Changes in the autolysis level, muscle stability and myofibrillar protein properties of Antarctic krill (Euphausia superba) during refrigerated storage

Abstract

The aim of the study was to investigate the autolysis phenomenon in Antarctic krill during the buffer storage under refrigeration (after harvesting and before processing), groups of whole krill (WK) and of tail (TL) were stored at 4 °C and evaluated at 0, 6, 24, 36 and 48 h. The changes observed in visual appearance, sensory evaluation and meat yield jointly proved that severe autolysis had occurred, and this was more pronounced in the WK group than in the TL group. Meanwhile, the hardness of WK and TL groups decreased by 51.2% and 23.3%, and the shear force also decreased significantly from 3.26 N to 1.77 N and 2.28 N, respectively. Combined with the disrupted muscle microstructure and the conversion of bound water to immobilised water, the muscle tissue was found to be less stable as affected by the autolysis. The properties and structure of myofibrillar protein were dramatically changed, as revealed by the increased myofibril fragmentation index, decreased sulfhydryl content, and fluorescence intensity. Therefore, Antarctic krill can be deemed susceptible to autolysis during the buffer storage, especially whole krill. The information gained in this study improves our understanding of the effect of autolysis on muscle stability and its protein basis in Antarctic krill.

Combining computer vision with the convolutional neural network to quantitatively analyse of the astaxanthin isomers in Antarctic krill meal

“…Owing to the high activity of their endogenous enzymes, Antarctic krill are susceptible to autolysis and dark discolouration, which rapidly deteriorates its freshness. Therefore, timely onboard processing is required after harvesting (Zheng, et al 2022). As a primary product obtained from onboard processing, krill meal is prepared through a series of processes including steaming, centrifugation, and drying.…”

Comparative metabolomics study on the quality of Antarctic krill (Euphausia superba) stored at different temperatures

“…The autolytic enzymes in Antarctic krill make it extremely autolytic, and it is generally frozen or dehulled to make Antarctic krill meat directly on board a ship within 3 h of harvesting, and then transported to land for secondary processing (Wu & Xie, 2010). Autolysis occurred rapidly in Antarctic krill within 48 h refrigerated storage，especially whole krill，and it will have an impact on the meat yield of Antarctic krill (Zheng et al ., 2022). The time and temperature of frozen Antarctic krill or Antarctic krill meat before processing can have a large impact on its quality, which is high in protein, prone to microbial growth and reproduction, and has problems with perishability and preservation (Sun et al ., 2022).…”