Storage Stability and Degradation Kinetics of Phytonutrients of Red Palm-pressed Mesocarp Olein

Red palm-pressed mesocarp olein (PPMO) contains plenty of naturally occurring phytonutrients. However, the application of PPMO in food is limited due to the lack of scientific data. In the study, stability and degradation kinetics of carotenoid and vitamin E in PPMO under two storage temperature, 23°C (with and without light) and 35℃ (without light), for a period of twelve months were performed. Amber bottles were used for optimum protection against damaging UV light. Both temperature and light conditions significantly influenced the total carotenoid and vitamin E contents of PPMO, as well as oil quality in terms of peroxide value and anisidine value to a different extent. Correlation analysis showed that oil quality was significantly but negatively correlated with phytonutrients. In addition, both zero- and first-order kinetic models were able to describe the degradation kinetics of the phytonutrients in PPMO. Zero-order was the best fit with higher correlation coefficients (R²) for both carotenoid and vitamin E contents, except for carotenoid that was kept at 23°C whereby first-order displayed the best fit. The half-life of carotenoid and vitamin E in PPMO were 40.8 months and 21.6 months, respectively under the optimised storage condition (23°C in amber bottles). In conclusion, storage of PPMO at lower temperature and in light-limited environment could effectively lower its oxidation rate and degradation rate of carotenoid and vitamin E, postulating its shelf life to be prolonged.