Journal of Food and Nutrition Research
ISSN (Print): 2333-1119 ISSN (Online): 2333-1240 Website: Editor-in-chief: Prabhat Kumar Mandal
Open Access
Journal Browser
Journal of Food and Nutrition Research. 2014, 2(3), 130-135
DOI: 10.12691/jfnr-2-3-7
Open AccessArticle

Pre-treatment of Soy Slurry with Viscozyme L and the Concentration of Sugars and Isoflavones and the Microstructure of Silken Tofu

Michele Rosset1, and Adelaide Del Pino Beléia2

1Instituto Federal de Educação, Ciência e Tecnologia do Paraná, Jacarezinho, Paraná, Brazil.

2Departamento de Ciência e Tecnologia de Alimentos, Centro de Ciências Agrárias, Universidade Estadual de Londrina, Londrina, Paraná, Brazil.

Pub. Date: April 21, 2014

Cite this paper:
Michele Rosset and Adelaide Del Pino Beléia. Pre-treatment of Soy Slurry with Viscozyme L and the Concentration of Sugars and Isoflavones and the Microstructure of Silken Tofu. Journal of Food and Nutrition Research. 2014; 2(3):130-135. doi: 10.12691/jfnr-2-3-7


Silken tofu which retains soluble solids present in the soymilk was investigated for differences in the microstructure, sugars and isoflavones content from regular silken. Soy slurry treated with Viscozyme L (2.5 mL/L) was incubated for 30 minutes at 55°C. Stachyose was the predominant oligosaccharide in treated tofu, 4.58 g/100 g and 3.30 g/100 g in control tofu, raffinose content was 1.21 and 0.75 g/100 g in treated and control tofu, respectively. Glucose was approximately duplicated in treated tofu (1.66 g/100 g) compared to control (0.74 g/100 g) while fructose content was three times higher (1.09 g/100 g). Comparing isoflavones content, malonyl conjugates were double the amount of the control tofu, with the exception of malonylgenistin, but the total amount of isoflavones was not different. The tofu of the treated slurry showed a fibrous three-dimensional network structure, but with larger protein aggregates and was more tightly connected than the control.

carbohydrase oligosaccharides soybean curd scanning electron microscopy

Creative CommonsThis work is licensed under a Creative Commons Attribution 4.0 International License. To view a copy of this license, visit


