Bulletin of the National Research Centre

Table 1 Taste components concentration in leaves of Welsh onion and fresh onion

From: Taste characteristics, volatile components, sensory properties, and antioxidant activity of fresh onion (Allium cepa L.) leaves

	Welsh onion leaves	Fresh onion leaves
Brix (%)	7.51 ± 0.31	5.87 ± 0.18^*
Sugars (g/100 g)
d-glucose	0.91 ± 0.04	0.91 ± 0.08
Fructose	1.11 ± 0.07	0.97 ± 0.06^*
Sucrose	0.36 ± 0.09	0.23 ± 0.07^*
Total	2.38 ± 0.07	2.12 ± 0.15^*
Degree of sweetness	2.34 ± 0.07	2.04 ± 0.14^*
Organic acids (mg/100 g)
L-tartaric acid	31.53 ± 0.75	12.96 ± 0.30^*
Formic acid	13.89 ± 0.26	13.67 ± 0.44
L-malic acid	738.11 ± 27.22	612.07 ± 14.13^*
Lactic acid	15.13 ± 1.79	14.95 ± 1.54
Acetic acid	26.07 ± 5.56	31.39 ± 1.68
Citric acid	45.02 ± 1.49	35.23 ± 1.23^*
Succinic acid	7.01 ± 0.16	3.05 ± 0.25^*
Fumaric acid	30.47 ± 3.44	6.71 ± 0.30^*
Total	907.23 ± 20.79	730.02 ± 17.43^*
Free amino acids (mg/100 g)
L-aspartate	10.10 ± 0.94	5.33 ± 0.72^*
L-glutamate	6.12 ± 0.72	7.40 ± 0.89^*
L-serine	50.31 ± 2.93	35.15 ± 2.01^*
Glycine	0.77 ± 0.04	0.31 ± 0.02^*
L-histidine	1.26 ± 0.09	0.93 ± 0.09^*
L-arginine	2.44 ± 0.09	0.97 ± 0.08^*
L-threonine	4.45 ± 1.13	3.72 ± 0.36
L-alanine	9.21 ± 1.31	4.64 ± 0.75^*
L-proline	4.32 ± 0.37	2.53 ± 0.25^*
L-tyrosine	2.09 ± 0.36	0.81 ± 0.19^*
L-valine	4.92 ± 0.97	2.35 ± 0.38^*
L-methionine	5.21 ± 0.28	4.23 ± 0.30^*
L-cystine	0.95 ± 0.09	0.80 ± 0.07^*
L-isoleucine	11.11 ± 0.66	9.21 ± 0.44^*
L-leucine	5.52 ± 0.99	3.38 ± 0.67^*
L-phenylalanine	9.19 ± 0.45	8.77 ± 0.42
L-lysine	3.36 ± 0.64	3.20 ± 0.33
Total	131.34 ± 10.22	93.72 ± 7.17^*
5′-Guanylate (mg/100 g)	0.35 ± 0.05	0.57 ± 0.05^*

Values are the mean ± SD (n = 5) ^* p < 0.05 (Welch's t test), compared between Welsh onion leaves and flesh onion leaves in each value

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