Chemical characteristics of potato chips fried in repeatedly used oils

Abstract

The objective of the study was to evaluate chemical properties of potato chips fried in repeatedly used oils. Potato chips were deep-fat fried in refined coconut oil (PRCO: potato chips), refined soybean oil (PRSO), pure olive oil (PPOO), and vegetable shortening (PVST). The potato chips were fried in 1, 20, 40, 60, and 80 times repeatedly used oils. Oils were extracted from PRCO (RCO: extracted oil), PRSO (RSO), PPOO (POO), and PVST (VST) and analyzed for oxidative stability. The PVST was higher in hexanal than the PRSO and PPOO (p<0.05). Nonanal and 2-decenal were most detected in the PPOO (p<0.05) and rarely in the PRSO. 2,4-Decadienal was least detected in the PRCO (p<0.05). PVST was lower in acrylamides than the other fried potato chips (p<0.05). Total polar compounds (TPC) in the RCO was lower than in the other extracted oils at the 80th repetition (p<0.05). Conjugated dienes (CD) were the highest in the RSO and the lowest in the RCO (p<0.05). Peroxide value (PV) of the RCO continuously increased during the repeated frying (p<0.05), while those of the POO and VST little changed. p-Anisidine value (p-AV) of the RCO was the lowest at all the repetitions (p<0.05), while those of the VST were the highest at the 1st, 20th, 40th, and 60th repetitions (p<0.05). Total oxidation (Totox) value of the RCO was the lowest at all the repetitions (p<0.05). In this study, PRCO might have less oxidative products considering aldehydes, CD, TPC, p-AV, and Totox value.