Antioxidant Properties, Analysis Of Harmful Ingredients Of Maillard Reaction Products And Study On The Fresh-Keeping Effects Of Products To Pork

In this paper, Maillard reaction products (MRPs) were prepared using two kinds of Maillard reaction systems (xylose-glycine and xylose-lysine reactions) which could generate the brightly colored pigments. Antioxidant Properties of Maillard reaction system and the fresh-keeping Effects of its different stages of colored products to pork were studied, in order to explore the application of functional food additives which had both new food pigment characteristics and antioxidant properties to provide the experimental data. There were three main chapters, Mainly researching from compounds in vitro, in vivo tests and safety aspects:1、Study on the spectroscopic characteristics and antioxidant properties of Maillard reaction systemPart (I):Maillard reaction products (MRPs) were prepared using xylose-glycine by model Maillard reaction. The pH value, absorbance and colour parameters of the Maillard reaction products were determined. In this research, the antioxidative activities of MRPs, including DPPH-radical scavenging activity, O2-.radical scavenging activity, iron-chelation activity, and POV value were studied. The results showed that MRPs became from colorless to blue, and finally changed to brown; the pH value and L*value declined gradually, a*value increased, b*value decreased, but they didn’t change significantly in the late (P<0.05). The products exhibited good iron-chelation activity (up to94.32%) and low POV value(minimum of only5.60meq/kg), but scavenging activity against DPPH-radical was not strong. In general, the products had strong antioxidant capacities. Part (II):Using xylose-lyscine Maillard reaction as a model system. The results showed that the brightly colored products of reaction system were red, as the reaction time going, the products became brown; during the first24hours the PH value decreased more significantly than any other time of it (P<0.05). The L*value decreased significantly during the first48hours, the decreased value accounted for92.3%of decreased levels of total, however, a*value and b*value both firstly increased and then decreased. The products exhibited relatively strong scavenging activity against DPPH-radical, which the highest O2-·radical clearance rate was97.69%; iron-chelation activity and oil antioxidant activity of the products were both better than0.4%of Tea Polyphenols (GTP).2、Analysis of harmful ingredients of MRPsIn view of the prepared two MRPs by the experiment, by chromatography method for qualitative and quantitative analyses of acrylamide,5-hydroxymethyl furfural, Benzo(a)pyrene, heterocyclic aromatic amines; as well as by spectroscopy and alcohol precipitation methods for qualitative analysis of melanoidins, respectively. The results showed that:(1)acrylamide,5-hydroxymethyl furfural, Benzo(a)pyrene, heterocyclic aromatic amines were not found in the two MRPs, may be due to the fact that several harmful ingredients were extremely low, below the minimum detectable limit, or MRPs did not contain these substances.(2)Xyl-Gly system began to generate melanoidins at120h, Xyl-Lys system started to accumulate melanoidins at144h. Therefore, melanoidins formation could be limited by controlling the time of Maillard reaction.3^Study on the fresh-keeping effects of MRPs to porkPart (I):Effects of MRPs(Xyl-Gly) products on antioxidant activity and color during storage of fresh pork were studied. Reaction products could reduce the MDA value to a certain extent and improve the T-AOC value, respectively,24h,48h and72h,96h treated groups were the best. The products could also improve the L*value and a*value significantly. Part (II):Effects of MRPs(Xyl-Lys) products on each indicator during storage of fresh pork were studied. The results displayed that the early reaction products could decreased the MDA value significantly, increased the T-AOC value, respectively,24h,72h and24h,48h treated groups were the best. In fifth day during storage, the L*value and a*value could improve significantly by MRPs.