缶詰内面の黒変に関する研究-I

Abstract

Iron-sulfide blackening of the headspace and liquid parts of tin cans was investi-gated. In the lid and bottom of the C-enameled can, a definite area of iron layer was exposed by scratching the enamel and the tin layers. These cans were filled to 2/3 volume with cysteine solution containing 0 to 4% NaCl at various pH values from 5 to 8. Other cans were 2/3 filled with an extractive of King crab meat containing the cysteine solution. The blackening of the iron surface was observed organoleptically and quantitatively for 6 months at 37°C. In the headspace, the blackening was accelerated by lower pH values and higher concentrations of NaCl. On the contrary, blackening of the liquid parts was remarka-ble at higher pH values and lower concentrations of NaCl. The existence of copper in the crab extractives accelerated the blackening. The acceleration was significant in the liquid part but not in the headspace.