基于稻谷加温加湿技术的γ-氨基丁酸富化

目的：提高糙米品质。方法：以γ-氨基丁酸（GABA）含量和谷氨酸脱羧酶活性作为指标，研究富化条件对GABA含量的影响；基于最优参数，通过分析富化过程中籽粒各部位GABA含量，揭示其迁移规律；最后分析该法对糙米品质的影响，并与浸泡法对比。结果：原料水分含量14.5%，富化温度65 ℃，最终水分含量20%，富化时间5 h时，GABA含量最高。富化过程中，GABA主要在糠层生成，在生成的同时向内部迁移，各碾减率的糙米GABA含量均在5 h达到峰值，但迁移率在4 h后趋于稳定，胚乳部分的GABA迁移率最高可达87.1%。与浸泡法相比，加温加湿法富化的糙米偏黄，爆腰率较低，米饭更柔软。结论：加温加湿法优于浸泡法，可用于制备高GABA含量的糙米和精米。

Enrichment of γ-aminobutyric acid based on rice heating and humidification technology

Objective: This study aimed to improve the quality of brown rice. Methods: The content of γ-aminobutyric acid (GABA) and the activity of glutamate decarboxylase were used as indicators to study the effect of enrichment conditions on GABA content. Based on the optimal parameters, GABA content in each part of the grain was analyzed to reveal the migration law of GABA. Finally, the effect of the method on the quality of brown rice was analyzed and compared with the soaking method. Results: The highest GABA content was obtained when the water content of the raw material was 14.5% with the final moisture content of 20%, enrichment at 65 ℃ for 5 h. During the enrichment process, GABA was mainly generated in the bran layer and then migrated inward. The content of GABA in brown rice with different milling rates reached the peak at 5 h, but the migration rate tended to be stable after 4 h. The highest migration rate of GABA in endosperm was 87.1%. Compared with the soaking method, the brown rice enriched by the heating and humidifying method showed a yellower color, lower waist burst rate and softer cooked rice. Conclusion: The heating and humidification method is superior to the soaking method and can be used to prepare brown rice and white rice with high GABA content.