Nondestructive determination of GABA in germinated brown rice with near infrared spectroscopy based on wavelet transform denoising

The objective of this study was to analyze the content ofγ-aminobutyric acid(GABA)in germinated brown rice(GBR)by using near-infrared spectroscopy(NIRS)and the pretreatment method of wavelet de-noising(WD).The prediction accuracy of the NIRS model established by the Daubechies5 wavelet basis function at 3 level denoising treatment is the highest,the correlation coefficient for calibration(rc)is 0.931,the root mean square error of calibration(RMSEC)is 0.4038 mg/100 g,the Bias of calibration is 0.006,the correlation coefficient for prediction(rp)is 0.916,the root mean square error of prediction(RMSEP)is 0.4329 mg/100 g,the Bias of prediction is 0.010,and the ratio of performance to deviation(RPD)is 4.911.Results showed that the predicted and actual values had high correlation.Therefore,these results indicate that the NIRS model treated by WD is feasible to detect GABA content in GBR rapidly and nondestructively.

比色法快速测定糙米中γ-氨基丁酸含量研究

基于Berthelot显色反应,研究了快速测定糙米中γ-氨基丁酸含量的比色法。结果表明,糙米或发芽糙米粉以60%乙醇溶液为溶剂,在70℃温度下回流提取2 h,其离心上清液以重蒸苯酚和次氯酸钠溶液作为显色剂显色反应,在645 nm处比色测定,以标准品为对照可以计算样品中γ-氨基丁酸含量。该方法简单、快速、经济,相对标准偏差(RSD)为0.98%,平均回收率为99.4%,适合于大量稻米品种中γ-氨基丁酸的定量分析。