Recycled cooking oils used for street foods in Kampala, Uganda: Quality and recycling frequency

Deep-fried foods are generally popular world over. To cut production costs, the oil used is often recycled. This is concerning because deep-frying is done aerobically at 160–190 °C leading to oil degradation and formation of hazardous compounds. This study evaluated the quality of cooking oil used t...

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Main Authors: Emmanuel Okalany, Stellah Byakika, Ivan Muzira Mukisa
Format: Article
Language:English
Published: Elsevier 2024-06-01
Series:Applied Food Research
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2772502224000222
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author Emmanuel Okalany
Stellah Byakika
Ivan Muzira Mukisa
author_facet Emmanuel Okalany
Stellah Byakika
Ivan Muzira Mukisa
author_sort Emmanuel Okalany
collection DOAJ
description Deep-fried foods are generally popular world over. To cut production costs, the oil used is often recycled. This is concerning because deep-frying is done aerobically at 160–190 °C leading to oil degradation and formation of hazardous compounds. This study evaluated the quality of cooking oil used to deep-fry potato chips (n = 35) and fish (n = 35) by street food-vendors in Kampala, Uganda. Additionally, a safe oil recycling frequency was determined by separately deep-frying several batches of fish and potato chips. After each frying cycle, the quality of oil was analyzed. Over 94 % of oils used to deep-fry chips and fish obtained from food vendors surpassed the recommended specification for peroxide value (10 mEq O2/Kg). Their mean peroxide values were about four times higher than the recommendation. Moreover, none of these oils met the Thiobarbituric acid specification of <2 mg DA/Kg. Oil samples used by vendors to deep-fry fish (100 %) and chips (60 %) had acid values beyond the quality specification of 0.6 mg KOH/g. Their moisture contents and oil densities were almost twice the recommendations. In contrast, their iodine value and color intensities were below the quality specifications. The recycling experiments showed that peroxide values remained consistent while other parameters exceeded quality specifications after the second deep-frying cycle. Therefore, recycled oils used by street-food vendors in Kampala are unsuitable for human consumption. The practice of cooking oil recycling should be discouraged, though it has financial implications especially for commercial food establishments.
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spelling doaj.art-f32aa232758b47de90c48798b802db1d2024-03-16T05:09:57ZengElsevierApplied Food Research2772-50222024-06-0141100409Recycled cooking oils used for street foods in Kampala, Uganda: Quality and recycling frequencyEmmanuel Okalany0Stellah Byakika1Ivan Muzira Mukisa2Department of Food Technology and Nutrition, School of Food Technology, Nutrition and Bioengineering, College of Agricultural and Environmental Sciences, Makerere University, P.O Box 7062, Kampala, UgandaCorresponding author.; Department of Food Technology and Nutrition, School of Food Technology, Nutrition and Bioengineering, College of Agricultural and Environmental Sciences, Makerere University, P.O Box 7062, Kampala, UgandaDepartment of Food Technology and Nutrition, School of Food Technology, Nutrition and Bioengineering, College of Agricultural and Environmental Sciences, Makerere University, P.O Box 7062, Kampala, UgandaDeep-fried foods are generally popular world over. To cut production costs, the oil used is often recycled. This is concerning because deep-frying is done aerobically at 160–190 °C leading to oil degradation and formation of hazardous compounds. This study evaluated the quality of cooking oil used to deep-fry potato chips (n = 35) and fish (n = 35) by street food-vendors in Kampala, Uganda. Additionally, a safe oil recycling frequency was determined by separately deep-frying several batches of fish and potato chips. After each frying cycle, the quality of oil was analyzed. Over 94 % of oils used to deep-fry chips and fish obtained from food vendors surpassed the recommended specification for peroxide value (10 mEq O2/Kg). Their mean peroxide values were about four times higher than the recommendation. Moreover, none of these oils met the Thiobarbituric acid specification of <2 mg DA/Kg. Oil samples used by vendors to deep-fry fish (100 %) and chips (60 %) had acid values beyond the quality specification of 0.6 mg KOH/g. Their moisture contents and oil densities were almost twice the recommendations. In contrast, their iodine value and color intensities were below the quality specifications. The recycling experiments showed that peroxide values remained consistent while other parameters exceeded quality specifications after the second deep-frying cycle. Therefore, recycled oils used by street-food vendors in Kampala are unsuitable for human consumption. The practice of cooking oil recycling should be discouraged, though it has financial implications especially for commercial food establishments.http://www.sciencedirect.com/science/article/pii/S2772502224000222Deep-fried foodsCooking oil qualityOil recyclingFishPotato chips
spellingShingle Emmanuel Okalany
Stellah Byakika
Ivan Muzira Mukisa
Recycled cooking oils used for street foods in Kampala, Uganda: Quality and recycling frequency
Applied Food Research
Deep-fried foods
Cooking oil quality
Oil recycling
Fish
Potato chips
title Recycled cooking oils used for street foods in Kampala, Uganda: Quality and recycling frequency
title_full Recycled cooking oils used for street foods in Kampala, Uganda: Quality and recycling frequency
title_fullStr Recycled cooking oils used for street foods in Kampala, Uganda: Quality and recycling frequency
title_full_unstemmed Recycled cooking oils used for street foods in Kampala, Uganda: Quality and recycling frequency
title_short Recycled cooking oils used for street foods in Kampala, Uganda: Quality and recycling frequency
title_sort recycled cooking oils used for street foods in kampala uganda quality and recycling frequency
topic Deep-fried foods
Cooking oil quality
Oil recycling
Fish
Potato chips
url http://www.sciencedirect.com/science/article/pii/S2772502224000222
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