|Published online: September 16, 2015||$US5.00|
The antioxidative effect of methanol and water chaya leaf extracts on Refined Soybean Oil (RSBO) stored for twelve months at room temperature (270C–330C) was determined by monitoring the colour, refractive index, free fatty acid (FFA), acid value (AV), and peroxide value (PV). Extracts of chaya leaf were prepared by separately dissolving dried, ground, and sieved orange peel into acetone, chloroform, ethylacetate, methanol, and water in ratio 1:10 for seventy-two hours. The methanol chaya leaf extract (MCLE) and water chaya leaf extract (WCLE) were separately added at varying concentrations (200 ppm to 1000 ppm) to RSBO. The oil was also dosed with 200 ppm Butylated Hydroxy Toluene (BHT). Maximum yield of extracts was obtained with water (14.33±1.10%) and methanol (12.56±0.98%). The colour and refractive index of RSBO containing the extracts ranged between 10.0–18.5 units and 1.470–1.472 respectively whereas the colour and refractive index of RSBO with no additive (0 ppm) and 200 ppm BHT were 8.0–10.0 units and 1.470 accordingly. The FFA and AV of RSBO containing methanol (expect 200 ppm) and water chaya leaf extracts were lower than RSBO containing no additive and 200 ppm BHT. The PV of RSBO containing chaya leaf extracts was lower than PV of RSBO that contained no additive and 200 ppm BHT. The methanol and water chaya leaf extracts are more effective than Butylated Hydroxy Toluene in combating both hydrolytic and oxidative rancidity of RSBO.
|Keywords:||Chaya Leaf Extracts, BHT, Refined Soybean Oil, Antioxidant, Quality Characteristics|
Food Studies: An Interdisciplinary Journal, Volume 5, Issue 4, December 2015, pp.59-69. Article: Print (Spiral Bound). Published online: September 16, 2015 (Article: Electronic (PDF File; 474.137KB)).
Lecturing/ Unit Head (Chemistry), Department of Science Laboratory Technology, Rufus Giwa Polytechnic, Owo, Owo, Ondo-State, Nigeria