IMPROVING THE NUTRITIONAL AND FUNCTIONAL QUALITIES OF FERMENTED SOYMILK BY LACTOBACILLUS RHAMNOSUS
Main Article Content
Abstract
Fermentation is widely used to enhance the nutritional and functional qualities of soy products. This study evaluated the improvements in soymilk fermented by Lactobacillus rhamnosus Yoba. Soymilk was fermented at 40°C for 16 hours, and samples were analyzed for proximate and anti-nutrient composition. The amino acid and phenolic acid profiles were evaluated using Gas Chromatography techniques, while the gamma-aminobutyric acid (GABA) and the isoflavone content were evaluated using High Performance Liquid Chromatography. Results showed that fermentation significantly increased fiber (0.89% to 1.48%), protein (3.15% to 5.25%), and carbohydrate (0.46% to 10.64%) contents, while moisture (88.73% to 75.86%) and ash (and 3.24% to 3.00%) contents decreased (p < 0.05). The concentration of six out of the ten anti-nutrients examined namely: Oxalate, Cardiac Glycoside, Phytate, Hemagglutinin, anthocyanin and Cyanogenic glycoside significantly decreased from 0.51mg/g to 0.39mg/g, 6.36% to 5.94%, 0.54% to 0.12%, 0.08mg/kg to 0.05mg/kg, 3.43% to 1.94% and 4.05mg to 3.24mg respectively. Nutritionally, fermentation enhanced six out of the nine essential amino acids namely: histidine, isoleucine, lysine, methionine, threonine, and tryptophan. Fermentation improved GABA from 1.34g/100g to 3.79g/100g. Most free phenolic acids increased, while the glucoside forms of isoflavones were significantly reduced. These findings suggest that fermentation with Lactobacillus rhamnosus substantially improves the nutritional and functional qualities of soymilk, supporting the incorporation of well-documented probiotics into food matrices for health benefits.
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Ajogwu, T., Osilo, C., Ohuche, J. C., Ozoh, C. N., Uzodimma, I., Nwiyi, I. U., Soludo, O. C., Okafor, O. I., Amalunweze, A. E., & Ekwealor, I. A. (2026). IMPROVING THE NUTRITIONAL AND FUNCTIONAL QUALITIES OF FERMENTED SOYMILK BY LACTOBACILLUS RHAMNOSUS. The Bioscientist Journal, 13(1), 113-126. https://doi.org/10.54117/the_bioscientist.v13i1.204
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References
Ajogwu, T. M. C., Osilo, C., Ohuche, J. C., Ozoh, C. N., Nwiyi, I. U., Soludo, O. C., Okafor, O.I. and Ekwealor, I. A. (2025). Antioxidant activity and quality evaluation of probiotic soymilk produced with Lactobacillus rhamnosus yoba as starter culture. European Journal of Nutrition and Food Safety, 17 (8):281-89.
Akomeng, Nicholas and Adusei, S. (2021). Organic solvent extraction and spectrophotometric quantification of total phenolic content of soil. Heliyon 7: e08388.
Armistice, C., Talknice, Z. J. and Tafadzwa, M. (2022). Effect of Lacticaseibacillus rhamnosus Yoba fermentation on physicochemical properties, amino acids, and antioxidant activity of cowpea-peanut milk. Hindawi Journal of Food Quality, 3:192-202.
Association of official Analytical Chemist. (AOAC) (1990). Official Methods of Analysis.15th ed. Washington DC, USA: AOAC International.
Association of Official Analytical Chemist. (AOAC) (2006). Official Methods of Analysis. 18th ed. Washington DC, USA: AOAC International.
Attarde D., Pawar J., Chaudhari B. and Pal S. (2010). Estimation of sterols content in edible oil and ghee samples. International Journal of Pharmaceutical Sciences Review and Research, 5(1) 021.
Danang, R., Veraita, W. and Wardani, T. S. (2021). Increased levels of fermented soymilk amino acids and effectiveness helping reduce uric acid serum in male white rats. 2nd International Conference of Health, Science and Technology ISBN: 978-623-92207- 16.
Danka, P. O., Dobrina, D. T., and Kalin, V. I. (2012). Simultaneous identification and determination of total content of amino acids in food supplements-tablets by gas chromatography. Asian Journal of Pharmaceutical and Clinical Research, 5(2):100- 120.
Darimiyya, H. and Anni, S. (2021). Characteristic and isoflavone level of soymilk fermented by single and mixed culture of Lactobacillus plantarum and yoghurt starter. Journal of Food and Nutrition Research, 9(1): 55-60.
