Batter Characteristics and Oil Penetration of Deep-Fried Breaded Fish Nuggets: Effect of Wheat Starch-Gluten Interaction

To understand the effect of the interaction between wheat starch (WS) and wheat gluten (WG) on batter characteristics and oil penetration of deep-fried breaded fish nuggets, batters were prepared using a WS and WG blend at the ratios of 15 : 1, 13 : 1, 11 : 1, 9 : 1, and 7 : 1 w/w, respectively, and batter-breaded fish nuggets (BBFNs) were fried at 170 degrees C for 40 s followed by 190 degrees C for 30 s. Moisture adsorption isotherms of WS and WG, viscosity, rheological behavior, and calorimetric properties of the batters were measured, and pick-up of BBFNs, thermogravimetric properties of the crust, and oil transport were investigated. The moisture absorption capacity of WG was higher than WS at a low water activity (0.04-0.65), while the opposite trend was observed at a highwater activity (0.65-0.88). As the proportion of WS decreased, the viscosity, G" and tan delta of batter, pick-up of BBFNs, temperature and enthalpy change (delta H) of protein denaturation and WS gelatinization, and oil penetration of BBFNs during deep-fat frying, which are decreased until reaching a minimum value at the ratio of 11 : 1 w/w, then increased (p < 0.05). However, G' of batter and thermogravimetry temperatures of crust exhibited the opposite trend. These results proved that the WS-WG interaction significantly affected the batter characteristics and oil penetration of BBFNs during deep-fat frying, which can be used to guide the manufacturing of low-fat fried BBFNs.