Effect Of Bleaching On Nutrient Substances Of Pistachio

Pistachio is a kind of nut that cracked naturally when ripen, of which shell color is cream, skin color is red purple, kernel color is jade green and nutrient substances are very rich. For the past few years, it's popular more and more as the snack food and the sales volume is year growth in domestic market. Some of the pistachio, selling in domestic market, of which shell color is white, skin color is gray, kernel color is faint yellow, is bleached before approaching market. It's very different in color between the bleached pistachio and the raw pistachio. It's only color different between the bleached pistachio and the raw pistachio on the suface. However, whether the nutrient substances in bleached pistahio destroyed or not is not studyed up to now. In this paper, the hydrogen peroxide and the sodium hydroxide were used as bleaching agents to bleach the pistachio and to detect the nutrient substances in the bleached pistachio. The conclusion is as follows:1. Effect of bleaching on total sugar, total protein, total fat and peroxide value of pitachio. The total sugar, total protein, total fat and the peroxide value in pistachio which was bleached by 7.5%of hydrogen peroxide were unchanged in contrast to the raw pistachio. The same nutrient substances content were unchanged as well in pistachio which was bleached by 7.5%of hydrogen peroxide and 0.5%sodium hydroxide.2. Effect of bleaching on mineral, amino acid and fatty acid of pistachio. The content of mineral, amino acids and fatty acids of pistachio bleached by 7.5%hydrogen peroxide were unchanged in contrast to raw pistachio. The content of mineral, amino acids and fatty acids of pistachio bleached by 7.5%hydrogen peroxide and 0.5%sodium hydroxide were unchanged in contrast to raw pistachio.3. Effect of bleaching on vitamins and anthocyandin. The thiamine content decreased 32%, the riboflavin decreased 32%, the cyanidin-3-O-galactoside and the cyandin-3-O-glucoside were undetected in bleached pistachio by 7.5%hydrogen peroxide in contrast to the raw pistachio. The thiamine content decreased 21%, the riboflavin decreased 31%, the cyanidin-3-O-galactoside and the cyandin-3-O-glucoside were undetected in bleached pistachio by 7.5%hydrogen peroxide and 0.5%sodium hydroxide in contrast to the raw pistachio.4. The reaction rate constant and the reaction kinetics of hydrogen peroxide and the anthocyandin was researched. Through experimental data analysis, the reaction mathematical model of hydrogen peroxide and anthocyandin was made. This model can accurately predict the anthocyandin content in pistachio bleached by hydrogen peroxide. Through the research on the nutrient in pistachio before and after bleaching, we consider that the bleaching process is not related to the《Sanitary Standards for Food Additives》and《Food Safety Law of the People's Republic of China》...