Abstract: Quick-frozen deep-fried dough sticks were made from aluminum-free deep-fried dough stick premix and the effects of pre-cooling time, pre-cooling temperature and freezing temperature on the physical characteristics (temperature variations, water content variations, and texture properties) and sensory evaluation were investigated in this study. The aim was to determine the optimal quick-freezing conditions. The results showed that with the increase in pre-cooling time and the decrease in pre-cooling and freezing temperature, the temperatures of the crust and core of deep-fried dough sticks were reduced gradually, and the cooling rates were accelerated gradually. In addition, the reduction in water content in the crust and core was increased with the increase in pre-cooling time and the decrease in pre-cooling temperature, but the reduction in water content was decreased after quick-freezing. Meanwhile, texture properties and sensory quality were improved with the increase in pre-cooling time and the decrease in pre-cooling and freezing temperature. Thus, pre-cooling at 0 ℃ for 45 min and freezing at –30 ℃ for 30 min were the optimal conditions for the production of quick-frozen deep-fried dough sticks.

Key words: pre-cooling, freezing, quality, quick-frozen deep-fried dough sticks