通气和金属离子双重胁迫对糙米萌发富集γ-氨基丁酸的影响

Effects of coercion germination with aeration and metal irons on the enrichment ofγ-aminobutyric acid in germinated brown rice

为缩短糙米的发芽周期、提高发芽糙米的γ-氨基丁酸(γ-aminobutyric acid,GABA)含量,研究了通气胁迫、金属离子胁迫以及双重胁迫处理对糙米(镇糯19号)发芽效果(GABA含量、发芽率和芽长)的影响。试验结果表明:全程通气胁迫处理能显著加快糙米萌发速度并提高发芽后期糙米中GABA的含量,但是会导致芽体过长;发芽21h后进行通气胁迫处理(9h)能在提高GABA含量的同时,有效控制芽长在0.2cm左右;采用钙离子(Ca^2+)或铝离子(Al^3+)进行胁迫萌发能大幅度提高发芽糙米中GABA的含量,当Ca^2+浓度为35mmol/L时,GABA增长率达到44.3%;双重胁迫萌发的最佳工艺条件为:糙米在35mmol/L的Ca^2+溶液中浸泡发芽21h后以1.5L/min的通气量通气9h,共发芽30h;在该条件下,镇糯19号胁迫萌发后γ-氨基丁酸含量达到28.18mg/100g,比正常发芽36h的样品提高了64.42%,发芽率提高了2.65%。可见,通气和金属离子双重胁迫可显著提高GABA含量并缩短发芽周期。

In order to shorten the germination cycle of brown rice and increase the content of γ-aminobutyric acid (GABA), the effects of aeration coercion, metal ion coercion and double stress treatment on brown rice (Zhen waxy rice 19) were studied.The effects of the content, germination rate and bud length showed that the aeration treatment during the whole germination process can significantly accelerate the germination rate of brown rice and increase the content of GABA in brown rice in the late germination stage.However, it would lead to the buds being too long.Aeration treatment for 9 h can effectively control the bud length of 0.2 cm while increasing GABA content.The coercion germination with calcium ion (Ca^2+) or aluminum ion (Al^3+) can greatly increase the content of GABA in germinated brown rice.When the Ca^2+ solution concentration was 35 mmol/L, the GABA growth rate reached 44.3%.The optimum conditions for the germination of double coercion treatment were as follows: brown rice immersed in 35 mmol/L Ca^2+ solution for 21 h and then ventilated with 1.5 L/min for 9 h.The germination process lasted for a total of 30 h.Under this condition, the content of γ-aminobutyric acid reached 28.18 mg/100 g which was 64.42% higher than that of normal germination for 36 h and the germination rate increased 2.65%.It can be seen that the double coercion treatment with both aeration and metal ions can significantly increase GABA content and shorten germination cycle.