Physico-chemical Analysis and Metallic Contamination of Reused Oil and Savory Snacks Available at University Canteens: Physico-chemical Analysis and Metallic Contamination of Reused Oil

Raheela Qamar; Afsheen Mushtaque Shah; Tasneem Gul Kazi; Beenish Khanzada; Farah Naz Memon

doi:10.54393/fbt.v5i2.175

Authors

Raheela Qamar Institute of Biochemistry, University of Sindh, Jamshoro, Pakistan
Afsheen Mushtaque Shah Institute of Biochemistry, University of Sindh, Jamshoro, Pakistan
Tasneem Gul Kazi National Center of Excellence of Analytical Chemistry, University of Sindh, Jamshoro, Pakistan
Beenish Khanzada Institute of Biochemistry, University of Sindh, Jamshoro, Pakistan
Farah Naz Memon Institute of Biochemistry, University of Sindh, Jamshoro, Pakistan

DOI:

https://doi.org/10.54393/fbt.v5i2.175

Keywords:

Reused Oil, Savory Snacks, Public Health, Toxic Metals, Permissible Limits

Abstract

Edible oils play a crucial role in our daily diet, providing energy, essential fatty acids, and vitamins. Frying is a common method for preparing many foods, but the deep-frying process can alter the composition of both oil and food. Objectives: To assess the potential health risks associated with the consumption of reused oil and savory snacks. Methods: A total of 25 oil samples, including Before Frying Oil (BFO) and After Frying Oil (AFO), as well as snack samples (samosa and pakora), were collected from the canteens of Sindh University, Jamshoro, Pakistan. Blood samples were collected from students studying at the main campus of Sindh University, Jamshoro, and control samples were also collected from individuals of the same age and gender. Elements like copper (Cu), iron (Fe), nickel (Ni), lead (Pb), zinc (Zn) and chromium (Cr) were analyzed from oil, blood and snacks samples by atomic absorption spectrometry. Results: Metals like Cu, Fe, Ni, Pb, Cr were increased along with Zn decrease in AFO samples whereas all metals like Cu, Fe, Ni, Pb, and Cr were found to increase and Zn was decreased in blood of consumers, Cu, Fe, Ni, Pb, Cr decrease in Samosa and Zn increase in Savory samples. Conclusions: Used cooking oil is dangerous for human health. People should avoid buying contaminated food items, especially savory snacks, from open markets because they are harmful to health.

References

Valle C, Echeverría F, Chávez V, Valenzuela R, Bustamante A. Deep‐Frying Impact on Food and Oil Chemical Composition: Strategies to Reduce Oil Absorption in the Final Product. Food Safety and Health. 2024 Oct; 2(4): 414-28. doi: 10.1002/fsh3.12056.

Sousa S, de Morais IL, Albuquerque G, Gelormini M, Santos M, Filipović-Hadžiomeragić A et al. Nutritional Content of Street Food and Takeaway Food Purchased in Urban Bosnia and Herzegovina. Foods. 2021 Oct; 10(11): 2594. doi: 10.3390/foods10112594.

Yulia C, Nikmawati EE, Widiaty I. Preliminary Study in Developing Traditional Street Foods as Nutrition Education Media for Indonesia Youth. Invotec XIII. 2017; 1: 1-7. doi: 10.17509/invotec.v13i1.6256.

Girma Z, Temesgen K, Dubale A, Waritu NC, Jemal M, Wakeyo MU. Food Handling Practices Among Street Food Vendors and Their Associated Factors in the Town Administration of Gamo Zone, Southern Ethiopia. Frontiers in Food Science and Technology. 2025 Feb; 5: 1445910. doi: 10.3389/frfst.2025.1445910.

Verma R and Mishra S. Street Food Vendor Handling Practices and Bacterial Contamination of Ready-To-Eat Foods. Acta Scientific Agriculture. 2023; 7(8): 50-61. doi: 10.31080/ASAG.2023.07.1288.

Correa KL, de Carvalho-Guimarães FB, Mourão ES, Oliveira Santos HC, da Costa Sanches SC, Lamarão ML et al. Physicochemical and Nutritional Properties of Vegetable Oils from Brazil Diversity and Their Applications in the Food Industry. Foods. 2024 May; 13(10): 1565. doi: 10.3390/foods13101565.

Mehany T, González-Sáiz JM, Pizarro C. Improving the Biostability of Extra Virgin Olive Oil with Olive Fruit Extract During Prolonged Deep Frying. Foods. 2025 Jan; 14(2): 260. doi: 10.3390/foods14020260.

Gholamibozanjani G, Leong SY, Oey I, Bremer P, Silcock P, Farid M. Heat and Mass Transfer Modeling to Predict Temperature Distribution During Potato Frying After Pre-Treatment with Pulsed Electric Field. Foods. 2021 Jul; 10(8): 1679. doi: 10.3390/foods10081679.

Abrante-Pascual S, Nieva-Echevarría B, Goicoechea-Oses E. Vegetable Oils and Their Use for Frying: A Review of Their Compositional Differences and Degradation. Foods. 2024 Dec; 13(24): 4186. doi: 10.3390/foods13244186.

Benmeziane F, Araba K, Belahcene A. Impact of Deep-Fat Frying Cycles on the Physicochemical Characteristics of Two Edible Vegetable Oils Marketed in Algeria. North African Journal of Food and Nutrition Research. 2024 Feb; 8(17): 21-31. doi: 10.51745/najfnr.8.17.21-31.

