Studies on tinapayan, an indigenous fish ferment in Central Mindanao [Philippines]

Tinapayan is a Maguindanaoan carbohydrate base on lactic acid (LA) fish ferment prepared by fermenting anaerobically-dried fillets of murrels (pangos) with a mixture of prefermented cooked rice, spices, and small amounts of salt and water. The product undergoes three stages of manufacture: production of tapal (stage 1), tapai a umay (stage 2) and tinapayan (stage 3). Tapai (ground rice, 50 percent water w/w, 2.0 percent w/w red pepper, and 0.01 percent w/w 2-week-old commercial tapai); tapai a umay (cooked non-glutinous rice and 1.5 percent w/w tapai; and tinapayan (24 h old tapai a umay); 2.5 percent w/w salt, 18.0 percent w/w languas (Curcuma zedearia Rengi, Resc.), 0.18 percent lemon grass (Cymbopogon citratus, 1.5 percent water w/w and dried murrel (Ophicephalus striatus) were produced in the laboratory following the indigenous process. Three groups of microorganisms (molds, yeasts and LABs) which are believed to originate from the commercial starter were found growing in association, in all three stages of tinapayan manufacture. At stage 1, molds and yeasts dominated the LABs proliferated only from 12-28 hrs when the moisture was 40-50 percent. The dried starter (9.49 percent moisture) contained log 9 cfu/g each of molds and yeasts, and log 3 cfu/g of LABs. At stage 2, the growth of LABs was favored, the molds and yeasts showed decreasing growth trends. The 24-hr old tapai a umay contained about log 6 cfu/g each of molds and yeasts, and log 5 cfu/g of LABs. The pH dropped to about 4.0 after 6 hours, and percent titratable acid (percent TA, expressed as lactic acid) ranged from 0.10 to 0.30 percent, and the moisture content increased to 67 percent. At stage 3, the molds and yeasts maintained their population at log 6 cfu/g. The LABs reached log 7 cfu/g on day 9. The pH of the system ranged from about 5.0 to 6.0 percent, TA had its peak at 10 percent and the product had an average salt content of 4.863 percent after the 15th day of fermentation. The addition of the 5 percent salt (about 7.0 percent in the final product) in P3 sample resulted in the reduction of yeasts to log 5 cfu/g and LABs to log 5 cfu/g and in the increase of molds to log 6 cfu/g. The pH and TA of the system were low (5.5-6.5), (0.51 percent average), respectively. The odor, flavor, and general acceptability of the cooked product was comparatively inferior to that of the market sample. Fish ferments with final salt contents of about 5.0 percent or less had better sensory and acceptability scores than did Ps sample. Both products attained the characteristic odor and flavor scores similar to the market sample in less than 15 days of fermentation