EFFECT OF ADDITION OF CITRIC ACID AND SODIUMBENZOATE ON THE KEEPING QUALITY OF SOYMILK

The greatest problem consumers encounter with soy milk remains its very short shelf life due to microbial activity. The combination of different preservation methods may just be the solution to the problem. The synergistic  effect of citric acid and sodium benzoate preservatives at various concentrations within their maximum permissible levels along with pasteurization, on the microbial keeping quality of home- made soy milk stored at ambient temperature was therefore, studied. This is with the intention of determining which combination is best for a prolonged shelf life. Fourteen soymilk samples were prepared by extracting the soymilk from whole, boiled and dehulled soybean seed, pasteurized, preserved and stored.  All soy milk samples were analyzed for proximate composition (moisture %, ash %, protein %, fat and carbohydrate %) and organoleptic properties (color, texture, taste, flavor, aroma and overall acceptability). Standard microbiological techniques were employed in the enumeration of potential spoilage organisms in soy milk samples evaluated to determine the shelf-stability of the soymilk during the period of storage. pH analysis of the soymilk samples was conducted throughout the period of storage and it was revealed that the pH of the samples reduced significantly (p