Characterization and Classification of Several Monofloral Iranian Honeys Based on Physicochemical Properties and Antioxidant Activity

Figures & data

TABLE 1 Monofloral honey samples and their collection regions

Type of honey	Collection region	Latitude	Longitude
Astragal (Milk vetch)	Shahr-e- Kord	32° 19’ 32’’ N	50° 51’ 52’’ E
Tamarisk	Shahr-e- Kord	32° 19’ 32’’ N	50° 51’ 52’’ E
Qanqal	Shahr-e- Kord	32° 19’ 32’’ N	50° 51’ 52’’ E
Dill	Tiran and Karvan	32° 42’ 00’’ N	51° 09’ 00’’ E
Parsley	Tiran and Karvan	32° 42’ 00’’ N	51° 09’ 00’’ E
Coriander	Tiran and Karvan	32° 42’ 00’’ N	51° 09’ 00’’ E
Ziziphus	Borazjan	29° 16’ 00’’ N	51° 12’ 00’’ E
Orange blossom	Shiraz	29° 37’ 04’’ N	52° 32’ 00’’ E
Thyme	Damavand	35° 43’ 04’’ N	52° 03’ 54’’ E
Alfalfa	Baharestan	32° 30’ 58’’ N	51° 47’ 54’’ E

TABLE 2 Physicochemical properties of Iranian monofloral honeys

Types of honey	Moisture (g/100 g honey)	pH	Ash (g/100 g honey)	Electrical conductivity (mS/cm)	Fructose (g/100 g honey)	Glucose (g/100 g honey)	Ratio of fructose/glucose	Diastase activity (Gothe)	HMF (mg/kg)
Coriander	15.6^abc ± 0.1	4.7^b ± 0.0	0.183^b ± 0.003	0.30^c ± 0.001	31.5^e ± 0.6	29.1^b ± 0.9	1.1^f ± 0.01	5.8^i ± 0.1	29.3^b ± 0.0
Dill	14.3^e ± 0.1	4.2^cd ± 0.0	0.164^c ± 0.004	0.36^b ± 0.004	39.2^a ± 0.3	31.5^a ± 0.4	1.2^cd ± 0.03	19.7^c ± 0.1	39.4^a ± 0.4
Ziziphus	15.5^bc ± 0.0	5.5^a ± 0.0	0.235^a ± 0.006	0.47^a ± 0.004	33.5^d ± 0.3	22.0^d ± 0.4	1.5^a ± 0.04	21.3^a ± 0.1	3.7^h ± 0.3
Thyme	15.9^ab ± 0.0	4.1^e ± 0.0	0.071^ef ± 0.006	0.18^f ± 0.004	36.9^b ± 0.3	28.3^b ± 0.4	1.3^bc ± 0.03	20.8^b ± 0.1	5.9^g ± 0.1
Parsley	15.4^cd ± 0.0	4.8^b ± 0.1	0.120^d ± 0.006	0.23^d ± 0.001	35.6^c ± 0.6	29.8^b ± 0.9	1.2^de ± 0.02	17.2^d ± 0.1	8.5^f ± 0.2
Qanqal	15.0^d ± 0.0	4.3^c ± 0.1	0.077^e ± 0.001	0.20^e ± 0.000	37.5^b ± 0.3	28.8^b ± 0.4	1.3^bc ± 0.03	13.2^f ± 0.1	10.1^e ± 0.3
Astragal (Milk vetch)	15.5^bc ± 0.2	4.2^de ± 0.0	0.050^g ± 0.001	0.15^h ± 0.003	25.4^f ± 0.6	19.2^e ± 0.9	1.3^b ± 0.03	12.3^g ± 0.1	5.9^g ± 0.1
Alfalfa	16.0^a ± 0.0	4.1^e ± 0.0	0.064^f ± 0.002	0.17^g ± 0.005	37.4^b ± 0.3	31.8^a ± 0.4	1.2^e ± 0.03	10.8^h ± 0.1	28.0^c ± 0.6
Tamarisk	15.1^d ± 0.4	4.1^e ± 0.0	0.052^g ± 0.002	0.16^h ± 0.004	35.9^c ± 0.6	26.7^c ± 0.9	1.3^b ± 0.02	13.8^e ± 0.1	2.2^i ± 0.2
Orange blossom	15.7^abc ± 0.3	4.4^c ± 0.1	0.018^h ± 0.002	0.12^i ± 0.001	36.6^bc ± 0.3	28.5^b ± 0.4	1.3^bc ± 0.03	6.32^i ± 0.1	11.0^d ± 0.1

Means with different letters in each column are significantly different (p > 0.05).

