Quality Evaluation of Some Commercially Fried Fast Food

Abstract

Frying process is popular among all classes of people for being a rapid food preparation process and for the unique characteristics of flavor and appearance.  However, the frying oil eventually contains a number of harmful components affect the oil quality and therefore affects the quality of foods. The objective of this work was to determine the quality of 50 fried fast food samples (ten for each), french fries, burgol kuba, under pressured breaded chicken, meat pastry and falafels collected randomly from restaurants. Chemical composition was analyzed for all samples and the oil was extracted. The samples extracted oil were analyzed for level of oxidation by measuring acid value (AV), peroxide value (PV), thiobarbituric acid-reactive substances (TBARS), conjugated dienes and triens and color index. Free radical scavenging activity was also determined by measuring the decrease in the visible absorbance of 2, 2-diphenyl-1-picrylhydrazyl (DPPH) at 517nm. Our results indicate wide variations in the composition and degree of oxidation of the extracted oils across all samples. Fat content the most important parameter here ranged from 8.25 in falafel to 22.10 % in burgle cuba.Falafel and French fries samples exceed the criteria of PV< 10 mequiv/kg.  All samples complied with the limits of acid value < 2.5 mg/g. Except for meat pastry all samples were in permissible limits of TBARS. The DPPH test showed that all tested samples have free radical-scavenging activity ranged from 72.2 in French fries to 82.6%in Falafel. Falafels samples showed darkening of oil color significantly higher than all samples followed by French fries. The data highlight the need to evaluate the antioxidant activity of food itself not only the oil used for frying and enforcing legal regulations to maintain food quality in fast food restaurants.

Keywords: fast food, oil stability, antioxidant activity.