Increased Phenolic Compounds in Potato Chips Vacuum Impregnated with Green Tea.

This studied tested the feasibility of producing vacuum fried potato chips enriched with antioxidants by introducing green tea extract using vacuum impregnation (VI) technology. Total phenolic content (TPC) was used to find the optimal VI parameters. Sliced potatoes were fried under vacuum at 110, 120, or 140 °C from 20 to 720 s to test the thermal degradability of the TPC. Three frying systems were also compared: vacuum frying (VF), dual-step (DS) frying, and atmospheric frying (AF). Green tea concentration of 5%, vacuum time of 10 min, and a pressure of 80 kPa gave the maximum TPC of 196.11 ± 15.41 mg GAE/100 g of dry matter. Samples fried at 120 °C showed an overall greater phenolic retention capacity compared to the chips fried at 140 and 110 °C. Using the optimal VI and VF parameters (140 °C, 100 s), the three frying systems were then compared. Samples fried using the AF system contained twice as much the oil content as those fried using the VF or DS systems. VF chips had the highest percentage in TPC increase (209%) while AF chips had the lowest (163%). A consumer panel found the samples fried under AF more acceptable and were given the highest scores for all quality. VI had a negative effect on the color scoring of the participants (they were dark). Overall, VI is a suitable precursor of VF to create potato chips with a high phenolic content. PRACTICAL APPLICATION: Vacuum impregnated potato chips with green tea extract have potential for manufacture of functional snacks that may influence the public into consuming phenol-rich fruit and vegetable snack.