Freezing-thawing Pretreatment for Dehydration of Food Waste

Abstract

Freezing-thawing dehydration, as a method with the less energy consumption for the reduction of food waste, was applied to about forty food-related samples chosen from vegetables and fruits, their waste, meat and fish, gel materials, and cooked food. Samples were frozen, thawed, and dehydrated either by centrifugation or compression. Freezing-thawing-dehydration treatment was very effective for vegetables and fruits, their waste, and gel materials to reduce their weight by 40 to 60% although it was not so effective for meat and fish. The average water content of samples decreased from 86. 0% to 76. 9% after the treatment. From these results and statistical data, 37% reduction in weight was expected for the total kitchen refuse. Freezing-thawing-dehydration is expected to be effective for transportation, incineration, and composting of food waste. © 2004, Japan Society for Food Engineering. All rights reserved.