Study On Restraining Retrogradation Of Buckwheat Starch And Application

Foodstuff which had high content of starch often retrograded when in depositing course, what was more, corn like buckwheat retrograded easier than other crop. Realizing mechanism of retrogradation and restraining retrogradation of starch had important sense to improving quality of foodstuff.This paper researched on the extracting technology of Buckwheat starch and the character by physics and chemistry methods. Also a befitting method was established to solve the problem of starch retrogradation via studying the different food additives and enzymes. The experiments studied on the producing technology of porridge made of Buckwheat as well as on theβ-amylase as the inhibitor in starch retrogradation process.As the results of the single factor experiments and orthogonal tests, the optimum conditions of the extracting technology of Buckwheat starch were that the concentration of H₂SO₃ was 0.2%, the weight ratio of material to water was 1:4, and the Buckwheat grains were immersed at 55℃for 2h. The rate of production to the raw materials was 76.35%. The contents of each conposings in Buckwheat starch were that 0.65%protein, 0.12%fattiness, 0.31%ashes, 8.67%water, 1.21%fiber, and 87.8%starch (amylose 23.1%).Food additives such as food gums, emulsifier and resistant starch were set in to prevent the Buckwheat starch from retrogradation. The results suggested that 2% malt dextrin, 0.8% guargum and 0.5% moniglycerides can enhance the ability of Buckwheat starch to inhibit retrogradation. The relative retrogradation degree of 2% malt dextrin was 19.99% after a week.The enzyme also had the ability to inhibit the retrogradation of Buckwheat starch; the results indicated that amylase had the most action. And the best parameter were that 0.15%β-amylases were disposed at 50℃for 30min. After a week, starch pastern viscosity was 125.6cp, retrogradation degree was 5.13%. The same result could be gotten by the method of differential scanning calorimeter. When porridge was braising in advance, Buckwheat was predealed withβ-amylase. The production had no evident of retrogradation for 6 months.The optimum compound of porridge was that 10g Buckwheat, 0.5g peanut, medlar and agaric, 5g jequirity, 10g sticky rice, 6g white sugar, and 0.1%additive in 300mL water.By comparing the contents of main nutritional components in the samples which were disposed with the ones without disposing, it was found that artifice of restraining retrogradation made no difference to nurture quality of porridge product.