Dried and powdered potato peel (7 g) were placed in a 100 mL
jacketed vessel through which water was circulated at 15 ± 0.5,
25 ± 0.5 and 35 ± 0.5 C with a flow rate of 0.5 L/min. Extraction
solvent (70 mL methanol) was added to the sample and the ultrasound
probe was submerged to a depth of 25 mm in the solvent