DOUGH IMPROVER

Abstract: A dough improver for improving the quality of bread, cake and the like baked products, contains a complex of a vital gluten and an emulsifier. The proportion of emulsifier in the complex to the dough improver is 1 to 20%, and the complex is obtained by mixing a vital gluten with a hydrated emulsifier in such a proportion that the water content in the mixture is in the range of from 10 to 35%, and allowing the mixture to stand.

Description: The present invention relates to dough improvers, i.e. compositions for improving the bread-making performance of a flour dough. More particularly, the present invention relates to dough improvers obtained by mixing vital gluten and an emulsifier. U.S. Patent Specification US-A-3,362,829 discloses that powdered vital gluten, if mixed at 68 to 70 °C with an emulsifier that is in liquid phase, shows excellent dispersibility in water. Since mixing is conducted in the absence of water in this method, the emulsifier does not complex with gluten protein (U.S. Patent Specification US-A-4,200,569), and hence it would not be expected to substantially improve food quality. U.S. Patent Specification US-A-3,880,824 discloses that powder of vital gluten, if mixed with an emulsifier in an inert organic solvent, shows excellent dispersibility in water. Since the emulsifier in this case also does not complex with gluten protein (US-A-4,200,569, above), it would not be expected to substantially improve food quality. U.S. Patent Specification US-A-4,035,519 discloses that the vital gluten obtained by mixing wet gluten (water content: 45 to 65%) at 45 to 65 °C with an emulsifier that is in liquid phase, followed by drying, disperses in water more readily and shows slightly better bread-quality-improving effect compared with ordinary vital gluten. The product obtained by this method is no more than emulsified gluten, with no complex being formed between the emulsifier and gluten protein (US-A-4,200,569, above). In addition, since a mass of wet gluten (water content: 45 to 65%) is used as starting material, intimate mixing with an emulsifier is very difficult, requiring, in commercial production, special equipment and huge energy outlays. Japanese Published Unexamined Patent Application JP-A-102148/82 discloses that powder of vital gluten with good dispersibility in water can be obtained by intimately mixing wet gluten (water content: 50 to 80%) with a phospholipid-containing compound, followed by drying and pulverization. Although this method is effective in improving the dispersibility of the gluten in water, no marked effect can be expected for improving the food quality, particularly the breadmaking quality. US-A-4,200,569 (above) discloses that complexes between gluten protein and anionic emulsifiers show excellent film-forming properties and serve as dough improvers in breadmaking. The complexes of this type are obtained by reaction of gliadin (substantially in solution) with an anionic emulsifier, or by mixing wet gluten (water content: 60% or higher) with a hydrated anionic emulsifier under vacuum. This method requires mixing under vacuum and is not advantageous economically. Furthermore, as the specification states, the effective emulsifier is limited only to anionic emulsifiers such as sodium dodecylsulfate, diacetyltartaric acid ester of monoglyceride and palmitoyl- l -aspartic acid ester, and no complex can be formed from the other anionic (e.g., calcium stearyl-lactylate and the succinic acid monoglyceride esters) and nonionic (e.g., fatty acid esters of sucrose, and monoglycerides emulsifier. Sodium dodecylsulfate, which is the most effective emulsifier, is not used in food processing. Hence, there are limitations upon the use to which this patent may be applied on a commercial basis. According to the present invention there is provided a method for the manufacture of a complex of vital gluten and an emulsifier for use as a dough improver, characterised in that vital gluten, in dry or wet form or a mixture of the two, is mixed with the emulsifier in hydrated form in an amount sufficient to provide from 1-20% by weight of emulsifier, based on the total weight of the dough improver (dry solids basis), thereby to form a mixture containing from 10-35% by weight of water, based on the total weight of the mixture, and that the mixture is allowed to stand. Commercial dry or wet gluten is used as the vital gluten in the present invention. Anionic and nonionic emulsifiers are used as emulsifiers. Examples of anionic emulsifiers include calcium stearoyl-lactylate, sodium stearoyl-lactylate, diacetyltartaric