Abstract: Shelled shrimps (Penaeus vannamei) vacuum-treated with sodium pyrophosphate, sodium tripolyphosphate, trehalose, alginate oligosaccharide or carrageenan oligosaccharide solutions were stored at −18 ℃ and evaluated for thawing loss, thermodynamic properties, myofibril protein content, Ca2+-ATPase activity, and surface hydrophobicity of myofibril proteins after 0, 30, 60 and 90 days and molecular mass distribution of proteins after 90 days. Our aim was to investigate the effect of different additives combined with vacuum permeation treatment on the stability of myofibrillar proteins from peeled shrimps. The results showed that compared with distilled water, vacuum treatment with each of the five additives effectively reduced the thawing loss of frozen shrimp muscle, improved the low-temperature stability of myofibrillar proteins, and inhibited their freeze denaturation. Among these additive, trehalose, alginate oligosaccharide and carrageenan oligosaccharide had more significant cryoprotective effects. This study can provide a basis for the research and utilization of natural antifreeze agents, and also provide a scientific basis for the processing of new shrimp products.

Key words: Litopenaeus vannamei; vacuum infiltration; saccharide; protein stability