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.