[关键词]
[摘要]
探讨不同糖类对冻藏温度波动下冷冻虾仁的抗冻保水作用。以南美白对虾为对象,以焦磷酸钠和蒸馏水分别为阳性和阴性对照,在-55 ℃与-24 ℃冻藏温度波动条件下,分析低聚木糖、卡拉胶寡糖、海藻糖和海藻胶寡糖对虾仁肌肉品质特性的影响。结果表明,在温度波动条件下冻藏144 d过程中,相比于蒸馏水处理组,低聚木糖、卡拉胶寡糖、海藻糖和海藻胶寡糖显著降低了冷冻虾仁的解冻损失率,其中最低的为卡拉胶寡糖组(8.58%)。且糖处理组有效维持了虾仁肌肉组织的质构特性,弹性和咀嚼性最佳分别为1.42 mm和6.80 mJ。同时,几种糖类物质减缓了重结晶虾仁的肌原纤维蛋白含量(106.10 mg/g~111.67 mg/g)、Ca2+-ATPase活性(0.124 U/mg~0.136 U/mg)和总巯基含量(7.6 mmol/L~8.1 mmol/L)的下降速率。微观结构观察发现,相比于蒸馏水组,糖类处理后的虾仁肌肉结缔组织结构较为完整,肌束间空隙较小,且并未发生大面积扭曲、断裂现象,其对冻藏虾仁组织结构具有较好的维持作用。由上,低聚木糖、卡拉胶寡糖、海藻糖和海藻胶寡糖可作为冷冻虾仁的抗冻保水剂加以开发与利用。
[Key word]
[Abstract]
The aim of this study was to explore the cryoprotective effects of different saccharides on whiteleg shrimp (Litopenaeus vannamei) muscle during frozen storage with temperature fluctuations. The effects of xylooligosaccharide, carrageenan oligosaccharide, trehalose, and algae oligosaccharide on quality characteristics of shrimp muscle were evaluated upon exposure to temperature fluctuations between -55 ℃ and -24 ℃, with sodium pyrophosphate and distilled water treatments as the positive and negative controls, respectively. The results showed that xylooligosaccharide, carrageenan oligosaccharide, trehalose, and alginic oligosaccharide significantly reduced the thawing loss of frozen shrimp, compared with the distilled water treated group (the lowest value was 8.58% in carrageenan oligosaccharide group) during 144 days of frozen storage with temperature fluctuations. These saccharides effectively maintained the texture properties of shrimp muscle, the optimum elasticity and chewiness were 1.42 mm and 6.80 mJ, respectively. Meanwhile, these saccharides soaking treatments also slowed the degradation of myofibrillar proteins (106.10 mg/g~111.67 mg/g), decreased Ca2+-ATPase activity (0.124 U/mg~0.136 U/mg) and total sulfhydryl content (7.6 mmol/L~8.1 mmol/L) in the shrimp muscle. Microstructure results showed that compared with distilled water group, the muscle connective structure of shrimp tissues treated with saccharides was more complete, the gap among muscle bundles was smaller, and there was no large area of distortion and rupture observed, which showed good maintenance effects on the microstructure of frozen shrimp tissues. These results suggest that the xylooligosaccharides, carrageenan oligosaccharides, trehalose, and alginate oligosaccharides can be developed and utilized as the antifreeze and water-retaining agents for frozen shrimps.
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[基金项目]
国家自然科学基金项目(31871871);浙江省自然科学基金项目(LY18C200008)