By: Rahayu WP1, Affandi E2, Rumin1
1Department of Food Science and Technology, Bogor Agricultural University
2Nutrition Research and Development Center, Department of Health Bogor
The presence of vitamin B12 in tempeh as vegetable food is very important for the people with low income and the vegetarian. In order to provide the tempeh which consistently contain B12 there is need to know the influences of mixed culture storage to the bacteria productivity in producing vitamin B12. Preliminary observation was to get the best mixed culture for storage. The variables used were the composition of inoculation ratios of mold and bacteria (1:0, 5:1, 1:1 and 1:5, w/w) respectively and the moisture content were (20±1, 15±1, 10±1 and 10±1 %) respectively. The cultures were packed and stored under the room temperature for 6 weeks to observe their organoleptic quality and vitamin B12 content in the tempeh production. Based on previous observation, the culture ratio of mold and bacterial 1:1 (w/w) and 1:5 (w/w) produced the higher vitamin B12 content of tempeh with quite good organoleptic quality and was not different from the control culture. Organoleptic quality of the tempeh produced from culture with 20% moisture content began to spoil at the third week at storage, whereas the culture with 10% moisture content was somewhat good until the sixth week storage. Smell evaluation of tempeh showed that inoculum ratio of mold and bacteria 1:1 (w/w) was not different from the control, whereas the ratio of mold and bacteria 1:5 (w/w) was unaccepted. It was concluded that the inoculums ratio of mold and bacteria 1:1 (w/w) and moisture content of 10% was recommended to produce the tempeh with a good organoleptic quality and significant amount of vitamin B12 13.71 mg/g (db) under the condition of incubation temperature 37oC for 24 hours until the fourth week of culture storage.
Keywords: tempeh, mixed culture, storage, Rhizopus oligosporus, Citrobacter freundii
Dimuat di Buletin Teknologi dan Industri Pangan, Volume 6 No. 1, 1995, ISSN 0216-2318