摘要
为了缩短山药干燥时间、减少色泽劣变,本文研究了山药在催化式红外干燥中不同烫漂前处理时间(0.5、1.0、2.0、3.0 min)、切片厚度(0.5、0.8、1.0、1.5 cm)和红外辐射距离(30、36、42、48 cm)条件下干燥曲线和产品色泽。研究表明:切片厚度和辐射距离对干燥时间有显著影响(p>0.05),切片厚度0.5 cm下干燥时间比切片厚度1.5 cm缩短约47.73%,辐射距离30 cm下干燥时间比辐射距离48 cm缩短约46.67%,减少切片厚度、缩短辐射距离能够有效提高干燥效率;烫漂时间(1.0、2.0、3.0 min)对山药干燥时间没有显著影响(p>0.05);山药整个干燥过程属于降速干燥,根据菲克第二定律,山药干燥水分有效扩散系数在1.4770×10-9~5.5043×10-9m2/s。不同条件下山药干燥后白度值(Whiteness index,WI)为56.19~78.78。通过对山药干燥时间和色泽的综合分析,优化的烫漂和干燥工艺为:热水烫漂1~2 min,切片厚度1.0 cm,辐射距离30 cm,干燥时间约160 min,WI值约为77.36。本研究为山药催化式红外干燥加工提供理论依据和技术支持。
The aim of this study was to shorten the drying time and reduce the color deterioration during drying process. The drying curves and product color were investigated under different hot water blanching pretreatment time （ 0.5,1.0,2.0,3.0 min ） , slice thickness （ 0.5,0.8,1.0,1.5 ram） and infrared radiation distance （ 30,36,42,48 era） by catalytic infrared drying.The results demonstrated that slice thickness and infrared radiation distance showed a significant impact on drying time （p 〈 0.05 ） , and the drying rate would be improved by reducing the slice thickness and shortening the radiation distance. The drying time under slice thickness of 0.5 cm was reduced by about 47.73% compared with the slice thickness of 1.5 cm,and drying time under radiation distance of 30 em was reduced by about 46.67% compared with the radiation distance of 48 em. Blanching pre -treatment time （ 1.0,2.0,3.0 min ）had no significant effect on drying time （p 〉 0.05 ）.Yam slices samples showed only a falling rate period and the moisture effective diffusivity was between 1.4770 × 10 ^-9 m^2/s and 5.5043 × 10^ -9 m^2/s by the Fiek＇ s second law.The whiteness index（WI） value of dried yam products were between 56.19 and 78.78 under different pre-treatment and drying conditions.Through the analysis of drying time and products＇ color, the optimum processing condition was blanching time for 1-2 min,slice thickness of 1.0 cm,infrared radiation distance of 30 cm,the drying time was about 160 rain and WI value was about 77.36.The results will provide a theoretic reference and technical supports for am slices drying process.
出处
《食品工业科技》
CAS
CSCD
北大核心
2017年第7期221-225,共5页
Science and Technology of Food Industry
基金
江苏自然科学基金(BK20160504)
中国博士后科学基金(2016M591789)
江苏省农产品物理加工重点实验室开放基金(JAPP2014-4)
江苏大学高级人才科研启动基金(15JDG060)
关键词
山药
催化式红外干燥
干燥特性
色泽
yam
catalytic infrared drying
drying characteristic
color
