Improving the crispness of microwave-reheated fish nuggets by adding chitosan-silica hybrid microcapsules to the batter

•Addition of thermal stable microcapsules accelerate the moisture loss from batter.•The batter blended with 1% microcapsules exhibited desirable pick-up.•Microcapsules facilitate water barrier forming by high temperature and pressure.•Addition of microcapsules improve crust crispness in microwave reheated nuggets.

In this study, thermostable microcapsules prepared with a hybrid of chitosan and silica (MCCS) as the shell material and soybean oil with a low specific heat capacity as the nucleus were applied to maintaining the crispness of microwave-reheated battered and breaded fish nuggets. The MCCS added batter at 1 g/100 mL concentration exhibited desirable rheological properties and a 40% pick-up rate, as well as a high cutting force, low deformation and desirable number of peaks in the cutting force profile of the fish nuggets reheated in a microwave oven. After microwave reheating, the moisture content of the crust was lower, and moisture content of the fish meat was higher, in the MCCS-containing nuggets than in the MCCS-free nuggets. This phenomenon suggested that the MCCS facilitated the formation of a water barrier by high temperature and high pressure during microwave reheating, which prevented moisture molecules from migrating from the fish meat to the crust.