Abstract:
Blends of wax-esters with beneficial health properties comprise: ≧ two different wax-esters in amounts of 5-95% and each having m.pt -10° C. to 80° C. blend displaying m.pt: 15 to 45% while &gt;80 wt % of wax-esters in blend have m.pt 20 to 60° C.; wax-esters derived from linear alcohols and linear carboxyl acids either of them having ≧8 C-atoms.

Description:
FIELD OF THE INVENTION 
     The invention relates to wax esters which are useful as healthy replacements for fats. 
     DESCRIPTION OF RELATED ART 
     Food products often contain fats. The consequence of the presence of fats in food products is that the caloric value of the food products is very high. Moreover fats, in particular saturated and trans fats are considered not being healthy. Therefore a trend exists to replace the fats of the food products by other components that are considered to be healthier. Examples of such fat replacers are eg denatured proteins with a small particle size. Fat replacers however should not only reduce the caloric content of the products but should also retain the fatty impression and the mouthfeel of fats. Further the fat replacers should be able to take over the structuring properties of fats. These requirements are however not fulfilled by the use of these denatured proteins. Other known fat replacers are derived from sugars and contain a high number of fatty acid residues. Although these fat replacers imitate the fatty impression very well they have other disadvantages such as an anal leakage problem when applied in the amounts necessary for fat replacers. 
     It will not have to be explained that fat replacers should also be safe for use in food products. So compounds that display detrimental properties when consumed are not applicable as fat replacer. 
     According to WO 95/28847 a number of wax esters can be applied in food products that have an emulsified fat phase. The wax esters act here as structuring components and are used in amounts of 1.5-6 wt % on fat phase. Wax esters that can be applied are bees wax, carnauba wax, candelilla wax, spermaceti wax, Japan wax, jojoba oil and hardened jojoba oil. In this reference it is not indicated that these wax esters can also be used as fat replacer or to reduce the caloric content of the food product. This can be explained by our finding that these wax esters, in particular jojoba oil have a detrimental effect in the form of body weight reduction/reduced growth, reduced food and water consumption and toxicological significant changes in several blood clinical chemistry parameters, such as plasma enzyme activities. Also histopathological changes in the mesenteric nodes and jejunum were observed when administrating higher proportions of these wax esters. On basis of above observations it was very unlikely that wax esters could be found that did not have the above detrimental properties. 
     Still we performed a study to find out whether wax esters could be found that could be used successfully in food products as fat replacer but that do not display the disadvantages of the wax esters from the prior art. This study resulted in the finding of novel wax ester blends that perform very well in fat based food products, that do not display detrimental health aspects and that can be used as fat replacers and to reduce the caloric intake of food products based on them. 
     SUMMARY OF THE INVENTION 
     Therefore our invention concerns in the first instance a blend of at least two different wax-esters, wherein the individual wax-esters each have a melting point between -10 and 80° C. while the blend displays a melting point between 15 and 45° C. and at least 80 wt % of the wax-esters, present in the blend has a melting point between 20 and 60° C., while the wax-esters are derived from linear alcohols and linear carboxylic acids each having an even number of carbon atoms, while either the alcohol or the acid residue or both have at least 8 C atoms, preferably the acid residue comprises 12-24 C-atoms, most preferably 16-22 C-atoms and wherein the blend comprises at least two wax esters each in amounts of 5-95 wt %. 
     DETAILED DESCRIPTION OF THE INVENTION 
     The wax esters can contain different fatty acid residues and different alcohol residues. Preferred wax ester blends however comprise wax esters wherein at least one of the wax-esters is derived from either a saturated or unsaturated carboxylic acid with at least 16 C atoms or from a saturated or unsaturated alcohol with at least 8 C atoms preferably at least 16 C atoms or from both simultaneously. 
     The most preferred wax esters are derived from saturated carboxylic acids with at least 18 C atoms, preferably being stearic acid. These wax esters give the best caloric reduction. 
     The carboxylic acids can thus be saturated but very useful wax esters are also obtained if the carboxylic residue is mono- or poly-, in particular diunsaturated and preferably have at least 18 C atoms, preferably being oleic acid and/or linoleic acid. Very beneficial wax esters are obtained if the carboxylic acid residues are long chain polyunsaturated fatty acids, such as arachidonic acid, EPA or DHA. Using these wax esters will incorporate the well known beneficial health aspects from these essential fatty acids in the food product. 
     The alcohol residue of our wax esters can be selected from saturated alcohols with at least 2, preferably at least 8, more preferably at least 12 and most preferably at least 18 C atoms. 
     Very beneficial combinations are obtained if the blend comprises at least one wax-ester derived from a saturated long chain alcohol, having at least 8, preferably at least 12 C atoms, more preferably at least 18 C atoms and an unsaturated carboxylic acid with at least 8, preferably at least 12 C atoms, more preferably at least 18 C atoms. 
     A main advantage of our novel blends is, that the trans fatty acid content is low, ie below 5 wt % and preferably below 2 wt %. 
     Our novel blends of wax esters are applied as fat replacer and are therefore in general used in combination with triglycerides. Part of the invention thus also are blends of wax-esters and triglycerides, which blends contain at least 20 wt %, preferably 25-95 wt % most preferably 30-90 wt % of the blend of wax-esters. 
     These blends preferably comprise vegetable triglycerides or fish derived triglycerides selected from the group consisting of: liquid oils, fractions of hardened liquid oils, hardened liquid oils, cocoa butter, cocoa butter equivalents, palm oil, fractions of palm oil, fish oils, fish oil fractions, hardened fish oils, fractions of hardened fish oils, enzymically made equivalents of the oils mentioned and mixtures of one or more of the oils mentioned. Also single cell oils can be used. 
     In order to be useful in food applications wherein the fat phase is used for structuring purposes it is advantageous if our blends of wax esters and triglycerides display an N-value-profile (NMR pulse, non stabilised) of: N20=5-80, preferably 15-60 N30=2-60, preferably 5-45 N35=&lt;20, preferably &lt;10, most preferably &lt;5 The N values were measured after subjecting the blend to the following temperature regime: melt at 80° C., cool to 0° C. and keep at 0° C. for 1 hr, warm up to measurement temperature and keep it there for half an hour and measure the N value by NMR pulse. 
     Although in principle our food products could be completely fat free, we found that the best results were obtained if our food compositions comprise a lipid phase, which is present for at least 10 wt % and which lipid phase comprises at least 20 wt % of a blend of wax-esters, preferably a blend. The amount of lipid phase is preferably at least 20 wt %, more preferably at least 30 wt % and most preferably at least 35 wt % based on food composition. 
     Examples of food products that can be made by using our blends of wax esters are: 
     i) a spread, preferably having a continuous fat phase with 10-90 wt % fat content and 90-10 wt % water 
     ii) a confectionery product 
     iii) ice creams, ice cream coatings, inclusions for ice creams 
     iv) dressings, mayonnaise, sauces 
     v) bakery fats 
     vi) cheese 
     According to another embodiment of our invention we use our wax esters or blends of wax esters and triglycerides in food products to structure the products and to lower the caloric content of the food product. 
     Part of our invention is also a process for the preparation of our blends of wax-esters. Although these wax-esters can be made by a chemical esterification of an alcohol and a fatty acid, we prefer to apply an enzymic conversion of fatty acids with preferably at least 8 C-atoms and aliphatic alcohols with at least 2 C-atoms. For this conversion any enzymic esterification catalyst can be applied. 
    
