Effects of vacuum and modified atmosphere packaging (MAP) on microbial flora, pH, total volatile basic nitrogen (TVB-N), trimethylamine (TMA-N), the exudates and sensory attributes in Pacific white shrimp (
Litopenaeus vannamei) during controlled freezing-point storage at −0.8°C for a period of 14 days were investigated. The results indicated vacuum packaging (VP), 40%CO
2/30%O
2/30%N
2 (MAP1) and 75%CO
2/10%O
2/15%N
2 (MAP2) were more effective for inhibiting growth of
Aeromonas spp.,
Pseudomonas spp., H
2S-producing bacteria (including
Shewanella putrefaciens) and
Enterobacteriaceae and decreasing TVB-N and TMA-N contents as compared to air packaging (AP). pH values of VP and MAP2 samples were significantly (
P < 0.05) lower than those of AP. Formation of exudates under AP, VP, MAP1 and MAP2 increased during the storage and the value was higher with the increase of CO
2 levels. Sensory evaluation indicated that the shelf-life of fresh Pacific white shrimp got extended and reached 7 days under VP, 9 days under MAP1 and 11 – 12 days for the optimum MA-packaged under MAP2 as compared to 4 days' shelf-life under aerobic storage.
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