Evaluation of fried edible oil and determination of trace elements content by FAAS

Abstract

Edible oils form an essential part of our daily diet. Edible oils are derived from a wide variety of plants and plant seeds and are used in many aspects of domestic and world-wide food production. Once the oil has been extracted from a plant seed, it is refined as needed for use in foods such as salad dressings, margarine, shortenings, snack foods and frying oil . Although the overall quality of the product is generally defined by its culinary benefits, the inorganic content of these oils has a very important role in terms of food safety and general product longevity. Trace elements in edible oils can act as autoxidation accelerators, altering the flavor and quality of the product over time. In Egypt home kitchen and most restaurants use edible oils for frying of many different kinds of foods. Edible oils resulting from frying processes were characterized via fatty acids composition and chemical characteristics (Acid value, peroxide value, iodine value, saponification value, unsap. matter and ester value). Spectroscopic analysis (FT-IR) was used to study the change in chemical structure of oil by frying oxidation process. The trace elements content were determined by Flame Atomic Absorption Spectrometry (FAAS). The concentration of trace elements are increased after frying by about two folds. The oil before and after frying was evaluated.