Lab. Marketing and Technology of Aquatic Products and Foods, Dept. of Ichthyology and Aquatic Environment, School of Agricultural Sciences, University of Thessaly, Fitokou street, 38446, N. Ionia, Volos, Greece.
DISAFA, Microbiology and Food Technology Sector, University of Turin, Largo Paolo Braccini 2, 10095 Grugliasco, Italy.
Food Res Int. 2020 Jun;132:109057. doi: 10.1016/j.foodres.2020.109057. Epub 2020 Feb 1.
Bacterial communities and Volatile Organic Compounds (VOCs) profile of deepwater rose shrimp (Parapenaeus longirostris) stored at 0 °C (ice) and 4 °C were investigated using 16S amplicon based sequencing and Solid phase micro-extraction (SPME) - Gas chromatography/mass spectrometry (GC/MS), respectively. The shelf-life of shrimps determined by sensory assessment was 5 and 2 days at 0 °C and 4 °C, respectively. Based on 16S analysis (culture-independed), the initial microbiota of shrimps mainly consists of Photobacterium, Candidatus Hepatoplasma, Psychrobacter, Acinetobacter and Delftia. Psychrobacter and Carnobacterium dominated during storage at both temperatures. Psychrobacter was the most dominant taxon at the end of shelf-life of chill-stored shrimps. A minor microbial population composed by Brevundimonas, Stenotrophomonas, Staphylococcus, Legionella, Acinetobacter, Bacillus, Escherichia-Shigella, Enterococcus, Enterobacter, Klebsiella was also detected. Those taxa may be originated from the environment due to an inadequate hygienic practice during fishing, handling and icing. VOCs such as ethanol, 3-methyl-1-butanol, 2-ethyl-1-hexanol, 3-hydroxy-2-butanone, indole etc., were found to be associated with shrimps at 4 °C, while acetone and dimethyl sulfide with shrimps in ice. Some VOCs, from microbial or chemical origin, increased in shrimps either at 0 °C (i.e. 1-octen-3-ol, trans-2-octenal) or at 4 °C (i.e. 3-methyl-1-butanol, indole), while 2-methylbutanal and 3-methylbutanal increased in both temperatures. A positive correlation between Psychrobacter with 2-ethyl-1-hexanol and Carnobacterium with 3-methyl-1-butanol was also observed. Concluding, we suggest the reinforcement of Good Hygiene Practices on fishing boats during fishing/handling, the rapid onboard icing and keeping shrimps iced avoiding even small increase of storage temperature that affects quality parameters (e.g. microbial population level, synthesis of microbiota, VOCs profile) in order to provide a product of the highest quality and safety in the market.
采用 16S 扩增子测序和固相微萃取（SPME）-气相色谱/质谱联用（GC/MS）分别研究了在 0°C（冰）和 4°C 下储存的深水玫瑰虾（Parapenaeus longirostris）的细菌群落和挥发性有机化合物（VOCs）谱。通过感官评估确定的虾的货架期分别为 0°C 和 4°C 下的 5 天和 2 天。基于 16S 分析（不依赖培养），虾的初始微生物群主要由发光杆菌、Candidatus Hepatoplasma、Psychrobacter、不动杆菌和 Delftia 组成。在两种温度下，Psychrobacter 和 Carnobacterium 占主导地位。Psychrobacter 是冷藏虾货架期结束时最占优势的分类群。还检测到由 Brevundimonas、 Stenotrophomonas、金黄色葡萄球菌、军团菌、不动杆菌、芽孢杆菌、大肠杆菌-志贺氏菌、肠球菌、肠杆菌、克雷伯氏菌组成的少量微生物种群。由于在捕鱼、处理和制冰过程中卫生实践不足，这些类群可能来自环境。在 4°C 下，发现乙醇、3-甲基-1-丁醇、2-乙基-1-己醇、3-羟基-2-丁酮、吲哚等 VOCs 与虾有关，而在冰中，丙酮和二甲基硫与虾有关。一些来自微生物或化学源的 VOCs，无论是在 0°C（即 1-辛烯-3-醇、反-2-辛烯醛）还是在 4°C（即 3-甲基-1-丁醇、吲哚），都在虾中增加，而 2-甲基丁醛和 3-甲基丁醛在两种温度下都增加。还观察到 Psychrobacter 与 2-乙基-1-己醇和 Carnobacterium 与 3-甲基-1-丁醇之间存在正相关。综上所述，我们建议在捕鱼/处理过程中加强渔船上的良好卫生规范，快速在船上制冰，并保持虾的冷冻状态，避免储存温度的微小升高，这会影响质量参数（例如微生物种群水平、微生物群落的合成、VOCs 谱），以便在市场上提供最高质量和安全性的产品。
