Journal of Food Processing & Technology

Abstract

Effect of Heating and of Short Exposure to Sunlight on Carotenoids Content of Crude Palm Oil

Dongho Dongmo FF, Ngono Ngane Annie, Demasse Mawamba Adélaide, Schweigert Florian and Gouado Inocent

This study was done to evaluate the effect of short exposure to sunlight and of heating on crude palm oil (CPO) quality particularly on its carotenoids content. Firstly, CPO was exposed to sunlight for 14 hrs. Then, samples were collected and kept at 4°C for analysis of carotenoids content, free fatty acid (FFA) and peroxide value (PV). Secondly, CPO was heated at 50°C, 120°C, 200°C or 400°C for 30 min, 60 min or 120 min and samples were cooled down and kept at 4°C until analysis of carotenoids content, FFA and PV. Finally, we studied the effect of heating of CPO in the food matrix (maize cake). Thus, maize cake was steamed on gas stove (100 ± 5°C) during exactly 1, 2, 3 or 4h and kept at 4°C until analysis of moisture and carotenoids contents. The results showed that short exposure to sunlight did not significantly affect carotenoids content, FFA and PV of CPO. However, heating accelerated the formation of peroxides and degradation of carotenoids. Destruction of carotenoids increased with both temperature and duration of exposure to heat. FFA did not significantly change during heating. Likewise, during heating of CPO in the food matrix, carotenoids content decreased significantly with cooking time. These results suggest that short exposure to sunlight does not have a significant effect on carotenoids content of CPO. But, its heating (directly or in the food matrix) results in significant degradation of carotenoids.