热板-微波联合真空冷冻干燥茭白工艺优化  

Optimization of hot-plate and microwave combined vacuum freeze drying process of water-oat

作　　者：颜建春[1] 胡志超[1] 吴朋来 谢焕雄[1] 魏海[1] 徐弘博[1] 高景魁[1] Yan Jianchun Hu Zhichao Wu Penglai Xie Huanxiong Wei Hai Xu Hongbo Gao Jingkui(Nanjing Research Institute of Agricultural Mechanization, Ministry of Agriculture, Nanjing 210014, China)

机构地区：[1]农业部南京农业机械化研究所,南京210014

出　　处：《农业工程学报》2017年第1期262-270,共9页Transactions of the Chinese Society of Agricultural Engineering

基　　金：江苏省农业科技自主创新资金(CX(14)2124);中国农业科学院科技创新工程(农产品分级与贮藏装备创新团队);国家自然科学青年基金(31301592)

摘　　要：为降低新鲜茭白冻干作业能耗,提高冻干成品的品质,以总能耗、体积保留率、复水比、色差值为考察指标,开展了热板冻干、微波冻干、热板-微波联合冻干试验研究。研究表明:35℃热板冻干后茭白品质好,但能耗高;60℃热板冻干能耗低,但水分升华过快对茭白微观结构造成较大破坏,降低了茭白品质;采用35℃热板冻干8 h后,再采用60℃热板冻干或3 k W微波冻干可有效降低冻干能耗,同时冻干后茭白品质良好。在此基础上,采用均匀设计法,开展热板-微波联合冻干工艺参数优化试验研究,通过逐步回归分析,得出了冻干总能耗、体积保留率、复水比、色差关于加热板温度、脱水转换点、微波功率的三元二次回归方程,并通过四维切面等位线图分析了上述4个考察指标受3个试验因素取值变化的影响机理。最后,采用综合加权评分和逐步回归分析得出综合指标关于加热板温度、脱水转换点、微波功率的回归方程,进一步确定加热板温度为30℃、脱水转换点为72%、微波功率为3 k W为最优的热板-微波联合冻干工艺参数,此时综合加权评价指标值76.07,总能耗、体积保留率、复水比、色差分别为90.6 k W·h、51.86%、10.59、4.32。该研究为制定产品优良、高效节能的冻干工艺提供参考。In order to reduce the energy consumption of freeze drying for fresh water-oat and to improve the quality of the finished lyophilized products, the tests of 3 different kinds of freeze drying, including hot-plate vacuum freeze drying, microwave vacuum freeze drying, hot-plate and microwave combined vacuum freeze drying, were launched with the assessment indicators of total energy consumption, and volume retention, rehydration rate and aberration for energy or quality results respectively. The study showed that the 35℃ hot-plate vacuum freeze drying could obtain high-quality finished products, but with too high energy consumption. The 60℃ hot-plate vacuum freeze drying or 3 k W microwave vacuum freeze drying could reduce energy consumption of lyophilization, but the quality of water-oat was impaired as well, because excessive moisture sublimation rate resulted in the more destruction of the microtexture in water-oat pieces. The method, which used 35℃ hot-plate vacuum freeze drying to dehydrate to a certain degree, and then used 60℃ hot-plate vacuum freeze drying or 3 k W microwave vacuum freeze drying, could effectively reduce energy consumption and obtain high-quality finished products at the same time. On this basis, the uniform design was used to carry out the test study on the optimization of process parameters of hot-plate and microwave combined vacuum freeze drying. In the test, hot-plate temperature, dehydration switching point and microwave power were considered as test factors, which were all divided into 13 levels. Besides, according to the actual work situation, the hot-plate temperature was from 30 to 60℃, the dehydration switching point was from 72% to 90%, and the microwave power was from 1.2 to 3 k W. According to the experimentally measured results, the stepwise regression analysis method was used to exclude the non-significant items, and then the quadratic regression equation of total energy consumption, volume retention ratio, rehydration rate and aberration for heating plate temperatur

关 键 词：干燥 微波 优化 热板 真空 加工工艺 

分 类 号：TQ028.6[化学工程] TS255.3[轻工技术与工程—农产品加工及贮藏工程]