EFFECT OF SODIUM METABISULFITE AND CITRIC ACID ON THE QUALITY OF CRAYFISH (ASTACUS LEPTODACTYLUS)

ABSTRACT

The aim of this study was the determination of the effect of sodium metabisulfite and citric acid on the quality of crayfish. The first group of crayfish (control) was boiled, chilled and packaged. The second group was treated with chemicals (100 g live crayfish for 1 L water, 0.1 g sodium metabisulfite and 0.5 g citric acid), then boiled, chilled and packaged. The last group was boiled with the same chemicals, chilled and packaged. Samples were stored at +4C. Treated samples were acceptable until the eighth day. However, the control samples spoiled according to the sensory analysis on the sixth day, and their pH, mesophilic and psychrophilic aerobic bacteria counts were (P < 0.05) higher than treated ones on that day. Using citric acid and sodium metabisulfite lower than the limits (50 mg/kg for cooked crustaceans according to Turkish and European Union legislations) improve the sensory quality and generally decrease the pH, mesophilic and psychrophilic aerobic bacteria counts of crayfish.

PRACTICAL APPLICATIONS

The results obtained from this study demonstrated that sodium metabisulfite and citric acid, used in limits determined by law, especially improve the sensory quality of crayfish. To maintain more remarkable results, using other chemicals with or without sodium metabisulfite and citric acid according to the legislations may be studied. These findings can be well utilized by researchers as well as manufacturers in their studies on improving the shelf life of crayfish. Based on our results, suitable methods of processing can be developed for improving the shelf life of crayfish.