Adding, as an active ingredient to a food or beverage product, the compound represented by formula (1), which is a 4-alkoxycinnamaldehyde derivative, imparts or enhances a desired fragrance, e.g. spicy, waxy, fatty, green, or metallic. Adding said compound as an active ingredient to a food or beverage product also has the effect of imparting or enhancing sweetness. In formula (1), R represents a hydrocarbon group comprising 2 to 4 carbon atoms.