Prepn. of shell-fish preservative

摘要

The additive is made by (1) preparing in a stirrer autoclave an aq. soln. of 55-75% water, 8-15% sodium hydroxide and 0.2-2% benzoic acid; (2) injecting into the autoclave 10-15% sulphur dioxide; and (3) subjecting the autoclave to pressure while stirring the aq. soln. - It prevents blackening by oxidn. of the enzyme tyrosine in the chitinous tissue of the shellfish.