Influence of trehalose and alginate oligosaccharides on ice crystal growth and recrystallization in whiteleg shrimp (Litopenaeus vannamei) during frozen storage with temperature fluctuations

The cryoprotective effects of trehalose and alginate oligosaccharides on peeled shrimp were investigated during frozen storage upon exposure to temperature fluctuations. The results indicated that significant improvements were found in thawing and cooking loss, myofibrillar protein content, Ca2+-ATPase activity, textural variables, and tissue microstructure in trehalose- and alginate oligosaccharide-treated shrimp as compared to those of water-treated samples. The overall cryoprotective effects were also better than that observed in Na4P2O7-treated samples. Inhibition of ice growth by trehalose and alginate oligosaccharides might play an important role in the cryoprotection of frozen shrimp subjected to temperature fluctuations. It was proposed that trehalose and alginate oligosaccharide molecules combine with ice crystals via the hydrogen bonds, hydrophobic, and/or electrostatic interactions, which suppressed the growth and recrystallization of ice crystals. Meanwhile, these incorporated saccharides affected the distribution and mobility of water molecules around muscle proteins, protecting them from mechanical damage caused by the large ice crystals.