26 
                 0.26 
                 0.20 
                 0.06 
               
               
                 Oil 
                 Emulsifier 
                 0.12 
                 0.21 
                 0.70 
                 0.42 
                 0.07 
                 0.42 
                 0.06 
                 0.28 
                 0.28 
                 0.20 
                 0.06 
               
               
                 phase 
                 Soybean oil 
                 5.57 
                 5.39 
                 4.41 
                 4.97 
                 5.67 
                 4.97 
                 2.21 
                 1.56 
                 1.56 
                 2.80 
                 3.29 
               
               
                   
                 PUFA oil 1 
                 5.69 
                 5.69 
                 5.69 
                 5.69 
                 5.69 
                 5.69 
                 6.35 
                 6.35 
                 6.35 
                 — 
                 — 
               
               
                   
                 PUFA oil 2 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 8.48 
                 8.48 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
               
            
               
                 Hard butter 
                 11.52 
                 11.52 
                 11.52 
                 11.52 
                 11.52 
                 11.52 
                 8.7 
                 8.71 
                 8.71 
                 11.96 
                 11.96 
               
               
                 Chocolate 1 
                 76.960 
                 76.960 
                 76.960 
                 76.960 
                 76.960 
                 76.960 
                 — 
                 — 
                 — 
                 76.090 
                 76.081 
               
               
                 Chocolate 2 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 82.581 
                 82.585 
                 82.580 
                 — 
                 — 
               
               
                 Total 
                 100.00 
                 100.00 
                 100.00 
                 100.00 
                 100.00 
                 100.00 
                 100.00 
                 100.00 
                 100.00 
                 100.00 
                 100.00 
               
               
                 Water-soluble solids content 
                 42.86 
                 39.13 
                 35.19 
                 36.37 
                 48.15 
                 36.37 
                 59.60 
                 49.51 
                 50.00 
                 57.45 
                 53.85 
               
               
                 in aqueous phase (wt %) 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 Amount of amino acid 
                 14.29 
                 8.70 
                 2.78 
                 4.55 
                 22.22 
                 4.55 
                 19.19 
                 3.88 
                 3.85 
                 2.13 
                 15.38 
               
               
                 in aqueous phase (wt %) 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 Amount of catechin 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 14.56 
                 28.89 
                 42.55 
                 — 
               
               
                 in aqueous phase (wt %) 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 Amount of aqueous phase 
                 0.14 
                 0.23 
                 0.72 
                 0.44 
                 0.09 
                 0.44 
                 0.10 
                 0.52 
                 0.52 
                 0.47 
                 0.13 
               
               
                 in chocolate-like food  
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 product (wt %) 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 Total amount of DHA and  
                 3.21 
                 3.21 
                 3.21 
                 3.21 
                 3.21 
                 3.21 
                 3.58 
                 3.58 
                 3.58 
                 3.97 
                 3.97 
               
               
                 EPA in chocolate-like food  
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 product (wt %) 
               
               
                   
               
               
                   
                   
                   
                   
                   
                   
                   
                 Comp. 
                 Comp. 
                 Comp. 
                 Comp. 
                 Comp. 
               
               
                   
                 Ex. 12 
                 Ex. 13 
                 Ex. 14  
                 Ex. 15 
                 Ex. 16 
                 Ex. 17 
                 Ex. 1 
                 Ex. 2 
                 Ex. 3 
                 Ex. 4 
                 Ex. 5 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
               
               
            
               
                 Aqueous 
                 Erythritol 
                 0.02 
                 0.02 
                 0.08 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 phase 
                 Sorbitol 
                 — 
                 — 
                 — 
                 0.23 
                 0.21 
                 0.03 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                   
                 Sugar 
                 0.03 
                 0.03 
                 — 
                 — 
                 — 
                 — 
                 — 
                 0.07 
                 — 
                 0.06 
                 — 
               
               
                   
                 Vitamin C 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 0.005 
                 — 
                 — 
                 — 
               
               
                   
