【摘要】 不同的干燥方式和干燥温度对香菇品质的影响不同。本研究选用中短波红外干燥和热风干燥以及不同干燥温度（50、60、70℃）对新鲜去茎香菇进行干燥处理,测定了香菇的干燥特性、硬度、体积收缩率、复水比、微观结构、营养物质、挥发性成分和单位能耗。结果表明:干燥工艺为MIRD70℃时香菇干燥时间最短,为532min,水分比和干基含水率都随着干燥时间的增加而减小。干燥工艺为MIRD50℃时香菇硬度相对较小,为13237.08g。干燥工艺为HAD50℃时体积收缩率相对较小,为73.77%。干燥工艺为HAD50℃时复水比相对较大,为312.68%,MIRD70℃时复水比为238.19%。干燥工艺为MIRD70℃、60℃和HAD 60℃时总糖含量相对较大,分别为26.66%、26.22%、26.28%。干燥工艺为MIRD70℃和HAD60℃时粗蛋白含量相对较大,分别为36.61%和36.64%。干燥工艺为MIRD70℃和MIRD50℃时可溶性糖含量相对较大,分别为2.83mg·100 g^-1和2.47mg·100 g^-1。所有干燥工艺的香菇维生素B2含量都较鲜香菇明显增加。在6种干燥工艺的干香菇中共鉴定出89种挥发性成分, HAD70℃时干制香菇挥发性成分种类最多,主要为1-辛烯-3-醇、异戊醇、正己醇、苯甲醇、苯乙醇、2-苯基-1-丙醇、二甲基三硫醚、2,3,5-三硫杂己烷、甲基磺酰甲烷、乙酸、异丁酸、异戊酸、4-羟基丁酸乙酰酯及丙位戊内酯。不同干燥工艺的单位能耗之间具有显著性差异,MIRD的单位能耗大于HAD,HAD70℃的单位能耗最小,为25.09kJ·kg^-1,MIRD70℃的单位能耗相对较大,为47.18kJ·kg^-1。主成分分析法对干制香菇各项指标进行综合评价的结果表明:中短波红外干燥的单位能耗高于热风干燥,但其他指标都优于热风干燥。过高的干燥温度和过长的干燥时间均会对干香菇的品质有负面影响。此外,中短波红外干燥70℃干燥香菇效果最好,中短波红外干燥60℃干燥效果次之,热风干燥50℃的产品较差。更多还原

【Abstract】 Different drying methods and drying temperatures have different effects on the quality of shiitake mushrooms. In this study,medium and short wave infrared drying（MIRD） and hot air drying（HAD） with various drying temperature（50,60,70℃） were used to dry shiitake mushrooms. The drying characteristics, hardness, volume shrinkage, rehydration ratio, microstructure, nutrient content,volatile components and unit energy consumption of shiitake mushrooms were determined. The results showed that the drying time of shiitake mushrooms was the shortest when the drying process was MIRD70℃, which was 532 min. The moisture ratio and dry basis moisture content both decreased with increasing of drying time. When the drying process was MIRD50℃, the hardness of shiitake mushrooms was relatively small, which was 13237.08 g. When the drying process was HAD50℃, the volume shrinkage rate was relatively small, which was 73.77%. When the drying process was HAD50℃, the rehydration ratio was relatively large, which was312.68%. When the drying process was MIRD70℃, the rehydration ratio was 238.19%. The total sugar content was relatively large when the drying process was MIRD 70℃, 60℃ and HAD 60℃, which were 26.66%, 26.22% and 26.28% respectively. When the drying process was MIRD 70℃ and HAD 60℃, the crude protein content was relatively large, which were 36.61% and 36.64%respectively. When the drying process was MIRD 70℃ and MIRD 50℃, the soluble sugar content was relatively large, which were2.83 mg · 100 g^-1 and 2.47 mg · 100 g^-1 respectively. The vitamin B2 content of shiitake mushrooms in all drying processes was significantly higher than that of fresh shiitake mushrooms. A total of 89 volatile components were identified in dried shiitake mushrooms from six drying processes. Shiitake mushrooms dried by HAD 70℃ had the largest variety of volatile components mainly including 1-Octen-3-ol, 3-Methyl-1-butanol, n-Hexanol, Benzyl alcohol, Phenethyl alcohol, 2-Phenyl-1-propanol, Dimethyl trisulfate, 2, 3, 5-Trithiahexane, Methyl sulfone, Acetic acid, Isobutyric acid, Isovaleric acid, 4-Hydroxybutyric acid and gammaValerolactone. There were significant differences between the unit energy consumption of different drying processes. The unit energy consumption of MIRD was higher than that of HAD. The unit energy consumption of HAD70℃ was the lowest, which was 25.09 kJ·kg^-1.The unit energy consumption of MIRD70℃ was relatively high, which was 47.18 kJ·kg^-1. The results of comprehensive evaluation of various indexes of dried shiitake mushrooms by principal component analysis（PCA） showed that the unit energy consumption of MIRD was higher than HAD, but other indexes were superior to HAD. Higher drying temperatures and extended drying duration can induce quality deterioration of dried shiitake mushrooms. In addition, the mushrooms were dried by MIRD 70℃ were the best, the mushrooms dried by MIRD60℃ were the second best, and the mushroom dried by HAD50℃ were the worst among the drying methods and drying conditions which were used in this work.更多还原