Effects of active coatings based on soluble portion of zedo gum on physicochemical, microbial, and antioxidant enzymes characteristics of white shrimp

The focus of current study was on the effectiveness of active coatings based on water-soluble portion of zedo gum (WZG) enriched with different concentrations of essential oils, obtained from Shirazi thyme and cinnamon (SEO and CEO, respectively) and their mixture, on the shelf-life of trimmed white shrimp. The coated shrimps were compared with two sets of controls in terms of antioxidant enzymes activities, bacteriological quality, physicochemical characteristics, and sensory evaluation during cold storage (4 ± 1 °C) for 10 days. The decreasing trend in the antioxidant enzymes activities was significantly retarded in the presence of active coatings. After 10 days, the maximum enzymes activity was measured in the coated shrimps containing EOs in the following order: 1% CEO > 1% CEO/SEO > 1% SEO. WZG active solutions revealed positive influence on decreasing the bacterial count to around 2 log CFU/g. Adhesive coatings also reduced the chemical deterioration indices significantly ( P < 0.05 ). The sensory parameters and acceptability of shrimps were increased in the presence of EOs.