Diana, M., Quílez, J., and Rafecas, M. (2014). Gamma-aminobutyric acid as a bioactive compound in foods: a review. Journal of Functional Foods, 10:407–420.
Doris, A. and Grace, F. (2022). Anti-nutrient reduction and nutrient retention capacity of fermentation, germination and combined germination-fermentation in legume processing. Applied Food Research, 2: e100059.
Ekkapon, H., Nut, K. and Supanimit, T. (2017). Variability of isoflavone content in soy milk products commercially available in thailand. Journal of Health Science and Medical Research, 36(2):117-126.
Fathy M. M., Asmaa I. E., Asmaa, N. E. and Mohamed, A. F. (2023). Evaluation of nutritional and physicochemical characteristics of soy yogurt by Lactobacillus plantarum KU985432 and Saccharomyces boulardii CNCMI 745.Scientific Reports, 13:13026.
Franz, C. M. A. P., Melanie, H., Julius, M. M., Hikmate. A., Nabil, B., Gregor, R., Antonio, G. and Wilhelm, H. H. (2014). African fermented foods and probiotics. International Journal of Food Microbiology, 190:84–96.
Harbome, J.B. (1993). Phytochemical Methods, a guide to modern techniques of plant analysis chapman and hall, an imprint of Thornson science, London, UK. Pp: 40-49.
Hatice, H. O., Hatice, K. Y., Amin, Y. and Per, E. J. S. (2025). Production of fermented soy and soy/cow milk products with probiotic Lacticaseibacillus rhamnosus GG strain. Food and Bioprocess Technology, 18:5736–5748.
Humyra, N., Kumkum, D., Anjuman, A. B. and Md. Anisur, R. M. (2018). Effects of grinding conditions on anti-nutrient and nutrient contents of soymilk. Journal of Bangladesh Agricultural University, 16(1): 158–163.
Kelley, W.I., Coffey, D.L. and Mueller, T. C. (1994). Liquid chromatographic determination of phenolic acids in soil. Journal of AOAC International, 77:805-809.
Kumar, V., Anita, R. and Lulua, H. (2016). Investigations of amino acids profile, fatty acids composition, isoflavones content and antioxidative properties in Soy okara. Asian Journal of Chemistry, 28(4):903-906.
Kumari, A., Angmo, K., Monika, S. and Bhalla, T. C. (2018). Functional and technological application of probiotic L. casei PLA5 in fermented soymilk. International Food Research Journal, 25(5): 2164-2172.
Kumari, S. and Chang, S. K. C. (2016). Effect of cooking on isoflavones, phenolic acids, and antioxidant activity in sprouts of Prosoy soybean (Glycine max). Journal of Food Science, 00: 0.
Lucas, G.M. and Markakas, M. (1975). Phytic acid and other phosphorus compounds of bean (Phaseolus vulgaris). Journal of Agricultural and Food Chemistry, 23:13-15.
Maria, L. M., Dustin, H., Sylvie, B., Christopher, J. C., Paul, D. C., Benoit, F., Michael G., Remco K., Gonca, P., Anne P., Eddy, J. S., and Robert, H. (2017). Health benefits of fermented foods: microbiota and beyond. Current Opinion in Biotechnology, 44:94– 102.
Mazumder, M.A.R. and Hongsprabhas, P. (2016). A review on nutrient quality of soymilk powder for malnourished population. Pakistan Journal of Nutrition, 15(6): 600–606.
Modgil, R. and Kumar, V. (2021). Soybean (Glycine max). In Oilseeds: Health attributes and food applications; Tanwar, A., Goyal, A., Eds. Springer: Singapore.
Molamma P. P., Conrad O. P. and Suresh V. (2005). Quantification of isoflavones in soymilk and tofu from South East Asia. International Journal of Food Properties, 8: 113-123.
Neda, M., Masoumeh, A. and Leila, Z. (2022). Harmful compounds of soy milk: characterization and reduction strategies. Journal of Food Science and Technology, 59(10):3723–3732.
Nevin, S., Busra, B. G. and Aybüke, C. S. (2017). Health benefits of fermented foods. Critical Reviews in Food Science and Nutrition, 59(3):506-527.
Obadina, A.O., Akinola, O.J., Shittu, T.A. and Bakare, H.A. (2013). Effect of natural fermentation on the chemical and nutritional composition of fermented soymilk nono. Nigerian Food Journal, 31(2):91–97.
