Apiacta 1, 2001

POLLEN COMBINATIONS OF HONEYS FROM () AND THEIR GEOGRAPHICAL DISTRIBUTION

María del Carmen SEIJO, María Victoria JATO, María Isabel IGLESIAS

Dpto. Bioloxia Vexetal e Ciencia do Solo. Facultade de Ciencias. Universidade de . Campus As Lagoas. 32004 Orense, España

Abstract The palynologic study of 530 samples of Galicia honey (from North-West of Spain) produced during the 1989-1992 period was achieved, with the aim in view of determining the geographical characterization of the producing areas. The used method was suggested by LOUVEAUX et al. (1978). The obtained results have allowed us establishing 15 producing areas. In each of them a pollen combination was determined, that was to be encountered in at least 75% of the samples. Its pollinic richness, the honeydew index, and the average number of pollen types per sample are shown. A total of 135 pollen types was identified. It is to be stressed the scarce presence of the honey flow elements in the Galician honeys, as well as their low pollinic contents, even if they proceeded as a majority from species that tend tio be hyper-represented in the pollinic spectrum of honey, such as the case of Castanea sativa Miller or Eucalyptus globulus Labill. Honeys are characterized by the absence or scarce presence of pollens originating from Mediterranean-type plants, such as the case of Diplotaxis erucoides DC., Hypecoum procumbens L., Olea europaea L., Cistus ladanifer L., Helianthus annuus L., Citrus, Lavandula etc., that are also present in other Spanish honeys with a similar botanical origin.

Key words: pollen combination / geographical distribution / honey / Galicia / Spain.

I. Introduction

The main objectives of melissopalynology are referring to the necessity of knowing the geographical and botanical origin of honeys, and therefore avoid frauds in selling this produce. The pollinic analysis of honey mirrors the flora visited by bees, and thus reveals itself one of the most effective methods in order to establish its geographical origin. Reading the pollinic spectra of the honeys in one area allows determining the presence of specific pollen combinations that may be used as geographical markers, thus helping tracing with more precision the territorial boundaries of the producing areas. The botanical origin of honey entails some concrete organoleptic characteristics, thus allowing gathering information that would permit the consumer recognizing the product in advance. The fact there are important variations in the organoleptic characteristics and, as a consequence, in the trading value, turns necessary knowing the honey sources the bee has been using when producing the said honey. Honey trading is mainly destined to those countries where the consume quota is not covered by the own production, or to those where the production costs of honey are higher, and, as a consequence, the price would be also higher. European countries have increased the honey imports since the beginning of the last century, thus some of this imported honey was sold fraudulently as a national production, omitting any origin information in the commercial label, and therefore entailing a profit (CRANE, 1975). Knowing the pollinic spectrum proper to honeys of each zone facilitates detecting this type of fraud. All these considerations, as well as the already proven usefulness of the used method, led us to achieve this work of characterizing the Galician honeys. The pioneer of the melissopalynology in Galicia was VIEITEZ (1950). Nowadays there is a large number of works about the honeys produced in that region (SÁNCHEZ and SAÉNZ, 1982; TERRADILLOS, 1988; AIRA et al., 1990; JATO et al., 1992; SEIJO et al., 1992; IGLESIAS et al., 1993; JANEIRO et al., 1993; SEIJO, 1994; SEIJO et al., 1994, among other), but never has been approached the study of honeys produced in the Galician area, nor their characterization, according to the producing areas. The present work intends zonifying the honey producing areas in Galicia, on the basis of pollens present in their pollinic spectra, both from the qualitative and quantitative point of view.

