中温热泵干燥龙眼果肉工艺优化研究  

Optimization of Technology for Drying Longan Pulp with Mild-temperature Heat Pump

作　　者：邱松山[1] 陈桂[1] 姜翠翠[1] 周如金[1] 

机构地区：[1]广东石油化工学院果蔬加工与贮藏工程技术开发中心,广东茂名525000

出　　处：《中国南方果树》2016年第6期25-31,38,共8页South China Fruits

基　　金：广东省教育部产学研项目(2013B090600032);广东高校果蔬加工与贮藏工程技术开发中心开放基金(2015B009);广东石油化工学院创新创业校级培育项目(2015pyA009)资助

摘　　要：为提高中温热泵干燥龙眼肉干制品品质及工业化应用,本文以龙眼为原料,采用Box-Behnken试验设计优化封闭式中温热泵干燥工艺参数,考察中温热泵干燥过程中干燥时间、温度、风速对龙眼肉总酸、总糖含量及色差等的影响,并采用响应面分析法建立其多元二次回归模型。结果表明,干燥温度60℃、干燥风速1.75m3/s条件下,干燥时间6~12h时龙眼肉色泽较好,干燥时间过长引起龙眼肉褐变,且样品总糖和总酸含量下降;干燥温度55~65℃时,龙眼肉色泽较好;干燥风速增大时样品总糖、总酸含量增加;干燥风速超过1.75m3/s时,龙眼肉中心温度约为58℃,龙眼肉褐变严重。封闭式热泵干燥龙眼肉的最优工艺参数为干燥时间11.50h,干燥温度65℃,干燥风速1.73m3/s,经最优的中温热泵干燥工艺制备的龙眼肉总色差7.98,总酸17.14%,总糖16.75%。In order to improve the quality of longan pulp products and industrial application of closed heat pump,a Box-Behnken experimental design was used to optimize the parameters to dry the longan pulp with closed heat dump.The effects of drying time,temperature and air velocity on the total contents of titratable acid,polysaccharide and△E were examined.A quadratic regression model was proposed.Results showed that the 60 ℃ of temperature and 6~12hdrying time produced better color of longan pulp with enhanced total contents of titratable acid and polysaccharide.The color of sample was superior with drying temperature at 55~65℃.Total contents of titratable acid and polysaccharide increased with the increase of air velocity.The bad browning of longan pulp was observed when the center temperature of longan pulp exceeded 58 ℃ and drying air velocity higher than 1.75m3/s.The optimal drying conditions were established as follows：1.73 m3/s of drying air velocity;65 ℃of temperature;11.50 hdrying time.Under these conditions,the total contents of polysaccharide and titratable acid of dried longan pulp reached 17.14% and 16.75%,respectively,and the total△E was 7.98.

关 键 词：龙眼肉 中温热泵干燥 BOX-BEHNKEN试验设计 

分 类 号：TS255.3[轻工技术与工程—农产品加工及贮藏工程]