Shelf Life Of White Shrimp Research Articles

Quality and Shelf Life of White Shrimp (Litopenaeus vannamei) Processed with High-Pressure Carbon Dioxide (HPCD) at Subcritical and Supercritical States

Phase changes of carbon dioxide (supercritical or subcritical) depend on its proximity to a pressure of 7.35 MPa and temperature of 31.1°C. Carbon dioxide becomes supercritical and subcritical when it is above and slightly below its critical point, respectively. This study aims to determine the effect of high-pressure CO2 treatments at a pressure of 900 psi, 950 psi (subcritical), and 1100 psi (supercritical) and at holding times of 5, 10, and 15 min on the quality parameters of white shrimp (Litopenaeus vannamei) and to determine the shelf life of white shrimp processed with the best treatment. The results showed that the interaction between pressure and holding time had a significantp<0.05effect on cholesterol, protein, moisture content, andb∗value, but pressure had a significant effect on carotene content. The best treatment was a supercritical CO2 treatment at 1100 psi for 10 min, which was determined based on a significant reduction in the number of microorganisms and no significant changes in color, texture, and fat content were observed compared with control. The best treatment was applied to process shrimps, which were then stored at 4°C to evaluate the effectiveness of scCO2 treatment on the shelf life. No significant changes were found in PV and lipid in treated and scCO2-treated shrimps during storage, but the treatment significantly affected pH, TVBN, and microbial counts. Among the samples, there was no hedonic difference in all sensory attributes. Supercritical CO2 treatment at 1100 psi for 10 min can be an alternative method for preservation of shrimps.

The Effects of Cold Plasma Application on Quality and Chemical Spoilage of Pacific White Shrimp (Litopenaeus vannamei) during Refrigerated Storage

ABSTRACTPacific white shrimp (Litopenaeus vannamei) is an important species in aquaculture worldwide. Post-mortem changes during cold storage reduce the quality of shrimp and shorten its shelf life. Cold plasma (CP) was applied for 45, 90, and 150s as T1, T2, and T3, respectively, to fresh harvested shrimp. The biochemical parameters and melanosis were analyzed in comparison to metabisulphite treated (TM) and control during 12 days of refrigerated storage. The results highlighted lower rate of increase in pH, total volatile base nitrogen (TVB-N) content, thiobarbituric acid reactive substances (TBARS), free fatty acid (FFA), peroxide value (PV), and fluorescent compounds (FC) in shrimp exposed to CP and metabisulphite compared to control (P < 0.05). Although CP lowered biochemical changes in T1 and T3 shrimp, T2 was the most effective treatment in reducing undesirable changes and improving quality of shrimp. In all storage periods, melanosis was significantly lower in T2, T3, and TM samples. Results demonstrate that CP exposure effectively decreases relative activity of polyphenol oxidase (PPO) enzyme, and prolonging the exposure to CP for 150 s resulted in 50% reduction in enzyme activity. We conclude that application of CP for 90 s was the most efficient circumstance to extend shelf life of white shrimp during cold storage.

Effect of Delayed Icing on the Quality of White Shrimp (Litopenaeus vannamei) during Chilled Storage

The effect of delayed icing on the quality of Litopenaeus vannamei was assessed by chemical, microbiological and sensory evaluation. Shrimps were divided into three lots. One lot was immediately iced and the other two lots were subjected to delayed icing after keeping in ambient conditions (30 ± 2C) for 2 and 4 h, respectively. White shrimp had a moisture content of 77.21%, protein 18.80%, ash 1.47% and fat 1.30% on wet weight basis. Total volatile basic nitrogen, trimethylamine, thiobarbituric acid and K value showed increasing trend during chilled storage. It was observed that there is a significant (P < 0.05) decrease in the hardness of shrimp meat during storage. Sensory evaluation indicated that the shelf life of white shrimp iced immediately after catch and 2 h delayed iced was approximately 9 days, whereas 4 h delayed iced sample had shortened shelf life of 6 days. Practical Applications Shrimp is one of the most traded and consumed aquatic product worldwide. Shrimps are rich in protein, containing very little fat and have significant cholesterol content. Shrimp is more prone to deterioration because of its high content of free amino acids and other soluble nonprotein nitrogenous substances that can serve as easily digestible nutrients for microbial growth. Chilled or iced preservation helps in delaying or reducing the bacterial growth, preventing browning and prolonging the shelf life of shrimp. Delayed icing of the catch at the site results in downgrading of the shrimp. The present study provides information about a baseline investigation of the shelf life and quality of Pacific white shrimp due to delayed icing. It can be useful to quantify the quality and shelf life of fresh shrimp prior to the application of preservative treatments to extend the shelf life.