Etude d’altération des huiles utilisées dans la fabrication des beignets commercialisés dans la ville de Bujumbura

Abstract

In Burundi, studies focusing on food quality control, particularly for fried products like doughnuts, are rare. Doughnuts are widely consumed in Bujumbura and the surrounding area. However, the oils used are generally unstable and undergo various forms of alteration during storage and frying (hydrolysis, oxidation, and polymerization), which modify their physicochemical and organoleptic characteristics. This study aimed to evaluate the quality of oils used for frying doughnuts sold in Bujumbura by determining their peroxide value, acid value, and lipid profile. The peroxide value, acid value and lipid profile were determined respectively by the standard method ISO3960:2017/A1:2020, ISO 660:2020 and ISO12966-2:2017 for the preparation of fatty acid methyl esters (FAME) followed by ISO 12966-4:2026 for the analysis of FAME by gas chromatography-FID. The statistical analysis was performed using SPSS software. An average peroxide value of 36.33±24.60 meq O2/Kg , 36.83±25.95 meq O2/Kg , and 37.01±24.93 meq O2/Kg was found respectively in the communes of Ntahangwa, Mukaza and Mugere , all statistically equal (P>0.05) . According to the results of this study, fried products, particularly doughnuts made informally and sold in the city of Bujumbura, are generally hyperperoxidized (IP= 36.47±24.40 (meq O2/Kg .) and are out of standard (IP> 10(meq O2/kg ). The mean acid value of 5.50 ± 2.49 mg KOH/g, 5.59 ± 2.71 mg KOH/g, and 5.74 ± 2.63 mg KOH/g were obtained in the communes of Ntahangwa , Mukaza , and Mugere , respectively, all statistically equivalent (P >0.05), corresponding to an overall acidity of 5.54 ± 2.57 mg KOH/g in the city of Bujumbura. According to the results of this study, it is clear that the oils used for frying doughnuts produced informally and sold are generally too acidic and fall outside the standards, as their acidity far exceeded 0.6 KOH/g (maximum acceptable value according to standards). Finally, the comparative analysis of fatty acid chromatograms from the control sample and the oil samples used for frying the doughnuts shows that the oils used for frying the doughnuts had qualitatively and quantitatively lost the fatty acids that consumers need, and their consumption exposes consumers to adverse effects. Indeed, the decomposition of fatty acids, producing potentially toxic products, notably free radicals, which, due to their high reactivity, generate other equally toxic products, exposes consumers to adverse effects such as oxidative stress, damage to cell membranes, proteins, and DNA, and an increased risk of chronic diseases such as cardiovascular disease, cancer, and liver and kidney damage.