Call Prefix : PR-T

Call Suffix : 1981

Call Cutter : T - FoSc 6

Location : SEARCA Library

Format : TD

Publisher : University of the Philippines Los Banos,

Publication Date : February 1981

Publication Place : Laguna, the Philippines :

Summary : An experiment was conducted to determine the effect of sodium chloride (4-8 percent), sorbic acid (0.2-2.0 percent), sorbitol (0.2-2.0 percent), propylene glycol (0.8-6.0 percent), and mixture of sodium chloride (10 percent) with other humectants on the storage characteristics of oven dried (50 degree C) "oncom." The chemical and microbial changes were studied throughout the storage period. Both sodium chloride and sorbic acid inhibited the microbial growth in the system. Even at high concentration, propylene glycol (6 percent) and sorbitol (0.2-2.0 percent) did not affect bacterial growth and mold and bacterial growth, respectively. Increasing the concentration of each humectant decreased water activity (Aw) and microbial population. Prolonged drying at 50 degree C reduced the moisture content and microbial population of the product. The increase of amino nitrogen content and the decrease of reducing sugar content during drying (50 degree C) of "oncom" did not kill all of the microorganisms present nor did it stop enzymatic reactions. However, during storage of dried "oncom," moisture content increased and the microbial load influenced the amino nitrogen formation, pH, and use of reducing sugar. With mixed humectants, the increase of amino nitrogen content and decrease of reducing sugar content were lower than those containing single humectant. In general, a high moisture level before storage gave poorer quality products that were acceptable only up to 60 days of storage. A low moisture level of dried "oncom" resulted through a longer oven drying period and gave a more stable product that lasted for more than 60 days. "Oncom" containing mixed humectants could be stored longer than those treated with single humectant.