                 Catechin 
                 — 
                 — 
                 0.200 
                 — 
                 0.020 
                 0.200 
                 — 
                 0.130 
                 — 
                 0.150 
                 — 
               
               
                   
                 Gly 
                 — 
                 — 
                 0.050 
                 0.050 
                 0.050 
                 0.050 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                   
                 Ser 
                 — 
                 — 
                 0.102 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                   
                 Glutamic acid 
                 — 
                 — 
                 0.102 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                   
                 Lysine  
                 0.020 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                   
                 hydrochloride 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                 Sodium aspartate 
                 — 
                 0.030 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                   
                 Water 
                 0.06 
                 0.06 
                 0.38 
                 0.20 
                 0.20 
                 0.20 
                 — 
                 0.14 
                 — 
                 0.15 
                 — 
               
               
                 Oil 
                 Emulsifier 
                 0.06 
                 0.06 
                 0.38 
                 0.20 
                 0.20 
                 0.20 
                 — 
                 0.23 
                 — 
                 0.23 
                 — 
               
               
                 phase 
                 Soybean oil 
                 3.29 
                 3.29 
                 2.19 
                 1.14 
                 1.14 
                 1.14 
                 5.83 
                 5.25 
                 2.36 
                 1.78 
                 3.48 
               
               
                   
                 PUFA oil 1 
                 — 
                 — 
                 — 
                 6.71 
                 6.71 
                 6.71 
                 5.69 
                 5.69 
                 6.35 
                 6.35 
                 — 
               
               
                   
                 PUFA oil 2 
                 8.48 
                 8.48 
                 8.48 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 8.48 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
               
            
               
                 Hard butter 
                 11.96 
                 11.96 
                 11.96 
                 8.52 
                 8.52 
                 8.52 
                 11.52 
                 11.52 
                 8.71 
                 8.71 
                 11.96 
               
               
                 Chocolate 1 
                 76.08 
                 76.07 
                 76.08 
                 82.950 
                 82.950 
                 82.950 
                 76.960 
                 76.965 
                 — 
                 — 
                 76.080 
               
               
                 Chocolate 2 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 82.580 
                 82.570 
                 — 
               
               
                 Total  
                 100.00 
                 100.00 
                 100.00 
                 100.00 
                 100.00 
                 100.00 
                 100.00 
                 100.00 
                 100.00 
                 100.00 
                 100.00 
               
               
                 Water-soluble solids content 
                 53.85 
                 57.14 
                 58.42 
                 58.33 
                 58.33 
                 58.33 
                 — 
                 59.42 
                 — 
                 58.33 
                 — 
               
               
                 in aqueous phase (wt %) 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 Amount of amino acid 
                 15.38 
                 21.43 
                 27.79 
                 10.42 
                 10.42 
                 10.42 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 in aqueous phase (wt %) 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 Amount of catechin 
                 — 
                 — 
                 21.88 
                 — 
                 4.17 
                 41.67 
                 — 
                 37.68 
                 — 
                 41.67 
                 — 
               
               
                 in aqueous phase (wt %) 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 Amount of aqueous phase 
                 0.13 
                 0.14 
                 0.91 
                 0.48 
                 0.48 
                 0.48 
                 — 
                 0.35 
                 — 
                 0.36 
                 — 
               
               
                 in chocolate-like food  
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 product (wt %) 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 Total amount of DHA and  
                 3.97 
                 3.97 
                 3.97 
                 3.78 
                 3.78 
                 3.78 
                 3.21 
                 3.21 
                 3.58 
                 3.58 
                 3.97 
               
               
                 EPA in chocolate-like food  
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 product (wt %) 
               
               
                   
               
               
                 (The formulations are in percent by weight. ) 
               
            
           
         
       