acid monoglyceride esters, succinic acid monoglyceride esters and citric acid monoglyceride esters. Typical examples of the nonionic emulsifiers include fatty acid esters of sucrose. These emulsifiers are used either alone or in combination. The emulsifier is used in the form of a hydrate to accelerate the reaction of the gluten protein with the emulsifier. A hydrated emulsifier is obtained by adding water to the emulsifier (at 50 - 70 °C) to a concentration of 5 to 20% (W/W) and stirring the mixture at a temperature of 50 - 70 °C while maintaining the pH at 5 to 7. A homogenizer or the like can if necessary be used to The dough improver of the present invention is preferably obtained as described below by using a hydrated emulsifier prepared as described above. A 5 to 20% (W/W) of hydrated emulsifier (the percentage represents the concentration of emulsifier in its hydrated form, and this applies throughout the specification and claims) is added to dry vital gluten, or to a mixture of dry vital gluten with a wet vital gluten, in such a proportion that the water content in the resulting mixture is in the range 10 to 35%, and the mixture is allowed to stand at 20 to 70 °C, preferably 40 to 60 °C, for from 5 to 30 minutes, followed, if necessary, by freeze-drying or flash-drying. The dough improver thus obtained contains 1 to 30%, preferably 5 to 20%, of emulsifier on a dry basis. When the emulsifier concentration is to be further enhanced, this is accomplished by pulverizing a dry product, further adding 5 to 20% hydrated emulsifier to the pulverized product, and treating the mixture in the same manner as above. The dough improver obtained by the method described above contains a complex of a vital gluten and an emulsifier. The proportion of emulsifier in the complex to the dough improver is 1 to 20%. The dough improver of the present invention is added to dough in an amount of 0.5 to 10% on a dry basis of wheat flour. The analytical and testing methods used in the present invention are described below. (1) Analysis of free and bound emulsifier Lipids are generally classified into two types by the state in which they exist in living bodies: bound lipids, which complex with protein, and free lipids, which do not complex. The latter can be extracted with a non-polar organic solvent, while the former cannot be extracted with a nonpolar organic solvent but can be extracted with a polar organic solvent. In the present invention, the emulsifier which can be extracted from dough improvers with chloroform is defined as "free emulsifier", the emulsifier which can be extracted with chloroform-methanol mixed solvent (2 : 1 by volume) is taken as "total emulsifier", and the amount of bound emulsifier is calculated by the following equation [Y. Pomeranz, "WHEAT; Chemistry and Technology (92nd edition)", p. 393 - 395, published from American Association of Cereal Chemists]: Bound Emulsifier = Total Emulsifier - Free Emulsifier Analytical methods adopted are hereinafter described. (a) Free emulsifier A dough improver of the present invention (20.0 g) was accurately weighed and extracted with 200 ml of chloroform at room temperature for 20 minutes with mechanical agitation. The extract was suction-filtered through a filter paper (Toyo Filter Paper No. 50), and the residue was again extracted with 200 ml of chloroform in the same manner as above. The two filtrates were combined and the combined solution was concentrated under reduced pressure. The residue was dried at 60 to 70°C until chloroform was substantially removed from the residue. An aliquot sample of chloroform extract was taken and its total nitrogen was measured by the micro Kjeldahl method. The amount of protein contained was calculated by multiplying the total nitrogen by the coefficient, 5.7. The amount of free emulsifier was obtained by subtracting the amount of protein from the total amount of extract. (b) Total emulsifier Analyzed in the same manner as in (a) above, except that a chloroform-methanol mixed solvent (2 : 1 by volume) was used as solvent in place of chloroform. (2) Breadmaking test Sample bread was made by the sponge and dough method, using 2%, based on the weight of wheat flour, of a dough improver of the present invention. The amount of water added to the sponge formulation was 252 ml when no dough improver was used, and 264 ml when the dough improver was used. The specific volume of raised bread was measured by the rapeseed displacement method, and the crumb grain was evaluated by organoleptic examination. Degree of staleness was measured using a baker's Compressimeter after two