To provide a highly safe tyrosinase activity inhibitor by a fish-derived component, a skin external preparation containing the inhibitor, a whitening cosmetic, and a food browning inhibitor.SOLUTION: The tyrosinase activity inhibitor comprising as an active ingredient a low molecular weight proteoglycan obtained by digesting salmon nasal cartilage proteoglycan with proteolytic enzyme Actinase E, a skin external preparation containing the inhibitor, whitening cosmetic, And food browning inhibitor. Preferably, the tyrosinase activity inhibitor contains 0.00033% by weight or more of low molecular weight proteoglycan.[Effect] As shown in FIG. 1, the tyrosinase activity inhibitor has a stronger tyrosinase activity inhibitory effect compared with kojic acid which has been conventionally known to have very potent inhibitory activity.BACKGROUND OF THE INVENTION【課題】魚類由来成分による安全性の高いチロシナーゼ活性阻害剤、該阻害剤を含有する皮膚外用剤、美白化粧料、並びに食品褐変防止剤の提供。【解決手段】サケ鼻軟骨プロテオグリカンを、タンパク質分解酵素アクチナーゼEで消化して得られる、低分子化プロテオグリカンを有効成分とするチロシナーゼ活性阻害剤、該阻害剤を含有する皮膚外用剤、美白化粧料、並びに食品褐変防止剤。好ましくは、低分子化プロテオグリカンを0.00033重量%以上含有するチロシナーゼ活性阻外剤。【効果】図1より、前記チロシナーゼ活性阻害剤は、従来から非常に強力な阻害活性を有することが知られているコウジ酸と比較しても、より強いチロシナーゼ活性阻害効果を有する。【選択図】図1
