Use of Ozone as A Disinfectant for Raw Animal Skins—Application as Short-Term Preservation in Leather Making

Abstract

Ozone is a strong oxidant and potent disinfecting agent. While the destruction of bacteria by ozone has been studied extensively on various food products, not much information is available on the effect of ozone on action with regard to preservation of raw skins/hides in leather making. Hence a detailed study has been undertaken in this aspect. Samples of fresh goatskins were treated with ozone for 0.5, 1, 1.5 and 2 hours and the microbial activity was monitored for a period of two weeks. Experimental skins were exposed to ozone gas at 2 g/h in a specially designed glass column reactor. A sample pair was exposed to ozone; while one sample was kept in open atmosphere in order to adopt conventional practices, the other was kept in a sealed bag at room temperature in order to eliminate the effects during post ozone treatment period. Conventional salting method was done separately as control for comparison with ozone treatment. Bacterial cell count was made from skin samples before and immediately after the ozone treatment as well as for control. Microbial growth in skin for different experiments was monitored by optical density measurement from the skin washings. These samples were also checked periodically for hair slip, quality and odor for different days. The results show that ozone could effectively eliminate the microorganisms present in the raw skin by ozone treatment for 30 min. It was also observed that the ozonized samples kept in the open environment were preserved while those kept in the sealed bag were putrefied in the period of 2 days. In addition, ozone-treated skins kept in the open environment were resistant to microbial action for periods more than two weeks. This opens up the possibility of applying ozone technology for short term preservation of skins and facilitates the elimination of common salt used for conventional preservation thereby reducing the pollution load.

Keywords:

• Ozone
• Anti-Microbial Action
• Preservation
• Raw Skin
• Leather Making
• Eco-friendly Method

ACKNOWLEDGMENTS

The authors thank Dr. A.B. Mandal, Director, CLRI and Dr. T. Ramasami, Secretary, DST, GOI for their encouragement. Dr. P.G. Rao, Director, NEIST, Jorhat, Assam for his valuable suggestions. We also thank Mr. P. Saravanan and Dr.(Ms). Gnanamani, Scientists CLRI, for their valuable help in the microbial assay.