Lighting food photography is challenging. If you are using natural light, the subject should be backlit with bounce cards . Place a black flag (card) above the lens to cut possible lens flare. Also use a lens shade.

If you are using artificial light use of a soft box or diffused light is preferable.
Unless you are going for a specific effect the light should not be too harsh. I prefer to use 1 light whenever possible. A trick we do is to use mirrors to reflect light highlights into key areas.