Screening for phenolic compounds and oxidative capacity of fruit peels, agricultural waste, and traditional herbal medicine for use as biodiesel fuel additive

Abstract

One of the most efficient ways to prevent biodiesel oxidation is to use antioxidant additives. In the present study, 19 plant extracts from fruit peels, agricultural waste, and traditional herbal medicine have been evaluated for their potency as antioxidants. Ripe mango peel exhibited the highest total phenolic content (TPC) (142.99 ± 2.64 mg GAE/g). The rambutan peel had the highest radical scavenging capacities for the DPPH (IC50 of 5.67 ± 0.47 μg/mL), ABTS (IC50 of 3.94 ± 0.17 μg/mL), FRAP (109.33 ± 2.97 mg AAE/g). The performance of their extracts in improving the oxidative stability of biodiesel was assessed by using the induction period (IP). The biodiesel (B100) without the extract showed an IP of 1.47 h, while it increased to 15.00, 12.18, 12.00, and 6.38 h with the ripe mango peel, raw mango peel, rambutan peel, and longan peel extracts, respectively, while the synthetic antioxidant butylated hydroxytoluene (BHT) exhibited an IP of 6.09 h. The IP of biodiesel blends with petrodiesel (B10) with antioxidants was greater than 24.00 h in all cases. According to the results obtained, the ripe mango peel extract is a good alternative to synthetic compounds used in palm oil-derived biodiesel to improve its storage stability.

Keywords

• antioxidant
• biodiesel
• fruit peels
• agricultural waste
• traditional herbal medicine