Abstract

Abimbola Peter Oluyori , Inyinbor Abosede Adejumoke, Dada Adewumi Oluwasogo, Oyedepo Grace Olapeju, Abodunrin Temitope Olabisi and Awolesi Oluwafemi

DOI : http://dx.doi.org/10.13005/ojc/350239

The oxidative instability of vegetable oils which contain polyunsaturated fatty acids and the health implication of synthetic antioxidants is the reason for the current intensive search for safer natural antioxidants. Hence, the total phenolic content and 2,2-diphenyl-1-picryhydrazyl (DPPH) radical scavenging activity of Fagara zanthoxyloides root and Zingiber officinale rhizome have been comparatively evaluated. Zingiber officinale cold extract (GC) exhibited highest DPPH scavenging activity as well as the highest TPC while the hot extract from Fagara zanthoxyloides root (FH) had more phenolic content than its cold counterpart. Consequently, the anti-oxidative potential of refined soybean oil fortified with GC and FH was investigated at 65°C (accelerated storage temperature) for a lenght of 24 days. Established indicators such as peroxide, p-anisidine and total oxidation value (TOTOX) were used to monitor the extent of lipid deterioration with butylated hydroxyanisole (BHA) as the positive control. Generally, GC was more effective in stabilizing the soybean oil. After 24 days of storage, soybean oil fortified with GC, FH and BHA achieved 68.58%, 57.50% and 67.56% retardation in the formation of primary oxidation products respectively. The lowest TOTOX (146.38) value was also observed in GC supplemented oil, suggesting that GC could be effectively employed as a replacement for BHA in soybean oil preservation. Hence, extracts from Zingiber officinale rhizome and Fagara zanthoxyloides roots can be explored as sources of natural antioxidants for application in the food industry.

Antioxidants; Fagara Zanthoxyloides; Ginger; Preservation; Soybean Oil

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