Some Physicochemical and Microscopic Characteristics of Greek Unifloral Honeys a Thrasyvoulou, J Manikis

Some physicochemical and microscopic characteristics of Greek unifloral honeys A Thrasyvoulou, J Manikis

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A Thrasyvoulou, J Manikis. Some physicochemical and microscopic characteristics of Greek unifloral honeys. Apidologie, Springer Verlag, 1995, 26 (6), pp.441-452. hal-00891310

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Some physicochemical and microscopic characteristics of Greek unifloral honeys

A Thrasyvoulou J Manikis

1 Laboratory of Apiculture-Sericulture, Aristotle University of Thessaloniki, 54006 Thessaloniki; 2 Union of Beekeeping Associations of Northern Greece, Prometheus 6, 55134 Kalamaria, Greece

(Received 20 February 1995; accepted 16 May 1995)

Summary — Water content, ash, HMF, diastase activity, electrical conductivity, pH, proline and microscopic characteristics of 174 samples of unifloral honeys from thyme, chestnut, cotton, heather, orange, sunflower, pine and fir honeydew have been analysed. Differences among the corresponding values are given. The honeys from pine, fir, chestnut and heather have a high pH, electrical conductivity and ash, but a low HMF. Thyme honey has high diastase and proline content where as orange honey shows the lowest values for pH, proline, diastase activity, ash and electrical conductivity. Sunflower and cotton honeys have no distinct characteristics. Predominant pollen was found in thyme, sunflower, heather and chestnut honeys. More than 20 pollen types were found in pine and thyme honeys, 15-20 in fir, sunflower and heather and 10-15 in chestnut, cotton and orange honeys. honey / unifloral / physicochemical characteristics / microscopic characteristics / Greece

INTRODUCTION fir honey, which represents 5% of the total annual production. It is derived from honey- The annual honey production of Greece is dew produced by the insects Physokermes estimated at 11 000 tons. A large portion is hemicryphus, Eulecanium sericeum and derived from honeydews from pine and fir Mindarus abietinus, parasites on Abies trees (Santas and Bikos, 1979). cephalonica Loudon and A borisiiregis Mattf, Pine honey constitutes about 60% of the (Santas, 1983). total annual honey production and is pro- The large variety of melliferous sources duced during autumn from honeydew also enables Greece to produce character- secreted by the insect Marchalina hellenica istic unifloral nectar honeys. The most well- (Gennadius), which is restricted to Pinus known is ’Hymettus honey’, which has been brutia Ten and P halepensis Miller (Boden- famous since antiquity (Crane, 1979). This heimer, 1953; Nikolopoulos, 1959; Kailidis, is a thyme honey which is mainly produced 1965). Another major honeydew honey is from Thymus capitatus L, T serpyllum L and Satureia spp. Thyme honey represents 10% their organoleptic, microscopic and physico- that were of the total crop (Santas and Bikos, 1979). chemical characteristics. Samples doubtful in origin were excluded from the study. Heather, sunflower, orange and cotton hon- All samples were kept in a refrigerator until chem- are also Greek unifloral eys major honeys ical analysis. that are produced in appreciable quantities which have not yet been estimated. Heather honey is produced mainly from Erica verti- Physicochemical analyses cillata Forskal and E carnea L during autumn. While sunflower honey from Water content, ash, HMF and diastase Helianthus annuus L is significant, it is pro- activity were measured as recommended the Codex duced in because of by decreasing quantities Alimentarius Commission (CAC, 1989). the small monetary rewards associated with The electrical was measured it. Cotton (Gossypium hirsutum L) and conductivity according to Louveaux et al (1973). The results on the other orange (Citrus spp) honeys, are expressed in millisiemens/cm. The pH was hand, usually appear on the Greek market measured in a 20% solution. Proline was esti- mixed with other blossom honeys. Finally, mated by using the method of Ough (1969) at chestnut honey, which is produced from the 520 nm, with the aid of a calibration curve nectar of Castanea sativa Mill, may be partly obtained from solutions of pure dry proline. Ten of honeydew origin because of the honey- samples of each category of honey were anal- for content. dew that is abundantly produced by the ysed proline insect Myzocallis castanicola Baker (San- tas, 1983). Melissopalynological analysis The physicochemical characteristics of Greek unifloral honeys were partly examined by Kodounis (1962), Thrasyvoulou and Melissopalynological analysis was carried out using the methods established by the Interna- Bladenopoulou (1984), Thrasyvoulou tional Commission of Bee Botany described by Bakandritsos and (1986), et al (1993) Louveaux et al (1978). Counts were expressed as Thrasyvoulou and Manikis (1993). Most of percentages after counting > 600 pollen grains. the published material appears in Greek The ratio of honeydew elements to the number of journals and is not easily accessible to the pollen grains (HDE/P) was estimated in honeydew international scientific community. In this honeys by counting fungal spores, hyphae, algae and 300 The fre- paper, we examine some characteristics of approximately pollen grains. classes of were as the Greek nectar to further quency pollen grains given major honeys predominant pollen (> 45%), secondary pollen contribute to the classification and charac- (16-45%), important minor pollen (3-15%) and terization of European unifloral honeys. minor pollen (1-3%.).

