Flavor improvement of fermented soy sauce by extrusion as soybean meal pretreatment

摘要

Flavor, an important index of soy sauce quality, includes odor and taste which mainly depend on volatile compounds and amino acids. Soy sauce made from extruded mixture of soy meal and flour (EMSF) was employed in fermentation to improve the flavor of final product. Combination of Headspace solid phase microextraction (HS-SPME) and GC-MS was employed to identify the volatile compounds, 40 volatile compounds were identified in soy sauce made from EMSF and 24 volatile compounds in soy sauce made form cooked mixture of soy meal and flour (CMSF). Pyrazines and their derivatives occupied one-third of the total content of volatile compounds. Both samples had the same amino acid number, while total content of amino acids and contents of 15 kinds of amino acids in soy sauce made from EMSF were significantly higher than CMSF.