胡萝卜热泵干燥工艺优化

目的:优化胡萝卜的热泵干燥工艺。方法:在单因素试验基础上,通过Box-Behnken试验设计,以色差、复水比和β-胡萝卜素含量为指标,研究初始温度、干燥温升和切片厚度对胡萝卜干燥品质的影响。建立回归方程,分析3个独立因素之间交互作用对响应值的影响,得到胡萝卜热泵干燥的最佳干燥工艺参数以及在此条件下的预测值,最后通过实验与预测值进行对比验证,确定最佳参数组合。结果:胡萝卜热泵干燥的最优工艺参数为:初始温度54.1℃,干燥温升9.25℃,切片厚度3.8 mm,此条件下的胡萝卜色差值为9.759,复水比为6.196,β-胡萝卜素含量为34.378 mg/100 g,其干制品色泽呈鲜亮橙红色,复水比高,β-胡萝卜素保留量高。结论:响应面法可确定胡萝卜热泵干燥的最佳工艺参数,使胡萝卜干制品的品质最佳。

Optimization of carrot heat pump drying process by response surface methodology

Objective:This study focuses on optimizing the heat pump drying process of carrot.Methods:On the basis of single factor experiment,Box-Behnken experiment was designed.Color difference,rehydration ratio and β-carotene content were used to study the effects of initial temperature,drying temperature rise and slice thickness on carrot drying quality.The regression equation was established,and the interaction between three independent factors on the response was analyzed.The optimal drying process parameters and the predicted values of carrot heat pump drying were obtained.Finally,the optimal parameters were determined by comparing the experimental results with the predicted values.Results:The optimal process parameters of carrot heat pump drying were as follows:the initial and drying temperature were 54.1℃ and 9.25℃ respectively,and the slice thickness was 3.8 mm.Under the control of these conditions,the color difference value of carrot was 9.759,the rehydration ratio was 6.196,with the content of β-carotene of 34.378 mg/100 g.The dried product was bright orange red,and the rehydration ratio and the retention of β-carotene were high.Conclusion:Response surface method can determine the best process parameters of carrot heat pump drying,and help to obtain the best quality of carrot dried products.