冷胁迫处理对马铃薯富集γ-氨基丁酸的影响

Effects of cold stress treatment on γ-aminobutyric acid accumulation in potato

以马铃薯为试材,采用-24、-68℃2种冷胁迫处理方法,研究不同冻结方式和解冻方式对马铃薯中γ-氨基丁酸(γ-amino butyric acid,GABA)含量的影响,接着采用先浸泡后冷冻的方法,对影响冷冻马铃薯中GABA含量的浸泡液组分进行研究并优化其最适浓度。结果表明,-24℃冷冻的马铃薯中GABA含量均高于-68℃,4种解冻方式中微波解冻下GABA含量最高,因此,冷胁迫处理马铃薯富集GABA的适宜条件为-24℃冷冻2 h,微波解冻2 min。4种浸泡液组分中谷氨酸钠(MSG)、Ca Cl2和Na Cl均有效提高马铃薯中GABA含量,VB6对提高马铃薯中GABA含量影响不显著;Box-Behnken试验结果显示,最优浸泡液组分为MSG浓度12.5 mg/m L、Ca Cl2浓度2.7 mmol/L和Na Cl浓度83.1 mmol/L,在此条件下马铃薯中GABA含量为51.37 mg/100 g,是原料的5.61倍,说明优化后的浸泡液组分能显著提高马铃薯中GABA含量。方差分析表明,所建的回归模型显著,能很好地预测马铃薯中GABA含量的变化。

With potato as experimental material, Effect of different freezing methods and thawing methods on y-aminobutyric acid （GABA） accumulation in potato were researched using -24 % and -68 % two cold stress treatment methods. Subsequently, adopting first soaking after freezing methods, the soaking solution components on GABA accumulation of potato were investigated and optimized. The results showed that GABA content of potato under -24℃ frozen was higher than under -68℃ frozen, GABA content of potato using microwave oven thawing among four thawing methods was the highest; therefore, the suitable condition of GABA accumulation in potato using cold stress treatment was -24℃ frozen for 2 h, 2 min using microwave oven thawing. MSG, CaCI2 and NaCl among four soaking solution components have significant enhancing effects on GABA accumulation of potato, but VB6 has non-significant effect. Box-Behnken experimental results displayed the optimum compositions of soaking solution were MSG 12.5 mg/mL, CaCl2 2.7 mmol/L, and NaCI 83.1 mmol/L. Under these conditions, GABA content of potato was 51.37 mg/100 g, 5.61-fold of material. This indicated that the optimized soaking solution compositions significantly increased GABA content of potato. Analysis of variance indicated that the regression model was significant, can forecast the changes of GABA accumulation in potato excellently.