Abstract: The by-products of segmented Xiang Pigs were extracted with 2 times water(W/W) by high pressure stewing method,and then this process was repeated for the filtrate residue.The two exttracts were collected together for subsequent experiments.In this study,some physicochemical indexes of the extracts and their fermented products by immobilized cells were analyzed,which included contents of soluble solid,dry matter and amino nitrogen,acidity and total bacterial count in gel bead as well as contents of free amino acid and hydrolyzing amino acid in partrial fermented products,and the single or mixture strains of three bacteria(Bacills Licheniformis1.892,Bacillus sublilis 1.807 and Lactobacillus fermentum) were respectively selected for preparing gel beads of immobilized cells as fermententation strains.The analysis results showed that γ-aminobutyric acid(GABA) content level in the extracts and their fermented products are noticeable,the GABA levels in free and hydrolyzing amino acids ranges are respectively 14.97 to 23.05 mg/100 g and 10.63 to 17 mg/100 g respectively,and the hydrolyzing glutamic acid contents as GABA precursor range from 195.53 to 245 mg/100g in the extracts and their partrial fermented products.Under the conditions of room temperature,immobilized cells prepared by adding 2.5% sodium alginate and firming for 30 min in 4% CaCl2 are favorable for obtaining better fermentation capacity,and the results of 6 repeatability experiments showed that the gel beads of immobilized cells are stable with the whole shape and definite fermentation properties.

Key words: Xiang Pig； by-product； immobilized cells； &gamma, -aminobutyric acid；