Freezing-thawing dehydration by centrifugation was applied for the reduction of food waste (kitchen refuse). Impedance analysis showed that plant cell membranes were severely disrupted by freezing-thawing so that plant tissue was easily dehydrated by this treatment. Freezing-thawing dehydration was also effective for gel materials, such as soyprotein curd, through freeze-denaturation but was not effective for animal tissue and cheese. The present method was applied to ten food materials to obtain about 50% reduction in weights suggesting its effectiveness for transportation, incineration, and composting of food waste.