Chemical preservation of whole broiler carcasses utilizing alkaline hydroxides

Abstract

The chemical preservation of whole broiler carcasses utilizing aqueous alkaline hydroxide solutions was examined as an alternative method of mortality management. Conversion of the preserved carcasses and solutions into an acceptable poultry by-product meal was examined. This research identified the basic parameters for effective preservative solutions that simultaneously hydrolyzed feathers and preserved the carcass. Euthanized, fully feathered, mature broilers were placed in potassium hydroxide (0.5 to 2.0 M) and sodium hydroxide (0.12 to 2.0 M) solutions for 5 and 10 d. Effectiveness was evaluated by visible feather degradation and carcass solubilization, odor production, inhibition of microbial growth, and solids content of the alkaline solutions. Sodium hydroxide at 1.9 and 2.0 M diffused throughout the carcass and produced adequate preservation without apparent putrefaction through 10 d. Aerobic bacteria were not recovered from sodium hydroxide solutions, carcass skin, or intestine samples at the 1.9 M concentration. Treatments of 2.0 M potassium hydroxide and a mixture of 1.5 M potassium hydroxide with 0.5 M sodium hydroxide produced the highest degree of carcass liquification at 10 d without visible putrefaction. Sodium hydroxide solution (2.0 M):carcass weight ratios ranging from 1:1 through 4:1 (wt:wt) were effective in preserving individual carcasses for more than 60 d without putrefaction.