(a) Beekeeping in Galicia

Galician beekeeping has much changed during the last 20 years, as from the use of fixist hives made mainly of cork or wood, they passed to mobile-type hives of more honey chambers. Migratory beekeeping is practically non-existant, due to the difficulty of choosing a proper location of facile access to apiaries. Beekeeping activity is very little professional, as from 3.000 beekeepers taken into the census, 5% Apiacta 1, 2001 possess more than 100 hives, 35%, between 20 and 100 hives, and 60% - less than 20 hives. Honey and wax are the only beekeeping products of commercial interest, although recently has begun a scarce trade with pollen. As concerns the honey production, each apiary is producing only one harvest a year, that is extracted mainly by centrifugation. The extracting time coincides with the months of June – July on the coast, and with September in the interior of the country. Approximately 1.000 metric tons are harvested a year, and their commercialization is made mainly liocally, that is directly from beekeepers to consumers, although in the recent years the founding of co/operatives favoured the wholesale trading.

II. Material and methods

Gathering samples was mainly achieved in the areas of major beekeeping development within each province. In order to establish the honey producing areas in the Galician territory, there were taken into account the results obtained in the pollinic analyses of 530 honey samples, of which 173 came from apiaries located in the province, 97 – in the province, 155 – in La Coruña, and 105 – in Orense. The used methods for analyzing honey are based on those suggested by LOUVEAUX et al. (1978).

(a) Quantitative analysis

The quantitative analysis and the honey flow index were determined starting from 20 g of honey. The count of the different elements of the honey flow and the pollen grains was achieved in a count chamber of Thoma-type, for each sample being realized at least two tests.

(b) Qualitative analysis

For the qualitative analysis the starting point were 30 g of honey. Pollen grains were Identified by means of an optic mycroscope model NIKON OPTIPHOT, increasing 400 and 1000 times, in the necessary cases. For counting each and every one of the different types present, count lines were pre-fixed in every preparation, so that, in all samples, different lines are to be read in the same order, until the minimum of 1.200 pollen grains per sample is reached. Once the absolute data are obtained, the relative percentages are then calculated, in order to compose the pollinic spectrum.

(c) Pollinic identification

For the purpose of pollen identifying, the pollen library was used as reference, composed of the Galician honey flora, that exists at the Faculty of Sciences of the University of Vigo, in Orense, as well as at the Faculty of Pharmacy at the University of de Compostela.There have also been used various guides and keys for pollinic identification. Once pollen has been recognized, and for expressing the obtained results, the categories were used, of species, genus or pollinic type. The latter indicates a related morphology for pollens would correspond to a vegetable species, and the generic name is adopted, when the described pollen is common to various species of the same genus.

(d) Honey typification

Once the pollinic spectrum was obtained, and when was about the honey typification, the following percentages were taken into account: - 70%, for honeys of Eucalyptus and Castanea sativa (LOUVEAUX, 1968; SERRA et al., 1987; SALA, 1991; VALENCIA, 1991); - 45%, for honeys of Rubus, Erica, or Cystus type (LOUVEAUX et al., 1978).

III. Results

From the study of the pollinic spectra of samples, we obtained specific combinations of pollens, able to characterize each production area. These combinations were found when taking into account the presence or absence of the same in honeys of each area, in at least 75% of them (see Tables I and II). In this way, the areas presented below, that appear in Map No. 1, are showing the following characteristics as concern their honeys. Apiacta 1, 2001

Table I Characteristic pollen combinations and their frequency in the area

Pollen combination Area % Castanea-Rubus-t. Campanula-Erica-t. Cytisus 1 88 Castanea-Rubus-Erica-t. Cytisus 2 100 Castanea-Rubus-Erica-t. Trifolium-t. Campanula-Centaurea 3 78 Castanea-Rubus-Erica-Eucalyptus-t. Cytisus 4 96 Eucalyptus-Castanea-Rubus-t. Cytisus 5 95 Eucalyptus-Castanea-Rubus-t. Cytisus-t. Conium-Salix 6 76 Eucalyptus-Castanea-Rubus-Erica 7 94 Eucalyptus-Castanea-Rubus-t. Cytisus-Echium-Erica 8 90 Eucalyptus-Castanea-Rubus-t. Cytisus-t. Trifolium-Erica 9 75 Eucalyptus-Castanea-Rubus-t. Cytisus-t. Trifolium 10 90 Eucalyptus-Castanea-Rubus-Erica 11 100 Castanea-Rubus-Erica-t. Cytisus-t. Prunus 12 90 Castanea-Rubus-t. Lotus-t. Cytisus-t. Campanula-Erica 13 96 Castanea-Rubus-t. Lotus-Erica-t. Campanula-t. Prunus-t. Cytisus 14 100 Castanea-Rubus-t. Lotus-Erica-t. Campanula-Echium 15 90