     
     For the emulsifier, a polyglycerol condensed ricinoleic acid ester “CRS-75” produced by Sakamoto Yakuhin Kogyo Co., Ltd., was used. 
     For the soybean oil, soybean sirasimeyu (refined soybean oil) produced by Fuji Oil Co., Ltd., was used. 
     For the glycine and serine, food additive grade glycine and serine produced by Kyowa Hakko Kogyo Co., Ltd., were used. For the other amino acids, those of food additive grade produced by Nippon Rika Co., Ltd., were used. 
     For PUFA oil 1, oil-and-fat containing EPA (19.09%) and DHA (37.31%) were used. 
     For PUFA oil 2, oil-and-fat containing EPA (1%) and DHA (45.8%) were used. 
     For the hard butter, “Melano SS600” as a tempering type hard butter produced by Fuji Oil Co., Ltd., was used. 
     For chocolate 1, “Milk Chocolate E” produced by Fuji Oil Co., Ltd., was used. 
     For chocolate 2, “Sweet Chocolate E” produced by Fuji Oil Co., Ltd., was used. 
     The water-soluble solids content was in the dissolved state in all of the Examples and Comparative Examples in which the aqueous phase was prepared. 
     Method for Preparing a Polyunsaturated-Fatty-Acid-Containing Chocolate-Like Food Product 
     1. The aqueous phase components shown in the formulations were dissolved in water. 
     2. The oil phase components shown in the formulations were mixed. 
     3. The aqueous phase was added to the oil phase, and a high-pressure homogenizer was used to obtain an oil-and-fat composition in the form of a water-in-oil emulsion. 
     4. The chocolate and hard butter were melted in hot water at 50 to 60° C. and mixed. 
     5. The oil-and-fat composition in the form of water-in-oil emulsion obtained in 3 was mixed with the product obtained in 4. 
     6. The resulting product was poured into a plastic container and solidified at 3 to 6° C. 
     Method of Evaluation of Polyunsaturated-Fatty-Acid-Containing Chocolate-Like Food Product 
     1. The chocolate-like food product samples were each placed into an aluminum deposition bag and stored at 20° C. while shielded from light. 
     2. A group of 3 panelists appropriately performed sensory evaluation in accordance with the following criteria. 
     3. Samples that obtained two or more points on Day 15 or later were evaluated as pass. 
     Sensory Evaluation Criteria 
     Three points: No unpleasant flavor as chocolate. 
     Two points: Some unpleasant flavor but acceptable. 
     One point: Strong unpleasant flavor and unacceptable. 
     
       
         
           
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 Results 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                   
                 Immediately 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                 after preparation 
                 Day 6 
                 Day 7 
                 Day 8 
                 Day 15 
                 Day 17 
                 Day 30 
                 Day 38 
                 Day 45 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                 Comp. 
                 3 
                 1 
                 — 
                 — 
                 1 
                 — 
                 1 
                 1 
                 1 
               
               
                 Ex. 1 
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 Comp. 
                 3 
                 3 
                 — 
                 — 
                 1 
                 — 
                 1 
                 1 
                 1 
               
               
                 Ex. 2 
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 Comp. 
                 3 
                 — 
                 — 
                 — 
                 1 
                 — 
                 — 
                 — 
                 — 
               
               
                 Ex. 3 
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 Comp. 
                 3 
                 — 
                 — 
                 — 
                 1 
                 — 
                 — 
                 — 
                 — 
               
               
                 Ex. 4 
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 Comp. 
                 3 
                 — 
                 1 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 Ex. 5 
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 Ex. 1 
                 3 
                 3 
                 — 
                 — 
                 3 
                 — 
                 3 
                 3 
                 1 
               
               
                 Ex. 2 
                 3 
                 3 
                 — 
                 — 
                 3 
                 — 
                 3 
                 3 
                 1 
               
               
                 Ex. 3 
                 3 
                 3 
                 — 
                 — 
                 3 
                 — 
                 3 
                 3 
                 1 
               
               
                 Ex. 4 
                 3 
                 3 
                 — 
                 — 
                 3 
                 — 
                 3 
                 2 
                 1 
               
               
                 Ex. 5 
                 3 
                 3 
                 — 
                 — 
                 3 
                 — 
                 3 
                 3 
                 1 
               
