Study On Inhibition Of AGEs By Highland Barley And Its By-Products

N?-Carboxymethyl-lysine(CML)and pyrraline are the most representative and studied compounds in advanced glycation end products.Studies have shown that the accumulation of CML and pyrraline in human body is related to many diseases,while dietary intake is the main source of CML and pyrraline.Therefore,controlling the intake of CML and pyrraline is important for preventing some chronic diseases.In this paper,the inhibitory effects of polyphenols on the CML in biscuits and simulation systems were investigated.The inhibition mechanism was preliminarily discussed by the capture experiments of active dicarbonyl compound.The baking conditions of biscuits were optimized with water content,hardness,color,sensory score and CML content.The results showed that the best baking conditions of biscuits were 190 °C and 8 min.Oil and sugar were optimized under the optimal baking conditions.The results showed that the maximum CML content in the biscuits prepared by the rapeseed oil as the source of oil and the sugar as the sugar source was 984.23 mg/kgPro.According to the ratio of raw materials in biscuits,a simulation system was constructed,of which glucose(Glu): lysine(Lys): linoleic acid(Lin)= 15:14:4(w/w/w).A variety of polyphenols were added to the biscuit and simulation system,and the results showed that all of them had a certain inhibitory effect on CML,all of which were inhibited by the capture of active dicarbonyl compounds.The maximum inhibition rate of resveratrol added to the 0.2 g/kg dough was up to 83%.Highland barley is a staple food in Northwest China.It is an important source of active compounds,including some polyphenols.The inhibitory effect of the extract of barley bran with different solvents on the CML in the biscuit simulation system was evaluated.The results showed that the 60% acetone highland barley bran extract has the highest total antioxidant activity,and the best inhibition rate of CML in the simulated system of 45.58%.The main phenolic acids in the 60% acetone highland barley bran extract were identified by HPLC-MS/MS-VWD,and five main phenolic acids were identified,including caffeic acid,syringic acid,p-coumaric acid,ferulic acid and erucic acid.The five phenolic acids were used to inhibit the CML in the simulation system and to remove the active dicarbonyl compound—the scavenging experiment of glyoxal.The results showed that all five phenolic acids could inhibit CML in varying degrees,and had a good clearance effect to glyoxal,and the clearance rate reached over 50%.It is indicated that adding barley bran to some staple foods,such as flour,making steamed bread,biscuits or bread,can effectively reduce the amount of CML in such products.Response surface methodology was applied to optimize the formation conditions of Pyrraline in the simulation system.The effect of reaction time,temperature,pH value of simulation system,and the concentration of glucose and lysine on the pyrraline formation in the simulation system were investigated by single factor experiment.Three factors affecting pyrraline production were selected: reaction time,temperature and glucose concentration.The response surface experiment was designed to analyze the effects of various factors and their interaction on pyrraline formation.The results show that when the reaction time is 36 min,the reaction temperature is 101 °C and the glucose concentration is 0.28 mol/L,the maximum value of pyrraline is 4.705 ?mol/L,which is close to the experimental value of 4.689 ?mol/L,and the model P value is less than 0.0001,indicating that the model is extremely significant;the Misfitting term is more than 0.05,indicating that the misplaced term is not significant,indicating that the model is not significant,indicating the model has good fitting effect on pyrraline production,and it can be used for prediction and analysis of pyrraline production.On this basis,the inhibitory effect of the extract of whole grain of highland barley and the extract of barley barley distiller's grains on pyrraline in the simulation system was investigated.The results showed that the whole grain of highland barley had a better inhibition effect on pyrraline and the inhibition rate reached 36.3%.The main polyphenols in whole grain of highland barley were isolated and identified by HPLC-VWD-MS/MS,and nine main polyphenols were isolated and identified,which were chlorogenic acid,vanilla acid,caffeic acid,syringic acid,catechin,p-coumaric acid,ferulic acid,erucic acid and quercetin.The inhibition experiments of pyrraline in the simulated system and the removal of the active dicarbonyl compound,3-Deoxyglucosone,were further scavenged by these nine polyphenols.The results showed that the nine polyphenols had different degrees of inhibition on pyrraline in the simulation system,but has no scavenging effect to 3-DG.It is presumed to inhibit the formation of pyrraline through other ways.