Temperature coefficient (Q10) and kinetic reaction for the shelf life evaluation: case study of Homnil rice-cookies

Abstract

This study aimed to determine the shelf life of Homnil rice-cookies under accelerated temperatures and humidity control 75% by using Q₁₀ and kinetic reaction. The cookies were random sampling every 1 wk for 7 wks. Changes in physicochemical quality of cookies sample was significantly increased (p<0.05) when increasing storage time; hardness (1.4-1.9 kg), rancidity (TBARs) (2.0-7.5 mg malonaldehyde/kg), water activity (0.63-0.65) and moisture (7.1-8.8%), except for color value L* a* b* was declined. These results were clarly found in high accelated temperature at 50°C than 40°C and 30°C. Approving to the reduction scores of sensory evaluation was obtained. Whereas the total plate count (1x10⁴ cfu/g), Coliform (<3 MPN/g) and E.coli (<3 MPN/g) were lower and safety for consumption over storage period for 7 wks. In this study, the rancidity index by using sensory score and TBARs value were choosen for quality deterioration to calculate the shelf-life of Homnil-rice cookies. At storage temperature 25°C, the shelf-life of Homnil-rice cookiess was around 60 days and 38 days when calculated by Q₁₀ at accelerated temperature at 30°C and 40°C; and 40°C and 50°C, respectively.  A shelf-life of cookies was about 22 days when evaluated by kinetic reaction.