Obadoni, B.O. and Ochuko, P.O. (2001). Phytochemical studies and comparative efficacy of the crude extracts of some homeostatic plants in Edo and Delta states of Nigeria. Global Journal of Pure and Applied Science, 8: 203-208.
Pearson DA (1976). Chemical analysis of foods (7th ed). Edinburgh: Churchill Livingston.
Pham, V. D., Somasundaram, S., Lee, S.H., Park, S.J.and Hong, S.H. (2016). Gamma- aminobutyric Acid production through GABA shunt by synthetic scaffolds introduction in recombinant Escherichia coli. Biotechnology and Bioprocess Engineering, 21:261– 267.
Phuong, H. L. E., Nills, P., Thien, T. L. E. and Katleen, R. (2021). Evaluation of γ-aminobutyric using a combination of enzymatic hydrolysis and lactic acid fermentation for γ- aminobutyric acid production from soymilk. LWT-Food Science and Technology, 142(2):111044.
Provan, G.L., Scobbie. L. and Chesson, A. (1994). Determination of phenolic acids in plant cell walls by microwave digestion. Journal of the Science Food and Agriculture, 64:63– 65.
Saadiya, A., Rouf, T. J. and Poonam S. (2018). Non-dairy probiotics; an emerging trend in health care products. International Journal of Current Microbiology and Applied Sciences, 7(10): 131-145.
Sanjukta, S., Rai, A.K., Muhammed, A., Jeyaram, K., and Talukdar, N.C. (2015). Enhancement of antioxidant properties of two soybean varieties of sikkim himalayan region by proteolytic Bacillus subtilis fermentation. Journal of Functional Food, 14:650-658.
Sasithorn, S., Bhagavathi, S. S., Periyanaina, K., Sartjin, P. and Chaiyavat, C. (2017). Lactic acid bacteria mediated fermented soybean as a potent nutraceutical candidate. Asian Pacific Journal of Tropical Biomedicine, 7(10): 930–936.
Shah, A.M., Tarfeen, N., Mohamed, H. and Song, Y. (2023). Fermented foods: their health- promoting components and potential effects on gut microbiota. Fermentation, 9(2):118.
Whitehead, D. C., Dibb, H., and Hartley, R. D. (1983). Bound phenolic compounds in water extracts of soils, plant roots and leaf litter. Soil Biology and Biochemistry. 15:133-136.
Xiaoming, Yu., Maninder, M., Baojun, Xu. and Hansong, Yu. (2020). Impact of Processing Technologies on Isoflavones, Phenolic Acids, and Antioxidant Capacities of Soymilk Prepared From 15 Soybean Varieties. Food Chemistry, 345: 612-655.
Yang, F., Chen, C., Ni, D., Yang, Y., Tian, J., Li, Y., Chen, S., Ye, X., Wang, L. (2023). Effects of fermentation on bioactivity and the composition of polyphenols contained in polyphenol-rich foods: a review. Foods, 12: 3315.
Zhang, W., Shen, Y., Li, Z., Xie, X., Gong, E., Tian, j., Si, X., Wang, Y., Gao.N., Shu, C., Meng, X., Li, B. and Liu, R.H. (2021). Effects of high hydrostatic pressure and thermal processing on anthocyanin content, polyphenol oxidase and β-glucosidase activities, color, and antioxidant activities of blueberry (Vaccinium Spp.) puree. Food Chemistry, 342:128564
Zhang, Y., Zhu, M., Lu, W., Zhang, C., Chen, D., Shah, N.P. and Xiao, C. (2023). Optimizing Levi lactobacillus brevis NPS-QW 145 fermentations for gamma-aminobutyric acid (GABA) production in soybean sprout yogurt-like product. Foods, 12:977.
Akomeng, Nicholas and Adusei, S. (2021). Organic solvent extraction and spectrophotometric quantification of total phenolic content of soil. Heliyon 7: e08388.
Armistice, C., Talknice, Z. J. and Tafadzwa, M. (2022). Effect of Lacticaseibacillus rhamnosus Yoba fermentation on physicochemical properties, amino acids, and antioxidant activity of cowpea-peanut milk. Hindawi Journal of Food Quality, 3:192-202.
Association of official Analytical Chemist. (AOAC) (1990). Official Methods of Analysis.15th ed. Washington DC, USA: AOAC International.
Association of Official Analytical Chemist. (AOAC) (2006). Official Methods of Analysis. 18th ed. Washington DC, USA: AOAC International.
