Cryoprotective effects of xylooligosaccharides and carrageenan oligosaccharides on cooked Litopenaeus vannamei during frozen storage

The aim of this work was to evaluate the cryoprotective and water-holding capacity of xylooligosaccharides and carrageenan oligosaccharides on cooked Litopenaeus vannamei during frozen storage.The results indicated that the thawing loss and cooking loss were significantly ( p < 0.05) decreased by xylooligosaccharides and carrageenan oligosaccharides treatment after.The cooking loss rate of the carrageenan oligosaccharide treatment group was 15.7%, and there was no significant difference with the sodium pyrophosphate treatment group ( p > 0.05) .The thawing loss rate of xylo-oligosaccharide was 7.10%, which was significantly lower than that of sodium pyrophosphate ( p < 0.05) .The a*value of xylooligosaccharides and carrageenan oligosaccharides treated shrimp was 8.7 and 11.29, which was significantly higher than that of sodium pyrophosphate 6.12 ( p < 0.05) .In addition, the moisture content, water activity and texture property were decreased in all treatments, while the samples treated with the oligosaccharides were better than other groups, and significantly higher than distilled water and sodium pyrophosphate treatment ( p < 0.05) . The microstructure study revealed that shrimp treated by the oligosaccharides, the muscle tissue structure was compact, and had no distortion, meanwhile there was no large holes in transaction, which indicated that the oligosaccharides restrained ice crystal grew bigger and kept the muscular tissue structure complete.The study can lay the foundation for developing a kind of safe, natural and harmless non-phosphate additive which is suitable for the frozen cooked Lvannamei.