Evaluation of Several Romanian Honeys Based on their Palynological and Biochemical Profiles

Figures & data

Table 1  Principal pollen types in samples (the percentage in the pollen spectra is expressed as a number of the samples in which the pollen type reaches the frequency)

	Acacia (n = 10)				Linden (n = 10)				Rape (n = 10)
Pollen type	R	I	A	D	R	I	A	D	R	I	A	D
Ambrosia type	1	—	—	—	—	—	—	—	—	—	—	—
Bellis perennis	1	—	—	—	2	1	—	—	—	—	—	—
Brassica napus type	—	2	6	2	2	4	3	—	—	—	—	10
Centaurea cyanus	2	—	—	—	—	1	—	—	—	—	—	—
Crataegus monogyna type	5	—	—	—	1	—	—	—	1	—	—	—
Echium	—	—	—	—	4	—	—	—	—	—	—	—
Fallopia	4	1	—	—	—	—	—	—	1	—	—	—
Filipendula	4	1	1	—	3	1	—	—	2	—	—	—
Fragaria type	6	1	—	—	2	—	—	—	1	—	—	—
Frangula alnus	2	2	—	—	—	—	—	—	—	—	—	—
Helianthus annuus	1	—	—	—	3	1	1	—	—	1	—	—
Ligustrum	2	—	—	—	—	—	—	—	3	—	—	—
Loranthus	5	1	—	—	—	—	—	—	—	—	—	—
Lotus	1	—	—	—	—	—	—	—	—	—	—	—
Melilotus	—	—	—	—	—	1	—	—	—	—	—	—
Onobrychis viciifolia	1	—	—	—	—	—	—	—	—	1	—	—
Origanum type	3	—	—	—	1	—	—	—	—	—	—	—
Plantago	3	1	—	—	1	—	—	—	1	—	—	—
Prunus	3	5	1	—	2	—	—	—	4	2	—	—
Quercus	2	2	—	—	1	—	—	—	1	2	—	—
Raphanus type	—	1	—	—	—	—	—	—	—	—	—	—
Robinia pseudoacacia	—	7	2	1	—	—	—	—	2	1	—	—
Rubus	4	3	—	—	1	—	—	—	3	—	—	—
Rumex	4	2	—	—	5	—	—	—	1	—	—	—
Salix	2	2	—	—	—	—	—	—	3	—	—	—
Sinapis type	—	2	—	—	—	—	—	—	—	3	—	—
Solidago	1	—	—	—	—	1	—	—	—	—	—	—
Symphytum officinale type	1	1	—	—	—	—	—	—	—	—	—	—
Taraxacum officinale type	1	—	—	—	1	—	—	—	—	1	—	—
Trifolium repens type	3	1	—	—	2	1	—	—	2	—	—	—
Vicia sativa type	2	—	—	—	—	—	—	—	—	—	—	—
Zea mays type	1	—	—	—	—	—	—	—	—	—	—	—
Tilia	2	2	—	—	—	—	1	9	1	—	1	—
Anthriscus type	—	—	—	—	1	—	1	—	1	—	—	—
Daucus carota type	—	—	—	—	2	—	—	—	2	—	—	—
Bifora radians	—	—	—	—	2	3	—	—	1	—	—	—
Vitis vinifera	3	1	—	—	—	—	—	—	—	—	—	—
Pollen grains/g honey (Mean)	1875				1852				7372

D: dominant pollen (>45%); A: secondary pollen (45–15%); I: important pollen (15–3%); R: minor pollen (<3%).

Table 2  Descriptive analysis of studied bioactive compounds and principal pollen types

Honey type	Acacia	Linden	Rape
N	10	10	10
Phenols (mg/100 g)	18.4 ± 5.6	42.1 ± 6.3*	23.7 ± 7.9
Flavonoids (mg/100 g)	1.3 ± 0.6*	3.2 ± 0.9	2.5 ± 0.9
RSA (%)	10.7 ± 6.1*	27.2 ± 6.6*	18.9 ± 5.1*
Robinia pseudoacacia (%)	18.4 ± 15.9*	0.1 ± 0.2	1.1 ± 1.3
Tilia (%)	2.0 ± 3.1	68.6 ± 16.6*	2 ± 5.0
Brassica napus (%)	34.4 ± 20.0*	10.2 ± 11.0*	80.5 ± 11.5*
Prunus (%)	6.1 ± 7.0*	0.7 ± 0.7	1.7 ± 1.7
Filipendula (%)	5.5 ±12.6*	0.9 ± 1.1	0.7 ± 0.9

Values are expressed as mean ± standard deviation.

*Marked values are significantly different at p < 0.05.

Figure 1  Honey classification (1-acacia, 2-linden, 3-rape) by PCA considering the most representative variables.

Table 3  Spearman rank correlations between each pair of variables

Variables	Total phenols	Total flavonoids	RSA
Robinia pseudoacacia	−0.664*	−0.745*	−0.474*
Tilia	0.819*	0.474*	0.688*
Brassica napus	−0.478*	−0.049	−0.299
Total phenols	—	0.703*	0.743*
Total flavonoids	0.703*	—	0.656*

*P-values below 0.05 indicate statistically significant non-zero correlations at the 95.0% confidence level.

Figure 2  Cluster classification of honey types according to their palynological features (Robinia pseudoacacia, Tilia, Brassica napus).

Table 4  Result of the two first components extracted in PCA and the factor score coefficients for the variables

Factor number	1	2
Eigenvalue	3.540	1.986
Variance (%)	50.58	28.37
Variance cumulative (%)	50.58	78.96
Factor score coefficients
Brassica napus	−0.913	−0.102
Tilia	0.700	0.479
Robinia pseudoacacia	0.060	−0.234
Pollen richness	−0.302	−0.022
Phenols content	0.416	0.503
Flavonoids content	0.081	0.240
RSA	0.167	0.931