Evaluation of the gamma-aminobutyric acid (GABA) content of soybean and mungbean by Near Infrared Spectroscopy

Abstract

Soybean and mungbean consists of Gamma aminobutyric acid (GABA). GABA is an inhibitory neurotransmitter. This research aimed to use Near Infrared Spectroscopy (NIRS) technique which is non-destructive technique to predict for GABA in soybean and mungbean grains. In 2013-2015, the soybean 310 samples (from Chang Mai Filed Crop Research Center, Lopburi Agricultural Research and Development Center, and markets), and 260 samples of mungbean (from Chai Nat Filed Crop Research Center, and markets) were collected and scanned the reflectance mode in the region 800-2500 nm. The experiment was conducted at Postharvest and Processing Research and Development Division, Department of Agriculture. The samples were analyzed for GABA by HPLC. The Least Squares Partial (PLS) linear regression models were calculated using the Unscrambler. The results showed the calibration for predicting GABA contents in soybean grains, the high correlations (R) = 0.90, Squared Correlation Coefficients (R²) = 0.82, Standard Error of Prediction (SEP) = 2.80 mg/100g, Standard Deviation (SD) = 6.50 mg/ 100g. The calibration for predicting GABA contents in mungbean grains, the high correlations (R) = 0.90, Squared Correlation Coefficients (R²) = 0.81, Standard Error of Prediction (SEP) = 2.02 mg/100g, Standard Deviation (SD) = 4.83 mg/100g. Therefore, the NIRS technique can predict GABA contents in soybean grains (0-30.83 mg/ 100g) and, mungbean grains (1.66-23.26 mg/100g).