Novel approach for the characterisation of Sicilian honeys based on the correlation of physico-chemical parameters and artificial senses

Figures & data

Table 1. Sample set.

Botanical origin	Provenance	Quantity
Chestnut	Catania, Trapani, Messina	8
Eucalyptus	Catania, Trapani, Messina, Ragusa	8
Sulla	Catania, Trapani, Palermo	5
Citrus	Catania, Trapani, Ragusa	7

Table 2. Instrumental specifications and operating parameters.

Instrument	iCAP-Q, Thermo Fischer, Waltham, MA, US
Nebulizer	Concentric type
Skimmer cones	Pt
Mass analyser	Quadrupole
Rf power	1548.6 W
Plasma argon flow rate	16 L min^−1
Auxiliary argon flow rate	0.8035 L min^−1
Nebulizer argon flow rate	1.06 L min^−1
Replicate time	1 s
Sweeps	20
Measurement mode	KED

Table 3. Sugars content of the different honey varieties.

Samples	Glucose, g/100g	Fructose, g/100g	Sucrose, g/100g	Fructose + Glucose, g/100g	Fructose/Glucose ratio
Citrus honeys (n = 7)
Min	31.10	36.22	0.66	67.69	1.09
Max	35.04	40.93	9.36	76.88	1.17
Mean	33.22^a	38.04	3.16	74.42^a	1.14^b
Median	33.02	37.17	1.95	76.68	1.16
Std. Dev.	1.73	2.74	3.59	4.14	0.04
Eucalyptus honeys (n = 8)
Min	25.00	36.70	1.32	60.99	1.16
Max	33.50	40.28	2.92	74.18	1.39
Mean	30.00^a	38.08	1.80	69.88^ab	1.28^b
Median	30.89	38.77	1.61	72.78	1.28
Std. Dev.	3.16	2.38	0.65	5.68	0.08
Sulla honeys (n = 5)
Min	30.39	36.86	2.56	69.89	1.20
Max	32.50	38.88	7.80	79.17	1.21
Mean	31.26^a	37.64	3.92	72.82^ab	1.20^b
Median	31.08	37.41	2.67	71.11	1.20
Std. Dev.	0.89	0.87	2.58	4.28	0.01
Chestnut honeys (n = 8)
Min	22.81	34.06	0.51	58.69	1.42
Max	25.05	43.05	1.43	67.83	1.84
Mean	23.78^b	37.67	0.85	62.31^b	1.59^a
Median	23.63	36.67	0.78	62.16	1.61
Std. Dev.	0.84	3.33	0.37	3.43	0.17

Different lower letters in the same column indicates the effect of botanical origin on sensors response (p < .05).

Table 4. Measured pH values.

Samples	pH	Std. Dev.
Chestnut honeys	4.98^a	0.38
Eucalyptus honeys	4.24^b	0.29
Sulla honeys	3.67^c	0.05
Citrus honeys	3.71^c	0.09

Different lower letters in the same column indicates the effect of botanical origin on sensors response (p < .05).

Figure 1. Spider chart obtained with the intensity of the E-tongue’ potentiometric sensors (Colour). (Colour online.)

Figure 2. Graphs showing the percentage abundance of the extracted colours within (a) Chestnut honeys, (b) Eucalyptus honeys, (c) Sulla honeys and (d) Citrus honeys (Colour). (Colour online.)

Table 5. Minerals content.

Samples	K, mg/g	Ca, mg/g	Mg, mg/g	Na, mg/g	Zn, µg/g	Fe, µg/g	Mn, µg/g
Citrus honeys (n = 7)
Min	0.12	0.02	0.01	0.05	1.96	1.41	0.15
Max	0.43	0.19	0.03	0.08	9.45	6.28	0.62
Mean	0.30^c	0.12	0.02^b	0.06^b	6.15	3.53	0.31^b
Median	0.33	0.12	0.02	0.06	6.48	2.57	0.24
Std. Dev.	0.12	0.06	0.01	0.01	2.74	2.04	0.19
Eucalyptus honeys (n = 8)
Min	0.76	0.09	0.02	0.13	2.52	2.86	0.74
Max	2.79	0.15	0.08	0.25	12.78	3.94	4.11
Mean	1.95^b	0.12	0.06^a	0.20^a	7.16	3.42	2.06^ab
Median	2.05	0.12	0.07	0.21	6.53	3.39	1.73
Std. Dev.	0.75	0.01	0.02	0.05	4.16	0.39	1.24
Sulla honeys (n = 5)
Min	0.23	0.05	0.01	0.06	1.77	2.98	0.22
Max	0.28	0.11	0.03	0.10	7.25	3.50	0.43
Mean	0.25^c	0.07	0.02^b	0.08^b	4.64	3.25	0.32^ab
Median	0.24	0.06	0.02	0.08	4.78	3.27	0.33
Std. Dev.	0.02	0.02	0.01	0.01	2.25	0.22	0.09
Chestnut honeys (n = 8)
Min	3.25	0.06	0.05	0.06	4.53	2.51	0.80
Max	5.28	0.13	0.10	0.09	8.87	6.11	6.12
Mean	4.41^a	0.09	0.08^a	0.07^b	5.74	4.53	3.03^a
Median	4.48	0.08	0.08	0.07	5.07	4.65	1.62
Std. Dev.	0.75	0.02	0.01	0.01	1.81	1.29	2.56

Different lower letters in the same column indicates the effect of botanical origin on sensors response (p < 0.05).

Table 6. Relationship between colour and mineral content.

Colour extracted	R	G	B	Colour appearance	Positive correlation	Negative correlation
2403	152	104	56		Mn	–
2948	184	136	72		Na	–
2966	184	152	104		Zn	–
3472	216	152	8		Mn	–
4057	248	216	152		–	K, Mg