不同干燥方式下沙丁鱼干燥特性的比较

为了研究不同干燥方式对沙丁鱼干燥特性的影响,采取冷风、热风、微波真空、冷风-微波真空和热风-微波真空5种干燥方式对沙丁鱼进行处理,研究不同干燥方式对沙丁鱼色泽、质构、水分变化、微观结构和干燥后对蛋白质二级结构的影响。结果表明,不同干燥方式对干制鱼肉色泽影响差异显著(p <0.05),微波真空干燥有助于提高鱼肉的亮度,并与鲜肉最为接近,冷风-微波真空在色度方面表现良好;不同干燥方式对质构影响显著(p <0.05),干燥方式中,微波真空干燥方式有降低硬度、咀嚼度;微观结构中热风和冷风处理后的肌肉纤维紧密,冷风-微波真空处理后的肌肉呈现疏松且密集的网状;干燥使得不易流动水大量流失,水分发生迁移,微波真空与热风-微波真空、冷风-微波真空干燥使肌肉纤维疏松;同时,干燥破坏了蛋白质二级结构,使得α-螺旋向β-折叠、无规则卷曲转化,冷风干燥对其二级结构的影响程度最小,结果为沙丁鱼的生产加工提供理论依据。

Comparison of Drying Characteristics of Sardines under Different Drying Methods

In order to study the effects of different drying methods on the drying characteristics of sardine meat,the sardines were treated by five drying methods: Cold air,hot air,microwave vacuum,cold air microwave vacuum and hot air microwave vacuum.The effects of different drying methods were studied on the color,texture,moisture content,microstructure and protein secondary structure of sardines.The results showed that the effect of different drying methods on color of dried fish was significantly different (p < 0.05).Microwave vacuum drying helped to increase the brightness of fish and was closest to fresh meat.And cold wind microwave vacuum showed good chromaticity. The effect of different drying methods on texture was significant (p < 0.05). In drying modes,microwave vacuum drying had the effect of reducing hardness,chewing degree and enhancing elasticity.The muscle fibers treated by hot air and cold air were close in microstructure.The muscle of cold air treated by microwave vacuum showed loose and dense reticular shape. Drying made a large amount of non-flowable water loss,moisture migration,microwave vacuum and hot air-microwave vacuum,cold air-microwave vacuum drying to loosen muscle fibers.At the same time,drying destroyed the protein secondary structure,making α-helix converted to β-sheet and random coil,and the effect of cold air drying on its secondary structure was minimal.The results would provide theoretical basis for the production and processing of sardines.