Netnapa Chana, Atcharaporn Muengpoon, Siriphat Pethkaew, Nattawadee Kulsin, Achariya Mahasuk, and Sirirat Srirat

DOI: 10.14456/sjst-psu.2022.139

pp. 1067 - 1074

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.