OHMIC THAWING OF SHRIMP: TECHNICAL FEASIBILITY AND ECONOMIC WORTH
Water availability and conservation has become one of the greatest concerns in both environmental and industrial circles. Shrimp processors in the Florida seafood industry are exploring ways to reduce, recycle, or reuse the processing water. Water used in the traditional water immersion thawing operation consumes almost half of the total plant's water use.
This project looks at the technology of ohmic heating to determine its technical and economic feasibility as an alternative to the current water immersion method of thawing. This method would reduce the cost of water used by the processing plant, and that of wastewater.
Consumer acceptance of ohmically thawed shrimp was analyzed through two taste panel studies to determine if a difference in sensory attributes between ohmic and water immersion thawed shrimp could be detected. In addition, the water content of shrimp thawed using both methods was determined and statistically compared for significant differences. Analysis confirms that there are no detectable differences in sensory perception between the two methods.
It was assumed that the volume of shrimp thawed by the ohmic heating system would be the same volume thawed by the current method. In order to economically compare the two systems, a scale-up of the experimental design was estimated in terms of electrical capacities and wastewater generated. Cost savings were estimated from the difference between the total annual operating cost of both thawing systems.
Using ohmic heating as an alternative to the water immersion thawing system currently being used by shrimp processors has the potential of reducing the amount of water used by the processors without altering the quality of the final product. The costs savings realized by a shrimp processor is $0.0139 per kilogram of shrimp. The cost savings of this process to a processing plant, producing 25,954.55 kg/day (57,200 lbs/day), is more than $95,000 per year. The economic worth, of using ohmic thawing to thaw frozen blocks of shrimp instead of water immersion thawing, using present worth calculation is estimated at more than two hundred thousand dollars ($200,000) at a twelve percent rate of return over three years. Using a ten percent budget of the present economic worth a research and development budget, for the processor above, can be estimated at approximately $20,337.