Green process to produce phytonutrients from crude palm oil: effects of phenolic antioxidants on tocols and carotene retention during enzymatic hydrolysis

The enzymatic hydrolysis of crude palm oil (CPO), followed by separation, has been studied as an alcohol-free alternative to concentrate and extract palm carotene and tocols. However, a considerable amount of palm phytonutrients may be lost during hydrolysis due to the production of free fatty acids (FFAs), which promote auto-oxidation. In this research, the effects of incorporating phenolic antioxidants, including butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), and tertiary butyl hydroquinone (TBHQ), on the enzymatic hydrolysis of CPO and the retention of phytonutrients were evaluated. The addition of phenolic antioxidants did not affect the production of FFAs. Meanwhile, its addition positively impacted the phytonutrients preservation as the retentions of carotene and tocols were increased up to over 90 %; a great improvement compared to the 58 % carotene and 23 % tocols retentions without phenolic antioxidants. The results indicated that TBHQ is the best-performing phenolic antioxidant, owing to its low steric hindrance and higher solubility in the water phase. The inclusion of 0.08 wt% TBHQ in the reaction improved the carotenes and tocols retentions to 88 % and 98 %, respectively, after 24 h of hydrolysis. In conclusion, adding phenolic antioxidants considerably enhances the preservation of palm carotene and tocols during enzymatic hydrolysis. The results of this study revealed that the phenolic antioxidants performed in the following order: TBHQ > BHT > BHA.