. 2017 Dec 12;27(2):333–342. doi: 10.1007/s10068-017-0281-1

Table 2.

The contents and true retention of vitamin C and vitamin K in fresh and cooked vegetables

Sample	Cooking treatment	Vitamin C		Vitamin K
Sample	Cooking treatment	CW^a (mg/kg)	TR^b (%)	CW^a (mg/kg)	TR^b (%)
Broccoli	Raw	668.04^c	100.00^b	1.54^a	100.00^a
	Boiled	370.04^d	52.85^d	1.59^a	98.89^a
	Blanched	615.42^c	88.86^c	1.69^a	108.81^a
	Steamed	761.48^b	111.21^a	1.90^a	123.08^a
	Microwaved	836.15^a	112.76^a	1.71^a	101.76^a
Chard	Raw	163.04^a	100.00^a	1.59^c	100.00^b
	Boiled	0.00^c	0.00^c	2.95^a	116.23^a
	Blanched	124.58^b	59.69^b	2.38^b	116.73^a
	Steamed	0.00^c	0.00^c	2.24^b	105.60^ab
	Microwaved	173.43^a	67.64^b	2.82^a	112.62^ab
Mallow	Raw	ND^c	ND	3.41^a	100.00^ab
	Boiled	ND	ND	3.00^a	81.75^b
	Blanched	ND	ND	2.17^b	56.71 ^cd
	Steamed	ND	ND	2.66^ab	69.33^bc
	Microwaved	ND	ND	2.03^b	44.28^d
Potato	Raw	58.30^a	100.00^a	0.02^b	100.00^b
	Boiled	30.57^c	49.79^c	0.03^a	141.16^a
	Blanched	44.73^b	73.20^b	0.02^b	94.71^b
	Steamed	51.08^b	83.65^b	0.03^a	75.98^c
	Microwaved	62.98^a	76.86^b	0.03^ab	95.32^b
Sweet potato	Raw	131.35^b	100.00^a	ND	ND
	Boiled	95.20^c	73.86^b	ND	ND
	Blanched	88.92^c	67.70^bc	ND	ND
	Steamed	81.32^c	59.44^c	ND	ND
	Microwaved	183.73^a	100.21^a	ND	ND
Carrot	Raw	39.92^b	100.00^a	0.04^b	100.00^a
	Boiled	56.62^d	55.33^c	0.04^b	85.02^ab
	Blanched	32.15 ^cd	72.71^b	0.03^b	71.86^b
	Steamed	33.49^bc	70.51^b	0.04^b	69.87^b
	Microwaved	63.00^a	92.02^a	0.06^a	85.35^ab
Crown daisy	Raw	ND	ND	1.19^c	100.00^a
	Boiled	ND	ND	1.70^a	100.11^a
	Blanched	ND	ND	1.31^bc	89.67^a
	Steamed	ND	ND	1.54^ab	89.42^a
	Microwaved	ND	ND	0.73^d	49.80^b
Perilla leaf	Raw	ND	ND	3.18^c	100.00^b
	Boiled	ND	ND	4.74^b	116.66^b
	Blanched	ND	ND	6.42^ab	171.67^a
	Steamed	ND	ND	7.80^a	215.65^a
	Microwaved	ND	ND	6.21^ab	169.88^a
Spinach	Raw	337.48^b	100.00^a	2.34^c	100.00^ab
	Boiled	220.14^d	40.12^c	3.69^ab	94.93^ab
	Blanched	283.96^c	57.85^b	3.35^bc	97.27^ab
	Steamed	262.78 ^cd	44.75^c	3.61^ab	87.70^b
	Microwaved	499.26^a	91.10^a	4.67^a	121.21^a
Zucchini	Raw	151.30^bc	100.00^a	0.19^c	100.00^a
	Boiled	131.82^c	63.71^b	0.23^b	87.09^b
	Blanched	163.86^b	87.01^a	0.23^b	93.78^ab
	Steamed	199.53^a	89.24^a	0.25^b	90.22^ab
	Microwaved	205.80^a	92.73^a	0.29^a	101.95^a

All values are means of duplicate cooking trial and duplicate analysis. Mean values in a row followed by different superscript letters are significantly (p < 0.05) different (Duncan’s multiple range test)

^a CW cooked weight

^bTR(%) = (Nc*Gc)/(Nr*Gr)*100, Nc = nutrient contents per gram of sample after cooking, Gc = gram of sample after cooking, Nr = nutrient content per gram of sample before cooking, Gr = gram of sample before cooking

^c ND not determined