食品科学

• 基础研究 • 上一篇    下一篇

未熟粒糙米低氧胁迫发芽期间生理生化变化研究

钱 行,杨润强,尹永琪,顾振新   

  1. 南京农业大学食品科技学院,江苏 南京 210095
  • 出版日期:2014-08-15 发布日期:2014-08-25

Physiological and Biochemical Changes during Germination of Immature Brown Rice under Hypoxia Stress

QIAN Hang, YANG Run-qiang, YIN Yong-qi, GU Zhen-xin   

  1. College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
  • Online:2014-08-15 Published:2014-08-25

摘要:

以未熟粒糙米为试材,研究其低氧胁迫发芽期间主要生理生化变化。结果表明:经低氧胁迫发芽48 h,未熟粒糙米的发芽率达79.3%,芽长为1.92 mm,呼吸强度提高5.6 倍,容重达0.79 g/mL;发芽期间其含水量快速增加后趋于平缓,淀粉含量持续下降,还原糖和游离氨基酸含量则逐渐增加,均与完熟粒糙米变化趋势一致且无显著性差异;未熟粒糙米中γ-氨基丁酸(γ-aminobutyric acid,GABA)含量随发芽时间延长呈逐渐增加趋势,发芽48 h时GABA含量增加1.08 倍,且谷氨酸脱羧酶(glutamate decarboxylase,GAD)活力和谷氨酸(glutamic acid,Glu)含量与对照组无显著差异。低氧胁迫下未熟粒发芽糙米中GABA含量与芽长、呼吸强度、游离氨基酸和GAD活力均呈极显著正相关(P<0.01),与淀粉和谷氨酸含量呈极显著负相关(P<0.01)。低氧胁迫发芽改善了未熟粒糙米营养品质,是富集GABA的良好原料。

关键词: 未熟粒糙米, 发芽, 低氧胁迫, 生理生化

Abstract:

The physiological and biochemical changes during germination of immature brown rice under hypoxia stress were
investigated. The results indicated that the germination rate of immature brown rice was 79.3%, shoot length was 1.92 mm,
respiration rate was increased by 6.6 times, and density was 0.79 g/mL, after 48 h of germination under hypoxia stress.
During germination, water content was increased firstly and then tended to be stable. Starch content showed a continuous
decline, while the contents of reducing sugars and free amino acids were increased. These changes were consistent with
those in mature brown rice and showed no significant difference. In addition, accumulation of γ-aminobutyric acid (GABA)
was accelerated with increasing germination time. GABA content was increased by 108% at 48 h. Meanwhile, glutamate
decarboxylase (GAD) activity and Glu content showed no significant difference from those of the mature brown rice.
GABA content in immature brown rice germinating under hypoxia stress was correlated significantly positively with sprout
length, respiration rate, free amino acid content and GAD activity, but significantly negatively with Glu and starch contents.
Germination of immature brown rice under hypoxia stress can improve its nutritional quality and provide an excellent
GABA-enriched material.

Key words: immature brown rice, germination, hypoxia stress, physiology and biochemistry

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