TABLE 3 Color characteristics of honey samples

Types of honey	L*	a*	b*	Color intensity
Coriander	18.98^j ± 0.03	23.01^a ± 0.02	31.64^f ± 0.04	1.917^a ± 0.007
Dill	29.94^i ± 0.02	18.55^b ± 0.03	47.68^c ± 0.02	1.038^b ± 0.025
Ziziphus	41.19^d ± 0.16	14.29^c ± 0.03	59.98^a ± 0.04	0.876^c ± 0.009
Thyme	41.39^c ± 0.00	11.34^d ± 0.00	49.81^b ± 0.02	0.520^e ± 0.011
Parsley	45.63^a ± 0.00	5.14^f ± 0.00	36.50^e ± 0.02	0.618^d ± 0.001
Qanqal	45.05^b ± 0.03	5.41^e ± 0.01	37.67^d ± 0.03	0.424^f ± 0.008
Astragal (Milk vetch)	30.12^h ± 0.02	2.63^i ± 0.01	23.91^h ± 0.01	0.412^f ± 0.001
Alfalfa	31.03^g ± 0.01	2.94^g ± 0.01	24.85^g ± 0.01	0.404^f ± 0.001
Tamarisk	32.47^f ± 0.00	2.27^j ± 0.01	21.80^j ± 0.02	0.342^g ± 0.002
Orange blossom	33.10^e ± 0.10	2.77^h ± 0.03	23.22^i ± 0.11	0.244^h ± 0.002

Means with different letters in each column are significantly different (p > 0.05).

TABLE 4 Total phenolic content, total flavonoid content, and antioxidant activity of honey samples

Types of honey	Total phenolic content (mg/100 g honey)	Total flavonoid content (mg/100 g honey)	Antioxidant activity (%)
Coriander	50.3^b ± 0.4	4.3^ab ± 0.1	54.2^a ± 0.3
Dill	32.5^c ± 1.1	4.1^b ± 0.2	49.6^b ± 0.0
Ziziphus	55.7^a ± 1.5	4.5^a ± 0.2	54.3^a ± 0.1
Thyme	28.5^d ± 2.7	3.2^d ± 0.0	49.3^bc ± 0.0
Parsley	28.3^d ± 0.9	3.6^c ± 0.2	47.1^cd ± 0.8
Qanqal	28.2^d ± 0.3	3.4^cd ± 0.1	46.9^d ± 2.3
Astragal (Milk vetch)	25.8^e ± 0.2	3.4^e ± 0.2	45.6^d ± 0.9
Alfalfa	26.4^de ± 0.1	2.0^fg ± 0.1	46.9^d ± 2.1
Tamarisk	24.6^e ± 0.3	2.1^f ± 0.1	46.7^d ± 0.0
Orange blossom	19.0^f ± 0.1	1.7^g ± 0.1	46.2^d ± 0.0

Means with different letters in each column are significantly different (p > 0.05).

FIGURE 1 Inhibition of enzymatic browning of honey samples in: (a) minced apple, (b) apple juice.

TABLE 5 Correlation between physicochemical parameters

	Moisture	pH	Electrical conductivity	Ash	Phenol	Flavonoid	Antioxidant activity	Color intensity	L*	a*	b*
Moisture	1
pH	0.065	1
Electrical conductivity	–0.342	0.765**	1
Ash	–0.258	0.791**	0.970**	1
Phenol	0.004	0.797**	0.869**	0.928**	1
Flavonoid	–0.343	0.673*	0.879**	0.924**	0.827**	1
Antioxidant activity	0.028	0.703*	0.829**	0.888**	0.955**	0.812**	1
Color intensity	–0.147	0.424	0.622	0.755*	0.772**	0.746*	0.822**	1
L*	–0.007	0.212	0.004	–0.07	–0.173	0.081	–0.24	–0.55	1
a*	–0.247	0.408	0.745*	0.805**	0.771**	0.834**	0.875**	0.915**	–0.387	1
b*	–0.19	0.567	0.787**	0.719*	0.612	0.792**	0.642*	0.296	0.438	0.584	1

*Correlation is significant at 0.05 level; **Correlation is significant at 0.01 level.

FIGURE 2 Dendrogram of honey samples according to cluster analysis on the basis of physicochemical properties using the Ward Method (1: coriander honey; 2: dill honey; 3: ziziphus honey; 4: thyme honey; 5: parsley honey; 6: qanqal honey; 7: astragal honey; 8: alfalfa honey; 9: tamarisk honey; 10: orange blossom honey).

FIGURE 3 Principal component analysis of honey samples (1: coriander honey; 2: dill honey; 3: ziziphus honey; 4: thyme honey; 5: parsley honey; 6: qanqal honey; 7: astragal honey; 8: alfalfa honey; 9: tamarisk honey; 10: orange blossom honey; A: ash; B: electrical conductivity; C: ratio of fructose/glucose; D: diastase activity; E: HMF; F: L*; G: a*; H: total phenolic content; I: total flavonoid content; J: antioxidant activity; K: inhibition of enzymatic browning in apple juice).