Quality Characteristics and Functionality of Coffee fortified with Hot-Water Extracts from Parts of Sweet Sapphire Grape

This study was conducted to develop a functional beverage utilizing Sweet Sapphire grapes, a fruit known for its unique flavor and abundance of bioactive and nutritional components. Analysis results showed that trigonelline content was the highest in coffee fortified with peel extract (1,364.65) and lowest in coffee with pulp extract (1,277.17). Chlorogenic acid was also highest in the peel extract coffee (1,202.90) and lowest in the pulp extract coffee (1,101.90). Caffeine content was highest in the peel extract coffee (4,875.10) and lowest in the whole-fruit extract coffee (4,478.16). The total polyphenol content was highest in the control group (8380.65), whereas among the extract-added samples, the whole-fruit extract coffee showed the highest value (7,300.90), followed by peel extract (6,098.77) as the lowest. DPPH radical scavenging activity was the highest in the whole-fruit extract coffee (78.16), lowest in the peel extract coffee (73.31), and 59.93 in the control. These results suggest that the whole Sweet Sapphire grape extract is the most suitable ingredient for developing functional beverages, as it provides lower caffeine content, higher total polyphenol levels, and stronger free radical scavenging activity. Moreover, using the whole grape rather than separating the peel and pulp may enhance antioxidant capacity and functional properties, supporting its potential as a novel ingredient for health-promoting coffee beverages. Further studies are recommended to optimize hot-water extraction conditions for Sweet Sapphire and other fruits rich in bioactive compounds to improve extraction efficiency and functionality.