摘要
目的研究超声预处理和湿度控制技术对香蕉干燥特性的影响,以缩短香蕉的干燥时间、减少色泽劣变。方法首先在超声波发生器功率为300 W,温度为30℃条件下对厚度为(5.0±0.1)mm的香蕉片进行单频(20,40,60 kHz)预处理,每个频率分3组,处理时间为20,30和40 min,得到的最佳超声预处理时间为30 min。再分别进行单频(20,40,60 kHz)、双频((20+40),(20+60),(40+60)kHz)和三频((20+40+60)kHz)的处理,在65℃条件下进行恒温热风干燥;在此基础上进行干燥介质相对湿度为5%,10%,15%的热风干燥。结果在超声波预处理中,单频(60 kHz)、双频((40+60)kHz)和三频((20+40+60)kHz)的超声波预处理对温湿度控制热风干燥速率的作用效果最佳,在同一干燥介质相对湿度条件下,干燥速率、复水率以及维生素C含量从大到小依次为三频((20+40+60)kHz)、双频((40+60)kHz)、单频(60 kHz)、空白对照组;在相同的超声波预处理条件下,干燥介质相对湿度越小,干燥速率和复水率越高,而维生素C含量越低。结论探索了不同相对湿度的干燥介质对超声预处理后的香蕉干燥特性的影响,为选择合适的干燥工艺提供了理论依据。
The work aims to study the effect of ultrasonic pretreatment and humidity control on banana drying characteristics, in order to shorten drying time and reduce color deterioration of banana. First, the banana chips with a thickness of(5.0±0.1) mm were pretreated with single frequency(20, 40, 60 kHz) at a power of 300 W and a temperature of 30 ℃. Each frequency was divided into 3 groups with treatment time of 20, 30 and 40 min, and the optimal ultrasonic pretreatment time obtained was 30 min. Then, single frequency(20, 40, 60 kHz), double frequency((20+40),(20+60),(40+60) kHz) and triple frequency((20+40+60) kHz) were respectively treated, and the constant temperature hot air drying was carried out at 65 ℃. On this basis, hot air drying with drying media’s relative humidity of 5%, 10% and 15% was carried out. In ultrasonic pretreatment, the ultrasonic pretreatment with single frequency(60 kHz), dual frequency((40+60) kHz) and triple frequency((20+40+60) kHz) had the best effect on the hot air drying rate under temperature and humidity control. Under the same relative humidity of dry medium, the order of drying rate, rehydration rate and Vc content from large to small in turn was triple frequency((20+40+60) kHz), dual frequency((40+60) kHz), single frequency(60 kHz) and blank control group. Under the same ultrasonic pretreatment conditions, the smaller the relative humidity of the drying medium, the higher the drying rate and the rehydration rate, and the lower the Vc content. The effects of drying media with different relative humidity on the drying characteristics of banana after ultrasonic pretreatment are explored to provide theoretical basis for selecting appropriate drying process.
作者
夏蓉
姬青华
周存山
陶汇源
卞晶晶
李雅思
XIA Rong;JI Qing-hua;ZHOU Cun-shan;TAO Hui-yuan;BIAN Jing-jing;LI Ya-si(Zhenjiang Heng Shun Biological Engineering Co.,Ltd.,Zhenjiang 212143,China;School of Food and Biological Engineering,Jiangsu University,Zhenjiang 212013,China)
出处
《包装工程》
CAS
北大核心
2019年第1期40-48,共9页
Packaging Engineering
基金
国家重点研发计划(2017YFD0400903-01
2016YFD0400705-04)
江苏省科技厅资助项目(BZ2016013)
镇江市科技局资助项目(NY2017015)
镇江市经济和信息化委员会资助项目(镇江制造2025领军人才计划)
关键词
香蕉
超声波预处理
干燥介质
湿度
banana
ultrasonic pretreatment
drying medium
humidity