Isah AG, Faruk AA, Musa U, Garba UM, Alhassan M, Abdullahi UB et al. Oxidation Stability and Cold Flow Properties of Biodiesel Synthesized from Castor Oil: Influence of Alkaline Catalysts Type and Purification Techniques. Materials Today: Proceedings. 2022 Jan; 57: 748-52. doi: 10.1016/j.matpr.2022.02.220.

Nayak PK, Dash UM, Rayaguru K, Krishnan KR. Physio‐Chemical Changes During Repeated Frying of Cooked Oil: A Review. Journal of Food Biochemistry. 2016 Jun; 40(3): 371-90. doi: 10.3923/pjn.2013.647.650.

Amos-Tautua BM and Onigbinde AO. Physicochemical Properties and Fatty Acid Profiles of Crude Oil Extracts from Three Vegetable Seeds. Pakistan Journal of Nutrition. 2013 Jul; 12(7): 647. doi: 10.1016/j.arabjc.2014.05.025.

Zahir E, Saeed R, Hameed MA, Yousuf A. Study of Physicochemical Properties of Edible Oil and Evaluation of Frying Oil Quality by Fourier Transform-Infrared (FT-IR) Spectroscopy. Arabian Journal of Chemistry. 2017 May; 10: S3870-6. doi: 10.18805/BKAP617.

Kamble PA, Gore SB, Relekar SS, Telvekar PA, Rathod RH, Belsare SS et al. Development of Fish Cracker from Indian Major Carp, Labeo Catla. Bhartiya Krishi Anusandhan Patrika. 2023; 38(2): 167-71. doi: 10.1186/s12889-024-19695-0.

Yohannes L, Feleke H, Melaku MS, Amare DE. Analysis of Heavy Metals and Minerals in Edible Vegetable Oils Produced and Marketed in Gondar City, Northwest Ethiopia. BioMed Central Public Health. 2024 Aug; 24(1): 2204. doi: 10.1590/s2175-97902022e21094.

Aydinoglu S. Iron and Zinc Determination in Dietary Supplements by Flame Atomic Absorption Spectrophotometry. Brazilian Journal of Pharmaceutical Sciences. 2022; 58: e21094. doi: 10.1515/chem-2018-0026.

Prkić A, Politeo N, Giljanović J, Sokol V, Bošković P, Brkljača M et al. Survey of Content of Cadmium, Calcium, Chromium, Copper, Iron, Lead, Magnesium, Manganese, Mercury, Sodium and Zinc in Chamomile and Green Tea Leaves by Electrothermal or Flame Atomizer Atomic Absorption Spectrometry. Open Chemistry. 2018 Mar; 16(1): 228-37. doi: 10.26656/fr.2017.6(5).608.

NurSyahirah S and Rozzamri A. Effects of Frying on Fish, Fish Products and Frying Oil—A Review. Food Research. 2022 Oct; 6(5): 14-32. doi: 10.1007/s13197-022-05472-7.

Zou M, Chen Y, Hu C, He D, Gao P. Physicochemical Properties of Rice Bran Blended Oil in Deep Frying by Principal Component Analysis. Journal of Food Science and Technology. 2022 Nov; 59(11): 4187-97. doi: 10.9790/1959-0140110.

Choudhary M and Grover K. Effect of Deep-Fat Frying on Physicochemical Properties of Rice Bran Oil Blends. Journal of Nursing and Health Sciences. 2013; 1(4): 1-0.

Alajtal AI, Sherami FE, Elbagermi MA. Acid, Peroxide, Ester and Saponification Values for Some Vegetable Oils Before and After Frying. AASCIT Journal of Materials. 2018; 4(2): 43-7. doi: 10.1016/j.jtemin.2024.100119.

Ashong GW, Ababio BA, Kwaansa-Ansah EE. Evaluation of Trace Metals and Quality of Selected Brands of Vegetable Cooking Oils Available on the Ghanaian Market. Journal of Trace Elements and Minerals. 2024 Jun; 8: 100119. doi: 10.1515/aep-2016-0029.

Szyczewski P, Frankowski M, Zioła-Frankowska A, Siepak J, Szyczewski T, Piotrowski P. A Comparative Study of the Content of Heavy Metals in Oils: Linseed Oil, Rapeseed Oil And Soybean Oil in Technological Production Processes. Archives of Environmental Protection. 2016. doi: 10.1088/1742-6596/1123/1/012064.

Nasir K, Khan M, Chandio TA, Bashir Y. Comparative Analysis of Essential and Toxic Elements in Water and Blood Samples of Kidney Patients in Quetta, Pakistan. In Journal of Physics: Conference Series. 2018 Nov; 1123(1): 012064. doi: 10.4314/jasem.v21i3.13.

Dada EO, Ojo ON, Njoku KL, Akinola MO. Assessing the Levels of Pb, Cd, Zn and Cu in Biscuits and Home-Made Snacks Obtained from Vendors in Two Tertiary Institutions in Lagos, Nigeria. Journal of Applied Sciences and Environmental Management. 2017 Jul; 21(3): 521-4.

Ahsan F, Sharif MK, Butt MS, Rauf A, Shariati MA, Imran M et al. Legumes and Leafy Vegetables Based Multi-Mix Pakoras To Alleviate Iron And Protein Deficiency Among School Aged Children. BioCell. 2019; 43(1).