Heated scallop-shell powder slurry treatment of shredded cabbage.

The main component of scallop-shell powder is calcium carbonate (CaCO 3 ). Through heat treatment, CaCO 3 in the shell is converted to CaO, which exhibits antibacterial activity. The disinfecting effect of heated scallop-shell powder on shredded cabbage was investigated for various powder concentrations (0.1 to 1.0 g dm -3 ) and treatment temperatures (10 to 40°C). Scallop-shell powder treatment was found to reduce the aerobic bacteria count in cabbage, with increasing effectiveness at higher powder concentrations and treatment temperatures. Coliforms were completely eliminated within 5 min with as little as 0.1 g dm 3 powder treatment. During storage at 4°C, aerobic bacterial counts did not increase after powder treatment, whereas counts increased with water-washing or sodium hypochlorite treatment at 200 μg dm 3. The inactivation pattern of bacterial cells in shredded cabbage involved an accelerated decline followed by an extended tail at powder concentrations of 0.1 and 0.5 g dm 3. We postulate that a fraction of bacterial cells in the initial population becomes tolerant to the shell powder. A proposed model accurately predicts the reducing bacterial counts on shredded cabbage by scallop-shell powder treatment. The decrease in the L-ascorbic acid content of shredded cabbage was approximately 20 to 30% for scallop-shell powder treatment at 0.1 and 0.5 g dm 3 (20°C), which is almost identical to that by sodium hypochlorite treatment at 200 μg dm -3 . Le carbonate de calcium contenu dans la coquille Saint-Jacques chauffee se transforme en CaO, qui possede une activite antibacterienne. Cette activite est testee sur du chou rape. Ce traitement reduit les bacteries aerobies. La variation de la teneur en acide ascorbique est egalement observee. Le traitement a la poudre de coquille Saint-Jacques chauffee est donc une bonne alternative aux desinfectants classiques, n'a pas d'effets nefastes sur la valeur nutritive et permet en plus, la reutilisation des coquilles.