An objective to be achieved by the present invention is to provide an ice-crystal growth inhibiting substance which has an excellent ice-crystal growth inhibiting activity suitable for practical use and which can be produced easily, efficiently and economically in safe steps usable in food production. Another objective of the present invention is to provide a method for producing the ice-crystal growth inhibiting substance, a polypeptide which is an active part of the ice-crystal growth inhibiting substance, as well as an ice-crystal growth inhibiting substance composition, a food, a biological sample protestant and a cosmetic each containing the ice-crystal growth inhibiting substance or the polypeptide. The ice-crystal growth inhibiting substance according to the present invention is characterized in that the ice-crystal growth inhibiting substance is derived from a plant, and has a molecular weight of 400 kDa or more as measured by gel filtration chromatography.본 발명은, 실용에 적합한 우수한 빙결정화 저해 활성을 갖고, 식품 제조에 이용할 수 있는 안전한 공정으로, 간단하고, 효율 좋고, 저렴하게 제조할 수 있는 빙결정화 저해 물질을 제공하는 것을 목적으로 한다. 또한, 본 발명은, 당해 빙결정화 저해 물질의 제조 방법, 당해 빙결정화 저해 물질의 활성 부분인 폴리펩티드, 및 당해 빙결정화 저해 물질 또는 폴리펩티드를 함유하는 빙결정화 저해 조성물, 식품, 생체 시료 보호제 및 화장품을 제공하는 것도 목적으로 한다. 본 발명에 관한 빙결정화 저해 물질은, 식물에 유래하고, 또한, 겔 여과 크로마토그래피에 의해 측정한 분자량이 400kDa 이상인 것을 특징으로 한다.
