| Nowadays, it is necessary to develop a non-thermal processing technology for ready-to-eat sea cucumber stored at room temperature, because dehydrated and frozen sea cucumber can not meet the growing requirement. Since sea cucumber can autolyze its nutrition after they are fished out of benthic areas, thus ready-to-eat sea cucumber industry are restricted. The aim of this work was to evaluate changes of the activities of auto-enzyme, edible quality, microstructure and storage quality of UHP treated sea cucumber. The main results were concluded as follows.(1)The effect of pressure, holding time and temperature on the edible quality(hardness, brittleness, springiness, cohesiveness and chewiness) and microstructure of sea cucumber were studied in this paper. According to the regression analysis, the impact of UHP on the water holding capacity of sea cucumber compliant with the opening down the quadratic equation. The increasing trend of L*and b*value and decreasing trend of a*value were observed after UHP processing. By scanning electron microscopy, it shown that muscle tissue of sea cucumber was porosity cube, which was depressed after UHP treatment. When pressure was400MPa, there was almost no pores on muscle tissue.(2)The effect of pressure, holding time and temperature on the changes of the main chemical composition and microorganism of sea cucumber were studied in this paper. It showed that under certain UHP conditions (pressure≥300MPa, holding time≥20min), protein and pH changed smoothly, the growth rate of AN, TMA and TCA soluble oligopeptide were reduced. There were no significant effects of temperature on each physico-chemical indicators. The results show promise as an alternative technology for extending the shelf life of sea cucumber. With increasing pressure and holding time, the residual microorganisms amount of soft canned sea cucumber was decreased, and be effectively controlled during the storage period. There is a synergistic relationship between the processing temperature and pressure, as the process increasing, the residual microorganisms amount of soft canned sea cucumber was decreased.(3)The effect of pressure, holding time and temperature on sea cucumber autolysis enzyme properties were studied in this paper. It showed that sea cucumber protease activity was decreased with increasing pressure and holding time. However, amylase activity was increased under low pressure(0-～100MPa) and short holding time(0～10min). By making use of Box-Behnken Test, the regression equation of the effects of UPH on the protease activity(Y1) and amylase activity(Y2) were shown below:Yi=11.39-0.49A-0.06B+0.08C+0.05AB-1.21AC+0.03BC-0.08A2-0.07B2-0.09C2Y2=21.72-0.78A-0.11B+0.16C+0.18AB+0.11AC+0.06BC-0.41A2-0.07B2-0.05C2It showed that when ultra-high pressure is600MPa, the holding time is30min, and temperatures reached15℃, the protease activity and diastasum activity of sea cucumber could reach the minimum value.(4)The change of protein content, pH, AN, TMA, TCA soluble oligopeptide, water holding capacity and microorganisms were studied to learn the effect of room-temperature storage and refrigerated storage on the storage quality of sea cucumber in this paper. It resulted that UHP-soft canned sea cucumber can be stored over two months(60days). The main physico-chemical indicators, water holding capacity and microorganism of refrigerated group were superior to room-temperature storage group. Thus, it was proved that UHP can be used to producting soft canned sea cucumber, which could be stored under room temperature. However, refrigerated storage can further control the product quality of soft canned sea cucumber. |
