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

Abstract

To understand the effect of the interaction between wheat starch ( $\mathrm{W}\mathrm{S}$ ) and wheat gluten ( $\mathrm{W}\mathrm{G}$ ) on batter characteristics and oil penetration of deep-fried breaded fish nuggets, batters were prepared using a $\mathrm{W}\mathrm{S}$ and $\mathrm{W}\mathrm{G}$ blend at the ratios of 15 : 1, 13 : 1, 11 : 1, 9 : 1, and 7 : 1 $\mathrm{w}/\mathrm{w}$ , respectively, and batter-breaded fish nuggets (BBFNs) were fried at 170°C for 40 s followed by 190°C for 30 s. Moisture adsorption isotherms of $\mathrm{W}\mathrm{S}$ and $\mathrm{W}\mathrm{G}$ , 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 $\mathrm{W}\mathrm{G}$ was higher than $\mathrm{W}\mathrm{S}$ 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 $\mathrm{W}\mathrm{S}$ decreased, the viscosity, $G”$ and tan δ of batter, pick-up of BBFNs, temperature and enthalpy change (ΔH) of protein denaturation and $\mathrm{W}\mathrm{S}$ gelatinization, and oil penetration of BBFNs during deep-fat frying, which are decreased until reaching a minimum value at the ratio of 11 : 1 $\mathrm{w}/\mathrm{w}$ , then increased ( $p<0.05$ ). However, G' of batter and thermogravimetry temperatures of crust exhibited the opposite trend. These results proved that the $\mathrm{W}\mathrm{S}$ – $\mathrm{W}\mathrm{G}$ 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.