days' standing at 25°C and expressed by relative value, with the value of control sample (no dough improver added) taken as 100. (3) Cake making test Sponge cakes were made according to a commonly used recipe (egg : soft wheat flour : sugar = 1 : 1 : 1). The dough improver was added in an amount of 5% based on the weight of flour. The amount of water added was 105 ml when the dough improver was added. The specific volume of cakes was measured by the rapeseed displacement method. The crumb grain and texture were evaluated by organoleptic examinations. The softness of the crumb was measured after 24 hours' standing at 15°C by using a creepmeter (Yamaden, Model RE-3305). Examples and Reference Examples are shown below. Example 1 In this example, 3.75 g of sodium stearoyl-lactylate was added to 32.25 ml of water (60°C) and an aqueous dispersion (pH: 4.6) was obtained. After adjusting the pH to 6.31 by addition of 1.5 ml of 2N-NaOH solution the mixture was stirred at 60°C for 20 minutes to prepare 10% hydrate of sodium stearoyl-lactylate. Then, 37.5 g of the hydrate was put to a mixer bowl containing 150 g of commercial vital gluten (water content: 7.7%) and held at 50°C. The mixture was agitated (Shinagawa Kogyo's Universal Mixer/Agitator Model 5DMr; anchor-shape hook used; 65 rpm x 2 minutes and 126 rpm x 8 minutes) until a homogeneous mixture was obtained (water content: 24.4%). The mixture was freeze-dried, and the dried product was crushed to a particle size finer than 42 mesh. The powder was further added to 37.5 g of 10% hydrated sodium stearoyl-lactylate, and the mixture was freeze-dried and pulverized in the same manner as above. The above-mentioned procedure, addition of 37.5 g of 10% hydrated sodium stearoyl-lactylate, lyophilization and pulverisation, was repeated once more. Thus, a total of 112.5 g of 10% hydrated sodium stearoyl-lactylate was added to yield 154 grams of dough improver A containing 7.0% sodium stearoyl-lactylate 6.7% total emulsifier, 3.5% free emulsifier, and 3.2% bound emulsifier (emulsifier binding rate: 48%). Example 2 Experiments were conducted in a similar manner to Example 1, except that emulsifiers listed in Table 1 were used. As shown in Table 1, 15% hydrated emulsifier was added in two partitions or portions (water content: 23.4% for the first mixture, and 19.0% for the second), and 7.5% hydrated emulsifier was added in four partitions (water content: 24.9% for the first mixture, and 20.4% for the second to the fourth), each giving a dough improver containing about 7.0% emulsifier. The results are shown in Table 1. Example 3 At present, powdery vital gluten is produced mainly by flash drying process, in which wet gluten is first mixed with a large amount of powdery vital gluten, followed by pulverization and drying. This Example shows a case in which a mixture of wet gluten and dry gluten is used as starting material according to flash drying process. At first, 3 g of sodium stearoyl-lactylate was added to 25.8 ml of water (60°C), giving an aqueous dispersion. After adjusting the pH to 6.2 by addition of 1.2 ml of 2N-NaOH solution, the mixture was stirred at 60°C for 20 minutes, affording 10% hydrate of sodium stearoyl-lactylate. Then, 180 g of commercial, dry vital gluten (water content: 7.7%) and 60 g of wet vital gluten (water content: 67%) were thoroughly mixed at 50°C in advance. Then, 30 g of the hydrated sodium stearoyl-lactylate prepared above was added, and the mixture was agitated at 50°C into a homogeneous state. The homogeneous mixture (water content: 30.2%) was freeze-dried, and the dried product was crushed to a particle size finer than 42 mesh. To the thus obtained powder were added wet vital gluten and 10% hydrated sodium stearoyl-lactylate in a respective amount identified in Table 2, the second mixing. The mixture was treated in the same manner as described above to obtain a powder. Adding vital gluten and 10% hydrated sodium stearoyl-lactylate in an amount identified at the third to fifth mixings, the above-mentioned procedure was repeated further three times, yielding 334 g of dough improver G containing 7.0% sodium stearoyl-lactylate (water content: 3.5%). This dough improver contained 6.8% of total emulsifier, 3.3% of free emulsifier, and 3.5% bound emulsifier (emulsifier binding rate: 51%). Reference Example 1 The effects of dough improvers A, F and G, obtained in Examples 1, 2 and 3 respectively, were compared with those of powder mixtures of vital gluten with emulsifiers. Table 3 lists the test groups, and Table 4 summarizes the properties of final doughs and the quality of final products after