Wheat Gluten Hydrolyzate Chelated Zinc And Its Application

Zinc is one of the essential trace elements of the body, and its content is second only to the iron. In human body, the zinc is participated in the composition of more than 300 kinds of enzymes and function proteins and played a very important role in regulating metabolic activity. It is closely related to body’s growth development, intelligence development, immune function, lipid metabolism and etc. Because of the lower absorbing power, in this text, we promoted the absorption of zinc by using amino acid and small peptide’s anxo-action, and studied the preparation technology of the polypeptide-zinc chelate. This product not only had a variety of physiological functions of wheat polypeptide and the high biology availability of microelements, but also had great significance for wheat gluten’s deep processing and comprehensive utilization. The main subjects of this study are hydrolysis conditions of gluten, chelating technology of hydrolyzate and the chelate’s application in bakery products.Firstly we used enzyme to hydrolyzed wheat gluten, scilicetly, it is let alkaline protease and proteinase neutral by a certain ratio while adding hydrolyzed mucedin, the effect was better. The test results showed that:when the ratio of enzyme (alkaline protease:proteinase neutral) was 5:4, the hydrolysis temperature was 55 ℃, enzyme concentration (E/S) was 1.0%, the substrate concentration was 5%, the initial pH of hydrolysis was 8.0 and the hydrolysis time was 3.5h, the degree of mucedin hydrolysis were highest, the highest value reached 14.6%.Secondly, to further enhance the degree of wheat mucedin hydrolysis, we tested the effect of ultrasonic assistant enzymic methods to the degree of wheat mucedin hydrolysis. Experiment of single factor were used to study the effect of substrate concentration, ultrasonic time and pH on the degree of hydrolysis, then get the best sphere of influence. Next through orthogonal test we get the optimum conditions, they were:substrate concentration of 10%, ultrasonic time was 8min, hydrolysis time 3h, pH value of 9.0, the degree of mucedin hydrolysis were highest, the highest value reached 15.28%.Using protein hydrolysis solution which were prepared as above methods as the raw material, we studied the preparation technology of the polypeptide-zinc chelate, and discussed the pH of the reaction liquid, the polypeptide solution with the mass ratio of zinc, peptide concentration, zinc source, reaction temperature and the reaction time on the chelating reaction. The optimum technology obtained chelate were tested by orthogonal test, it showed as follows:the pH of reaction solution was 6, the mass ratio of zinc and peptide were 2:1, temperature was 70 ℃, the polypeptide precursor concentrations was 0.03g/mL, reaction time was 50mins. Under this conditions, the yield of zinc chelating was 70.07%. To make this chelate technology more simple or convenient, we did experiment with zinc sulphate heptahydrate as the source of zinc, studied the effect of gluten hydrolysis and zinc ion mass ratio, microwave chelating time, microwave chelating power and the pH on chelating reaction by single factor experiment, then used orthogonal experiment to get the best chelating process conditions, they were:gluten hydrolysis and zinc ion mass ratio of 3:1, microwave chelating time was l0min, microwave chelating power of 350W, under these conditions, the chelating yield was 72.7% and the chelating rate was 85.3%. This method could significantly shorten the time required for chelating, made the operation more convenient, and the chelating rate was higher.To take full advantage of Chelating Zinc, we studied gluten hydrolysis chelating zinc as a nutritional fortifier in baking food. First we studied the application of chelates in bread recipe, studied the chelating zinc dosage, amount of sugar added, the amount of water added, the added amount of fat on bread quality by single factor experiment. Orthogonal test to determine the best formulation of the product:flour 500g, chelating zinc 10g, water 250g, sugar 100g, fat 50g, salt l0g, yeast 5g, bread improver 5g. At the same time, we studied the application of chelating zinc in cake by single factor and orthogonal experiments. The result showed that:egg amount was 300%, the amount of gluten Chelating Zinc was 2%, oil 45% and the temperature was 180℃, the production of wheat gluten Chelating Zinc chiffon cakes taste the best in flavor and texture. The finding showed: added wheat gluten chelate zinc in baking food, the baking foods’ color, texture and flavor would have been improved, especially zinc content had been significantly improved, this results provided some theoretical supports to gluten chelating zinc as a nutritional fortifier added to baked foods.