Efeito da temperatura de armazenamento sobre a estabilidade do camarão cinza submetido à defumação líquida

Abstract

The Pacific white shrimp, Litopenaeus vannamei, is known as having high economic and nutritional value, but with rapid deterioration due to the presence of non-protein nitrogenous compounds and high-water activity. Thus, the use of technologies that increase the commercial shelf life of this product and add value such as, smoking, should be studied. The main form of smoking fish is the traditional hot. Nevertheless, liquid smoking has some advantages over traditional smoking, such as easy application, fast processing, low cost, and less deposition of smoke contaminants. However, for commercial use, knowledge of the shelf life of smoked shrimp with liquid smoke at different storage temperatures is necessary. Therefore, the study aimed to evaluate the effect of storage temperature (refrigeration at 4 ± 2 °C or freezing at -18 ± 2 °C) on the physicochemical and microbiological stability of the smoked Pacific white shrimp with liquid smoke for 60 days of storage. The physicochemical tests were monitored by: pH, water activity (aw), water holding capacity (WHC), moisture, lipid oxidation (TBARS), total volatile nitrogen bases (TVB-N), color CIE L* (luminosity), a* (red to green color intensity), b* (blue to yellow color intensity), hardness and cohesiveness. Microbiological stability was monitored by analyzing the total counts of psychrotrophic aerobics, molds and yeasts, Escherichia coli, Staphylococcus aureus, and Salmonella sp. The refrigerated shrimp showed a greater decrease in moisture (37 g/100 g) compared to the frozen (47 g/100 g); decrease in aw (0.93 - frozen and 0.90 - refrigerated) and color L* (45 - frozen and 37 - refrigerated), a* (13.5 - frozen and 10.3 - refrigerated) and b* (26, 4 - frozen and 20.3 - refrigerated); increase in CRA (94% - frozen and 97.45% - refrigerated), cohesiveness (0.21 - frozen and 0.31 - refrigerated), hardness (24N - frozen and 39.9N - refrigerated), TBARS (0.6 mg malonaldehyde/kg - frozen and 0.8 mg malonaldehyde/kg - refrigerated), TVB-N (13 mgN/100g - frozen and 28.12 mgN/100g - refrigerated) and pH (7.25 - frozen and 8.3 - refrigerated) reaching the maximum allowed by legislation on the 15th day of storage. The microbial quality of both was within the standards required by Brazilian legislation (Brasil, 2019 a, b, c). Thus, shrimp smoked with liquid smoke have good physicochemical and microbiological characteristics during 60 days of storage frozen (-18 °C) and 15 days refrigerated (-4 °C).