海藻糖、海藻胶及寡糖对蒸煮南美白对虾的抗冻保水作用

为探索海藻糖类在冷冻熟制水产品中的应用效果，以蒸煮南美白对虾为研究对象，以焦磷酸钠为阳性对照，研究海藻糖、海藻胶及寡糖对蒸煮虾仁的抗冻、保水作用。结果表明：－18 ℃冻藏6 周后，1.0 g/100 mL海藻糖、海藻胶寡糖浸泡处理，显著降低了冷冻蒸煮虾仁解冻和蒸煮损失率（P＜0.05），其与焦磷酸钠保水效果无显著性差异（P＞0.05）。在整个冻藏期内，0.5、1.0 g/100 mL海藻糖和海藻胶寡糖处理，虾仁肌肉a*值保持效果显著优于其他处理组（P＜0.05），表明该2 种糖类对蒸煮虾仁色泽具有较好的保护。随着冻藏时间延长，不同处理组虾仁水分含量、水分活度和质构特性均呈逐渐下降趋势，其中以海藻糖、海藻胶寡糖处理对虾仁水分、质构特性保持效果较好，且显著优于蒸馏水和焦磷酸钠组（P＜0.05）。经组织结构观察发现，1.0 g/100 mL海藻胶寡糖处理虾仁，肌纤维排列致密、无扭曲变形，且肌肉中无较大间隙或孔洞产生，表明海藻胶寡糖具有抑制肌肉间隙冰晶生长、保护肌肉组织完整性的作用。结果可为开发一种安全、高效、适用于冷冻蒸煮虾仁的无磷保水剂提供参考。

Comparison of the Cryoprotective Effects of Trehalose,Alginate and Alginate-Derived Oligosaccharides on Cooked Shrimp (Litopenaeus vannamei)

The aim of this work was to evaluate the cryoprotective effects and water-holding capacities of trehalose,
alginate and agal oligosaccharides on cooked white shrimp (Litopenaeus vannamei) during frozen storage using sodium
pyrophosphate as the positive control. The results indicated that the thawing and cooking loss of shrimp were significantly
(P < 0.05) decreased by trehalose and alginate-derived oligosaccharides treatments both at 1.0 g/100 mL after 6 weeks
of storage (−18 ℃), showing no significant difference when compared with sodium pyrophosphate treatment at the same
concentration. The a* value of cooked shrimp was maintained significantly (P < 0.05) better by 0.5 and 1.0 g/100 mL
trehalose and alginate-derived oligosaccharides during the whole frozen storage, which indicated that the two saccharides
had good cryoprotective effects on the color of cooked shrimp. In addition, the moisture content, water activity and texture
of cooked shrimp in all treatments gradually fell during 6-week frozen storage, while the moisture and texture properties
of samples treated with trehalose and alginate oligosaccharides were better than those of the other groups, and significantly
higher than those of the distilled water and sodium pyrophosphate treatment (P < 0.05). The microstructure analysis revealed
that the tissue structure of shrimps treated with 1.0 g/100 mL alginate oligosaccharides were compact, and showed no
distortion. Meanwhile there were no large holes on the cross-section, indicating that alginate oligosaccharides restrained ice
crystal growth and completely kept the muscular tissue structure. This study can lay the foundation for developing a safe,
natural and harmless non-phosphate additive suitable for the frozen cooked shrimp.