Table 3.

Means of main minerals, organic acids, sugars, physico-chemical characteristics and other chemical compounds in maple syrups produced from sap collected with control vacuum level (20 InHg) and high-vacuum level (28 InHg) in the tubing system with respective P-values.

Analysis	Control - 20 InHg		High vacuum - 28 InHg
	Meana	SDb	Mean	SD	p value
Minerals (μg/g)
Potassium	1670.10	213.95	1701.13	296.55	0.84
Calcium	1691.08	1191.53	1618.20	1078.37	1.00
Magnesium	191.88	67.32	195.70	87.32	0.93
Sodium	10.58	1.66	12.35	3.52	0.63
Zinc	3.79	0.45	4.77	1.75	0.42
Manganese	13.50	20.07	24.84	36.26	0.34
Organic Acids (μg/g)
Oxalic	28.73	12.68	23.36	7.23	0.39
Quinic	84.03	69.61	184.77	381.97	0.11
Pyruvic	471.66	50.14	380.13	136.80	0.11
Malic	5278.90	1490.48	5611.82	2238.20	0.87
Fumaric	291.74	91.39	287.60	146.15	0.95
Succinic	1624.00	1631.12	1754.91	1700.16	0.63
Sugars (%)
Sucrose	64.37	3.79	64.37	3.76	0.63
Glucose	0.44	0.60	0.26	0.34	0.20
Fructose	0.33	0.48	0.43	0.76	0.42
Physico-chemical
pH	7.30	0.52	7.09	1.04	0.67
Conductivity (uS/cm)	212.32	37.80	220.63	41.57	0.38
Transmittance (%; 560 nm)	63.49	13.08	74.38	11.40	0.15
Other analysis
ABAc (ng/g)	212.10	85.10	161.00	56.00	0.25
Auxin (ng/g)	730.30	129.00	804.00	160.60	0.35
Total protein (%)	0.25	0.15	0.27	0.21	0.57
Total nitrogen content (μg/g)	308.60	72.89	304.74	135.13	0.35
Total phenolic content (μg/g)	62.33	5.18	64.08	5.99	0.60
Organoleptic evaluation
Taste defectsd	3/6	─	3/6	─

^aN = 6.

^bStandard deviation.

^cAbscisic acid.

^dNumber of syrups out of 6 with unidentified defect corresponding to the symbol √R4 (according to grading standard system in Quebec). Remaining syrups were free of defects.