| Research on Effects of different Ca2+ concentration and aeration amount on physiological and processing quality of germinating brown rice were carried out in this paper in order to provide theoretical basis for research and development of products of germinated brown rice rich in GABA.A method of paper electrophoresis- spectrometric assay for GABA and Glu in brown rice was established. Contents of GABA and Glu had a good linear relation with A515 value at a range of 10-80 nmol GABA and Glu concentration. The R2 of two linear relations reached 0.992 and 0.993 respectively and average recovery ratios in GABA and Glu standard samples 104% and 106% respectively. Relative variation in repeated experimental tests was less than 5%. The data obtained from this method was almost equal to that obtained from amino acid analyzer. This indicated that the result from this assay method was reliable.Effect of temperature and aerating treatment on physiological activities of and GABA, soluble protein and other essential substances in germinating brown rice immersed into water was carried out. It was shown that at a range of 16-40℃, the growth rate and respiratory density of brown rice shoot were accelerated and enhanced. The contents of GABA, Glu and total free amino acids in germinated brown rice increased while soluble proteins decreased. Reducing sugar content in germinated brown rice increased while starch hydrolyzed. The content of reducing sugar reached maximum at a temperature of 32℃, Aerating treatment at speed of 0-2.0 L·min-1 could be in favor of germination and respiratory metabolism of brown rice, acceleration of starch hydrolysis, reduction of soluble proteins and formation of reducing sugar and free amino acids in germinating brown rice. The maximum content of GABA in germinating brown rice had been observed in the aerated treatment group at a speed of 1.0 L· min-1Immersed into the solutions containing 0.5, 2.5 and 10.0 mmol· L-1 Ca2+ respectively and aerated at a speed of 1.50 L· min-1, Brown rice germinated. The growth status, respiratory density of and several compounds contents in germinating brown rice were observed and assayed. The results suggested that Ca2+ could play double roles in brown rice germination, i.e. 0.5 and 2.5 mmol· L-1 Ca2+ could accelerate the growth of brown rice shoot, but 10 mmol· L-1 Ca2+ inhibit this process.It was also observed that three Ca2+ concentrations mentioned above all enhanced respiratory density of germinating brown rice, increased GABA contents and impeded the accumulation of Glu in germinating brown rice. These indexes above were dependent on Ca2+ concentration. But on the contents of soluble proteins, free amino acids, starch and reducing sugar, Ca2+ concentration had little effect.After soaked into the solutions containing 0-5.0 mmol· L-1 Ca2+ for 24 h, then placed in plate, brown rice germinated in thermostat at 25 ℃. Some physiological indexes of and GABA, soluble proteins and other essential compounds in germinating brown rice were assessed. It was found out that the length of brown rice shoot and respiratory density of geminating brown rice increased over time and the contents of GABA, Glu, reducing sugar and free amino acids in germinating brown rice also increased over time, but the content of proteins had a trend of increase at begin and decrease at end. Of which, 0.5 mmol· L-1 Ca2+ had significant effect on the growth of brown rice shoot , respiratory density and formation of GABA while the best effects on the increase of reducing sugar and free amino acids contents in germinating brown rice were observed in the group treated with a Ca2+ concentration of 5.0 mmol· L-1.
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