EFFECT OF FRYING AND STORAGE ON OXIDATIVE STABILITY OF OIL BLENDS AND QUALITY ATTRIBUTES OF BISCUITS PREPARED WITH THE BLENDS

摘要

The changes occurring in groundnut (GO), sunflower (SO) and palm olein (PO) oil and their blends containing GO: PO: SO at ratios 40:30:30, 50:30:20 and 60:30:10 for blend 1, 2 and 3, respectively, during storage (6 months, room temperature) and repeated frying (200 °C for 30 s) of biscuits were monitored. The parameters assessed were: free fatty acid (FFA) and peroxide value (PV). Also the chemical composition, total energy, in vitro protein digestibility, PV and FFA of the biscuits prepared with the blended oils were also determined. The FFA of PO were lower than that of GO and SO during storage and frying period. However, blending of oils further decreased the FFA with blend 3 oil having the lowest value during storage and frying with biscuits. The PV of SO was lower than that of the oils tested during storage. However, at the end of the frying period, blended oils had lowest PV with blend 2 having the lowest value. No significant differences were observed in the chemical composition, total energy and in-vitro protein digestibility of the biscuits prepared with the blends but with the storage period the values decreased. Similar observation occurred in the PV and FFA of biscuits but the values increased with increase in storage period. Biscuits prepared with blend 2 had lowest PV and FFA during storage. Oxidative stability of oils during repeated frying and storage can be improved by blending groundnut, palm olein and sunflower oils at a ratio of 60:30:10.