成分

1. Origins, structure, and basic meaning

• Structure: 成分(せいぶん) is a noun for an ingredient or component making up food or another substance.
• Basic usage: Food ingredients appear in 食品の成分, while components contained in water appear in 水に含まれる成分.

2. Common pitfalls and similar expressions

• Food and substances
  • In food contexts it can mean ingredients or contents; in analysis it identifies components of a substance.
• Containment pattern
  • State what contains a component as in 水に含まれる成分, marking the containing substance with に.