Changes to the chemical and microbiological characteristics of Leucaena leucocephala seeds during tempeh fermentation in Pacitan, East Java

Lamtoro tempeh is a traditional Indonesian fermented food made from lamtoro (Leucaenaleucocephala). In Pacitan, it is usually fermented using usar (a traditional tempehinoculum made from senggani leaves). The fermentation process takes 42 hrs and duringthis period, there are changes in the chemical and microbiological characteristics of thelamtoro seeds. To study these changes, samples were collected and tested for chemicalcharacteristics (water content, ash content, dissolved protein, pH, and total acid titration)and microbiological characteristics (the number of fungi, yeast, and lactic acid bacteria)every 6 hrs during the 42 hrs fermentation. During fermentation, the water contentincreased significantly in the initial 6 hrs of fermentation and then tended to stabilize untilthe 42-hour. The ash content increased, while the dissolved protein content increased fromthe 0-hour to the 36-hour of fermentation but dropped at the 42-hour. The pH level of thelamtoro tempeh decreased from 0-hour until 30-hour and then increased until the end ofthe fermentation period. However, the level of total acid titration increased during thelamtoro tempeh fermentation. The growth of fungi, yeast and lactic acid bacteria initiallydeclined but then gradually increased until the end of fermentation (42-hour). Thefermentation time was found to affect both the number of microbes and the chemicalcharacteristics of the lamtoro tempeh from the Pacitan area.