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Nine (9) Gram-positive bacteria, isolated from 8-day old fermenting durian (tempoyak) made in the Philippines were classified and subjected to phenotypic analyses. Based on morphological and biochemical characteristics, the lactic acid bacteria (LAB) isolates were identified as Lactobacillus plantarum, Lactobacillus sp, Weissella paramesenteroides and Pediococcus acidilactici. This is the first report for the presence of Weissella sp and Pediococcus sp in tempoyak. Live cells of LABs in tempoyak makes it a functional food and probably with potential as probiotic product.

Purple sweet potatoes contain anthocyanins which could function as a natural food colorant, and an antioxidant.One of the problems in handling the fresh roots is their susceptibility during storage, and to extend their uses, fresh purple sweet potato could be processed into flour. However, during flouring process, the properties of the purple sweet potato may undergo some changes such as partial gelatinization of the starch and discolorization. Therefore, the purpose of this study was to investigate the effect of pre-heating treatment during flouring process on degree of gelatinization, the anthocyanin content, the antioxidant activity and the total phenolic content of heat treated purple sweet potato flour. Other objectives were to observed the changes in the starch properties such as rheological properties, granular appearance of the heat treated-purple sweet potato flour. Pre-heating treatment of purple sweet potato flour was prepared by heating grated purple sweet potato in a single rotary drum cooker at 90°C for 15, 30, 45, 60 and 75 min, followed by drying in a cabinet dryer at 60°C for 8 h. The results showed the longer pre-heating time at 90°C had caused increase in the degree of gelatinization, increase in total phenolic and anthocyanin retention. In addition, differences in gelatinization temperature, maximum viscosity, paste stability and retrogradation, and differences in scanning electron microscope (SEM) of granular appearance were also observed. The overall results indicated that pre-heating treatment can be used for modifying the physical, chemical and rheological properties to suit various applications and preserving functional properties of purple sweet potato flour.

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