Effect of tocopherols, tocotrienols, β-carotene, and chlorophyll on the photo-oxidative stability of red palm oil.

Effect of tocols, β-carotene, and chlorophyll on photo-oxidative stability of red palm oil (RPO) were studied. Model systems of triacylglycerols+tocols, triacylglycerols+β-carotene, triacylglycerols +tocols+β-carotene, and triacylglycerols+tocols+β-carotene+chlorophyll were exposed to fluorescent light at intensities of 5,000, 10,000, and 15,000 lux for 7 h at 30±2°C. Changes in concentrations of tocopherols, tocotrienols, β-carotene, chlorophyll, and peroxide values were evaluated every hour. Light intensity accelerated degradation of tocols in the triacylglycerols+tocols system and β-carotene in the triacylglycerols+β-carotene system. Gamma-tocotrienol showed the highest degradation rate and β-carotene was the most sensitive compound to changes in light intensity, indicated by the lowest light intensity coefficient (zi) value. The presence of tocols and β-carotene together showed protective effects for the photo-oxidative stability of RPO. The presence of chlorophyll increased the rate of photo-oxidation at high light intensities. Interactions between tocols and β-carotene contributed to the photo-oxidative stability of RPO.