Attarde D., Pawar J., Chaudhari B. and Pal S. (2010). Estimation of sterols content in edible oil and ghee samples. International Journal of Pharmaceutical Sciences Review and Research, 5(1) 021.
Danang, R., Veraita, W. and Wardani, T. S. (2021). Increased levels of fermented soymilk amino acids and effectiveness helping reduce uric acid serum in male white rats. 2nd International Conference of Health, Science and Technology ISBN: 978-623-92207- 16.
Danka, P. O., Dobrina, D. T., and Kalin, V. I. (2012). Simultaneous identification and determination of total content of amino acids in food supplements-tablets by gas chromatography. Asian Journal of Pharmaceutical and Clinical Research, 5(2):100- 120.
Darimiyya, H. and Anni, S. (2021). Characteristic and isoflavone level of soymilk fermented by single and mixed culture of Lactobacillus plantarum and yoghurt starter. Journal of Food and Nutrition Research, 9(1): 55-60.
Diana, M., Quílez, J., and Rafecas, M. (2014). Gamma-aminobutyric acid as a bioactive compound in foods: a review. Journal of Functional Foods, 10:407–420.
Doris, A. and Grace, F. (2022). Anti-nutrient reduction and nutrient retention capacity of fermentation, germination and combined germination-fermentation in legume processing. Applied Food Research, 2: e100059.
Ekkapon, H., Nut, K. and Supanimit, T. (2017). Variability of isoflavone content in soy milk products commercially available in thailand. Journal of Health Science and Medical Research, 36(2):117-126.
Fathy M. M., Asmaa I. E., Asmaa, N. E. and Mohamed, A. F. (2023). Evaluation of nutritional and physicochemical characteristics of soy yogurt by Lactobacillus plantarum KU985432 and Saccharomyces boulardii CNCMI 745.Scientific Reports, 13:13026.
Franz, C. M. A. P., Melanie, H., Julius, M. M., Hikmate. A., Nabil, B., Gregor, R., Antonio, G. and Wilhelm, H. H. (2014). African fermented foods and probiotics. International Journal of Food Microbiology, 190:84–96.
Harbome, J.B. (1993). Phytochemical Methods, a guide to modern techniques of plant analysis chapman and hall, an imprint of Thornson science, London, UK. Pp: 40-49.
Hatice, H. O., Hatice, K. Y., Amin, Y. and Per, E. J. S. (2025). Production of fermented soy and soy/cow milk products with probiotic Lacticaseibacillus rhamnosus GG strain. Food and Bioprocess Technology, 18:5736–5748.
Humyra, N., Kumkum, D., Anjuman, A. B. and Md. Anisur, R. M. (2018). Effects of grinding conditions on anti-nutrient and nutrient contents of soymilk. Journal of Bangladesh Agricultural University, 16(1): 158–163.
Kelley, W.I., Coffey, D.L. and Mueller, T. C. (1994). Liquid chromatographic determination of phenolic acids in soil. Journal of AOAC International, 77:805-809.
Kumar, V., Anita, R. and Lulua, H. (2016). Investigations of amino acids profile, fatty acids composition, isoflavones content and antioxidative properties in Soy okara. Asian Journal of Chemistry, 28(4):903-906.
Kumari, A., Angmo, K., Monika, S. and Bhalla, T. C. (2018). Functional and technological application of probiotic L. casei PLA5 in fermented soymilk. International Food Research Journal, 25(5): 2164-2172.
Kumari, S. and Chang, S. K. C. (2016). Effect of cooking on isoflavones, phenolic acids, and antioxidant activity in sprouts of Prosoy soybean (Glycine max). Journal of Food Science, 00: 0.
Lucas, G.M. and Markakas, M. (1975). Phytic acid and other phosphorus compounds of bean (Phaseolus vulgaris). Journal of Agricultural and Food Chemistry, 23:13-15.
Maria, L. M., Dustin, H., Sylvie, B., Christopher, J. C., Paul, D. C., Benoit, F., Michael G., Remco K., Gonca, P., Anne P., Eddy, J. S., and Robert, H. (2017). Health benefits of fermented foods: microbiota and beyond. Current Opinion in Biotechnology, 44:94– 102.
Mazumder, M.A.R. and Hongsprabhas, P. (2016). A review on nutrient quality of soymilk powder for malnourished population. Pakistan Journal of Nutrition, 15(6): 600–606.
Modgil, R. and Kumar, V. (2021). Soybean (Glycine max). In Oilseeds: Health attributes and food applications; Tanwar, A., Goyal, A., Eds. Springer: Singapore.
