The Maillard Reaction Of Inulin And The Properties Of It’s Derivatives

Inulin(In) is a functional biological polysaccharide, it has a good water solubility, antioxidant and antibacterial properties. In Britain, the United States and other countries, inulin are extensively used as natural food ingredients. Maillard reaction is commonly occur in food processing, production and storage process, and Maillard reaction products have the characters of natural, non-toxic and antioxidant activities, thus they always have a very good application value. Inulin is a kind of reducing suger, inulin can occur Maillard reaction with the process of production and storage, but the study about the structure and the properties of inulin Maillard products was still rare. This paper studied the antioxidant activities and emulsifying properties of Maillard derivatives of inulin, in order to provide valued references for the research of inulin Maillard products.The Maillard reaction was occurred by heating inulin and amino acid(alanine, arginine and histidine) at 100℃. Three kinds of derivatives were prepared(Maillard reaction time was 10 h, 40 h and 70h). The products of different reaction systems were prepared. pH, UV-vis absorbance and fluorescence were determined during Maillard reaction and the derivatives were characterized by FTIR, reducing suger content were determined. Their antioxidant activities and emulsifying properties were evaluated. The results are shown as following:1. Through the Maillard reaction, the results revealed that the pH of the reaction system decreased during Maillard reaction; The UV-vis absorbance and the fluorescence intensity increased during the reaction; Infrared spectrum analysis showed that the Maillard derivatives retained the characteristic absorption peaks of inulin;2. The results of Maillard reaction of inulin with alanine showed that the derivatives of inulin had stronger antioxidant activity than inulin itself, but they were weaker than tea polyphenol(the positive control group); The antioxidant properties increased with the increase of reaction time(the derivatives prepared by 70 h had the best antioxidant activity, the derivatives prepared by 40 h were better, the derivatives prepared by 10 h were the weakest). While the ratio of carbonyl in the inulin and amino in the alanine was 1:5, the percentage of reducing sugar was lowest,the derivatives had the best antioxidant activity, the ratio of 1:1 were better, the ratio of 5:1 were the weakest, the antioxidant activity was related to reducing sugar.3. The results of Maillard reaction of inulin with arginine showed that all of the inulin derivatives had better antioxidant activity than inulin itself. And when the ratio of carbonyl in the inulin and amino in the arginine was 1:1, the derivatives had the best antioxidant activity, the 1:5 system were better, and the 5:1 system were the weakest. Different reaction time exhibited the different antioxidant properties, the results showed that the antioxidant activity of derivatives increased with the increase of reaction time.4. The results of Maillard reaction of inulin with histidine showed that all of the inulin derivatives had strong antioxidant activity compared to inulin, but they were less than the positive control group(tea polyphenol); The antioxidant activity increased with the increase of reaction time. The ratio of carbonyl and amino had impact on the antioxidant activity, when the ratio of carbonyl and amino was 1:5, the antioxidant activity of the derivatives were the strongest and the 5:1 systems were the weakest; The results were that antioxidant activity relative to reaction time and the ratio of carbonyl and amino.5. Compared the oxidation resistance of maillard products of Inulin with the above three amino acid, under the conditions of same ratio of carbonyl and amino and the reaction time, different kinds of amino acids had influence on the nature of maillard reaction products; the order of the oxidation resistance of maillard reaction products was IA15-70 > IR11-70 > IH15-70, it showed that inulin and alanine maillard reaction products had the best oxidation resistance, and it has a lower reducing suger content. The simplest amino acid, the lowest reducing suger content, and the highest antioxidation.6. The results of emulsifying property Maillard reaction of inulin with arginine showed that at the same reaction time, when the ratio of carbonyl and amino was 5:1, reducing suger content was highest, emulsifying property of the derivatives was the highest, 1:1 was the better and weakest was 1:5, this showed that the higher of reducing sugar content, the higher of the emulsifying property; Under the same carbonyl ammonia ratio, emulsifying property of maillard reaction products were increased with the increase of reaction time; When compared the emulsifying properties of inulin-alanine maillard products and inulin-arginine maillard products, the results showed that the alanine and inulin maillard reaction can better improved the emulsifying property of inulin.This paper studied the Maillard reaction between inulin and three kinds of amino acid(alanine, arginine, histidine), prepared the derivatives of different systems and reaction time. pH, UV-vis absorbance and fluorescence were determined during Maillard reaction and the derivatives were characterized by FTIR.; Their antioxidant activities and emulsifying properties were evaluated, and revealed the influence of different amino acids, carbonyl ammonia ratio and reaction time on the antioxidant and emulsifying properties; These results could provide experimental basis and theoretical reference for the development of inulin Maillard reaction products.