Effects of frying and food items on the physicochemical properties of palm oil obtained from Nigeria

The consumption of palm oil has particularly increased in Nigeria due to increased population, lifestyle changes, and its health benefits. The conversion and recycling of the ever-growing food waste from household and commercial is one of the known cost-effective and sustainable management strategies. This study investigates the effect of processing on the physicochemical properties of palm oil. Neat palm oil (NPO) and waste palm oil (WPO) samples, derived from frying four different Nigerian food items, were analyzed to determine changes in their physicochemical properties. The outcome of the investigation reveals that higher temperature during frying and contamination from different food items weakens the molecular structure of the palm oil thereby reducing the quality and stability of the samples which is expressed by the differences in their physicochemical properties. The density, peroxide value, and carbon, hydrogen, and oxygen (CHO) values of NPO were 886 kg/m3, 9.473 meqO2/kg, and 39.233% while that of the WPO samples vary between 3.989–4.692 kg/m3, 10.858–15.362 meqO2/kg, and 52.346–58.468%, for density, peroxide value, and CHO, respectively. The result of the descriptive statistics shows that in the 1 series, the mean ± standard deviation (SD) [coefficient of variation (CV%)] is 119.76 ± 263.87 (220.33%). Both the SD and CV% are greater than the mean; this is due to the heterogeneous nature of the parameter values in the samples. When subjected to inferential statistical analysis, the results show that the error of prediction of relationship in NPO sample versus WPO samples is just 5.290% whereas the reduction in the error is 94.71%. More collaborative investigations are needed to determine the ease of conversion to biodiesel and the properties of biodiesel produced from WPO used to fry different Nigerian food items.