Determination Of Eleven Antioxidants In Nuts By Reversed

Nuts food is mainly made from fruit and vegetable seeds, nuts and other raw materials, which contains up to 40%-60%of the fat. These fat is mostly unsaturated fatty acids (oleic acid, linoleic acid, linolenic acid, etc.) glyceride and less stable, during long-term or improperly storage, will gradually hydrolysis or oxidation by air, water, light, heat and microbiology.Neutral fat broken down into the lower fatty acids, aldehydes, ketones and other substances, and thus degenerate rancidity.In order to prevent rancidity of food deterioration, we usually add antioxidants to avert or slow down the deterioration in foods for maintaining its original character and nutritional value in the food processing.Common antioxidants in food can be divided into two categories, natural antioxidants, including rosemary, vitamin E, vitamin C, polyphenols, phytic acid, etc.; and those for the synthetic antioxidants, including butylated hydroxyanisole (BHA), butylated hydroxy-cresol (BHT), propyl gallate (PG), t-butyl hydroquinone (TBHQ) and so on. Antioxidants as food additives are strictly limited requirements, but also other reports that some antioxidants has some side effects. Currently, the U.S. allows the use of antioxidants in food for 24 species,12 species in Germany, Britain and Japan each of 11 species, Canada and France are eight kinds, the provisions of China GB2760-1996 allows the use of antioxidants in food for 15 species, including butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), propyl gallate (PG), D-sodium erythorbate, polyphenols, phytic acid, t-butyl hydroquinone (TBHQ), Licorice antioxidants, ascorbic acid, calcium, cephalin, ascorbic acid palmitate, Okinawa didodecyl behalf dipropionate,4-hexyl resorcinol, ascorbic acid and rosemary extracts.On the content of antioxidants in food testing, in two steps:sample preparation and analysis of testing. Sample food antioxidant content testing is a critical step, sample preparation process, good or bad results often influence the accuracy. Recently, more and more people's attention and detection technology development and progress, on the content of antioxidants in food research more and more research and development has moved from one component to simultaneously detect a variety of antioxidants.At present, the standard system of determination methods for antioxidants in food is not perfect, and we still have no residue detection methods for glycyrrhizic acid, carnosol and rosmarinic acid phenol antioxidants in food; catechins in tea effect only as a component the determination of methodological standards. Although some antioxidants have determination methods, but relevant steps of those methods for mono-component are complicated. The system can not realize simultaneous multi-element analysis.In this thesis, we establish a high performance liquid chromatography (HPLC) method for determination multi-antioxidants in nuts with solid-phase extraction (SPE). The Sensitivity, accuracy, precision of method all reached the testing requirements for antioxidants, the detection limit is far below the world's major countries related to the limited development of standards for food products in China to carry out a variety of nuts provide effective anti-oxidants technical support.