Effects of glazing and Arthrospira platensis on physical and chemical characterization of Litopenaeus vannamei fillets during frozen storage

In the current study, glazing with water and Arthrospira (Spirulina) platensis extract (SPE) were used to keep the quality characteristics of Litopenaeus vannamei intact during frozen storage. For this purpose, fresh shrimps were dipped into water diluted with 0.3, 1.0, and 1.3% of SPE solutions before freezing, then glazed and stored at -18°C for 150 days. Quality loss of shrimp was measured by pH, peroxide value (PV), total volatile basic nitrogen (TVB-N), thiobarbituric acid (TBA), textural properties, (hardness and cohesiveness) and sensory characteristics. The variation range of pH, PV, TVB-N, and TBA after 150 days increased to 7.67–7.82 , 2.69–2.75 meq per kg O2 lipid, 28.04–29.92 mg/100g, 2.48–2.81 mg per kg MDA, respectively. The values of cohesiveness, hardness and sensory of all groups decreased after 150 days. Results showed that compared to the unglazed control samples, glazing treatment reduced the quality loss of shrimp during the 150 days of frozen storage. Results also illustrated that Spirulina glazed shrimp samples had lower TVB-N, PV, TBA, and higher textural and sensory properties compared to the other treatments.