Changes in quality attributes during storage of togwa, a lactic acid fermented gruel

Microbiological, physicochemical and sensory quality changes in togwa durin g storage at ambient tropical temperatures were monitored in unpasteurized and pasteurized samples with added sodium benzoate, potassium sorbate, prop ionic acid or a combination of sodium benzoate and potassium sorbate. The u ntreated samples were unacceptable within 48 h after production. Organic ac ids, volatile flavor compounds and fermentable sugars were monitored in unt reated samples for up to 96 h. Ethanol, 2-methyl-1-propanol, 2-methyl-1-pro panal 3-methyl-1-butanol, 3-methyl-1-butanal, acetone, acetoin, lactic, suc cinic and formic acid increased significantly within 48 h. Pyroglutamic and pyruvic acid decreased and then increased, while uric acid and sugars decr eased within 96 h. Sodium benzoate, potassium sorbate or their combination extended the shelf-life of the control samples by four days. Pasteurization at 97C/10 min reduced the total mesophilic bacteria, lactic acid bacteria, yeasts and Enterobacteriaceae counts to nil and maintained the pH, titrata ble acidity, specific gravity, and total soluble content constant, and the products were mildly acceptable during storage for up to 60 days. Pasteuriz ation alone was comparable to the combined effects of pasteurization and tr eatment with preservatives on the quality of the product. Pasteurization al one may therefore be appropriate for small-scale production and increased c ommercialization.