Table II Principal characteristics of the samples of each area Monofloral Area N P C.M. I.M. MILFL. C R E ER L Cl 1 52 21 II, III NULL 27 13 12 - - - - 2 45 22 II, III NULL 20 20 2 - 3 - - 3 60 22 II, III NULL 33 19 8 - - - - 4 31 28 I, II NULL 26 - - 4 - - 1 5 21 29 I, II NULL 17 - - 4 - - - 6 49 26 II NULL 21 1 - 27 - - - 7 18 28 II, III NULL 12 1 1 2 - - 2 8 15 26 II NULL 8 - 2 4 - - 1 9 13 25 I, II NULL 9 - 1 - 1 - 1 10 72 25 II NULL 48 6 8 8 2 - - 11 50 27 I, II NULL 28 5 1 12 4 12 53 28 II, III LOW 33 4 14 - 1 1 - 13 23 32 III, IV, V LOW 13 10 - - - - - 14 18 31 II, III, IV LOW 14 3 - - - 1 - 15 10 30 II, III LOW 8 1 - - 1 - -

N: Number of samples; P: Average of pollen types; C.M.: Maurizio classes; I.M.: Honeydew index C: Monofloral honeys of Castanea; E: Monofloral honeys of Eucalyptus; Cy: Monofloral honeys of Cytisus; R: Monofloral honeys of Rubus; Er: Monofloral honeys of Erica; L: Monofloral honeys of Lotus.

Map 1 – Geographical situation of the 15 production areas of Galician honeys

Apiacta 1, 2001

1. Region of Deza – – Lemos –

52 samples were studied, in which the combination Castanea-Rubus-t.Campanula-Erica-t. Cytisus was present in the 88% of the samples. Other pollens of importance to characterize honeys of that area are: t. Lotus, and t. Trifolium. The average number of pollinic types per sample was 21, and, generally, all honeys are classified into the 2nd and 3rd classes of Maurizio. The honeydew index is null or low for all of them. As concerns the typification of honeys, 13 of them are monofloral – of Castanea, 12 of Rubus, and 27 are poly- floral.

2. Region of O Caurel-Ancares-Fonsagrada

45 honeys were studied, where the Castanea-Rubus-Erica-t. Cytisus combination was present in 100%. Other important pollens for their characterization are the following: t. Lotus and t. Prunus. The aver- age number of pollinic types is 22, that are grouped according to their pollinic content into the 2nd and 3rd classes of Maurizio. The honeydew index is null or low in all samples.There were typified 20 monofloral hon- eys of Castanea, 3 of Erica, 2 of Rubus, and 20 polyfloral.

3. Region of A Ulloa-Lugo-Vilalba

60 honey samples of that origin were studied. The pollen combination that characterizes them con- sist in Castanea-Rubus-Erica-t. Trifolium- t. Campanula-Centaurea, being present in 78% of honeys. The average number of pollen types per sample was 22. These honeys belong in the 2nd and 3rd classes of Mau- rizio. The honeydew index is null or low for all of them. From the typification, 19 monofloral honeys of Casta- nea, 8 of Rubus, and 33 polyfloral ones have resulted.

4. Region of Mondoñedo-Viveiro-Ribadeo

31 samples were studied. In 96% of them, there is present the pollen combination formed by Casta- nea-Rubus-Erica-Eucalyptus-t. Cytisus. Other important pollens are: Calluna vulgaris, Echium, and Reseda. The average number of pollen types per sample was 28. According to their pollen content, they group into the 1st and 2nd classes of Maurizio. The honeydew index is null in all honeys. As concerns the typification, 4 of the are monofloral, of Eucalyptus, 1 of t. Cytisus, and 26 – polyfloral.

