熟制对虾虾仁超高压杀菌主要参数探讨

Sterilization of pre-cooked peeled shrimp using high pressure

实验通过不同的压力和保压时间处理虾仁,以此考察超高压的杀菌效果以及对产品品质的影响。结果表明,压力是影响杀菌效果的主要因素,当压力为600MPa,保压时间为20min时,虾仁中接种的大肠杆菌、金黄色葡萄球菌、沙门氏菌和枯草芽孢杆菌总数分别下降7.1、7.0、7.2和4.3个log。枯草芽孢杆菌对高压最不敏感。超高压处理对产品的理化性质有一定影响,随着压力增大,水分含量有所减小,但幅度不大,色泽L值减小,红度a值无显著影响,硬度、弹性和咀嚼度都增大。在4℃低温保藏过程中,虾仁硬度有所增大,弹性无明显变化,而色泽红度呈现先缓慢增大后下降的趋势。感官评定结果表明,经600MPa保压15min的样品在4℃保藏60d后最被喜爱,120d后仍可被接受。

The influences of high pressure （HP） on the texture, color, moisture content and microbiological activity of pre-cooked peeled products were evaluated. The results of sterilization and the impact on quality of product by HP were evaluated through varied pressure levels and holding pressure time. The results show that reduction of E. coli, Staphylococcus aureus, salmonella and Bacillus subtilis inoculated in shrimps was achieved about 7.1, 7.0, 7.2 and 4.3 logs, respectively at 600 MPa for 20 min. The color of shrimp products is one of the most important sensorial characteristics for its acceptance by consumers. High pressure has effect on the physical and chemical properties of pre-cooked peeled products. As the applied pressure increased, the moisture content and the color L values decreased, and the a value did not change a lot, while the hardness, springiness and chewiness increased significantly. During storage at 4 ℃, the hardness of HP-treated sample inceased somewhat and springiness almost remained unchanged, while the a value increased slowly and then decreasedsignificantly . Sensory tests were practiced after the pre-cooked peeled products with the treatment at 600 MPa for 15 min stored at 4 ℃ for 120 days, the result showed that the samples stored for 60 days were most favorable,and those stored for 120 days were still acceptable .