Optimization of the Processes for γ-Aminobutyric Acid Enrichment in Germinated Quinoa under Co-treatment of Sodium Glutamate and Ascorbic Acid and Its Cholate Adsorption Capacity

Monosodium glutamate(MSG)and ascorbic acid(ASA)were used as stresses to co-treat Qingli 2 quinoa for the germination of γ-amniobutyric acid(GABA). The effects of immersion and germination factors on GABA content in germinated quinoa were studied and the optimal enrichment parameters were obtained,furthermore,the cholate adsorption capacity of germinated quinoa was explored. Results showed that the MSG concentration of 2 mg/mL and ASA concentration of 6 mg/mL were beneficial to increase GABA content in germinated quinoa. Based on the orthogonal experiment,the optimal conditions for GABA enrichment under co-treatment of MSG and ASA were immersion time of 6 h,soaking temperature of 25 ℃,germination time of 48 h and germination temperature of 25 ℃,and the GABA content could be 1.613 mg/g under these conditions,which was 3.07 and 2.26 times of GABA content in quinoa seeds and control quinoa treated by deionized water,respectively.Cholate adsorption tests showed that the quinoa before and after germination had strong binding ability to taurocholate and glycocholate. Among them,the quinoa raw material was the highest(177.68 and 179.53 mg/g),followed by deionized water germinated quinoa(150.25 and 163.12 mg/g)and stressed conditions germinated quinoa(125.17 and 144.92 mg/g).Thus,the bile salt binding capacity of quinoa showed a downward trend after germination. This study provided a theoretical basis for the investigation of quinoa germination and the development of GABA riched functional foods.