Study On The Preparation Of Bacon Flavor And Its Antioxidant Activity

Bacon is a traditional cured meat product in China,which is very popular with consumers.However,most of them are raw meat products which have been simply rough-processed.So,it is urgent to carry out the research on deep processing of bacon.At present,there were many researches on meat flavor,however,the flavor of bacon had not been reported.The meat flavor was mostly prepared by Maillard reaction,many studies had shown that the product of Maillard reaction had antioxidant activity under a certain technological conditions.Therefore,Sichuan bacon were hydrolyzed by suitable enzymes,and then the enzymatic hydrolysate was modified with Maillard reaction in order to get bacon flavor,which had not only outstanding meat but also strong antioxidant activity in this paper.The details were as follows:1.Optimization of enzymatic hydrolysis of baconThe Sichuan bacon was hydrolyzed by neutrase and flavor enzyme.The optimal processes conditions were obtained using response surface methodology and the degree of hydrolysis was used as the response value,and the optimum conditions were neutrase-flavor enzyme ratio of1:2,original p H(5-6)enzyme addition of 0.35 %,solid-liquid ratio of1:2,enzymolysis temperature of 47 ?,enzymolysis time of 5 h.Under the conditions,the DH could reach 8.77 %.2.Study on the antioxidant activity of Maillard reactants based on hydrolysate of baconTo investigate the antioxidant activity of Maillard reaction products based on bacon hydrolysate,which was reacted with glucose.The optimal processes conditions were obtained using response surface methodology and the DPPH radical-scavenging was used as the response value.Then the reducing capacities,·OH radical-scavenging and total antioxidant capacity of different concentration of MPRs were studied.The optimum conditions were p H 5.2,time of 120 min,sugaraddition of 4 %,temperature of 120?.Under these condicions,the DPPH radical-scavenging can reach as high as 91.62 %;the MPRs showed strong reducing capacities,the IC50 value of ·OH radical-scavenging was 6.14 %;the total antioxidant capacity reached0.55 u/g protein at the concentration of 10 %.3.Preparation of bacon flavorThe effects of the factors,such as amino acids,ammonium thiosulfate,reducing sugar,reaction time,and temperature,on the preparation of flavor based on bacon hydrolysate were studied.The results showed that the optimum process were reduce sugar addition of4 %,L-cysteine addition of 0.1 %,thiamine ion addition of 0.3 %,the temperature of 110?,the time of 40 min.Under these conditions,the prepared bacon flavor had high antioxidant activity and full of meat flavor.The DPPH radical-scavenging can reach as high as 86.37 %.4.Preliminary mechanism analysis of AntioxidantSmoked bacon,air-dried bacon and fresh pork were hydrolyzed by enzyme and modified by Maillard reaction respectively.Then the antioxidant properties,free amino acids,volatile components,the molecular weight distribution,electronic nose and electronic tongue were compared.The results showed that the molecular weight distribution was similar among the samples.In terms of antioxidant activity and free amino acid content,Maillard reaction products were higher than enzymatic hydrolysis solution;the difference between smoked bacon and air-dried bacon was very small,and a slightly higher antioxidant activity or free amino acid content were watched in smoked bacon.While both of which were stronger than those of fresh meat.The electronic nose and electronic tongue can distinguish the three kinds of samples very well.The distance between smoked bacon and air-dried bacon in electronic tongue were close,showing that the whole taste of them was close.In electronic nose,there was a big difference between smoked bacon and air-dried bacon after enzymatic hydrolysis,and after Maillard reaction,this difference was decreased.The differencebetween fresh sample and bacon sample,whether in electronic tongue or electronic nose,was relatively great.A total of 160 kinds of volatile components were detected in all of the samples,and in terms of the quantity,smoked bacon>air-dried bacon>fresh bacon.The bacon flavor based on smoked bacon had more antioxidant than thsoe based on non-smoked bacon or fresh pork.