Shanghai Engineering Research Center of Aquatic Product Processing & Preservation College of Food Science & Technology, Shanghai Ocean Univ., Shanghai, 201306, P. R. China.
J Food Sci. 2013 Dec;78(12):M1878-84. doi: 10.1111/1750-3841.12305.
The importance of spoilage-related bacteria in fresh Pacific white shrimp (Litopenaeus vannamei) under different modified atmospheres (MAs) at 4 °C and the effect of O2 were demonstrated in the current study. The changes of bacterial communities in MA-packed shrimp during cold storage were studied by a combined method of plate counts with isolation and identification. Three gas mixtures were applied: 80% CO2 /5% O2 /15% N2, 80% CO2 /10% O2 /10% N2 and 80% CO2 /20% O2, and unsealed packages of shrimp were used as the control. In addition, the TVB-N, pH, whiteness index, and sensory scores were also determined to evaluate the quality changes of shrimp. MA packaging effectively inhibited the increase of total psychrotrophic bacteria counts and H2 S-producing bacteria counts by about 1.7 and 2.1 log cycles, respectively. The growth of Gram-negative spoilage bacteria in shrimp, including Shewanella spp., Aeromonas spp., and Pseudomonas spp., was inhibited by MA packaging, but the growth rate of Gram-positive bacteria such as lactic acid bacteria (LAB) and Brochothrix spp. were less affected by MA as effectively as Gram-negative bacteria. In comparison with the MA-packaged samples, the counts of H2 S producers in shrimp under a CO2 -enriched atmosphere with 20% O2 were slightly lower than the count in samples under an atmosphere with 5% O2 . However, MA with 20% O2 led to higher concentrations of TVB-N, and lower whiteness values and sensory scores. The shelf life of shrimp under 80% CO2 /10% O2 /10% N2 has been prolonged by > 6 d in comparison with the control according to the sensory scores.
本研究旨在探讨不同气体混合比例（80% CO2 /5% O2 /15% N2、80% CO2 /10% O2 /10% N2 和 80% CO2 /20% O2）对 4°C 下新鲜太平洋白虾（Litopenaeus vannamei）在不同改良气氛（MA）中腐败相关细菌的影响及其对 O2 的作用。通过平板计数和分离鉴定相结合的方法，研究了冷藏过程中 MA 包装虾中细菌群落的变化。此外，还测定了 TVB-N、pH 值、白度指数和感官评分，以评估虾的质量变化。MA 包装有效地抑制了总嗜冷菌和 H2 S 产生菌的增加，分别约为 1.7 和 2.1 个对数周期。MA 包装抑制了虾中革兰氏阴性腐败菌（如希瓦氏菌属、气单胞菌属和假单胞菌属）的生长，但革兰氏阳性菌（如乳酸菌和布鲁氏菌属）的生长速度受 MA 包装的影响不如革兰氏阴性菌那么有效。与 MA 包装样品相比，20% O2 富 CO2 气氛下虾中 H2 S 产生菌的数量略低于 5% O2 气氛下的数量。然而，MA 中 20% O2 导致 TVB-N 浓度较高，白度值和感官评分较低。根据感官评分，80% CO2 /10% O2 /10% N2 下虾的货架期比对照延长了>6d。
