Effects of High-Pressure Process (HPP) Treatment of Tempoyak on Microbial Growth

Abstract

Tempoyak is a fermented durian paste made from an overripe durian under partial anaerobic conditions in a tight closed container. The anaerobic fermentation conducted by Lactic acid bacteria (LAB) can take place from 3 to 8 days in ambient temperature range from 24°C to 34°C and the final pH value is around 3.96 to 4.08. This study focus on the effectiveness of the High-Pressure Process (HPP) in Tempoyak and the relationship between pressure treatment with microbial activity in treated Tempoyak. A High- Pressure treatment of 600 MPa for 5 min on packed tempoyak was applied. Analysis of the pH, moisture content, total plate count (TPC), color and sensory were performed. Throughout four weeks of storage, the result of pH and moisture content showed no significant changes under chilled temperature (–4°C) for non-treated and HPP-Treated samples. The total plate count showed the microbial level of non-treated sample to be slightly higher when compared to HPP sample in both storage conditions. The L* values also showed significant change in the color analysis of the samples. From the analysis performed, HPP was proven to reduce the microbial activity in the tempoyak.