This study was conducted in an effort to investigate the effect of Maillard reaction products (MRPs) on enzymatic browning of burdock and their anti-oxidant activity. The MRPs were prepared by heating glucose and amino acids at 90°C, which served to produce a strong inhibitory effect on burdock polyphenol oxidase. As the reaction time of the solution containing glucose and amino acid increased at 90°C, the production of MRPs increased and intensity of the brown color deepened. When MRPs were prepared by heating at 90°C for five hours, the absorbance of MRPs from glucose and lysine was 6.44, while those of glucose and glycine was 1.95. The MRPs synthesized from the glucose and lysine also reduced the pH of MRPs from 5.60 to 4.51, but those from glucose and glycine decreased slightly from 5.57 to 5.33. The Michealis-Menten constant value (Km) of burdock PPO with pyrocatechol as a substrate was 16.0 mM, and MRPs were a non-competitive inhibitor against burdock PPO. The anti-oxidant activity of MRPs was measured by evaluating its radical scavenging activities of DPPH radicals, ABTS radicals and reducing power. The color intensity of MRPs produced by lysine and glucose were deeper than that produced by glucose and glycine. It was also found that MRPs produced from glucose and lysine exhibited stronger anti-oxidant properties than those produced by glucose and glycine.

이 연구는 고지방 및 고 콜레스테롤식이(HD)를 먹인 rat에서의 저지질혈증 및 항염증 효과에 영향을 미치는 카제인과 유당(cMRP) 그리고 락토바실러스 fermentum H9 (FcMRP)에 의해 발효된 cMRP에 의해 반응된 마일라드 반응 생성물의 효과를 조사했다. HD 식이를 실시한 rat은 정상적인 식이를 먹인 rat과 비교했을 때, 간의 트리글리세리드 농도가 유의적으로 증가했다. 이는 HD 그룹에 비해서 Simvastatin, L. fermentum H9(H9), cMRP, FcMRP의 처리기간의 총 트리글리세리드를 감소시킨 것으로 나타났다. 조직학적 분석에서 cMRP, F-cMRP 및 H9-를 먹인 rat에서 간과 대동맥 조직의 지질 축적이 감소한 것으로 관찰되었다. 또한, F-cMRP와 cMRP는 HD 그룹에서 내중막 두께를 감소시켰다. 게다가 H9, Cmrp, F-cMRP 처리는 ICAM-1 및 VCAM-1의 발현수준을 유의적으로 감소시켰지만, MCP-1의 발현 수준은 유의하게 감소시키지 못했다. 특히, ICAM-1과 VCAM-1의 발현은 HD 그룹에 비해 F-cMRP 그룹에서 유의적으로 감소했다. 이 연구 결과는 낙농 식품의 cMRP와 F-cMRP가 심혈관계 질환, 특히 죽상 동맥 경화증을 예방하거나 치료하는데 잠재적으로 사용될 수 있음을 시사한다.

The Maillard reaction is a complex reaction that occurs between carbonyl and amine groups during food pro-cessing and storage. In addition, it produces a large number of Maillard reaction products (MRPs), which have an importantrole in determining food characteristics including aroma, color, flavor, and texture. Importantly, recent studies have beenconducted that the Maillard reaction products and their ferments with lactic acid bacteria (LAB) induced specific biologicalcharacteristics including antimicrobial, antioxidative, and antihypertensive activities as well as improved their physiologicalfeatures such as the heat stability and emulsifying properties. Therefore, we described on new insights for enhanced physi-ologic and biologic functions of MRPs through LAB fermentation.

The objective of current study is to determine antioxidant activities of Maillard reaction products (MRPs) obtained from Maillard reaction model systems with different combinations of 15 individual amino acids and 3 different sugars(glucose, fructose and lactose). Antioxidant activities of MRPs were determined using techniques of measuring DPPH and ABTS-radical scavenging activities. The results indicated that radical scavenging activities of MRPs were significantly increased compared to individually thermal treated amino acids and sugars. Among the model systems, the systems containing glycine or lysine + sugars (glucose, fructose and fructose) displayed the stronger DPPH and ABTS radical scavenging activities than other model systems. In addition, when the thermal treatment time was increased, radical scavenging activities of MRPs were increased in a reaction time-dependent manner. Further investigation using bioassay-directed fractionation was performed using two model systems (glycine+glucose, lysine+glucose) which displayed the strongest radical scavenging activities. The reaction solution were subjected to partition with a different polarity of solvent (hexane, ethyl acetate, n-butanol, and water) for evaluation of their radical scavenging activity. Among them, ethyl acetate fraction exhibited the strongest DPPH-radical scavenging activity in both model systems.

The purposes of this study were to investigate the Maillard reactions of some oligosaccharides with lysine and the antioxidative effects of the ethanol extracts from their reaction mixtures on the soybean oil. The Maillard reactions were carried out of 2% oligosaccharides such as palatinose (PN), fructooligosaccharide (FO), isomaltooligosaccharide (IMO) with 2% lysine (L) for 24 hours heating at 60, 80, 100℃. The color intensity of Maillard reaction mixtures were determined by UV-VIS spectrophotometer upon reaction time and temperature. And the antioxidative effects on the soybean oil of each ethanol extract from Maillard reaction mixture of each oligosaccharide were measured by peroxide value (POV). POV's of soybean oil including reaction extracts were determined regularly every 2 days during 20 days storaged at 60±1℃. The results were obtained as follows: 1. The color intensity of the Maillard reaction mixtures were raised highly as the browning temperature and time increased. The color intensity of PN L browning mixture was the highest. The order of high color intensity at 100℃ was PN L〉FO L〉Glu L〉IMO L. 2. Comparing the antioxidative effect of Maillard reaction product (at 100℃, for 12 hours) of each oligosaccharide to that of BHT and TBHQ, the order of high antioxidative effect was TBHQ〉IMO L〉BHT〉Glu L〉PN L〉FO L. 3. From these results, it was known that PN L shown as high brown color intensity was appeared low antioxidative effect, while IMO L shown as low brown color intensity was appeared high antioxidative effect. So, it was recognized that there was no relation between brown color intensity and antioxidative effect.

Backgound : Inflammatory bowel diseases (IBDs) are chronic disorders that are characterized by intestinal epithelial inflammation and injury. Currently, the most employed therapies are antibiotics and anti-inflammatory drugs; however, the side effects limit long-term effectiveness. Methods and Results : We evaluated the impact of glucose-lysine Maillard reaction products (Glc-Lys MRPs) on colitis, induced in rats by an administration of 5% dextran sulfate sodium (DSS) in drinking water. Glc-Lys MRPs ameliorate DSS-induced colitis, as determined by a decrease in disease. index activity, colon weight/length ratio, nitric oxide levels in serum, recovery of body weight loss, colon length and serum lysozyme levels. Furthermore, Glc-Lys MRPs increase the glutathione content and the activity of glutathione peroxidase, superoxide dismutase and catalase, and inhibit lipid peroxidation and myeloperoxidase activity in colon tissues. In particular, Glc-Lys MRPs suppress the mRNA level of the inflammatory cytokines and nuclear factor-κB in colon tissues. Conclusion : This study suggests the potential of Glc-Lys MRPs in preventing or treating IBDs.