不同糖类对反复冻融下 冻藏南美白对虾虾仁品质特性的影响

为探讨不同糖类对反复冻融下冻藏南美白对虾品质特性的影响,以3%低聚木糖、3%卡拉胶寡糖、3%海藻糖、3%海藻胶寡糖和3%焦磷酸钠(阳性对照)浸泡处理南美白对虾虾仁后,在-55~4 ℃循环冷冻-解冻过程中,分析冻藏虾仁肌肉解冻损失率、L^*值、质构特性、肌原纤维蛋白含量、总巯基含量及肌原纤维蛋白Ca²⁺-ATPase活性等变化情况。结果表明,经反复冻融6次后,蒸馏水组虾仁解冻损失率和L^*值分别显著增加46.2%和11.7%,而其咀嚼性、硬度、肌原纤维蛋白含量、Ca²⁺-ATPase活性和总巯基含量则分别显著下降了57.5%、43.8%、14.0%、29.7%和23.4%(P<0.05)。相比于蒸馏水组,几种糖类浸泡处理,均对冻藏虾仁表现出一定的保水及蛋白质冷冻变性抑制效果。其中,卡拉胶寡糖处理虾仁,经6次冻融后其肌肉解冻损失率和L^*值增加至5.65%和47.35,而其咀嚼性、硬度、肌原纤维蛋白含量、Ca²⁺-ATPase活性和总巯基含量则维持在5.43 mJ、1.28 mm、95.24 mg/g、0.093 U/mg和7.31 mmol/L,相比于其它几种糖类,卡拉胶寡糖对虾仁品质特性的保护作用较好。综上,糖类处理对温度波动下的冻藏南美白对虾有重要的冷冻保护效果,其可为冻藏虾仁的品质保障技术提供一定的理论依据。

Effect of Different Saccharides on the Quality of Peeled Shrimp During Frozen Storage with Freeze-thaw Cycles

To investigate the effects of different saccharides on the quality of frozen shrimp(Litopenaeus vannamei)under freeze-thaw cycles conditions,the cryoprotective effects of 3% xylooligosaccharide,3% carrageenan oligosaccharide,3% trehalose,and 3% alginate oligosaccharides(the 3% sodium pyrophosphate treatment as positive control)on peeled shrimp during the circulated freezing-thawing(-55~4 ℃)process was investigated by monitoring the thawing loss rate,L* value,texture characteristics,myofibrillar protein content,sulfhydryl content,and Ca2+-ATPase activity. The results showed that the thawing loss and L* value of control shrimp significantly increased to 46.2% and 11.7%,while the chewiness,hardness,myofibrillar protein content,Ca2+-ATPase activity,and total sulfhydryl content decreased significantly by 57.5%,43.8%,14.0%,29.7%,and 23.4%(P<0.05)after 6 cycles of the repeated freezing and thawing. Compared with the distilled water group,the saccharides soaking showed good water holding capacity and inhibition effects on the protein denaturation in frozen shrimp. After 6 cycles of treatment,the thawing loss and L* value of shrimp muscle treated with 3% carrageenan oligosaccharide increased to 5.65% and 47.35,while the chewiness,hardness,myofibrillar protein content,Ca2+-ATPase activity,and total sulfhydryl content maintained at 5.43 mJ,1.28 mm,95.24 mg/g,0.093 U/mg and 7.31 mmol/L,respectively. The protection on the quality characteristics of the shrimp was better than the other saccharide treatments. In conclusion,the saccharides treatments played important roles in the peeled shrimp during frozen storage with temperature fluctuations,which provided a theoretical basis for the quality assurance of frozen shrimp.