two days' storage. As is apparent from Table 4, the dough improvers of the present invention (Test Groups III, V and VI) show better effects than the other Groups. Reference Example 2 The effects of the dough improvers obtained in Examples 1 and 2 were tested. The results are shown in Tables 5 and 6. As is apparent from Table 6, the dough improvers of the present invention (Test Groups III to VIII) show better effects than the other groups. Reference Example 3 The effects of the dough improvers obtained in Examples 1 and 3 in cake making were compared with those of powder mixture of commercial vital gluten with sodium stearoyl-lactylate. Table 7 lists the test groups, and Table 8 shows the quality of cakes after one day's storage. As is apparent from Table 8, the dough improvers of the present invention (Test Groups III and IV) show better effects than the other Groups in improving the quality of cakes (particularly, crumb grain, texture and softness). Reference Example 4 The effects of the dough improvers obtained in Examples 1 and 2 in improving the quality of cakes were tested. The results are shown in Tables 9 and 10. As is apparent from Table 10, the dough improvers of the present invention (Test Groups III to VIII) show better effects of improving the quality of cakes then the other Groups. Reference Example 5 The dough improvers of the present invention obtained in Examples 1 and 2 were compared in dispersibility in water with the corresponding powder mixtures (commercial vital gluten plus emulsifier). The result is summarized in Table II. At first, 2 g of sample power and 3 ml of water were placed in a test tube, and the mixture was stirred with glass rod. The condition was observed at one-minute intervals, and dispersibility was evaluated based on the condition after 10 minutes' stirring. As is apparent from Table 11, the dough improvers of the present invention are dispersed in water more readily than the corresponding powder mixtures of commercial vital gluten plus emulsifier.

Claims: A method for the manufacture of a complex of vital gluten and an emulsifier for use as a dough improver, characterised in that vital gluten, in dry or wet form or a mixture of the two, is mixed with the emulsifier in hydrated form in an amount sufficient to provide from 1-20% by weight of emulsifier, based on the total weight of the dough improver (dry solids basis), thereby to form a mixture containing from 10-35% by weight of water, based on the total weight of the mixture, and that the mixture is allowed to stand. A method according to Claim 1, characterised in that the emulsifier used is an anionic or non-ionic emulsifier. A method according to Claim 1, characterised in that the emulsifier is calcium stearoyl-lactylate, sodium stearoyl-lactylate, a diacetyltartaric acid monoglyceride ester, a succinic acid monoglyceride ester or a citric acid monoglyceride ester. A method according to Claim 1, characterised in that the emulsifier is a fatty acid ester of sucrose. A method according to any one of Claims 1 to 4, characterised in that, after mixing, the mixture is allowed to stand for 5 to 30 minutes at a temperature in the range 20-70°C. A method according to Claim 5, characterised in that, after mixing, the mixture is allowed to stand for 5 to 30 minutes at a temperature in the range 40-60°C. A method according to any one of Claims 1 to 6, characterised in that after standing, the mixture is freeze or flash dried. A method according to Claim 7, characterised in that, after drying, the emulsifier content is enhanced by adding further hydrated emulsifier to the dry, pulverised vital gluten/emulsifier complex, said further emulsifier being added in an amount of from 5-20% by weight (dry solids basis) based on the total composition and allowing the mixture comprising said vital gluten/emulsifier complex and said further emulsifier to stand. A method of improving the baking qualities of bread dough which comprises adding a dough improver thereto comprising a complex of vital gluten and an emulsifier, characterised in that the dough improver used is a vital gluten/emulsifier complex obtained by the method claimed in any one of Claims 1 to 8, the vital gluten/emulsifier complex being added in the bread dough in an amount of from 0.5 to 10% by weight based in the weight of flour (dry weight basis). A bread dough obtained by the method of Claim 9, and including baked bread products produced therefrom.

Inventors: EGI, MAKOTO, INOUE, SEIJIRO, OHTA, SHIGENORI
Applicants: KYOWA HAKKO KOGYO CO., LTD.
Application year: 1986
Main classification: A21D2
IPC codes: A21D2