[1]  Hymowitz, T., Collins, F. I., Panczner, J., & Walker, W. M., “Relationship between the content of oil, protein and sugars in soybeans seed,” Agronomy Journal, 64 (2), 613-616, 1972.
[2]  Oliveira, M. A., Carrão-Panizzi, M. C., Mandarino, J. M. G., Leite, R. S., Campos Filho, P. J., & Vicentini, M. B., “Quantification of the sugars, oligosaccharides and starch in special soybean genotypes/cultivars (Glycine Max (L) Merril) for human consumption,” Brazilian Journal of Food Technology, 13 (1), 23-29, 2010.
[3]  Taira, H., “Quality of soybean for processed foods in Japan,” Japanese Agricultural Research Quarterly, 24 (3), 224-230, 1990.
[4]  Mussatto, S. I., & Mancilha, I. M., “Non-digestible oligosaccharides: A review,” Carbohydrate Polymers, 68 (3), 587-597, 2007.
[5]  Coward, L., Barnes, N. C., Setchell, K. D. R., & Barnes, S., “Genistein, daidzein, and their β-glycoside conjugates: antitumor isoflavones in soybean foods from American and Asian diets,” Journal of Agricultural and Food Chemistry, 41 (11), 1961-1967, 1993.
[6]  Bedani, R., & Rossi, E. A., “Isoflavonas: bioquímica, fisiologia e implicações para a saúde,” Boletim CEPPA, 23 (2), 231-264, 2005.
[7]  Martínez, J. M. G., “Isoflavonas en mujeres menopáusicas”, Medicina Clínica, 127 (9), 352-356, 2006.
[8]  Liu, K., “Soybeans: Chemistry, Technology and Utilization,” Chapman & Hall, New York, 1997, 165-198.
[9]  Coward, L., Smith, M., Kirk, M., & Barnes, S., “Chemical modification of isoflavones in soyfoods during cooking and processing,” The American Journal of Clinical Nutrition, 68 (6), 1486 S-1491 S, 1998.
[10]  Anon, Product sheet of Viscozyme L. Novo Nordisk A/S, Enzymes process division, Bagsvaerd, Denmark, 2008.
[11]  Gu, X., Campbell, L. J., & Euston, S. R., “Influence of sugars on the characteristics of glucono-δ-lactone-induced soy protein isolate gels,” Food Hydrocolloids, 23 (2), 314-326, 2009.
[12]  Min, S., Yu, Y., & Martin, S. ST., “Effect of soybean varieties and growing locations on the physical and chemical properties of soymilk and tofu,” Journal of Food Science, 70 (1), C 8-C 12, 2005.
[13]  Shen, C. F., De Man, L., Buzzell, R. I., & De Man, J. M., “Yield and quality of tofu as affected by soybean and soymilk characteristics: Glucono-delta-lactone coagulant,” Journal of Food Science, 56 (1), 109-112, 1991.
[14]  Rosset, M., Prudencio, S. H., & Beléia, A. D. P., “Viscozyme L action on soy slurry affects carbohydrates and antioxidant properties of silken tofu,” Food Science and Technology International, 18 (6), 531-538, 2012.
[15]  Masuda, R., Kaneko, K., & Yamashita, I., “Sugar and cyclitol determination in vegetables by HPLC using postcolumn fluorescent derivatization,” Journal of Food Science, 61 (6), 1186-1190, 1996.
[16]  Mandarino, J. M. G., Carrão-Panizzi, M. C., & Masuda, R., “Composition content of sugars in soybean seeds of Brazilian cultivars and genotypes of Embrapa Germoplasm collection,” in International Soybean Processing and Utilization Conference, Tsukuba: Korin Publishing, 77-78, 2000.
[17]  Kudou, S., Fleury, Y., Welti, D., Magnolato, D., Uchida, T., Kitamura, K., & Okubo, K., “Malonil isoflavone in soybeans seeds (Gyicine max [Merrill]),” Agriculture and Biological Chemistry, 55 (9), 2227- 2233, 1991.
[18]  Carrão-Panizzi, M. C., & Bordingnon, J. R., “Activity of beta-glucosidase and levels of isoflavone in soybeans cultivars affected by the environment,” Pesquisa Agropecuária Brasileira, 35 (5), 873-878, 2000.
[19]  Kao, F. J., Su, N. W., & Lee, M. H., “Effect of calcium sulfate concentration in soymilk on the microstructure of firm tofu and the protein constitutions in tofu whey,” Journal of Agricultural and Food Chemistry, 51 (21), 6211-6216, 2003.
[20]  STATSOFT, Statistica for Windows, Tulsa: Stasoft, 2007.
[21]  Wang, H. J, & Murphy, P. A., “Mass balance study of isoflavones during soybean processing,” Journal of Agriculture and Food Chemistry, 44 (8), 2377-2383, 1996.
[22]  Hui, E., Henning, S. M., Park, N., Heber, D., & Go V. L. W., “Genistein and daidzein/glycitein content in tofu,” Journal of Food Composition and Analysis, 14 (2), 199-206, 2001.
[23]  Fukutake, M., Takahashi, M., Ishida, K., Kawamurai, H., Sugimura, T., & Wakabayashi, K., “Quantification of genistein and genistin in soybeans and soybean products,” Food and Chemical Toxicology, 34 (5), 457-461, 1996.
[24]  Han, J. S., & Kim, M., “Effects of chitooligosaccharide on the physicochemical, textural and sensory properties of tofu,” Journal of Texture Studies, 33 (1), 1-14, 2002.
[25]  Boye, J. I., Alli, I., Ramaswamy, H., & Raghavan, V. G. S., “Interactive effects of factors affecting gelation of whey protein,” Journal of Food Science, 62 (1), 57-65, 1997.