Table 6.
The effect on hardness of butterbur stems by freezing and thawing methods

Treatment	Freezing treatment	Thawing treatment	Hardness (kg)
Raw	−	−	3.74±0.79
Blanched	−	−	3.87±0.33
Blanched	-20°C	4°C	0.33±0.17
		25°C	0.58±0.43
		Running water	0.48±1.52
		Microwave	0.61±0.23
	-40°C	4°C	0.41±0.22
		25°C	0.52±0.18
		Running water	0.79±0.26
		Microwave	0.52±0.17
	Immersion (-50°C)	4°C	2.14±0.46
		25°C	2.33±0.42
		Running water	2.84±0.84
		Microwave	2.51±0.96