5. Region of Baixo Miño--A Paradanta

21 samples were studied, in which the pollen combination of Eucalyptus-Castanea-Rubus-t. Cytisus is to be found in 95% of them. Other important pollens are: Erica and t. Lotus. In the case of the A Paradanta region, the pollen of Sesamoides show important values, that characterize honeys in the area. The average number of pollen types per sample was 29. These honeys are grouped into the 1st and 2nd classes of Mauri- zio. The honeydew index was null or low in all of them. There were typified 4 monofloral honeys of Eucalyp- tus, and 17 polyfloral ones.

6. Region of Vigo-Pontevedra-O Salnés-Barbanza

The number of the examined samples was 49. In 76% of the samples there was present the combi- nation Eucalyptus-Castanea-Rubus-t. Cytisus-t. Conium-Salix. The average number of pollen types per sample was 26. All samples belonged in the 2nd class of Maurizio, and did not show any honeydew indexes. 27 honeys were monofloral, of Eucalyptus, 1 of Castanea, and 21 were polyfloral.

7. Region of Terra de Montes-Tabeirós

18 samples were studied, in which the combination Eucalyptus-Castanea-Rubus- Erica was present in 94%. Other pollens of importance for the characterization are: t. Cytisus and Salix. The average number of pollen types per sample was 28. They belong to the 2nd and 3rd classes of Maurizio.The honeydew index is of no account for all of them. There were typified 2 monofloral honeys of Eucalyptus, 1 of Castanea, 1 of Ru- bus, 2 of t. Cyrtisus, and 12 polyfloral samples. Apiacta 1, 2001

8. Region of Padrón-Santiago

In this region 15 samples were gathered. In the 90% of honeys the combination was present, formed by Eucalyptus-Castanea-Rubus-t. Cytisus-Echium-Erica. The average number of pollen types per sample is 26. All of them belong in the 2nd class of Maurizio, and their honeydew index is null. As concerns the typifica- tion, 4 are monofloral honeys of Eucalyptus, 2 of Rubus, 1 of t. Cytisus, and 8 are polyfloral.

9. Region of -Bergantiños

13 honeys were studied, in which the pollen combination Eucalyptus-Castanea-Rubus-t. Cytisus-t. Tri- folium-Erica was present in 75% of them. The average number of pollen types per sample was 25. They belong in the 1st and 2nd classes of Maurizio. Their honeydew index is null. Regarding the typification, 2 are monofloral honeys, of t. Cytisus, 1 of Erica australis, 1 of Rubus, and 9 are polyfloral.

10. Region of -Arzúa-A Coruña--As Pontes

72 honeys were studied. 90% of them show the pollen combination Eucalyptus-Castanea-Rubus-t. Cytisus-t. Trifolium. Other important pollens are: Erica and t. Campanula. The average number of pollen types per sample is 25. Al of them belong in the 2nd class of Maurizio, and their honeydew index is null. 8 of them are monofloral, of Eucalyptus, 8 of Rubus, 6 of Castanea, 2 of Erica, and 48 are polyfloral.

11. Region of -Ortigueira

50 honeys were examined of this origin. Eucalyptus-Castanea-Rubus-Erica is the pollen combination that characterizes these honey-flows, being present in 100% of them. Other less important pollens are: t. Trifolium and t. Cytisus. The average number of pollen types is 27, being classified into to 1st and 2nd classes of Maurizio. The honeydew index is null in all of them. From the typification 11 monofloral honeys of Eucalyp- tus resulted, as well as 5 of Castanea, 4 of Erica, 1 of Rubus, and 29 polyfloral honeys.