               
                 Ex. 6 
                 3 
                 3 
                 — 
                 — 
                 3 
                 — 
                 3 
                 2 
                 1 
               
               
                 Ex. 7 
                 3 
                 — 
                 — 
                 — 
                 3 
                 — 
                 — 
                 — 
                 — 
               
               
                 Ex. 8 
                 3 
                 — 
                 — 
                 — 
                 3 
                 — 
                 — 
                 — 
                 — 
               
               
                 Ex. 9 
                 3 
                 — 
                 — 
                 — 
                 3 
                 — 
                 — 
                 — 
                 — 
               
               
                 Ex. 10 
                 3 
                 — 
                 3 
                 — 
                 — 
                 3 
                 — 
                 — 
                 — 
               
               
                 Ex. 11 
                 3 
                 — 
                 3 
                 — 
                 — 
                 3 
                 — 
                 — 
                 — 
               
               
                 Ex. 12 
                 3 
                 — 
                 3 
                 — 
                 — 
                 3 
                 — 
                 — 
                 — 
               
               
                 Ex. 13 
                 3 
                 — 
                 3 
                 — 
                 — 
                 3 
                 — 
                 — 
                 — 
               
               
                 Ex. 14 
                 3 
                 — 
                 3 
                 — 
                 — 
                 3 
                 — 
                 — 
                 — 
               
               
                 Ex. 15 
                 3 
                 — 
                 — 
                 3 
                 2 
                 — 
                 — 
                 — 
                 — 
               
               
                 Ex. 16 
                 3 
                 — 
                 — 
                 3 
                 3 
                 — 
                 — 
                 — 
                 — 
               
               
                 Ex. 17 
                 3 
                 — 
                 — 
                 3 
                 3 
                 — 
                 — 
                 — 
                 — 
               
               
                   
               
            
           
         
       
     
     Discussion 
     The use of vitamin C, which is a common anti-oxidant, gave flavor characteristic to vitamin C, which was incompatible with the flavor of chocolate, resulting in a low evaluation score. 
     The use of amino acid as an anti-oxidant achieved sufficiently strong antioxidative activity, and also did not interfere with the flavor of chocolate, making it possible to obtain excellent products. 
     Study 2 
     To evaluate the antioxidative activity with the use of various amino acids under uniform conditions, tests were performed by adjusting the molar concentrations to be equal to each other. 
     Table 3 shows the formulations. Samples for evaluation of antioxidative activity were prepared in accordance with the “Method for preparing samples for evaluation of antioxidative activity” section. 
     The obtained samples were evaluated by the “Method of evaluation of antioxidative activity” section. Table 4 shows the results. 
     
       
         
           
               
             
               
                 TABLE 3 
               
               
                   
               
               
                 Formulations 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                   
                 Study 
                 Study 
                 Study 
                 Study 
                 Study 
                 Study 
                 Study 
                 Study 
                 Study 
                 Study 
               
               
                   
                 2-1 
                 2-2 
                 2-3 
                 2-4 
                 2-5 
                 2-6 
                 2-7 
                 2-8 
                 2-9 
                 2-10 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
               
            
               
                 Aqueous 
                 Glycine 
                   
                 0.086 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 phase 
                 Leucine 
                   
                   
                 0.151 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                 Isoleucine 
                   
                   
                   
                 0.151 
                   
                   
                   
                   
                   
                   
               
               
                   
                 Arginine 
                   
                   
                   
                   
                 0.200 
                   
                   
                   
                   
                   
               
               
                   
                 Asparagine 
                   
                   
                   
                   
                   
                 0.173 
                   
                   
                   
                   
               
               
                   
                 monohydrate 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                 Glutamine 
                   
                   
                   
                   
                   
                   
                 0.168 
                   
                   
                   
               
               
                   
                 Methionine 
                   
                   
                   
                   
                   
                   
                   
                 0.172 
                   
                   
               
               
                   
                 Threonine 
                   
                   
                   
                   
                   
