Quality assessment of used edible fats and oils by local vendors of Faisalabad

Abstract

Fats and oils are both economically and scientifically important in food systems and play an important role in nutrition. The principal causes of fat degradation are oxidation and hydrogenation, which have a detrimental impact on quality aspects of oils and fats such as color, texture, flavor, aroma, consistency, and appearance. The current research was conducted to determine the oil degradation factors by collecting fifty samples of fried oils used by street vendors from twenty-five different locations in Faisalabad area in order to assess the quality parameters of locally available fats and oil products. Procured samples underwent physicochemical tests to determine the degree of degradation and oxidation. The parameters analyzed for quality evaluation include free fatty acids (FFA), peroxide value (PV), iodine value (IV), saponification value (SV), viscosity, refractive index (RI), p-anisidine value (p-AV), thiobarbeturic acid value (TBA), specific gravity (SG) and fatty acid profile through gas chromatograph equipped with flame ionization detector. The analyses revealed significant oxidation and degradation in many of the vendor fried fats and oil that were procured. Physicochemical characteristics as well as oxidative stability attributes were deviated from the standard values defined by Codex Alimentarius and Punjab Pure Food Regulations (PPFR). In majority of the samples, the fatty acid profile exhibited increased levels of trans-9-elaidic acid and linolelaidic acid, indicating the presence of trans-fatty acid because of hydrogenation and high-temperature frying of fats and oils. The overall quality of most procured samples was in decline from recommended standards and unsuitable for frying and edible purposes