Optimization of Enzymatic Hydrolysis Process of Chicken Bone Homogenate and Its Flavor Components Analysis before and after Enzymatic Hydrolysis

Objective: To investigate the flavor difference of chicken bone homogenate before and after enzymatic hydrolysis. Methods: On the basis of single factor experiments, response surface experimental design was used to optimize the enzymatic hydrolysis process of chicken bone homogenate. Then, the amino acid automatic analyzer and headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) combined with taste activity value (TAV) and odor activity value (OAV) were used to carry out the key free amino acids and volatile aroma compounds for the flavor. Results: The optimal process was as follows: Time 5.1 h, enzyme addition 0.61%, solid-liquid ratio 1:3 g/mL, hydrolysis degree 33.68%±1.53%. The degree of hydrolysis was verified (33.24%±0.61%). A total of 13 free amino acids had TAV greater than 1, among which 8 free amino acids had TAV greater than 10, which made great contribution to the taste of chicken bone homogenate. A total of 92 volatile compounds were identified, 63 before and 66 after enzymatic hydrolysis. The 13 and 16 compounds of OAV≥1 was found before and after enzymatic hydrolysis, including 4 alcohols, 2 esters, 2 furans and 9 aldehydes. Before the enzymatic hydrolysis, the chicken bone homogenate had a strong fat flavor, but after the enzymatic hydrolysis, the fat flavor was weakened, and the roasted, bean and melon and meat flavor were increased at the same time, which increased the overall flavor. Conclusion: This paper would provide experimental basis for the study of flavor components of chicken bone homogenate before and after enzymatic hydrolysis.