Assessment of potentials of Moringa oleifera seed oil in enhancing the frying quality of soybean oil

Abstract

This study investigated the effects of mixing Moringa oleifera seed oil with soybean (Glycine max) seed oil in enhancing the physical and chemical properties of soybean oil during repetitive frying. Different blends (100:0, 50:50, and 70:30) of soybean and M. oleifera seed oils were formulated, while soybean oil served as control. All these oil samples were used for frying potato (Ipomoea batatas) slices. The quality of the fried oil samples was evaluated by determining the smoke point, refractive index (RI), viscosity, colour, peroxide value, iodine value, and free fatty acid (FFA). The range of values obtained were smoke point (158.7-172.3°C), RI (1.46-1.49°C), colour (6.0-9.42), viscosity (0.41-2.13 mm2/s), peroxide value (0.93-5.16 meq/kg), iodine value (87.16-64.71 mg/100 g), and FFA (0.3-1.95%), for different blends of soybean and M. oleifera seed oils and control. In terms of changes in the chemical and physical properties, during frying, soybean/M. oleifera seed oil mix of 70:30 had the lowest reduction in iodine value (87.56-68.73 mg/100 g), lowest increase in peroxide value (0.93-1.86 meq/kg) and FFA value (0.3-0.65%), while no changes in RI (1.47°C) was observed. The study revealed that mixing of soybean seed oil with M. oleifera seed oil at a ratio of 70:30 enhanced the physical and chemical properties of the soybean oil after two repetitive frying.