                   
                   
                   
                 0.137 
                   
               
               
                   
                 Histidine 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 0.178 
               
               
                   
                 Sugar 
                 8.00 
                 7.91 
                 7.85 
                 7.85 
                 7.80 
                 7.85 
                 7.83 
                 7.83 
                 7.86 
                 7.82 
               
               
                   
                 powder 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                 Water 
                 8 
                 8 
                 8 
                 8 
                 8 
                 8 
                 8 
                 8 
                 8 
                 8 
               
               
                 Oil 
                 Emulsifier 
                 12 
                 12 
                 12 
                 12 
                 12 
                 12 
                 12 
                 12 
                 12 
                 12 
               
               
                 phase 
                 Soybean oil 
                 72.0 
                 72.004 
                 71.999 
                 71.999 
                 72.000 
                 71.998 
                 72.002 
                 71.998 
                 72.003  
                 72.002 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 Total 
                 100.0 
                 100.0 
                 100.0 
                 100.0 
                 100.0 
                 100.0 
                 100.0 
                 100.0 
                 100.0 
                 100.0 
               
               
                 Solids content in  
                 50 
                 50 
                 50 
                 50 
                 50 
                 50 
                 50 
                 50 
                 50 
                 50 
               
               
                 aqueous phase (%) 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 Amino acid con- 
                 — 
                 144 
                 144 
                 144 
                 144 
                 144 
                 144 
                 144 
                 144 
                 144 
               
               
                 centration (mM)  
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 in aqueous phase 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 Particle size (μm) 
                 48.94 
                 46.85 
                 45.91 
                 45.92 
                 46.41 
                 46.34 
                 52.15 
                 53.2 
                 52.55 
                 51.9 
               
               
                 5° C. after 1 day 
               
               
                   
               
               
                   
                 Study 
                 Study 
                 Study 
                 Study 
                 Study 
                 Study 
                 Study 
                 Study 
                 Study 
                 Study 
               
               
                   
                 2-11 
                 2-12 
                 2-13 
                 2-14 
                 2-15 
                 2-16 
                 2-17 
                 2-18 
                 2-19 
                 2-20 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
               
            
               
                 Aqueous 
                 Alanine 
                 0.102 
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 phase 
                 Lysine 
                   
                 0.21 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                 hydrochloride 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                 Proline 
                   
                   
                 0.132 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                 Serine 
                   
                   
                   
                 0.121 
                   
                   
                   
                   
                   
                   
               
               
                   
                 Valine 
                   
                   
                   
                   
                 0.135 
                   
                   
                   
                   
                   
               
               
                   
                 Sodium 
                   
                   
                   
                   
                   
                 0.194 
                   
                   
                   
                   
               
               
                   
                 glutamate 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                 Sodium 
                   
                   
                   
                   
                   
                   
                 0.204 
                   
                   
                   
               
               
                   
                 aspartate 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                 Cysteine 
                   
                   
                   
                   
                   
                   
                   
                 0.024 
                   
                   
               
               
                   
                 Phenylalanine 
                   
                   
                   
                   
                   
                   
                   
                   
                 0.033 
                   
               
               
                   
                 Tryptophan 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 0.041 
               
               
                   
                 Sugar 
                 7.9 
                 7.79 
                 7.87 
                 7.88 
                 7.87 
                 7.81 
                 7.98 
                 7.8 
                 7.97 
                 7.96 
               
               
                   
                 powder 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                 Water 
                 8 
                 8 
                 8 
                 8 
                 8 
                 8 
                 8 
                 8 
                 8 
                 8 
               
               
                 Oil 
                 Emulsifier 
                 12 
                 12 
                 12 
                 12 
                 12 
                 12 
                 12 
                 12 
                 12 
                 12 
               
               
                 phase 
                 Soybean oil 
                 71.998 
                 72 
                 71.998 
                 71.999  
                 71.995 
                 71.996 
                 71.816 
                 72.176 
                 71.997  
                 71.999 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 Total 
                 100.0 
                 100.0 
                 100.0 
                 100.0 
                 100.0 
                 100.0 
                 100.0 
                 100.0 
                 100.0 
                 100.0 
               
