Application of the leaves of Phellodendron amurense on new type of foods (novel food)

Abstract

Amur cork tree (Phellodendron amurense Rupr., “Kihada” in Japanese) has been one of the most important medicinal raw materials in Japan since ancient times, used in various mixed oriental herbal medicines (mainly gastrointestinal), e.g. “Sankogan”. We researched the leaves of Phellodendron amurense as a material for a new type of food (health-promoting food), in terms of ingredients and its property, suitability for food processing and acceptability for consumers. After cutting off, the leaves were so quickly steamed (for enzyme inactivation), freeze-dried, and turned to powder (up to 0.1 mm in diameter). Finally, they were packed and stored in the refrigerator. An analysis revealed that there is no caffeine in the leaves, and they are safer than coffee, black tea, green tea, and chocolate. However, they contain a high content of calcium, folic acid, dietary fi ber, polyphenols, ß-carotene, and lutein. Also, we found that a 50% ethanol extract of the leaves had an antibacterial effect against Streptococcus mutans (a cariogenic bacterium), comparable to that of green tea. We have been trying to develop food products using the leaves, such as cakes, cookies, and teas. The leaves did not change their original green color even after baking. Any problem couldn’t be observed before or after mixing, dissolving, baking, etc., necessary for manufacturing sweets. Preliminary sensory test revealed that tested sweets were all well accepted, and there was no complaint above the color, taste and flavor. We are going to develop also other foods and drinks for pregnant women, children, and elderly people.