Variables optimized in the extraction of tea saponins.

Method	Variable	Method	Variable
Common extraction	Particle size	Microwave-assisted extraction	Microwave power
	Liquid–solid ratio		Microwave treatment time
	Extraction time	Ultrasound-assisted extraction	Ultrasonic power
	Extraction temperature		Ultrasonic frequency
	Number of extractions		Ultrasonic treatment time
Alcohol extraction	Alcohol type	Light-wave-assisted extraction	Light-wave treatment time
	Alcohol volume fraction	Supercritical fluid CO2 extraction	Pressure
Aqueous enzymatic extraction	Fungus type		Medium
	Fungus concentration		CO2 flow rate