Cutting of Food Products by Ice-particles in a Water-jet

Of the costs in preparation of a finished food product, the most significant lies in its processing, packaging and distribution. Strict health and environmental standards form a major reason for these costs. Meat products in particular have the highest processing costs of all fresh food products. This procedure is highly labour intensive. It is undertaken by skilled operators, usually certified by standards agencies. Portioning and fat trimming are typical manual tasks. Within abattoirs, many primary cuts are performed by mechanical methods such as the band and circular saw. European and UK legislation requires that stainless steel blades are used in cutting in abattoirs. Although these are regularly steam sterilised, avoidance of possible cross-contamination of undesired bacteria from one carcass to another during cutting with the same blade cannot be completely guaranteed. Although the use of disposable knives and saws for cutting of individual carcasses could eliminate such concerns, these procedures are too costly and impractical for implementation. These difficulties could be overcome by unconventional methods whereby the instrument or ‘knife’ is a fine high pressure water-jet which itself is continually ‘refreshed’ during cutting. The effects of cutting with plain, filtered water-jets have already been utilised in the food processing industry: vegetables and soft meats are known to have been effectively prepared in this way. When the water-jet is insufficiently abrasive to cut harder parts of the meat, such as bone or larger cross-sections, abrasive water-jet cutting may be required. Typical hard abrasives such as garnet used in water-jet cutting are unacceptable for food processing. Alternative acceptable abrasives including salt, sugar and starch crystals have been found to be insufficiently effective. The present paper is concerned with an investigation into the use of frozen water in the form of suspended ice particles as an abrasive. Such a medium would simple melt if left behind in the meat. The size and shape of these ice particles will be discussed. Preliminary results will be presented. An early outcome is that the ice-jet would be initially limited to large scale commercial applications owing to the cost of water-jet equipment.