干燥方式对树莓干燥特性、品质和微观结构的影响  

Effects of Drying Methods on the Drying Characteristics, Quality and Microstructure of Raspberry

作　　者：司旭[1] 陈芹芹[1] 毕金峰[1] 吴昕烨[1] 李兆路 

机构地区：[1]中国农业科学院农产品加工研究所/农业部农产品加工重点实验室,北京100193

出　　处：《中国食品学报》2016年第10期130-138,共9页Journal of Chinese Institute Of Food Science and Technology

基　　金：公益性行业(农业)科研专项(201303073);新疆生产建设兵团科技支疆计划(2013AB020)

摘　　要：为了丰富树莓加工产品种类,提高树莓干燥效率和品质,采用热风、红外和真空冷冻干燥3种方法对树莓进行干燥处理,研究其对干燥特性、色泽、复水性、花青素保留率、抗氧化活性和微观结构的影响。试验结果表明:在干燥特性方面,红外干燥时间最短,其次为热风干燥,而真空冷冻干燥时间分别为以上两种干燥方式的9倍和4.5倍。采用7种常见的干燥模型对热风和红外干燥过程拟合,结果 Page模型拟合效果最好。在物理性质方面,真空冷冻干燥产品的色泽和复水性明显优于热风和红外干燥,而红外干燥又明显优于热风干燥。品质指标方面,真空冷冻干燥树莓的花青素保留率虽然最高(63.33%),但是其抗氧化能力损失最多,而红外干燥树莓ABTS、DPPH自由基清除能力和铁还原能力保留率最高,分别为61.70%,45.10%和56.38%。微观结构方面,真空冷冻干燥树莓的组织结构保持较为完整,红外干燥产品结构疏松,而热风干燥树莓组织受到严重破坏。综合评价,红外干燥效率最高,且干燥后的产品抗氧化能力最强,其它品质也较好,可作为最佳干燥方式应用于生产中。In order to enrich the product category and improve the drying efficiency and quality of raspberries, the effects of different drying methods on the drying characteristics and quality of raspberries were explored. Raspberries were subjected to three different drying methods： hot-air drying（AD）, infrared radiation drying（IRD） and vacuum freeze drying（FD）. The effects of above three drying methods on the drying characteristics, color, rehydration, anthocyanin retention, antioxidant activity and microstructure of raspberries were evaluated. From the results, it was found that IRD used the least drying time and presented the highest drying efficiency, then AD. However, the drying time of FD was 9and 4.5 times of IRD and AD. Seven common drying models were used to describe AD and IRD processes, and Page model showed the best fitting effect estimated from determination coefficient（R^2）, chi-square（χ~2） and root-mean-square error（RMSE）. In terms of physical properties, the color and rehydration properties of products under VFD were better than that of AD and IRD, moreover IRD was better than AD. In the case of quality indexes, raspberries obtained by FD presented the highest anthocyanin retention（63.33%）, but the highest antioxidant activity losses. IRD was noted to show the strongest antioxidant activity, with the highest ABTS and DPPH radical scavenging and ferric reducing capacity retention of 61.70%, 45.10% and 56.38%, respectively. The structure of raspberries under FD was maintained well, and that under IRD was porous. By contrast, the texture of products obtained by AD was seriously destroyed judged by scanning electron microscope. Through comprehensive evaluation, IRD with the highest drying efficiency, antioxidant activity and better physical and nutritional properties was recommended to be the optimum drying method applied to production.

关 键 词：树莓 热风干燥 红外干燥 真空冷冻干燥 干燥特性 品质 微观结构 

分 类 号：TS255.3[轻工技术与工程—农产品加工及贮藏工程]