广式蓉沙类包点速冻和复热过程中温度和水分变化
Temperature and moisture changes during Cantonese lotus-seed-paste and bean- paste buns under quick- frozen and steam reheating
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摘要: 主要研究了广式蓉沙类包点(豆沙包和莲蓉包)各层(皮、瓤和馅)在速冻和蒸汽复热过程中的温度和湿基含水率的变化。结果表明:在预冷速冻过程中,包点各层温度下降速率为皮>瓤>馅,莲蓉包各层的降温速率均大于豆沙包的;包点的w皮、w瓤和w馅均显著下降(p<0.05),其中w皮的下降量最大,两种包点相比,莲蓉包w皮的降低量较大,而豆沙包w瓤和w馅的降低量则较大。在蒸汽复热过程中,包点的升温曲线符合Logistic模型,升温速率为皮>瓤>馅,莲蓉包各层的k值均大于豆沙包的;包点的w皮、w瓤和w馅均显著增加(p<0.05),其中w皮的增加量最大,两种包点相比,莲蓉包w皮的增加量较大,而w瓤和w馅的增加量则较小,与预冷前的包点的w皮、w瓤和w馅相比差别不大,说明蒸汽复热可以为广式蓉沙类包点补偿一部分水分。Abstract: 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.