Temperature and moisture changes during Cantonese lotus-seed-paste and bean- paste buns under quick- frozen and steam reheating

This article studied the temperature and wet basis moisture content changes of layers ( crust, crumb and stuffing) during Cantonese lotus- seed- paste and red- bean- paste buns under quick- frozen and steam reheating ( frozen storage two months later) .The results showed that: the temperature drop rate of crust in buns was the biggest, while the stuffing was the smallest, and the cooling rate of each layer in lotus- seed- paste bun were bigger than red- seed- paste bun's during pre- cooling and quick- frozen process.The water content of the crust, crumb and stuffing for buns were significantly decreased ( p < 0.05) , which the crusts showed the maximum reductions of water contents. Compared with the each layer of two buns, the crust of lotus- seed- paste bun, the crumb and stuffing of red bean paste bun showed the bigger reductions of water contents respectively. In the process of steam reheating, the temperature rising curves of buns conformed to the Logistic model, and the regular pattern of each layer heating rates in buns was agreed with the temperature drop rate.The k value of each layer in lotus- seed- paste bun were bigger than red- seed- paste bun's.The water content of the crust, crumb and stuffing of buns were significantly increased ( p < 0.05) , which the crusts showed the maximum addition of water contents.Compared with the each layer of two buns, the crust of lotus- seed- paste bun, the crumb and stuffing of red bean paste bun showed the bigger addition of water contents respectively. This proved that steam reheating could supply some moisture for Cantonese lotus- seed- paste and bean- paste buns.