Optimization of Neutralization in the Integrated Refining of Red Palm Oil: Effects on Free Fatty Acids and Water Content

Abstract

Red Palm Oil (RPO) is widely recognized for its high provitamin A content, especially carotenoids, and its abundance of natural antioxidants such as tocopherols and tocotrienols. These compounds make RPO a valuable functional food ingredient with significant nutritional and health benefits. However, refining RPO remains challenging because improvements in oil quality must be achieved without causing substantial losses of these bioactive compounds. This study evaluated an integrated refining sequence consisting of degumming, bleaching, neutralization, and deodorization applied to crude palm oil under moderate temperature conditions to maintain nutritional quality. The effects of NaOH concentration (14–18 Be) and reaction time (10–20 minutes) were investigated as the main variables influencing free fatty acid (FFA) reduction and water content stability. The results showed that the neutralization step was the most decisive stage, achieving an FFA reduction of nearly 60%, substantially higher than the reductions obtained during degumming–bleaching (28%) and deodorization (17%). The optimum operating condition was observed at 15 minutes with an appropriate NaOH concentration, where FFA reached its lowest level while water content remained relatively stable. In contrast, extending the reaction time beyond the optimum increased FFA levels, likely due to reverse hydrolysis caused by excess water formation during the process. Overall, this study defines an effective processing window for refining RPO under mild conditions and identifies neutralization as the critical control step. Further work is recommended to evaluate carotenoid retention and antioxidant stability throughout the refining sequence.