2. Materials and Methods2.1. SCG Extraction by Hydrothermal Method. Samples of SCG were collected from Arabica coffee beans in 85°C Bakery Cafe, Taiwan. Five grams of SCG and 35 mL of ´ deionized water (DI water) were first added to a Teflon beaker; the beaker was then sealed in a stainless steel sample chamber, placed in an autoclave, and heated at 5°C/min from room temperature to 150°C. At 150°C, the temperature was kept constant for 3 hours, and then the sample was cooled naturally to room temperature over 12 hours. Subsequently, the sample was extracted and filtered to obtain the extract solution of SCG. .e extract solution was then freeze-dried to obtain SCG extracts.