Molamma P. P., Conrad O. P. and Suresh V. (2005). Quantification of isoflavones in soymilk and tofu from South East Asia. International Journal of Food Properties, 8: 113-123.
Neda, M., Masoumeh, A. and Leila, Z. (2022). Harmful compounds of soy milk: characterization and reduction strategies. Journal of Food Science and Technology, 59(10):3723–3732.
Nevin, S., Busra, B. G. and Aybüke, C. S. (2017). Health benefits of fermented foods. Critical Reviews in Food Science and Nutrition, 59(3):506-527.
Obadina, A.O., Akinola, O.J., Shittu, T.A. and Bakare, H.A. (2013). Effect of natural fermentation on the chemical and nutritional composition of fermented soymilk nono. Nigerian Food Journal, 31(2):91–97.
Obadoni, B.O. and Ochuko, P.O. (2001). Phytochemical studies and comparative efficacy of the crude extracts of some homeostatic plants in Edo and Delta states of Nigeria. Global Journal of Pure and Applied Science, 8: 203-208.
Pearson DA (1976). Chemical analysis of foods (7th ed). Edinburgh: Churchill Livingston.
Pham, V. D., Somasundaram, S., Lee, S.H., Park, S.J.and Hong, S.H. (2016). Gamma- aminobutyric Acid production through GABA shunt by synthetic scaffolds introduction in recombinant Escherichia coli. Biotechnology and Bioprocess Engineering, 21:261– 267.
Phuong, H. L. E., Nills, P., Thien, T. L. E. and Katleen, R. (2021). Evaluation of γ-aminobutyric using a combination of enzymatic hydrolysis and lactic acid fermentation for γ- aminobutyric acid production from soymilk. LWT-Food Science and Technology, 142(2):111044.
Provan, G.L., Scobbie. L. and Chesson, A. (1994). Determination of phenolic acids in plant cell walls by microwave digestion. Journal of the Science Food and Agriculture, 64:63– 65.
Saadiya, A., Rouf, T. J. and Poonam S. (2018). Non-dairy probiotics; an emerging trend in health care products. International Journal of Current Microbiology and Applied Sciences, 7(10): 131-145.
Sanjukta, S., Rai, A.K., Muhammed, A., Jeyaram, K., and Talukdar, N.C. (2015). Enhancement of antioxidant properties of two soybean varieties of sikkim himalayan region by proteolytic Bacillus subtilis fermentation. Journal of Functional Food, 14:650-658.
Sasithorn, S., Bhagavathi, S. S., Periyanaina, K., Sartjin, P. and Chaiyavat, C. (2017). Lactic acid bacteria mediated fermented soybean as a potent nutraceutical candidate. Asian Pacific Journal of Tropical Biomedicine, 7(10): 930–936.
Shah, A.M., Tarfeen, N., Mohamed, H. and Song, Y. (2023). Fermented foods: their health- promoting components and potential effects on gut microbiota. Fermentation, 9(2):118.
Whitehead, D. C., Dibb, H., and Hartley, R. D. (1983). Bound phenolic compounds in water extracts of soils, plant roots and leaf litter. Soil Biology and Biochemistry. 15:133-136.
Xiaoming, Yu., Maninder, M., Baojun, Xu. and Hansong, Yu. (2020). Impact of Processing Technologies on Isoflavones, Phenolic Acids, and Antioxidant Capacities of Soymilk Prepared From 15 Soybean Varieties. Food Chemistry, 345: 612-655.
Yang, F., Chen, C., Ni, D., Yang, Y., Tian, J., Li, Y., Chen, S., Ye, X., Wang, L. (2023). Effects of fermentation on bioactivity and the composition of polyphenols contained in polyphenol-rich foods: a review. Foods, 12: 3315.
Zhang, W., Shen, Y., Li, Z., Xie, X., Gong, E., Tian, j., Si, X., Wang, Y., Gao.N., Shu, C., Meng, X., Li, B. and Liu, R.H. (2021). Effects of high hydrostatic pressure and thermal processing on anthocyanin content, polyphenol oxidase and β-glucosidase activities, color, and antioxidant activities of blueberry (Vaccinium Spp.) puree. Food Chemistry, 342:128564
Zhang, Y., Zhu, M., Lu, W., Zhang, C., Chen, D., Shah, N.P. and Xiao, C. (2023). Optimizing Levi lactobacillus brevis NPS-QW 145 fermentations for gamma-aminobutyric acid (GABA) production in soybean sprout yogurt-like product. Foods, 12:977.