Formation And Control Of Advanced Glycation End Products In The Canned Fish Food System

Advanced glycation end products(AGEs)are present in most thermally processed food matrices.Many studies have shown that AGEs are closely related to the pathogenesis of several diseases.Therefore,a comprehensive and in-depth study of the mechanisms and factors influencing the generation of AGEs is of great practical importance.As a typical representative of high-protein foods,fish products are an important source of AGEs in the diet.This study correlates the formation of AGEs with the food processing process,two typical AGEs([N~?-(carboxymethyl)-lysine,CML]and[N~?-(carboxyethyl)-lysine,CEL])were selected as target substances for the study of canned fish,a fish canned simulation system was developed to investigate the relationship between processing and process formulation and the generation of AGEs in canned fish.To investigate the mechanism of AGEs generation in canned fish and the factors influencing the generation of AGEs in canned fish using a simulated system in combination with commercially available canned fish,to enable more information on the levels of AGEs in food and to provide a theoretical basis for the assessment of dietary intake of AGEs.The main research content and results of this thesis are summarized as follows:(1)Investigation of the nutrient content of commercially available canned fish to determine the distribution of nutrients(proteins,reducing sugars,fatty acids,amino acids)in different canned fish;The levels of CML and CEL contents in canned fish were determined to try to discuss tentatively the possible formation association between nutrients and late glycosylation end products.The results show that:The protein of canned fish is between 11.60%and 26.00%,with herring having the lowest protein content and sardines the highest;Reducing sugar content levels ranged from64.70-248.0 mg/g,with anchovy having the lowest reducing sugar content and trout the highest;The fatty acid differences and major fatty acid ratios of different canned fish in terms of saturated fatty acids(PFA),monounsaturated fatty acids(MUFA)and polyunsaturated fatty acids(PUFA)are reflected.Among them,mackerel,swordfish and salmon EPA and DHA content accounted for 72%,77%and 81%of polyunsaturated fatty acids,respectively.The total amino acids of different canned fish ranged from 1036.04-1644.05 mg/kg.The total amount of essential amino acids ranged from 363.30-803.25 mg/kg,with trout having the highest essential amino acid content and walleye having the lowest.The total essential amino acids of different canned fish accounted for 36.62%-49.69%of the total amino acids(TEAA/TAA).There was a positive correlation between protein in nutrients and the associated hazards CML(0.46)and CEL(0.73).Methionine(Met)and lysine(Lys)had negative correlation with CML,-0.53,-0.50 respectively;There was a positive correlation between 9c12c-C18:2 and CML 0.61;Reducing sugars did not correlate with the associated hazards CML and CEL.The correlations among the nutrients were not obvious enough,with some degree of correlation between the fatty acids C17:0,C18:0,9c12c-C18:2,C18:3n-3 and most amino acids.(2)To simulate the production of canned swordfish and determine the effects of three different processing methods,namely steaming,air-drying and deep-frying,on the end products of late glycosylation and to analyze the correlation between nutrients and AGEs.The results showed that the distribution of CML and CEL in simulated canned swordfish was in the following order:deep-fried>air-dried>boiled.The contents were 1608.12 mg/kg for CML frying,3653.67 mg/kg for CEL frying;1025.10 mg/kg for CML air-drying,2485.16 mg/kg for CEL air-drying;250.32 mg/kg for CML boiling,721.83 mg/kg for CEL boiling.Reducing sugar level:fried 214.02mg/g>boiled 206.13mg/g>air-dried 200.99 mg/g.The total amino acids of simulated canned swordfish were 686.67 mg/kg air-dried>615.16 mg/kg boiled>484.36 mg/kg fried,and the total essential amino acids were 356.05 mg/kg air-dried>276.12 mg/kg boiled>214.33 mg/kg fried.The total essential amino acids of the three types of simulated canned okra fish:steamed,air-dried,and fried,accounted for45%,53%,and 44%of the total amino acids(TEAA/TAA),respectively.All 18amino acids in the nutrients,except aspartic acid(Asp),glutamic acid(Glu)and tryptophan(Trp),showed good correlation with CML and CEL to different degrees,and most of them had negative correlation with CML and CEL.Most fatty acids show a negative correlation with CML and CEL.There was a positive correlation between reducing sugars and CML(0.53)and CEL(0.50)and a weak negative correlation between protein and CML and CEL,-0.43 and-0.46,respectively.(3)The formation pattern of late glycosylation end-products was investigated by simulating the canned system of fried swordfish and adjusting different process formulations.The results show that:No added vegetable oil system with CML content of 12.55 mg/kg and CEL content of 61.27 mg/kg;No added table salt system with CML content of 6.32 mg/kg and CEL content of 10.29 mg/kg.No added sugar system,CML content is 8.37 mg/kg,CEL content is 10.79 mg/kg;No added pepper system,CML content is 9.95 mg/kg,CEL content is 29.86 mg/kg;No added wine system,CML content is 6.16 mg/kg,CEL content is 16.23 mg/kg.The reducing sugar content of the five simulated okra systems ranged from 172.31-265.86 mg/g.The total amino acids ranged from 524.48-687.40 mg/kg,and the total essential amino acids accounted for 44%-49%of the total amino acids(TEAA/TAA).Among them,no added salt,sugar,pepper system TEAA/TAA are 48%.All 18 amino acids in nutrients,except cysteine(Cys),showed different degrees of correlation with CML and CEL,and most amino acids had positive correlation with CML and CEL.There was a negative correlation between 9c C16:1 and CEL(-0.52)in fatty acids;Reducing sugars showed almost no correlation with CML and CEL.Protein showed a weak positive correlation with CML and CEL,0.37 and 0.57,respectively.