Influence of Mulberry Leaf Powder Additive on Chemical and Physical Characteristics of Wheat and Rice Flour Butter Cookies

People of all age groups consume cookies every day. Consumers’ preferences for cookies supplemented with functional plant raw materials have recently increased. Therefore, this research aimed to investigate the influence of a mulberry leaf additive on the proximate and mineral compositions, total phenolic and total chlorophyll content, antioxidant activity, and the hardness and color properties of butter cookies. Wheat and rice flour butter cookies were prepared by replacing the flour with mulberry leaf powder at 0, 4, 8, and 12% (w/w). The results revealed that the investigated chemical and physical characteristics of butter cookies depend on the flour used (rice or wheat) and the addition of mulberry leaf powder. Wheat and rice flour cookies with 12% mulberry leaf powder had the significantly highest contents of fiber (20.34 and 20.23%, respectively), ash (1.73 and 1.75%, respectively), K (170.22 and 160.22 mg 100 g⁻¹, respectively), and Ca (170.45 and 160.68 mg 100 g⁻¹, respectively). The rice flour cookies enriched with 12% leaf powder had the greatest amounts of total phenolics (1.48 mg 100 g⁻¹), Zn (12.25 mg kg⁻¹), Mn (6.28 mg kg⁻¹), Cu (1.95 mg kg⁻¹), and antioxidant activity (67.98%). However, the wheat cookies without mulberry leaf powder contained the most B (9.12 mg kg⁻¹), while the no-added rice cookies contained the most Fe (14.30 mg kg⁻¹). Replacing flour with leaf powder increased the cookies’ hardness and decreased their lightness. In conclusion, enriching butter cookies with freeze-dried mulberry leaves can improve their nutritional value and antioxidant activity.