Study On Enzymatic Hydrolysis Of Peony Seed Meal And Flavor And Safety Of Maillard Reaction Products

In this study,the optimal conditions of enzymatic hydrolysis of peony seed meal were studied to obtain the better flavor substrate peptide.The effects of different sugars on the structure and flavor characteristics of Maillard reaction products(MRPs)were compared.In addition,the safety of MRPs derived peony seed meal in SD rats was studied by subchronic toxicity test.The results can provide theoretical basis for the application of peony seed meal in seasoning.Firstly,the peony seed meal was hydrolyzed by Alcalase and Flavourzyme step by step,and the degree of hydrolysis(DH)was optimized by response surface test.The optimal enzymatic conditions for the peony seed meal were as follows: the initial p H value of the solution was 8.5 with the substrate concentration of 5%,after hydrolyzed with 3550 U/g Alcalase protease at 50 ? for 3.4 h,the p H value was adjusted to 6.5,and then with 620 U/g Flavourzyme protease at 55 ? for 4.2 h.Under this condition,the DH of peony seed meal hydrolysates was 16.48%.Secondly,the effects of different sugars on the structure and flavor characteristics of MRPs were studied.The results revealed that the flavor and taste of MRPs formed by different sugars were different.Compared with disaccharide and oligosaccharide,monosaccharide was more suitable for preparing MRPs with stronger sensory characteristics.Fourier transform infrared spectra(FT-IR)spectra revealed the structural changes in MRPs after the addition of different sugars.The UV absorption intensity,fluorescence intensity,degree of browning,and degree of substitution(DS)of monosaccharide MRPs were greater than the MRPs formed by maltose and xylooligosaccharide.The molecular weight distribution of 128-500 and 500-1,000 Da accounted for the majority of MRPs samples.Compared with other MRPs,the MRPs produced by ribose and xylose have higher content of sulfur-containing compounds and umami amino acids,which was responsible for stronger meaty and umami flavors.The mouthfulness and continuity of monosaccharide MRPs were greater than disaccharide MRPs.The disaccharide MRPs with the higher content of bitter amino acids exhibited higher bitterness.Lastly,the safety of peony seed meal hydrolysates derived MRPs as flavor enhancer was evaluated by subchronic toxicity test.The results revealed that when the daily intake of MRPs was less than 0.45 g/kg BW/day,compared with the control group,there were no significant differences in body weight,feed consumption,hematology,serum biochemistry,and histopathology in the test group.