Physico-chemical changes of oils used for food frying from roadside food venders in Kampala Capital City Authority: a case study conducted in Wandegeya, Kikoni, Kasubi, Kikumikikumi and Nankulabye

Abstract

Commercial deep-fat frying is a common cooking method. Fried foods have unique sensory and organoleptic properties, which makes deep fried foods largely enjoyed by consumers. The objective of this study was to analyze the quality of oils used by street food venders for deep frying, focusing on the physical and chemical properties of oils and the also on the attitudes and practices by the food venders. Oil samples were randomly collected from street food venders and, from the food technology chemistry laboratory, their physical and chemical properties were determined. A survey questionnaire was used to assess the attitudes and perception the venders on the oils and over 30% of the respondents, recycled oils for more than 6 times that is recommended by UNBS. The analyzed chemical properties of the collected oil samples were Iodine Value, Peroxide Value, Acid Value and Free Fatty Acids. The results obtained were analyzed using XLSTART 2019 Version. The LSD between the means was determined using Fisher’s method at p<0.05. For some of the oil samples, their chemical properties significantly differed from the international codex standards. Peroxide Value of the samples ranged from 6.001±0.64 meq to 57.152±2.5 meq, the acid value for the other oil samples ranged from 1.300±0.1mg KOHg-1 to 0.316±0.05mg KOHg-1, the Iodine values obtained ranged from 21.366±0.92g to 4.561±0.68g and the %Free Fatty Acid value ranged from 0.161±0.03% to 0.658±0.05%. The physical properties of the oil samples analyzed were viscosity, and colour. Viscosity of oil sample ranged from 86.881±0.10 to 248.230±0.31Pas. Strict regulations should be put in place to guard consumers’ lives and also sensitizing the venders on the negative effects of recycling oils. There should be massive sensitization of street food venders to improve their attitudes and perceptions on the oils.