               
                 Solids content in  
                 50 
                 50 
                 50 
                 50 
                 50 
                 50 
                 50 
                 50 
                 50 
                 50 
               
               
                 aqueous phase (%) 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 Amino acid con- 
                 144 
                 144 
                 144 
                 144 
                 144 
                 144 
                 144 
                 25 
                 25 
                 25 
               
               
                 centration (mM)  
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 in aqueous phase 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 Particle size (μm) 
                 52.04 
                 53.20 
                 52.50 
                 50.08 
                 49.72 
                 50.64 
                 54.13 
                 52.07 
                 48.00 
                 49.82 
               
               
                   
               
               
                 (The formulations are in percent by weight. ) 
               
            
           
         
       
     
     For the emulsifier, polyglycerol condensed ricinoleic acid ester “CRS-75” produced by Sakamoto Yakuhin Kogyo Co., Ltd., was used. 
     Method for Preparing Samples for Evaluation of Antioxidative Activity 
     1. The aqueous phase components shown in the formulations were dissolved in water. 
     2. The oil phase components shown in the formulations were mixed. 
     3. The aqueous phase was added to the oil phase, and a high-pressure homogenizer was used to obtain an oil-and-fat composition in the form of water-in-oil emulsion. 
     Method of Evaluation of Antioxidative Activity 
     1. Each sample was added to fish oil containing DHA (20.0%) and EPA (5.7%) such that the ratio of sample:fish oil=1:9, followed by stirring. 
     2. The oxidation stability of the liquid mixture obtained in 1 above was evaluated using a CDM measurement device (Rancimat produced by Metrohm) at 96° C. at an air blowing rate of 20.0 L/h with a sample introducing amount of 3.0 g. 
     3. The samples that had a CDM value equal to or greater than that of Study 2-1 were evaluated as pass. 
     
       
         
           
               
             
               
                 TABLE 4 
               
               
                   
               
               
                 Results 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                   
                 Study 
                 Study 
                 Study 
                 Study 
                 Study 
                 Study 
                 Study 
                 Study 
                 Study 
                 Study 
               
               
                   
                 2-1 
                 2-2 
                 2-3 
                 2-4 
                 2-5 
                 2-6 
                 2-7 
                 2-8 
                 2-9 
                 2-10 
               
               
                   
               
               
                 CDM  
                 6.15 
                 8.45 
                 8.97 
                 8.9 
                 8.21 
                 8.04 
                 7.62 
                 10.08 
                 8.61 
                 8.21 
               
               
                 value (hrs) 
               
               
                   
               
               
                   
                 Study 
                 Study 
                 Study 
                 Study 
                 Study 
                 Study 
                 Study 
                 Study 
                 Study 
                 Study 
               
               
                   
                 2-11 
                 2-12 
                 2-13 
                 2-14 
                 2-15 
                 2-16 
                 2-17 
                 2-18 
                 2-19 
                 2-20 
               
               
                   
               
               
                 CDM  
                 8.72 
                 8.87 
                 10.09 
                 8.27 
                 8.91 
                 8.02 
                 8.28 
                 7.32 
                 7.28 
                 8.13 
               
               
                 value (hrs) 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                   
               
            
           
         
       
     
     Discussion 
     For amino acids of high solubility, the amino acid concentrations in the aqueous phase were adjusted to 144 mM for evaluation. For amino acids of low solubility, the amino acid concentrations in the aqueous phase were adjusted to 25 mM for evaluation. 
     The results showed a tendency of improvement in antioxidative activity with the use of any of these amino acids, compared to samples to which amino acids were not added. 
     Although chocolate-like food products were not prepared in Study 2, it is presumed that the effects would be achieved if a chocolate-like food product that contained DHA and EPA in a total amount of 0.02 to 10 wt % were prepared with the use of each of the tested amino acids in this study.