Effect of frying cycles on the physical, chemical and antioxidant properties of selected plant oils during deep-fat frying of potato chips

Abstract

ABSTRACT: The changes occurring in soybean (SBO), sesame seed (SSO), almond (AO) and avocado (APO) oils during repeated frying cycles of potato chips were monitored. Potato chips were fried up to 5 cycles and the free fatty acid (FFA), peroxide value (PV), iodine value (IV), moisture, colour, smoke point and antioxidant properties of the oils at different frying cycles were assessed. SBO exceeded FFA limits after two cycles, while SSO and AO exceeded limits after four cycles. Moisture content of SBO, SSO and AO for first and second frying cycles was within acceptable limits. APO consistently exceeded FFA and moisture limits while PV of all oils remained within the permissible limit throughout the cycles. SBO and APO showed significant decreases in L* and b* values. Sesame seed oil displayed the highest reductions in phenolic content, flavonoid content, and antioxidant capacity, followed by avocado oil while almond oil exhibited the highest decline in total antioxidant, indicating a potential loss of antioxidant properties. These findings emphasize the detrimental impact of frying cycles on the physicochemical and antioxidant properties of these oils, raising concerns about their potential health benefits.

Keywords

• Frying cycles
• Oils
• Physicochemical changes
• Antioxidant properties