3.1. Effect of frying cycles on moisture content and oil uptake
The moisture as well as oil uptake in the intermittent use of frying oil up to 6 cycles during deep-fat frying of poori are
shown in Fig. 1. It was found that there was no significant (p > 0.05) difference in the moisture content of poori fried in oils subjected to increased number of frying cycles. The oil uptake in the product was found to increase significantly from 28.46 to 36.85% with an increase in number of frying cycles from 1 to 6. The higher oil uptake may be due to the increase in degradation products and viscosity of the frying medium due to thermal polymerization and or oxidative deterioration during cooling, which leads to the higher oil absorption by the fried product (Blumenthal, 1991). The increase in viscosity of the oil with an increase in frying cycles results in thickness of boundary layer between the food being fried and the frying oil, which consequently results in higher oil uptake (Bouchonet al., 2003; Moyano and Pedreschi, 2006).