Avaliação físico-química e microbiológica do camarão cinza (Litopenaeus vannamei) submetido à defumação líquida em diferentes temperaturas e tempos de processamento

Abstract

The gray shrimp (Litopeaneus vannamei) is one of the most cultivated fish species in the world due to its good performance in captivity, great market acceptance and its meat rich in protein. However, it presents a reduced shelf life due to the high water activity and a pH close to neutrality. One way to preserve shrimp and increase its shelf life is the use of liquid smoking, which is cleaner and healthier than traditional smoking. The objective of the study was to evaluate physicochemical and microbiological aspects of shrimp subjected to the liquid smoking process by testing different times and temperature. Before smoking, liquid smoke (20% dilution) was sprayed on the cleaned and salted shrimp. The shrimp were smoked in an oven with the following treatments: A - 80°C/5h, B - 85°C/4h, C - 90°C/3h. Analyses of yield, shrinkage percentage, color, texture, water holding capacity (WCR), water activity, moisture percentage and microbiological analyses were performed. The liquid smoking of shrimp at 80°C for 5 hours (Treatment A) caused lower yield, higher percentage of shrinkage, higher water holding capacity, higher hardness and lower percentage of moisture and water activity. In the shrimp submitted to smoking at 90°C for 3 hours (Treatment C) there was a higher yield, lower percentage of shrinkage, lower water holding capacity, lower hardness and higher percentage of moisture and water activity. The color of the shrimp showed no difference (P<0.05) among the proposed treatments. In the microbiological analysis, the results were within the standard required by Brazilian legislation. This shows that the variation of two hours of smoking time (3 to 5 hours) causes more influence, except for color, on the physicochemical aspects than the variation of 10°C (80 to 90°C) in the temperature of the process. It is concluded that the liquid smoking of shrimp at a combination of 90°C for 3 hours is more suitable because it causes a higher yield, a lower percentage of shrinkage and a softer (lower hardness) and juicier product (higher percentage of moisture), having a great potential for production and commercialization.