Hide, bating industry

Chrome Tanning. The original chrome tanning was a two-bath process. The unhaired hides, delimed and bated, were treated with a solution of sodium bichromate [10588-01-9]. The amount of bichromate used was about 3—5% based on the weight of the hides. The bichromate was absorbed or adsorbed into the hide, the solution drained, and the hides refloated. Sodium bisulfite was added and two important reactions resulted in the formation of a basic chromium and coUoidal sulfur in the hide. This gave a chrome taimage and also helped to fiH the hide with the soHd sulfur. This cmde system, which continued in the industry in some types of leather for over 50 years, is obsolete. 

The use of enzymes for the manufacture of leather played a major role for the industrial scale production of enzymes. For the preparation of hides and skins for tanning, the early tanners kept the dehaired skins in a warm suspension of the dungs of dogs of birds. Wood was the first in 1898 to show that the bating action of the unpleasant dungs was caused by the enzymes (pepsin, trypsin, lipase) which they contained. In the context... 

Application of pancratic enzymes in the leather industry for the bating of hides. Rohm... 

Processes carried out at a pH of 7-9 represent the most efficient use of this type of enzyme. The first industrial process involving this type of protease was in the bating of hides to remove the debris from the skin after liming, and to impart softness and air exchange to the finished leather. Although pancreatic bates are still in general use proteases derived from Aspergillus flavus-oryzae and Bacillus subtilis now supple ment them. 

The earliest practical uses of papain were medicinal, e.g., in the treatment of dyspepsia and intestinal worms (86). Today most of the papain is consumed by various industries. Thus, it is used commercially for tenderizing meat, in the textile industry to prevent wool shrinkage, in the brewing industry to prevent oxidation and chill hazes in beer, in the tanning industry to bate skins and hides, and..in the manufacture of chewing gum. It is difficult to estimate the world consumption however, the United States alone imports about 500,000 pounds of crude papain annually (161). 

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