Pollen Combinations of Honeys from Galicia (Spain) and Their Geographical Distribution

Apiacta 1, 2001 POLLEN COMBINATIONS OF HONEYS FROM GALICIA (SPAIN) 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 Vigo. 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 Lugo province, 97 – in the Pontevedra 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 Santiago 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.

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