不同干燥方式对红托竹荪复水特性及其品质的影响

Effects of Different Drying Methods on Rehydration Characteristics and Quality of Dictyophora rubrovolvata

目的:研究不同干燥方式对红托竹荪复水特性及品质的影响。方法:将真空冷冻、热风、微波干燥的3种红托竹荪干品在45℃温水中复水至平衡,以色差仪、气相色谱-质谱法(Gas chromatography-mass spectrometer,GC-MS)和紫外分光光度计,比较竹荪复水比、质构、香气和营养的差异。结果:复水比:真空冷冻(12.48)>热风(9.63)>微波(8.64);色差:真空冷冻(12.090)<热风(15.893)<微波(19.240);剪切力:热风(1402.56 g)>真空冷冻(1215.34 g)>微波(983.47 g)。真空冷冻竹荪复水特性好,剪切力适中,色泽最好,除多糖外,营养物质最接近鲜品。热风干燥竹荪复水比居中剪切力较大,质地偏硬,色泽较差,难以保留营养物质。微波干燥竹荪复水性最差,质地偏软,色泽与鲜品相差大,但多糖含量接近鲜品。真空冷冻、热风和微波干制红托竹荪复水后分别检测出81、102、80种香气物质,其中醇、烃、酯和酮类为红托竹荪香气物质的重要组成部分。真空冷冻可以保留香气物质;热风干燥有利于含硫化合物种类和数量的生成,因此香气物质种类最丰富;微波干燥除了增加酚类之外其余香气物质均有损耗。结论:总体来看,真空冷冻对红托竹荪品质影响最小,在一定程度上保留了香气物质,其次是热风干燥,且有益于香气物质的生成和富集。综上,真空冷冻和热风干燥均可用于红托竹荪干燥,可根据时间、成本、品质等不同要求来选择干燥方式。

Objective:To study the effects of different drying methods on rehydration characteristics and quality of Dictyophora rubrovolvata.Methods:Three kinds of dried Dictyophora rubrovolvata by vacuum freezing,hot air and microwave were rehydrated to equilibrium in warm water at 45℃,and the rehydration ratio,texture,aroma and nutrition of Dictyophora rubrovolvata were compared by color difference meter,gas chromatography-mass spectrometer(GC-MS)and ultraviolet spectrophotometer.Results:The rehydration ratio was vacuum freezing(12.48)>hot air(9.63)>microwave(8.64).Color difference:vacuum freezing(12.090)vacuum freezing(1215.34 g)>microwave(983.47 g).Vacuum-frozen Dictyophora rubrovolvata has good rehydration characteristics,moderate shear force,and its color is close to fresh products.Except polysaccharide,the nutrients are closest to fresh products.The rehydration ratio of Dictyophora rubrovolvata dried by hot air is in the middle,and shear force is larger,and the texture is hard and the color is poor,so it is difficult to retain nutrients.Microwave-dried Dictyophora rubrovolvata has the worst rehydration,soft texture,and different color from fresh ones,but the polysaccharide content is close to fresh ones.After vacuum freezing,hot air and microwave drying Dictyophora rubrovolvata was rehydrated,81,102,80 kinds of aroma substances were detected respectively,among which alcohols,hydrocarbons,esters and ketones were the important components of aroma substances of Dictyophora rubrovolvata.Vacuum freezing can keep the aroma substances,and hot air drying is beneficial to the generation of sulfur-containing compounds,so the aroma substances are the most abundant,and microwave drying loses all the aroma substances except phenols.Conclusion:Generally speaking,vacuum freezing has the least effect on the quality of Dictyophora rubrovolvata,and the aroma substances are retained to some extent,followed by hot air drying,which is beneficial to the generation and enrichment of aroma substances.To sum up,both vacuum freezing and hot air drying can be used to dry Dictyophora rubrovolvata,and the drying method can be selected according to different requirements such as time,cost and quality.