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Response surface optimization of enzymatic hydrolysis of germinated brown rice for higher reducing sugar production

Vo Minh Hoang Nguyen Duc Toan
Published 10/05/2022

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How to Cite
Vo Minh Hoang, Nguyen Duc Toan. "Response surface optimization of enzymatic hydrolysis of germinated brown rice for higher reducing sugar production". Vietnam Journal of Food Control. vol. 5, no. 4 (en), pp. 645-657, 2022

Main Article Content


The hydrolysis of germ rice by the use of α-amylase and glucoamylase enzymes will help increase the reducing sugar content, reduce viscosity, and improve the yield of milk solution compared to the traditional extraction method. The liquefaction experiment was arranged with two factors, which are substrate ratio: α-amylase concentration and α-amylase concentration: different hydrolysis time. The saccharification experiment was carried out based on a multivariate model according to the Central Composite Design method. As a result, a 1 : 2 substrate ratio, 0.5% α-amylase concentration (approx. 11U/g starch) and 50 minutes hydrolysis time were selected as the basis for the next experiment. Analysis of variance in the regression model showed that the quadratic model was significant (p < 0.0001). Lack of fit (p > 0.05) this indicates that the model is suitable for all data. The reliability of the model R2 = 0.993 shows that the built regression model fits the data set 99.3%. CV = 1.19% indicated a better precision and reliability of the experiments carried out. Optimal conditions for hydrolysis of glucoamylase concentration of 0.399% (approx. 119.863U/g starch), temperature of 59.813°C and hydrolysis time of 160.468 minutes gave the highest DE content at 25.245% and higher than the non-enzymatic method (DE = 8.985 ± 0.062).


nutrition drink, starch hydrolysis, reducing sugar, germinated brown rice.


[1]. S. Roohinejad, H. Mirhosseini, N. Saari, and M. Shuhaimi, “Evaluation of GABA, crude protein and amino acid composition from different varieties of Malaysian’s brown rice,” Australia Journal of Crop Science, vol. 3, no. 4, pp. 184-190, 2009.
[2]. A. Moongngarm and N. Saetung, “Comparison of chemical compositions and bioactive compounds of germinated rough rice and brown rice,” Food Chemistry, vol. 122, no. 3, pp. 782-788, 2010.
[3]. C. T. T. Quynh, N. H. Dung, and L. Q. Dat, “Production of germinated brown rice (gaba rice) from Vietnamese brown rice,” Vietnam Journal of Science and Technology, vol. 51, no. 1, pp. 63-71, 2013.
[4]. D. Karladee and S. Suriyong, “γ-Aminobutyric acid (GABA) content in different varieties of brown rice during germination,” Science Asia, vol. 38, no. 1, pp. 13-17, 2012.
[5]. Q. Zhang, J. Xiang, L. Zhang, X. Zhu, J. Evers, W. V. D. Werf and L. Duan, “Optimizing soaking and germination conditions to improve gamma-aminobutyric acid content in japonica and indica germinated brown rice,” Journal of Functional Foods, vol. 10, pp. 283-291, 2014.
[6]. S. Thitinunsomboon, S. Keeratipibul, and A. Boonsiriwit, “Enhancing gammaaminobutyric acid content in germinated brown rice by repeated treatment of soaking and incubation,” Food Science and Technology International, vol. 19, no. 1, pp. 25-33, 2013.
[7]. A. Moongngarm, T. Moontree, P. Deedpinrum, and K. Padtong, “Functional Properties of Brown Rice Flour as Affected by Germination,” APCBEE Procedia, vol. 8, pp. 41-46, 2014.
[8]. D. H. Cho and S. T. Lim, “Germinated brown rice and its bio-functional compounds,” Food Chemistry, vol. 196, pp. 259-271, 2016.
[9]. P. Jannoey, H. Niamsup, S. Lumyong, and S. Tajima, “γ-Aminobutyric acid (GABA) accumulations in rice during germination,” Chiang Mai Journal-Science, vol. 37, no. 1, pp. 124-133, 2010.
[10]. F. Wu, N. Yang, A. Touré, Z. Jin, and X. Xu, “Germinated Brown Rice and Its Role in Human Health,” Crit. Rev. Food Sci. Nutr., vol. 53, no. 5, pp. 451–463, 2013.
[11]. K. Inoue, T. Ochiai, M. Kasao, K. Hayakawa, M. Kimura and H. Sansawa, “Bloodpressure-lowering effect of a novel fermented milk containing γ-aminobutyric acid (GABA) in mild hypertensives,” European Journal of Clinical Nutrition, vol. 57, no. 3, pp. 490-495, 2003.
[12]. K. Hayakawa, M. Kimura, K. Kasaha, K. Matsumoto, H. Sansawa, and Y. Yamori, “Effect of a γ-aminobutyric acid-enriched dairy product on the blood pressure of spontaneously hypertensive and normotensive Wistar–Kyoto rats,” The Bristis Journal of Nutrition, vol. 92, no. 3, pp. 411-417, 2004.
[13]. M. Watanabe, T. Maeda, K. Tsukahara, H. Kayahara, and N. Morita, “Application of pregerminated brown rice for breadmaking,” Cereal Chemistry, vol. 81, no. 4, pp. 450-455, 2004.
[14]. N. Morita, T. Maeda, M. Watanabe, and S. Yano, “Pre-germinated brown rice substituted bread: Dough characteristics and bread structure,” International Journal of Food Properties, vol. 10, no. 4, pp. 779-789, 2007.
[15]. I. F. Bolarinwa and K. Muhammad, “Functional properties, antioxidant activities and storage stability of cookies from germinated brown rice and rice-potato starch composite flour,” Pertanika Journal of Tropical Agricultural Science, vol. 42, no. 2, pp. 503-518, 2019.
[16]. J. Krisch and B. Szajáni, “Ethanol and acetic acid tolerance in free and immobilized cells of Saccharomyces cerevisiae and Acetobacter aceti,” Biotechnology Letters, vol. 19, no. 6, pp. 525-528, 1997.
[17]. D. T. N. Hanh and N. M. Thuy, “The use of α-amylase enzyme in starch hydrolysis from Red rice,” Scientific Journal Can Tho University, no. 1, pp. 61-67, 2014.
[18]. N. M. Thuy, Đ. C. Dinh, and N. T. M. Tuyen, “Enzymatic hydrolysis optimization of rice starch for rice milk processing using the Central Composite Design (CCD) and response surface methodology,” Scientific Journal Can Tho University, vol. 37, no. 2, tr. 30-38, 2015.
[19]. G. L. Miller, “Use of Dinitrosalicylic Acid Reagent for Determination of Reducing Sugar,” Analytical Chemistry, vol. 31, no. 3, pp. 426-428, 1959.
[20]. N. D. Luong, C. Cuong, N. A. Tuyet, L. T. T. Tiên, H. N. Oanh, N. T. Hương, P. T. Huyen, and T. T. Hang, Enzyme Technology. National University Ho Chi Minh City Publishing House, 2004.
[21]. B. C. Tu, T. T. T. Nga, L. N. D. Duy, and N. C. Ha, “Study on the processing of germinated brown rice sterilized milk in bottle,” Scientific Journal Can Tho University, no. 1, pp.1-8, 2016.