12. Region of Orense-Celanova-Xinzo de Limia

53 honeys, proceeding from that region, were studied. In them, the combination Castanea-Rubus- Erica-t. Cytisus-t. Prunus is present in 90%. Other very frequent pollens, but of less importance, are: t. Cam- panula and Echium. Incidentally, Cynoglossum, Hypericum, Myosotis, and Eucalyptus can show values of less importance. It’s to be stressed the presence of some Leguminosae (t. Melilotus and t. Medicago). The average number of pollen types is 28, in most cases being classified, by their pollen content, into the 2nd and 3rd classes of Maurizio. The honeydew index is incidentally average, but in most cases is low. In its turn, that large amplitude area can be divided into two subzones. In one of them (Northern area), there are frequently produced Rubus honeys, this taxon being the most important in most of cases; nonetheless, in the Southern area, Castanea appears frequently as the most represented taxon. 14 monoflo- ral honeys of Rubus were typified, 4 monofloral of Castanea sativa, 1 of Erica, 1 of t. Lotus, and 33 polyfloral honeys.

13. Region of Trives

23 honeys of that region were studied.The Castanea-Rubus-t. Lotus-t. Cytisus-t. Campanula-Erica combination was present in 96% of them. This area, whose geographic situation could be defined as moun- tainous, as regards the pollen spectra shows a dominance of Castanea sativa in the areas of major altitude. The abundance of cultivated meadows facilitates appearing bush and pasture vegetation, and other species as Rubus, t. Cytisus, t. Campanula, t. Lotus, and Erica are frequently important taxons. Although with low repre- sentation percentages (< 4%), Hypericum is very frequent in those honeys. The average number of pollen types per sample is 32, showing low proportions of elements indicating the honeydew. By their content in pollen grains per gram of honey, they are to be classified into 3rd, 4th, and 5th classes of Maurizio. 10 monofloral Cas- tanea honeys were typified, this area being that of most production of this honey type, as well as 13 polyfloral honeys.

14. Region of Verín

18 samples were studied from this area. The Castanea-Rubus-t. Lotus-Erica-t. Campanula-t. Prunus- t. Cytisus combination is present in 100% of samples. Besides these taxons, there is frequent the appear- Apiacta 1, 2001 ance of Anarrhinum (94% of honeys), as well as other types, as Sedum, Echium, and Myosotis, that can pre- sent values of a certain importance. Lavandula, a characteristic taxon for the honeys of the Mediterranean areas, that exists in this region, was sporadically identified in the pollinic spectra, but always with less than 1% percentages. The average number of pollen types per sample was 31, the indicating elements of honey- dew being very little represented; therefore, the honeydew index was low. By their content in pollen grains per gram of honey, they are grouped in the 2nd, 3rd, and 5th classes. There were typified 3 monofloral honeys of Castanea sativa, 1 of t. Lotus, and 14 polyfloral ones.

15. Region of O Bolo-

It is a mountain area, where 10 samples were studied, whose main characteristic is the Castanea- Rubus-t. Lotus-Ericaceae-t. Campanula-Echium combination in 90% of samples. There is also important the presence of t. Prunus, t. Cytisus, and Anarrhinum. The average number of pollen types per sample was 30. The honeydew index was low in all samples. By ther pollinic content, they group in the 2nd and 3rd classes. There was typified 1 monofloral honey of Castanea, 1 of Erica, and 8 polyfloral honeys.