    
     EXAMPLES 
     1 Preparation of Stearyl Oleate 
     Preparation 
     Stearyl alcohol (477 g) and oleic acid (523 g) were placed in a 2-liter rotary evaporator flask with 2% Mucor miehei lipase immobilised on Duolite (SP392 ex. Novo). The mixture was heated to 65° C. in a waterbath and vacuum was applied to remove water generated during the reaction. Stirring was achieved by rotating the flask using a rotary evaporator. The reaction was allowed to proceed for four hours. 
     The above procedure was repeated twice (i.e. a total of three batches were prepared). 
     The combined reaction products were heated to a temperature of 120° C. by steam in a stirred jacketed vessel. A calculated amount of sodium hydroxide solution was added to the vessel in order to neutralise free fatty acid. The sodium soap formed was run off from the bottom of the vessel. To remove final traces of soap, the oil was washed several times with boiling water, the soap/water mixture being run off from the bottom of the vessel after settling. 
     The remaining reaction product was dried using a rotary evaporator under vacuum at a temperature of 90° C. The dried wax product was then bleached by stirring with C300 bleaching earth for 30 minutes at a temperature of 90° C. followed by filtration. 
     Analysis 
     Fatty acids were analyzed by GC of the methyl esters while fatty alcohols were analyzed by GC without further preparation. 
     
