Shelf life of tempeh processed with sub-supercritical carbon dioxides

Tempeh, a fermented soybean-based food originally from Indonesia, is a remarkably nutritious functional food with health benefits. Unfortunately, tempeh is highly perishable, with a shelf life of 24 – 48 hours. The goal of this research was to evaluate the possibility of a sub-supercritical CO2 technique to increase the shelf life of tempeh by measuring the changes in the L* (lightness) value and texture of tempeh via application of a kinetic approach and, based on the observations, to estimate its shelf life. Tempeh was processed with sub-supercritical CO2 at 6.3 MPa for 10 min, then together with unprocessed tempeh (control), stored for 5 days at temperatures of 20, 30 and 40 °C. The Accelerated Self-Life Test (ASLT) with the Arrhenius model was used to measure the shelf life of processed and control tempeh. The calculated shelf life of processed tempeh using the ASLT by the Arrhenius method was 2.43 days at 20 °C, 3.7 days at 30 °C and 1.4 days at 40 °C, and the shelf life of unprocessed tempeh was 3.33 days at 20 °C, 2.90 days at 30 °C and 2.56 days at 40 °C. The conclusion was that the use of sub-supercritical CO2 at 6.3 MPa for 10 min increased the shelf life of tempeh stored at 30 °C.