Combinatorial Enzyme Hydrolysis of Chicken Bone Extracts and Analysis of the Volatile Flavor Compounds of Hydrolysate

The aim of the article is to study the effect of different enzyme to substrate(E/S) ratios,temperatures,and combination of papain and flavourzyme(enzyme added orders) on hydrolysis of chicken bone extracts by orthogonal experiment.The result showed that the optimum hydrolysis process with the combinatorial enzyme were solid-liquid ratio 1:3,40℃,pH 7.0,first adding 1500 U·g-1 papain hydrolysis 2h,after enzyme deactivation then adding 1200 U·g-1 flavourzyme hydrolysis 2h.With this hydrolysis process,the hydrolysate has the highest degree of hydrolysis(DH) and nitrogen recovery(NR) and lowest surface hydrophobicity.Under the optimal condition,a total of 26 volatile were determined using solid phase microextraction gas chromatography and mass spectrometry(SPME-GC-MS),which includes pyrazines 41.94%,alcohols 21.83%,hydrocarbons 18.09% and a little aldehydes,ketones and phenols.The pyrazines was the highest contents of total volatile components and made a significant contribution to meat-like aroma,especially 2,3,5-trimethylpyrazine and 2,5-dimethylpyrazine.