Industrial frying of crisps. Influence of the unsaturation degree of frying fat on the oxidative stability during storage

Abstract

Oxidative stability of crisps fried in two vegetable oils: sunflower oil (SO) and partially hydrogenated sunflower oil (PHSO), was studied. Crisps were stored at temperature at daylight, at 40ºC in oven, and a -23ºC as a control. Evaluation of the samples was carried out by chemical and sensory analyses. Rancid odour and flavour were detected at 180 and 49 days of storage, at room temperature and 40ºC respectively. In parallel, Peroxide value (PV), polar compounds (PC) and TGox increased, while alpha tocopherol (AT) and the induction time (IT) decreased, confirming the low oxidative stability of the crisps fried in SO. On the contrary, crisps fried in PHSO, showed a good oxidative stability in both storage conditions until the end of the storage (210 days). Chemical analyses confirmed the high stability of crisps fried in PHSO and hence the influence of fatty acid composition in crisps shelf life. Statistical analysis showed a good correlation between PV, PC, TGox and AT. Finally, shelf life of crisps fried in SO was estimated from PV and it was found that one day of storage at 40ºC was equivalent at 4.9 days at room temperature.

Keywords

• partially hydrogenated sunflower oil
• potatoes chips
• stability
• sunflower oil
• unsaturation degree