Effect of Soaking Temperature and Time on GABA and Total Phenolic Content of Germinated Brown Rice (Phitsanulok 2)

Main Article Content

Kanjana Singh
Piyawan Simapisan
Suwanna Decharatanangkoon
Niramon Utama-ang
Niramon Utama-ang*


Rice grains riched in gamma-amino butyric acid (GABA) are increasingly popular, particularly in the health food market. It has a major inhibitory effect on neurotransmitter function, cancer cell and also reduces blood pressure. GABA contents in rice were investigated during germination. GABA levels in rice are influenced by many factors including the duration of seed incubating, soaking temperature, soaking time or in pre-germinated brown rice. The objective of this study was to investigate the effect of soaking temperature and time conditions on GABA content of brown rice germination. Phitsanulok 2 rice was germinated following a central composited design with different soaking temperature durations (20-40oC) and time (60-300 min) for 10 treatments, then incubating at 25oC for 24 hr. Physical quality, pH of soaking water, protein, GABA and total phenolic compound (TPC) content were analyzed. The results showed that GABA content and TPC increased from 6.71 mg/100g, 13.68 mgGAE/100g of dry sample (raw material) to 18.74 mg/100g, 33.95 mgGAE/100g of dry sample, respectively. Regression model showed that an increase of soaking temperature and time affected on an increase of GABA content (p≤0.05) as well as TPC. On the other hand, an increase of soaking temperature and time significantly decrease pH of soaking water (p≤0.05). The optimum conditions regarding soaking temperature and time were 33oC for 300 min, which provided the highest GABA content (18.74 mg/100g), TPC (33.95 mg/100g) and pH of soaking water (5.7). This indicated that soaking conditions for germinated Phitsanulok 2 rice could increase the nutrition value of rice as functional food product.

Keywords: brown rice, germination, GABA, total phenolic compound, Phitsanulok 2 rice

*Corresponding author: Tel: +66 863558814 Fax: +66 53948230
E-mail: niramon.u@cmu.ac.th


Download data is not yet available.

Article Details

Research Articles


[1] Poritosh, R., Takahiro, O., Hiroshi, O., Nobutaka, N. and Takeo, S., 2011. Processing conditions, rice properties, health and environment. International Journal of Environmental Research and Public Health, 8, 1957-1976.
[2] Shitanda, D., Nishiyama, Y. and Koide, S., 2000. Performance analysis of an impeller husker considering the physical and mechanical properties of paddy rice. Journal of Agricultural Engineering Research, 79, 195-203.
[3] Ohtsubo, K., Suzuki, K., Yasui, Y. and Kasumi, T., 2004. Bio-functional components in the processed pre-germinated brown rice by a twin-screw extruder. Journal of Food Composition and Analysis, 18, 303-316.
[4] Mohan, B.H., Malleshi, M.G. and Koseki, T., 2010. Physico-chemical characteristics and non-starch polysaccharide contents of Indica and Japonica brown rice and their malts, LWT-Food Science and Technology, 122(3), 782-788.
[5] Mayer, R.R., Cherry, J.H. and Rhodes, D., 1990. Effects of heat shock on amino acid metabolism of Cowpea cells. Journal of Plant Physiology, 94(2), 796-810.
[6] Manyam, B.V., Katz, L., Hare, T.A., Kanifefski, K. and Tremblay, R.D., 1981. Isoniazid induced elevation of cerebrospinal fluid (CSF) GABA levels and effects on chorea in Huntington’s disease. Journal The Annals of Neurology, 10, 35-37.
[7] Rhodes, D., Handa, S. and Bressan, R.A., 1986. Metabolic changes associated with adaptation of plant cells to water stress. Journal of Plant Physiology, 82(4), 890-903.
[8] AOAC International., 2000. Official Methods of Analysis, 17th ed. USA: Association of Analytical Communities.
[9] Kahionen, M.P., Hopia, A.I., Vuorela, H.J., Rauha, J.P., Pihlaja, K., Kujala, T.S. and Heinonen M., 1999. Antioxidant activity of plant extracts containing phenolic compounds. Journal of Agricultural and Food Chemistry, 47, 3954-3962.
[10] Zhao, M., Ma, Y., Wei, Z., Yuan, W.X., Zhang, C.H., Xue, X.T. and Zhou H.J., 2011. Determination and comparison of γ-aminobutyric acid (GABA) content in pu-erh and other types of Chinese tea. Journal of Agricultural and Food Chemistry, 59(8), 3641-3648.
[11] Varanyaond, W., Tungtrakul, P., Surojanametakul, V., Watansiritham, L. and Luxiang, W., 2005. Effects of water soaking on gamma-aminobutyric acid (GABA) in germ of different Thai rice varieties. Kasetsart Journal - Natural Science, 39, 411-415.
[12] Puangwerakul Y., 2007. Malts and wort characteristics of 42 cereal rice varieties cultivated in Thailand. Kasetsart Journal - Natural Science, 41, 15-20.
[13] Wijngaard, H.H., Ulmer, H.M., Neumann, M. and Arendt, E.K., 2005. The effect of sleeping time on the final malt quality of buckwheat. Journal of The Institute of Brewing, 117, 275-281.
[14] Banchuen, J., Thammarutwasik, P., Ooraikul, B., Wuttijumnong, P. and Sirivingpaisal P., 2012. Effect of germinating processes on bioactive component of Sangyod Muang Phatthalung rice. Thai Journal of Agricultural Science, 32(3), 219-230.
[15] Sunte, J., Srijesdaruk, S. and Tangwongchai, R., 2007. Effect of soaking and germinating process on gamma-aminobutyric acid (GABA) content in germinated brown rice (Hommali 105). Journal of Agricultural Science, 38, 103-106.
[16] Watcharaparpaiboon, W., Laohakunjit, N., Kerdchoechuen, O. and Photchanachai, S., 2010. An improved process for high quality and nutrition of brown rice production. Food Science and Technology International, 16(2), 147-158.
[17] Liu, Q.S., Pu, L. and Poo, M., 2005. Repeated cocaine exposure in vivo facilitates LTP induction in midbrain dopamine neurons. Nature, 437, 1027-1031.
[18] Sindhu, S.C. and Khetarpaul, N., 2004. Development, acceptability and nutritional evaluation of an indigenous food blend fermented with probiotic organisms. Nutrition and Food Science, 35, 20-27.
[19] Tsai, Y.H., Kung, H.F., Chang, S.C., Lee, T.M. and Wei, C.I., 2006. Histamine formation by histamine-forming bacteria in douchi a Chinese traditional fermented soybean product. Food Chemistry, 103(4), 1305-1311.
[20] Maisont S. and Narkrugsa, W., 2010. Effects of salt, moisture content and microwave power on puffing qualities of puffed rice. Kasetsart Journal - Natural Science, 44, 912-923.
[21] Howll, K.A., Narsai, R., Carrol, A., Ivanova, A., Lohsw, M. and Usadel, B., 2009. Mapping metabolic and transcript temporal switches during germination in rice highlights specific transcription factors and the role of RNA instability in the germination process. Journal of Plant Physiology, 149, 961-980.
[22] Komatsuzaki, N., Tsukahara, K., Toyoshima, H., Suzuki, T., Shimizu, N. and Kimura, T., 2007. Effect of soaking and gaseous treatment on GABA content in germinated brown rice. Journal of Food Engineering, 78, 556-560.