         ______________________________________%       C16:0     C18:0   C18:1   C18:2 C20.1______________________________________Oleic   0.7       2.6     90.7    5.6   0.3acidStearyl           &gt;99alcohol______________________________________ 
    
     Lipid classes were determined by HPLC: 
     
         ______________________________________   Component           %______________________________________   Alcohol 0.1   Wax Ester           &gt;99______________________________________ 
    
     Separation according to molecular weight was carried out by GC of the wax esters: 
     
         ______________________________________CarbonNumber    C34           C36    C38______________________________________Stearyl   1.2           98.3   0.5Oleate______________________________________ 
    
     N-values were measured: 
     
         ______________________________________Wax Ester  N20      N25    N30    N32.5 N35______________________________________Stearyl Oleate      94.2     0______________________________________ 
    
     2. Preparation of Behenyl Linoleate/Oleate 
     Preparation 
     Following the method for stearyl oleate according to example 1, behenyl alcohol (524 g) was reacted with fatty acids produced by hydrolysis of sunflower oil (476 g). 
     After bleaching the resultant wax ester was heated to 35° C. and centrifuged at 3000 G for 30 minutes at 3100 rpm before decanting off the behenyl linoleate/oleate mixture. This removed much of the saturated wax esters. 
     Analysis 
     Fatty acids were analyzed by GC of the methyl esters while fatty alcohols were analyzed by GC without further preparation. 
     
         __________________________________________________________________________%     C14:0     C16:0         C16:1             C18:0                 C18:1                     C18:2                         C18:3                             C20:0                                 C20.1                                     C22:0__________________________________________________________________________Sunflower 0.3 4.4 0.2 1.5 27.3                     65.4                         0.5 0.1 0.3 0oilhydrolysateBehenyl                                   &gt;99alcohol__________________________________________________________________________ 
    
     Lipid classes were determined by HPLC and show the presence of glycerides due to incomplete hydrolysis of the sunflower oil: 
     
         ______________________________________  Component           %______________________________________  Alcohol  1.0  Diglyceride           0.4  Triglyceride           0.6  Monoglyceride/           0.8  Other  Wax Ester           97.2______________________________________ 
    
     Separation according to molecular weight was carried out by GC of the wax esters: 
     
         ______________________________________CarbonNumber   36        38     40       42  44______________________________________Behenyl  2.4       8.6    86.3     1.8 0.9Linoleate/Oleate______________________________________ 
    
     
         __________________________________________________________________________Fatty acid methyl esters were prepared from the wax ester and analyzed byGC:Acid C14:0    C16:0        C16:1            C18:0                C18:1                    C18:2                        C18:3                            C20:0                                C20:1                                    C22:0__________________________________________________________________________Behenyl0.5 2.1 0.2 0.4 29.2                    67.4                        0.3 0   0   0Linoleate/Oleate__________________________________________________________________________5 N-values were measured unstabilised:Wax Ester N20    N25    N30    N32.5  N35__________________________________________________________________________Behenyl   85.1   84.2   79.9   52.8   0Linoleate/Oleate__________________________________________________________________________ 
    
     3. Preparation of Chocolate Coating 
     The following recipe was applied: 
     
         ______________________________________cocoa powder (10/12)    16    wt %skimm. milk powder      8Icing sugar             55Blend of:               21olein fraction of behenic esters ofsunflower acids (cf: ex. 2)and sunflower oil (ratio: 80:20)Lecithin                0.2______________________________________ 
    
     This mixture was treated on a Buhler triple roller. The resulting product was conched for 5 hrs at 50-60° C., using 88 wt % of the paste resulting from the Buhler roller and 12 wt % of the same olein-fraction of behenic esters of sunflower acids and sunflower oil. 
     Rubber corks were coated with the conched mixture. The chocolate solidified quickly and did not bloom (stored 70 days at 20° C. or 6 weeks at 25° C.).