IV. Dicussion

The most important differences in the study of the Galician honeys, according to their geographical ori- gin, consist in the quantitative variation of the most important pollen types. So, within the Galician territory, there is possible to delimit two distinct production areas, that is, the coast and the interior. Between both of them there is a transition strip, variable in extension, where honeys of that origin show mixed characteristic features. In this area polyfloral honeys are mostly produced, with balanced proportions of the Castanea sativa and Eucalyptus globulus species. The domain in the pollen spectra of other species, as Erica and Rubus is more certain. By its high presence, the latter taxon mentioned characterizes honeys produced in the Lugo prov- ince, and in the counterforts of the Oriental mountain ranges. As regards the differentiation among the counties, the main differences are to be noticed in the values of the most important five pollen types (Castanea sativa, Eucalyptus, Rubus, t. Cytisus, and Erica). Some- times, other pollen types can be considered markers of well determined areas. The areas 4, 5, 6, 7, 8, 9, 10, and 11, that correspond to the Galician coastal border, intensely re- populated with Eucalyptus globulus, are characterized by the presence of that pollen type, in high percent- age in all honeys. They are the areas producing monofloral eucalyptus honey. In the interior areas (1, 2, 3, 12, 13, 14, and 15), Castanea sativa is the taxon best represented, accompanied by Rubus. Besides, by their frequency of appearance, 0other pollen types can serve as typical indicators, when characterizing areas at small scale; thus, Erica is important in the areas 1, 2, 3, 4, 7, 7, 8, 9, 11, 12, 13, 14, and 15, all these ar- eas having a noticeable extension of bushes, essentially owing to their geographical situation in agriculturally abandoned or hard to cultivate areas (e.g. abrupt slopes, mountain areas etc.). The Campanula pollen type is frequent in the agricultural areas that are mainly dedicated to dairy and stock production. That is why natu- ral and cultivated prairies abound (1, 3, 13, 14, and 15). The Cytisus pollen type show a similar behavior to Erica, that abounds in the honeys proceeding. From those areas where are important extensions of thickets or open forest terrain (1, 2, 4, 5, 6, 8, 9, 10, 12, 13, and 14). The presence of Salix and t. Conium is more characteristic in the area 6, what can be owed to the fact that in that area the most interesting honey production species is Eucalyptus, that blossoms very early (beginning of the year), which makes a better representation of coincidentally blossoming plants to be noticed, other plants, even if abundant, being rejected, that are not so made use of, as the beekeeper is advancing the honey harvesting period. In the Orense province, the Prunus type is frequent in the areas 12 and 14, as it essentially proceeds from the presence of cultivated fruit trees. Other taxons are showing an exceptional abundance. Thus, in the La Coruña province, is frequent the presence of Hedera helix L. Some counties in the Lugo province (area 3), are characterized by high values of the Trifolium type. Campanula shows important values in the area 1. In the areas 14, 15, and in the South- East of area 2, of Mediterranean vegetation, is frequent the presence of Lavandula stoechas L. and Cistus ladanifer L., always with percentages lower than 1%. In the A Paradanta county, included in the area 5, is common the presence of Sesamoides in honeys, as well as the Acacia and Zea mays L. (proceeding from honey plants) appear residually in Pontevedra (area 6) honeys (< 1%), but nevertheless characteristically. In Orense county honeys (12, 13, 14, 15), Anarrhinum is a pollen frequently encountered in the pollen spectra of honeys. Apiacta 1, 2001

V. Conclusions

It is to be stressed the scarce presence of honeydew elements in the Galician honeys, as well as their low pollen content, in opposition to what could be expected in most highly represented species (Castanea sativa and Eucalyptus). This fact is related to the type of hives the beekeeper is currently using (e.g., mobile, of the Langstroth type), and to the type of honey extraction, by centrifugation. The characterization and differentiation of the Galician honeys with regard to other Spanish honeys is not complicated, and only in the territory bordering the Asturias y León provinces (LUIS & GÓMEZ, 1989; VALENCIA, 1991; LUIS et al., 1993) honeys are produced, with pollen spectra very similar to the Galician ones, that impede the differentiation. There are honeys that bring out the absence of pollens of Mediterra- nean plants. So, the absence or scarce presence of Diplotaxis erucoides DC., Hypecoum procumbens L., Olea europaea L., Cistus ladanifer L., Helianthus annuus L., Citrus, Lavandula, etc., that is, pollens well rep- resented in other honeys of Spain and the European South, that allow their facile differentiation (BATTAG- LINI et al., 1973; RICCIARDELLI, 1979; LOUVEAUX & ABED, 1984; DAMBLON, 1988; PÉREZ DE ZA- BALZA, 1989; VALENCIA, 1991; HIDALGO, 1993).

Acknowledgements

This work was funded by the Xunta of Galicia.

LITERATURE

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