RSM applied for optimization of deep-fat fried ripe plantain slices and study of oxidation kinetics of oil by a DSC and polar methods

Abstract

Response surface methodology with Doehlert design was applied to optimize the frying of ripe plantain slices of Musa paradisiaca variety “Harton”. The effects of frying temperature, duration and amount of plantain and their interactions were assessed on water content, lipid content, hardness and color measurements. These parameters were studied during the deep frying process using soybean oil, largely consumed in Congo compared to a typical frying oil (Frial oil) used in France. Based on surface responses, the optimal conditions to achieve the good quality of final fried plantain were predicted for both oils at 170 °C during 3.00 min using 180 g of plantain for the soybean oil and 3.15 min for the Frial oil. Using the optimal frying conditions, the lipid degradation was evaluated by measuring the increase of the Total Polar Compounds (TPC). Oils fryer samples were taken every 4 h during ten consecutive days. Values of TPC increased significantly until 17 % for the Frial oil and 26.2 % for the soybean oil. The peak temperatures (ΔT), based on cooling thermograms, were also correlated with TPC increasing. They decreased from −50.2 to −53.7 °C for Frial oil and from −52.43 to −61.87 °C for soybean oil at the end of frying processes.