Conversion Of α,β-unsaturated Carbonyl Compounds In The Presence Of Nature Amino Acids

α,β-Unsaturated carbonyl compounds occur widely in food. They are naturally formed in food as a result of enzymatic and/or spontaneous lipid oxidation. Because of their α,β-unsaturated carbonyl structure the compounds are highly reactive towards matrials such as amino acids in food system, which results in a big reduction of food nutritional value, sometimes even causes a problem to people’s health. Therefore, from a nutritional and metabolic point of view, it is of great significance to research the potential chemical changes of a,p-unsaturated carbonyl compounds in the food system.Currently, most of the studies on the conversion of carbonyl compounds in the amino acids in the food are binary system, which is unsaturated carbonyl compounds or saturated carbonyl compounds interactions with amino acids, etc.; The study on the ternary system which is the conversion of saturated carbonyl compounds and unsaturated carbonyl compounds in the precense of amino acids is very few; And most of the research is carried out in the condition of high temperature. Therefore, we try to study the ternary system in room temperature. According to references, we synthesized a series of standard products which were characterized by MS, FT-IR and 1HNMR.This paper consists of three parts.Part 1. Literature review. The purpose of this review is to provide a comprehensive summary on the research significance of carbonyl compounds in food, the ways of their formation and their dangers in food systems, the chemical properties of carbonyl compounds in the food system and their participate reactions, and the organic reactions by amino acids catalysis.Part 2. Amino acid catalytic the reation of EVK and hexanal. The products which from amino acid-hexanal-EVK system were identified to be more than 18 kinds of compounds based on their chromatographic and spectral properties as well as by comparison with the authentic samples. And the structure of 9 kinds of products was confirmed, which are 1-methoxypentan-3-one, methyl hexanoate,1,1-dimethoxyhexane, hexanoic acid, ethyl hexanoate, 1-(6-ethyl-3,4-dihydro-2H-pyran-2-yl)-propanone, 4-methylenenonane-3,7-dione,2-butyl-2-octenal and 5-hydroxy-4-methylenedecan-3-one, respectively. We also investigate the effect of different reaction time, reaction temperature, water content and metal cations on the amino acid-hexanal-EVK system. Experimental resulted show that the amount of the products rose with the reaction time extending, particularly the content of 2-butyl-2-octenal was increasing quickly; the change of the water content has a small impact on the other products except acetals. The content of 1-methoxypentan-3-one and 1,1-dimethoxyhexane were increased by added some metal ions and the content of 2-butyl-2-octenal was decreased; Effects of different metal ions on the forming of these compounds are different. The effect on the amino acid-hexanal-EVK system from different reaction temperature is remarkable, and it would produce some small molecule compounds at high reaction temperature.Part 3. Amino acid catalytic the reation of hexanal and OHE. On the base of the study of amino acid-hexanal-EVK system, the anticipated result of amino acid-hexanal-OHE system was obtained by use same research tools and methods. Because of its extreme reactivity, liable to have reaction with some chemical substances such as amino acid, which is difficult to detect by GC as the product is less volatile material. The products about participation in reaction of OHE are very enormous, but their contents are very small, and 1-(furan-2-yl)ethanol is found in relatively high levels in the amino acid-hexanal-OHE system. The change of the reaction time, water content and reaction temperature in the. The effect of the amino acid-hexanal-OHE system on differet reaction time, water content and reaction temperature are similar to what you see in the amino acid-EVK-hexanal system; The content of 1,1-dimethoxyhexane and 6,6-diethoxy -hex-4-en-3-one were increased by added some metal ions as well as the content of 2-butyl-2-octenal.Part 4. Amino acid catalytic to convert OHE into 2-vinylfuran. This chapter mainly research the effect of the different factors on the formation of 2-vinylfuran, which are amino acid, the content of amino, reaction temperature, reaction time, the content of water, pH, metal cations and the food additives. The study found that the effect of different amino acids on the formation of 2-vinylfuran is different, in which methionine and serine is most conducive to form 2-vinylfuran. When the mole ratio of amino acid to OHE 20:1, the 2-vinylfuran content reach to maximum. The water content has small effect on the formation of 2-vinylfuran, but adding food additives and metal ions of Fe3+, Cu2+ and Zn2+ are detrimental to the formation of 2-vinylfuran. We also can observe that, it facilitate 2-vinylfuran formation in acid condition, but suppress its formation in alkaline condition.