Abstract
With increase in deep fat-frying dishes using a lot of cooking oil in households, the amount of waste oil for each person per year has reached to around 1100g. To conserve the limited fat resources and prevent environmental pollution, the frying conditions in 92 families were surveyed by the questionaire and the chemical and physical characterization of waste oils were examined. The acid value, peroxide value, TBA value, viscosity and color (L, a, b, chroma) of waste oils were found to be essentially similar to those of fresh oils. As frying oils are generally discarded after use for a short time, pouring of oil during cooking did not give any significant affects on the above parameters of frying oils. The major reasons for replacement of frying oil were color, concern for health and generation of greasy taste. The recycling of waste oil is carried out only to a limited extent. To promote the conservation of fat resources, frying oil is recommended to be used more often before replacement, because the most of waste oil from households were found to be hardly deteriorated.
