南美白对虾即食虾仁常温贮藏品质变化与货架期研究

为确定南美白对虾即食虾仁常温贮藏货架期及残留菌种类,采用感官、理化、微生物和电子鼻等分析其品质变化及货架期,并使用16SrRNA测序法鉴定残留菌。结果表明,初始感官品质良好,物理和化学指标均符合标准;常温贮藏中水分含量、水分活度、pH、盐分和色泽(红度和黄度)前4个月无显著性差异,之后水分含量和水分活度降低,盐分和pH升高,红度和黄度存在波动;咀嚼性、硬度和弹性前3个月无显著差异,之后先升后降,而贮藏期间内聚性有波动性。常温贮藏9个月内TVBN和TBA均符合限量要求,菌落总数低于103 CFU/g,个别胀袋虾中残留菌为地衣芽孢杆菌与枯草芽孢杆菌。综合感官、化学和微生物等评定指标,结合电子鼻对即食南美白对虾虾仁品质进行区分,确定其货架期为9个月。

Quality changes and shelf life of ready-to-eat Penaeus vannamei stored in ambient temperature

The shelf life and survival bacterial species of ready-to-eat Penaeus vannamei during ambient temperature storage were studied. The quality changes and shelf life were observed by the sensory, physico-chemical, microbiological evaluation and electronic nose analysis, the bacteria species were identified by 16S rRNA sequencing. The results showed that initial sensory quality, physical and chemical indicators was pretty good. In the first 4 months, the water content, water activity, pH, sanility and color (red degree and yellow degree) had no significant differences, and then, the water content and Aw decreased, but pH and sanility increased, while the red degree and yellow degree fluctuated; The chewiness, hardness and elasticity had no siginficant differece in the first 3 months, and then increased firstly and decreased secondly, which kept fluctuating in cohesive force in the storage. TVBN and TBA did not exceed the limited value during the 9 months ambient temperature storage, with the total colony lower than 1 000 CFU/g; Bacillus licheniformis and Bacillus subtilis were found to be residue in individual expansion bags. In conclusion, through previous criteria of sensory, physicochemical and microbiological evaluation, the shelf life of Penaeus vannamei was 9 months.