The purpose of an emulsifier in margarine is to:

The primary purpose of an emulsifier in margarine is to keep water and fat from separating. Emulsifiers are compounds that help stabilize mixtures of two immiscible substances, such as oil and water, by reducing surface tension. In margarine, emulsifiers ensure that the fat and water components blend together smoothly and uniformly, providing a consistent texture and preventing separation over time. This stability is crucial for maintaining the product's quality, texture, and shelf life. Without emulsifiers, margarine could experience a breakdown, leading to a layer of oil on the surface, which would negatively affect the appearance and usability of the product.