褐藻酸钠裂解物对冷冻南美白对虾品质的影响

以褐藻酸钠为原料,采用过氧化氢氧化法制备褐藻酸钠裂解物,分析了裂解物对南美白对虾Penaeus vannamei虾仁质量的效果,并研究了对虾仁冷冻后品质的影响.结果表明,褐藻酸钠裂解物中的分子量大于6 kDa的裂解物HDX-A能有效改善冷冻后水分流失,虾仁经1％的浸泡液处理1h后进行冻藏不同时间后再解冻,HDX-A能够有效地阻止水分流失,从而保持虾仁水分且随时间的延长其保持能力并不减弱,而且随浸泡溶液浓度的增加效果增强.HDX-A主要是通过增加自由水含量而避免了冷冻后虾仁水分和营养流失.HDX-A还可有效地降低冷冻虾仁的蒸煮损失,1.5％处理的样品蒸煮损失最低,整体上蒸煮损失低于20％,120d时仅为15.6％左右,显著低于对照(P＜0.05).HDX-A可通过降低冷冻虾仁水分流失改善了粘弹性和破断力等流变学特性,提高了产品品质,可作为无磷品质改良剂替代复合磷酸盐.

Effect of alginate pyrolysis product on the quality of frozen white leg shrimp Penaeus vannamei

The sodium alginate pyrolysis products were obtained through H2O2 oxidation. The effect of the main component (HDX-A, molecular weight over 6 kDa)on the quality of cryo-preserved peeled white leg shrimp Penaeus vannamei was studied. It was found that HDX-A effectively prevented water and nutrition losses of the frozen white leg shrimp after being marinated in 1% alginate pyrolysis solution. The effect improved with the increase of HDX-A concentration and the marinating time. The cooking loss of the frozen white leg shrimp could be obviously declined by lower than 20% by HDX-A. The cooking loss of the sample that marinated in the 1.5% HDX-A solution was about 15.6% after being frozen for 120 days, which was significantly less than the control (P<0.05). The rheological parameters such as break strength and viscoelasticity of the frozen white leg shrimp were improved by HDX-A through increasing the water holding capacity. HDX-A would be used as a replacement for phosphate compound in frozen white leg shrimp for improving quality.