Table 1 Effect of freezing, thawing methods on total color difference value (ΔE) in blanched sweet potato stems with air containing packaging

Freezing method	Thawing method	Color

		L^*	a^*	b^*	ΔE

Control		40.63±1.77^bc	-3.62±1.53^a	9.94±3.34^bc	-

Conventional freezing -20°C	Room temperature	41.15±1.79^bAx	-3.41±1.27^aABx	10.10±2.14^bcBx	2.77±1.31^c
	Running water	41.42±1.67^abAxy	-3.20±0.92^aAx	10.08±2.50^bcBy	2.92±1.33^c
	HF1)	40.99±2.75^bAx	-4.05±1.38^aBx	12.12±3.19^aAx	4.22±2.49^ab
	MW2)	40.71±2.18^bcAx	-3.93±1.05^aABx	11.28±2.13^abABx	3.17±1.35^c

Conventional freezing -40°C	Room temperature	40.79±1.42^bcBx	-3.52±0.88^aAx	10.26±2.00^bcBCx	2.21±1.33^c
	Running water	42.38±2.06^aAx	-4.03±1.30^aAy	12.25±3.02^aAx	4.31±2.11^a
	HF	39.64±1.95^cdBy	-3.47±1.20^aAx	9.52±2.36^bcCy	3.14±1.29^c
	MW	40.14±2.69^bcdBxy	-3.88±0.91^aAx	12.28±2.58^abABx	3.87±2.13^bc

Immersion freezing-40°C	Room temperature	40.40±1.37^bcdAx	-3.58±1.29^aAx	9.69±2.62^bcAx	2.79±1.52^c
	Running water	40.88±1.84^bcAy	-3.39±1.26^aAxy	9.38±2.32^cAy	2.96±1.27^c
	HF	39.34±1.28^dBy	-3.23±1.11^aAx	9.30±2.02^cAy	2.69±1.32^c
	MW	39.18±1.11^dBy	-3.75±1.16^aAx	10.35±2.31^bcAx	2.91±1.19^c

^a-dMeans with different superscripts within the whole column are significantly different (p<0.05).
^A-CMeans with different superscripts within the same freezing method are significantly different (p<0.05).
^x-yMeans with different superscripts within the same thawing method are significantly different (p<0.05).
¹⁾High frequency thawing.
²⁾Microwave thawing.