苹果片真空浸渍强化铁工艺及干燥特性

Process and Characteristics of Iron-fortified Apple Slices by Vacuum Impregnation Followed by Drying

为提高苹果中铁含量,研究以焦磷酸铁为强化剂,采用真空浸渍法对苹果进行铁强化。通过单因素和响应面试验优化真空浸渍工艺参数,并对最佳工艺浸渍样品进行热风干燥、真空干燥和冷冻干燥。结果表明:当温度为40℃,真空度为49 kPa,真空时间为16 min,常压时间为17 min时,苹果强化铁含量为7.32 mg/100 g,与鲜样相比提高了14.51倍;维生素C含量为2.156 mg/100 g,下降了32.24%。热风干燥过程中,真空浸渍样品干燥时间比常压浸渍和新鲜样品缩短了25%,表明真空浸渍可以促进样品干燥速率。干燥动力学结果表明Page模型更适用于建立苹果片薄层干燥数学模型。研究获得了苹果片真空浸渍强化铁及工艺参数,为苹果强化铁的制备提供依据。

This research aimed to fortify the iron content with the ferric pyrophosphate in apples by using the vacuum impregnation technology(VI), and to evaluate the effects of the impregnation temperature, vacuum degree, vacuum impregnation time and atmospheric time to properties of apples impregnated. Based on the Box-Behnken central composite design, the response surface methodology(RSM) was applied to optimize the vacuum impregnation technology conditions by using the iron content as the response value. The apples impregnated with the optimum condition were dried by the air drying(AD). The results showed that optimum conditions were 40 ℃ of temperature, 49 kPa of vacuum degree, 16 min of vacuum impregnation time and 17 min of atmospheric time, and the iron content and vitamin C content are 7.32 mg/100 g and 2.156 mg/100 g, respectively. The value of the iron content was 14.51 times higher than that of apples, and the content of vitamin C decreases by 32.24%. Ferric pyrophosphate impregnation increased the sample drying rates and positively influences the physical properties of the AD product. The vacuum impregnation technology could be considered as a new approach for fortifying iron in apples. The results of this research might provide a basis for iron-fortified apples with vacuum impregnation technology.