The Microbiologycal, Physical, and Chemical Changes of Petis Liquid during Dry Spontaneous Fermentation

Abstract

Spontaneous fermentation will produce unstable product. It’s caused by the variety of microbe, uncontrolled environmental of fermentation, and the variety of substance and process. Therefore, exploration research to understand the microbiologycal, physical, and chemical during fermentation is needed. The experiment was aimed to obtain early information that may be used as standard in using lactic acid bacteria as starter media in improving fermentation process. The research was conducted at the laboratory of Microbiology, PSPG of Gadjah Mada University, Yogyakarta. The dillution and plating method were used to observe mocrobiological changes such as total microbial changes, coliform, yeast, lactic acid bacteria, and bioamine producer bacteria. Physical changes was perceived from its performance, colour, physical meat and odour. While, chemical changes were observed through dissolved protein, carbohydrate (sugar reduction), fat, salt, bioamine as histamine, total acid, and Aw. It was resulted that pH and titrated- acid during fermentation are constant relatively, Sugar reduction and dissolve protein increased due to the degradation of carbohydrate and protein component. Meanwhile, these decreased because of microbial metabolism. Microbiologycal changes indicated that lactic acid bacteriapopulation constancly 105 CFU/g during fermentation. These were suspected significantly inhibited coliform growth (f rom 105 at the start of fermentation to 103 at the end of fermentation) , and bioamine producer from 106 to 103. Keywords : dry spontaneous fermentation, salt, lactic acid bacteria.