Functionality Analysis of Spent Coffee Ground Extracts Obtained by the Hydrothermal Method

Table 2

Total phenolic contents in SCG obtained using various methods.

Extraction conditions	Total phenolic content (mg GAE/g SCG)	References
Hydrothermal method (5 g SCG/35 mL, 150°C, 3 h)	9.44 ± 0.90	Present study
Hydrothermal method (1 g SCG/20 mL, 120°C, 20 min)	32.92	[19]
Hydrothermal method (6 g SCG/160 mL, 180∼240°C)	33.1∼51.2	[22]
Hydrothermal method (1 g SCG/15 mL, 200°C, 50 min)	40.36	[23]
60% methanol (1 g SCG/40 mL, 90 min)	16	[1]
Water (2 g SCG/100 mL, 60°C, 30 min)	6.33∼19.62	[20]
Water (24 g SCG/400 mL, 80°C, 10 min)	17.44	[24]
Pressurized liquid (70% ethanol, 195°C, 10 min)	19∼26	[25]
Ultrasound-assisted extraction (1 g SCG/17 mL ethanol, 40°C, 40 min)	33.84	[21]