Quality of Reused Frying Oils from Various Fried Food Vendors in Ho Municipality

Abstract

Background: Frying makes food tasty; therefore, most people prefer the intake of fried foods to unfried foods. Oil for frying is mostly used again due to cost, and this can pose health hazards to the consumer. The aim of this study was to evaluate the quality of reused frying oils. Methods: Twenty samples of reused oils collected from fried food vendors in May 2021. Using an experimental study, the samples were analysed and Peroxide, Free Fatty Acid (FFA), Saponification, Iodine Values as well as rancidity and beta carotene were determined. Data from laboratory assays were analysed with Microsoft excel 2013 and SPSS v.26.0. Results: Moisture content was observed to decrease as median from 1.19% (0.20-4.04%) for oils reused after a day to 0.60% for oils reused after 2 days with a significant effect (p-value=0.049), indicating that the quality of reused frying oil was affected by repeated use. The moisture content was also observed to be higher in oils in which plant products were fried compared to those in which animal products were fried. The Peroxide Value was recorded as 16.80 (5.80-55.80) and 21.90 (11.50-32.30) mEq/kg for oils with 10-20 and 21-40 min frying times, respectively; whilst their moisture content decreased from 0.97 (0.19-2.55) to 0.68% (0.60-0.77%) for 10-20 and 21-40 min, respectively. The authors also observed that factors such as the duration of reuse and storage after frying, conditions of storage, type of food fried in the oil, and the period of frying per food batch impacted the quality attributes of the reused oils. The FFA composition for instance increased with the duration of use of the oils. Furthermore, oils stored in plastic bottles recorded higher FFA values compared to those stored in frying pans. Conclusion: The findings show the need for fried food vendors to reduce the duration of storage of reused frying oil, and avoid storage conditions that expose oils to excess light. Also, the development of quality standards for highly patronised oils needs to be established to ascertain the impact of low-temperature long-time and high-temperature short-time treatments of the oils among non-existent jurisdictions. DOI: 10.18502/jfqhc.11.3.16591

Keywords

• food handling
• fatty acids
• esters
• oxidative stress
• peroxides