不同干燥方法对南美白对虾理化特性和微观结构的影响

Effects of Different Drying Methods on Physicochemical Properties and Microstructure of Penaeus vannamei

为探究不同干燥方法对南美白对虾理化特性和微观结构的影响,本研究分析了中短波红外干燥(mediumshort wave infrared drying,MSWID)和热风干燥(hot air drying,HAD)后南美白对虾的干燥特性、色泽、质构特性、水分分布、虾青素含量、抗氧化能力和微观结构的变化。结果表明:随着干燥温度的升高,南美白对虾水分含量逐渐减小,70℃下MSWID比HAD时间缩短16.67%,且色泽更加鲜亮。南美白对虾的硬度、胶着性和咀嚼性均随干燥温度的升高而显著提高(P<0.05),但温度对弹性无显著影响(P>0.05)。核磁共振成像结果显示,MSWID的水分迁移速率高于HAD。微观结构观察结果表明,MSWID组南美白对虾肌纤维组织较HAD组更加疏松多孔。两种干燥方式下,随温度升高,南美白对虾蛋白二级结构中α-螺旋相对含量均先升高后降低,β-折叠相对含量均先降低后升高。MSWID组南美白对虾的虾青素含量及抗氧化能力均比相同温度下HAD组低。综合比较MSWID和HAD处理后的南美白对虾品质,结果表明MSWID优于HAD,因此MSWID是一种有应用前景的南美白对虾干燥方式。

In order to explore the effects of different drying methods on the physicochemical properties and microstructure of Penaeus vannamei,the drying characteristics,color,texture,water distribution,astaxanthin content,antioxidant capacity and microstructure of P.vannamei were analyzed after medium-short wave infrared drying(MSWID)or hot air drying(HAD).The results showed that with the increase in drying temperature,the moisture content of P.vannamei decreased gradually,and MSWID could reduce the drying time of P.vannamei by 16.67%and make its color brighter compared with HAD at 70℃.The hardness,gumminess and chewiness of P.vannamei were significantly increased with increasing drying temperature(P<0.05),but the springiness was not significantly affected by drying temperature(P>0.05).According to magnetic resonance imaging(MRI)results,the rate of water migration during MSWID was faster than that during HAD.Besides,the results of microstructure observation indicated that the muscle fiber of P.vannamei became looser and more porous after MSWID compared with HAD.For both drying treatments,theα-helix relative content of shrimp proteins first increased and then decreased,and theβ-fold relative content showed a contrary trend.The astaxanthin content of MSWID dried shrimp was lower than that of HAD dried shrimp,and so was the antioxidant capacity.The quality of MSWID dried P.vannamei was better than that of HAD dried P.vannamei,indicating MSWID to be a promising drying method for P.vannamei.