Effect of cyclic moisture conditioning treatment onγ-aminobutyric acid content of germinated brown rice

In order to increase content of γ-aminobutyric acid(GABA) in germinated brown rice, a new technique of germinated brown rice was presented, using repeated moisture conditioning treatment instead of soaking treatment. A central composite rotatable orthogonal experimental design of response surface methodology was employed. Taking brown rice as raw material, the influences of three parameters of repeated moisture conditioning treatment on the content of GABA were investigated, and the three parameters were moisture adding amount, interval time and temperature. The content of GABA was attained with repeated moisture conditioning treatment and soaking treatment. Experimental results showed that the parameters of repeated moisture conditioning treatment had significant impact on the content of GABA (p<0.05). The sequence of influence from significant to common was once moisture adding amount, interval time and temperature. In the optimum condition where single moisture adding amount was 1.6%, interval time 67min, and temperature 31℃, the content of GABA was 27.33 mg/100g. The content of GABA was 2.09 fold of repeated moisture conditioning treatment compared with soaking treatment. This research can provide a theoretical basis for the new technology of germinated brown rice.