Preservation of the Nutritional Quality of Soymilk by Heat Treatment

Adeniyi P.O.^1, and Ajayi K.²

¹Institute of Agricultural Research and Training, Obafemi Awolowo University, Apata, Ibadan, Nigeria

²Department of Human Nutrition and Dietetics, Afe Babalola University, Ado Ekiti, Ekiti, Nigeria

Cite this paper:
Adeniyi P.O. and Ajayi K.. Preservation of the Nutritional Quality of Soymilk by Heat Treatment. American Journal of Food and Nutrition. 2020; 8(2):40-46. doi: 10.12691/ajfn-8-2-4

Abstract

Household soymilk preparation is labor intensive and time consuming, hence, in order to encourage soymilk consumption there is need for safe, easy, available, accessible and affordable measure of preserving the nutritional and safety quality for at least a few days after preparation even in areas of poor power supply that makes refrigeration unreliable. This experimental study was therefore designed to determine the effect of boiling for three consecutive days on the nutritional, physical, sensory and microbial properties of soymilk with a view of preserving the milk for consumption within the first three days after preparation. Soymilk was prepared using standard procedure. A sample was taken on the day of production (SM0) and set as control. This was subjected to boiling for 5 minutes twice a day (morning, 7a.m. and evening, 5p.m.) without covering the pot for three consecutive days and samples were designated as SM1, SM2 and SM3 respectively. Proximate composition, thiamine, riboflavin, niacin, vitamin C, mineral composition as well as pH, viscosity, specific gravity, microbial status and sensory properties were assayed using standard analytical methods. Mean data were compared using analysis of variance at p ≤ 0.05. Nutritional components of the soymilk sample increased with increase in days of preservation by boiling but the moisture content reduced significantly relative to control. Similarly specific gravity and viscosity increased while the pH reduced, though not significantly, throughout the experimentation period. The soymilk samples were free of coliforms throughout the preservation period while the microbial load fell within acceptable range for safe consumption. The sensory scores for taste, mouth feel, aroma and overall acceptability throughout the experimentation period was 8 which denotes ‘like very much’ except for color which reduced significantly to 7.79 in SM3 which is still acceptable. Boiling of soymilk for three consecutive days after production did not adversely alter its nutritional, physical, microbial and sensory properties except color which was impaired at the third day. Household preservation of soymilk by boiling should encourage its consumption especially in areas where refrigeration is not easily available.

Keywords:
soymilk nutritional quality boiling food and nutrition security

This work is licensed under a Creative Commons Attribution 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/

References:

[1]	Sharma S., Kaur M., Goyal R. and B.S. Gill. Physical characteristics and nutritional composition of some new soybean (Glycine max L. Merril) genotypes. Journal of Food Science and Technology 2014; 51(3): 551-557.
[2]	Wang H. and P.A. Murphy. Isoflavone composition of American and Japanese soybeans in Iowa: Effects of variety, crop year and location. Journal of Agricultural and Food Chemistry 1994; 42(8): 1674-1677.
[3]	Messina M. Modern application for an ancient bean: soybeans and the prevention and treatment of chronic disease. The Journal of Nutrition 1995; 125(3): 5675-5695.
[4]	Singh B.P., Yadav D. and S. Vij. Soybean bioactive molecules: current trend and future prospective. In: Merillon J.M., Ramawat K. (eds) Bioactive molecules in food. Reference Series in Phytochemistry 2019, Springer, Cham, Switzerland.
[5]	Maziya-Dixon B., Akinyele I.O., Oguntona E.B., Nokoe S., Sanusi R.A. and E. Harris. Nigeria food consumption and nutrition survey 2001-2003. International Institute of Tropical Agriculture (I.I.T.A.) 2004, Nigeria.
[6]	Kundu P., Dhankhar J. and A. Sharma. Development of non-dairy milk alternative using soymilk and almond milk. Current Research in Nutrition and Food Science 2018; 6(1).
[7]	Mohammed M.A., Haggar I.S. and M. Hasbalrasol. Effect of different processing methods on chemical composition and sensory quality of soymilk. International Journal of Fermented Foods 2017; 6(2): 100-108.
[8]	El-Tawab A.M.A. Soymilk as an unconventional alternative of milk for sucking calves. International Research Journal of Animal and Veterinary Sciences 2019: 1(1): 1-10.
[9]	Oseni M.O. Household’s access to electricity and energy consumption pattern in Nigeria. Renewable and Sustainable Energy Review 2012; 16(1): 990-995.
[10]	Madukwe E. and P.E Eme. Chemical evaluation and sensory attributes of soymilk fortified with carrot powder. African Journal of Food Science 2012; 6(20): 483-486.
[11]	Kirk R.S and R. Sawyer. Pearson’s Composition and Analyses of Foods, 9th edition, 2005, Longman, United Kingdom.
[12]	Harrigan W.F and M.E. McCance. Laboratory methods in food and dairy microbiology, 1976, Academic Press, London.
[13]	Walfe K.A. Use of reference standards for sensory evaluation of product quality. Food and Agriculture Organization of the United Nations. Available from: www.agris.fao.org [internet]. Accessed: 2019 January 28.
[14]	Lakshmanan R., Lamballerie M. and S. Jung. Effect of soybean-to-water ration and pH on pressurized soymilk properties. Journal of Food Science 2006; 71(9): 384-391.
[15]	Nwoke F.U. and M.C. Umelo. Nutritional and sensory quality of soymilk produced from different improved varieties of soybean. Pakistan Journal of Nutrition 2015; 14(12): 898- 906.
[16]	Chua S., Ng M., Craig D., Liu X., Chen S. and P. Ho. Microbiological guidelines for food. Centre for Food Safety 2014, Hong Kong.
[17]	Adeleke O.E., Adeniyi B.A. and A.A. Akinrinmisi. Microbiological quality of local soymilk: A public health appraisal. African Journal of Biomedical Research 2000; 3: 89-92.