Leavener

膨張剤（ぼうちょうざい）（= leavening agent (such as sourdough, yeast, baking powder)）

Leaveners produce tiny air bubbles (mainly carbon dioxide) which help foods that are baked or cooked to rise.

膨張剤は小さな気泡（主に二酸化炭素）を生成し、焼いたり調理したりした食品が盛り上がるのを助けます。