IHAB TEWFIK, UNIVERSITY OF WESTMINSTER, UNITED KINGDOM
HANAA ISMAIL, UNIVERSITY OF ALEXANDRIA, EGYPT
SUNDUS TEWFIK, LONDON METROPOLITAN UNIVERSITY, UNITED KINGDOM
Abstract: Many governments are determined to control the local trade of street-vended foods that are prepared and sold by street vendors. This growing practice is encouraged by the rise in urban populations, economical crisis and increase of unemployment among adults who tend to regard vending food as a reasonable way for income generation. Currently in the Middle East, there is a wide range of oriental recipes that are on sale at affordable prices and available to most socioeconomic levels. Deep fried food products come top of the selling list as they are cheap, culturally acceptable diet and palatable by Middle Eastern communities. Nevertheless, chemical and biological hazards are always associated with such type of foods. This article focusses on the chemical quality of vegetable oils that are used to prepare street food products. This has been demonstrated by a controlled laboratory trial, which mimicked the thermal abuse of vegetables oils by street food vendors. Samples of cooking oil (sunflower oil, corn oil, blend of cottonseed and sunflower oil and palm oil) revealed that there is a significant increase with heating time (7, 12 and 25 h) in saturated fatty acids. Levels of polyunsaturated fatty acids, on the other hand, tended to decrease with the heating time for these oils. Thermal oxidation induced chemical deterioration of cooking oils, in addition to some physical changes (darkening of the original colour, burnt smell, changes in viscosity and evolution of smoke during frying). Vulnerable group, particularly children and pregnant mothers, are at eminent risk of health complications through the cumulative effect of ingesting chemically abused cooking oils. Nutritional adequacy of programme aimed to improve the quality of street food products, behaviours and attitudes of the vendors should be introduced by governments, to re-assure food safety, health and well being.
Keywords: Street-Vended Foods, Intermittent Heating of Vegetable Oils, Unsaturated Fatty Acids, Chemical Deterioration, Thermal Oxidation