Even when a raw material containing soy protein is used as an alternative raw material for eggs in a sponge-like food, an alternative raw material for eggs that does not adversely affect the quality of the food, such as when a cake is rolled and deformed to produce a cake Providing an alternative egg material that is less prone to sponge cracking. A spongy food egg substitute characterized by containing a hydrolyzate of soybean material that satisfies all of the following requirements (A) to (C). (A) The soybean material contains a soybean whey component, and the protein content is 30% by weight or more and less than 70% by weight in the solid content, and (B) the degree of hydrolysis is 10 to 20 as 0.22M TCA solubility. The breaking force measured using a heated gel card meter of a solution having a solid content of 22% by weight (C) is 5 g or more and less than 100 g using a pressure sensitive shaft with a diameter of 8 mm and a load of 100 g. There is.卵の代替原料として大豆蛋白質を含む原料をスポンジ状食品に使用した場合でも該食品の品質に悪影響を及ぼしにくい卵の代替原料、例えばスポンジケーキをロールし変形させてケーキを製造するような場合でも、スポンジの割れが発生しにくい卵の代替原料を提供する。 下記要件（Ａ）～（Ｃ）を全て満たす大豆素材の加水分解物を含有することを特徴とする、スポンジ状食品用卵代替物。（Ａ）大豆素材は大豆ホエー成分を含有し、かつ蛋白質含量が固形分中３０重量％以上７０重量％未満であること、（Ｂ）加水分解度が０．２２Ｍ ＴＣＡ可溶率として１０～２０％であること、（Ｃ）固形分２２重量％溶液の加熱ゲルのカードメーターを用いて測定した破断力が、直径８ｍｍの感圧軸を用い、荷重を１００ｇとした場合、５ｇ以上１００ｇ未満であること。
