To investigate the antioxidant activity and physicochemical properties of oil, sunflower (SFO) and corn oil (CO) and their combinations with sesame oil (SO) were prepared. The analyses of fatty acid composition (GC-FID), oxidative stability index (Rancimat), smoke point, and antioxidant activity (DPPH) were done on oil samples. Then, the frying process in presence of potato chips was done for 3 days at 180°C. Oil samples were gathered after each frying cycle and chemical analysis (peroxide value, free fatty acid, p-anisidine value, TOTOX, total polar content, TBARS, and conjugated diene and triene) was measured. The major fatty acid composition of oil samples was linoleic acid, oleic acid, palmitic acid, and stearic acid. The OSI of oil samples was reported as CSO > SSO > SO > CO > SFO . The smoke point of all samples was in the standard limit. The SFO with 266.50°C had the highest smoke point. The antioxidant activity of samples was reported as SO > CSO > CO > SSO > SFO . The IC50 of SO was 52.17 mg/g which was higher than other samples. The result of frying indicated that prolonged heating process would increase the thermal oxidation. It was shown that oils blended with SO had good stability during deep frying. Therefore, blending oil with SO is considered as an economic approach to improve the oil oxidation stability.

Dietary exposure was introduced as the primary way Bisphenol A (BPA) enters the human body. Although significant efforts have been made to analyze BPA's presence in different foodstuffs, less attention has been given to introducing the conditions that facilitate BPA release. This review aimed to mention possible factors affecting BPA release into foods and beverages. According to the results, the critical factors in BPA release are temperature, manufacturing process, food and packaging type, pH, mineral elements, repeated use, irradiation, washing, contact time, and using detergents. It showed that using PC containers, high temperature and pH, storage under solar irradiation, alkaline detergents, water hardness, and repeated use could increase the BPA release from containers into foodstuff. During various conditions, hydrolysis of the carbonate linkage and d-spacing will increase. Considering these parameters and limiting the use of PC containers, the potential risk of BPA exposure could be eliminated.

Background: Oils and fats are among the important constituents of foods. Lipid oxidation can cause changes in taste, flavor, smell, color, texture, and nutritional value of the foods. Deep-fat frying (temperatures of 150 to 200 °C) leads to a series of chemical and physical reactions, so that the oil is oxidized, polymerized, and hydrolyzed. Methods: In a current descriptive cross-sectional study, 100 oil samples were obtained from fast food shops in Yazd city during the spring and summer of 2018. A checklist was prepared including the oil type (oil or fat), odor, color, smoke, and duration of use. The peroxide value (PV), p-anisidine value (p-AV), free fatty acid (FFA) levels, and total polar compound (TPC) of the samples were examined. Results: We found that 93% of the oil samples were in form of liquid. In term of color, 45% of the samples had a dark color and about 57% had an undesirable odor during cooking. In 23% of the fast food shops in Yazd, oil is used more than two days. The measurement of peroxide value showed that 73 samples had peroxide values higher than the allowable limits. The allowable average peroxide value was estimated as 2.33 meq/kg. Results showed that 56 samples had allowable FFA level (less than one), while the others were classified as oxidized oils. The p-AV in 55% of the oil samples were higher than 4. According to the results, 46% of the frying oil samples had TPC of higher than 25%, which showed that they should be discarded. Conclusion: The results showed that majority of the fast food shops in Yazd used highly oxidized oils to prepare their food. The absorption of such oils by food can endanger the public health. Therefore, continuous monitoring of fast foods and restaurants as well as training the staff seem necessary.