A chewing gum composition includes at least one biodegradable gum base polymer, at least one sweetener and at least one flavor, the composition having low tack effected by a plurality of side chains attached to the backbone of at least one gum base polymer. In particular, the present invention relates to a method of estimating a channel under a channel environment where interference between neighboring base stations exists in a mobile communication network using an orthogonal frequency division multiplexing method. The colors of the subject under observation lighting are calculated from observation-time lighting data.