Table 2. Water content, pH, shear force and functional bitter compounds of two leafy vegetables according to cultivation type

			Batavia
			Hydroponically grown		Soil-grown
			BAH1	BAH2	BAH3	BAN
			Mean SD	Mean SD	Mean SD	Mean SD
Water content		(%)	96.77^a±0.02	96.15^b±0.07	95.32^d±0.05	95.56^c±0.08
pH			6.08^b±0.01	6.00^c±0.02	5.03^d±0.03	6.13^a±0.01
Shear force	Top	(N)	15.28^c±4.00	27.35^b±4.68	39.62^a±3.77	43.45^a±6.08
	Mid	(N)	15.69^c±2.45	27.34^b±4.16	43.15^a±4.88	42.69^a±8.11
	Low	(N)	9.53^c±2.09	15.84^b±3.60	21.00^b±3.46	38.40^a±10.89
Functional	Lactucin	(mg/kg)	0.99^a±0.20	0.27^c±0.05	0.18^c±0.07	0.55^b±0.06
Bitter compounds	Lactucopicrin	(mg/kg)	80.49^a±15.27	17.88^c±0.91	31.70^bc±2.91	35.98^b±2.92
Bitter compounds	Total content	(mg/kg)	81.48	18.15	31.88	36.53

			Butterhead
			Hydroponically grown		Soil-grown
			BUH1	BUH2	BUH3	BUN
			Mean SD	Mean SD	Mean SD	Mean SD
Water content		(%)	96.91^a±0.04	96.45^b±0.02	94.66^d±0.08	95.61^c±0.05
pH			6.05^a±0.02	5.89^b±0.02	5.23^c±0.00	5.83^b±0.06
Shear force	Top	(N)	18.96^c±6.48	15.09^c±3.33	23.65^b±2.36	35.89^a±5.89
	Mid	(N)	20.68^c±5.79	23.21^c±3.18	33.47^b±2.69	44.30^a±5.46
	Low	(N)	15.02^c±2.57	22.52^b±2.08	21.85^b±1.29	31.40^a±6.09
Functional	Lactucin	(mg/kg)	2.30^b±0.07	2.10^b±0.83	2.80^b±0.16	4.79^a±0.44
Bitter compounds	Lactucopicrin	(mg/kg)	75.88^a±1.81	38.62^c±6.22	49.82^b±1.87	80.78^a±2.80
Bitter compounds	Total content	(mg/kg)	78.18	40.72	52.62	85.57

Average of measurements (n=3)±standard deviation
Mean values with the same letter in a row are not significantly different at p<0.05.
Hydroponically grown batavia: BAH1 (farm A), BAH2 (farm B), BAH3 (farm C); butterhead: BUH1 (farm A), BUH2 (farm B), BUH3 (farm C)
Soil-grown batavia: BAN (farm D); butterhead: BUN (farm D).