MATERIALS AND METHODS RESULTS AND DISCUSSION

Sampling Physicochemical characteristics

Fresh samples of pine, fir, chestnut, thyme, sun- Table I shows the mean results and basic heather and flower, cotton, orange honeys pro- statistics obtained from the physicochemical duced in different regions of Greece were collected from beekeepers between 1989 and 1993. analyses, the percentage of the main pollen Their classification as unifloral honey was based in the unifloral honeys and the HDE/P ratio on their origin (information from beekeepers) and in the honeydew honeys. Water content Electrical conductivity

The majority of Greek honey was found to Honeydew and chestnut honeys had the be low in moisture and therefore virtually highest conductivity while orange honey had safe from fermentation. Average moisture the lowest. Sunflower and thyme honeys content (16.8%) was 4.2% lower than the gave similar values; the same was found maximum allowable content for honey by for heather and cotton honeys. the CAC The values were (1989). greatest The high mean and wide range of elec- also lower than the maximum permissible trical conductivity of chestnut honeys level of 21 % with the of 2 sam- exception are noteworthy. Similar results were reported ples of heather honey. Fir honey had the by Piazza et al (1986, 1991) who showed lowest moisture content (15.2%) and that nectar chestnut had honeydew- heather the highest (18.6%). like characteristics (high pH, ash and con- The average moisture content of Greek ductivity) but differed from honeydew hon- fir, thyme, heather, sunflower, chestnut and eys by its negative specific rotatory value. orange honeys (16.8%) was lower than the The conductivity of Greek heather honey corresponding value for Italian (17.3%; agrees with that of the French (Pourtallier Accorti et al, 1986) and French (17.6%; and Taliercio, 1970), Italian (Persano Oddo Pourtallier and Taliercio, 1970) honeys. The et al, 1988) and Spanish (Serra Bonvehi distinct low water content of fir honey is in and Granados Tarres,1993) heather hon- agreement with Accorti et al (1986). eys. The high water content for heather agrees with values reported in other countries (Spettoli et al, 1982; Accorti et al, 1986; Ash Serra Bonvehi and Granados Tarres, 1993). Since the of heather have majority honeys The highest ash content was found in hon- high water content, the specification of Cal- eydew and chestnut honeys and the low- luna in the standards for compositional est in orange nectar honey. Two samples honey is not considered as necessary. of fir honey (12.5%) and all the chestnut honeys exceeded the maximum tolerance of the CAC standard. Such high ash content pH indicates an increased nutritional value of honey rather than adulteration (Feinberg, Honey from orange trees had the lowest 1951). pH, whereas pine, fir and chestnut honeys The high values of pH, ash, and electri- had the highest. Heather honey gave an cal conductivity of Greek honeydew hon- average pH, value of 4.2, placing it between eys are similar to data given for the average flower honeys and honeydew. composition of honeydews from other coun- The pH values of Greek unifloral hon- tries (Kirkwood et al, 1960; White et al, eys are in agreement with those found by 1962; Stefanini, 1984; Talpay, 1985; Accorti Pourtallier and Taliercio (1970), Accorti et al et al, 1986). These features can be used (1986), Sabatier (1988), and Serra Bon- to distinguish between honeydew and blos- vehi and Granados Tarres (1993), but not som honeys as supplementary to their dif- with those of Mohamed et al (1982) who ferent microscopic and organoleptic char- found an average pH value of 6.2 in thyme acteristics. The low coefficient of variation honey. (CV%) of electrical conductivity of pine and fir honeys (11.5 and 13.5% respectively) HMF indicates uniformity, which confirms the view that conductivity is a characteristic of The HMF content is a criterion of the fresh- the plant species from which the honey is ness and heat of Fresh derived, and is not influenced by differences processing honey. honey may contain small amounts of HMF in the weather, year of harvest or geo- which exceed 10 graphical origin (Vorwohl, 1964). The cor- (White, 1979), rarely mg/kg relation coefficient (r) of the relationship (Rodgers, 1979). The averages and maxi- between ash and electrical conductivity of mum values (Vmax) of our samples are the different types of Greek unifloral honey smaller than this figure, except for heather was more than 0.97 except in chestnut and orange honey which had one sample honey, where it was 0.41. High linear rela- with 11.9 and 10.7 mg/kg HMF, respectively. tionships between the 2 parameters were Uncommonly high HMF was also found in found by Accorti et al (1987), Piazza et al Italian heather honey (Accorti et al, 1986; (1991), Sancho et al (1991) and Bianchi Persano Oddo et al, 1988). Fir and pine (1992). honeys have the lowest HMF values, whereas sunflower, orange, thyme and cot- moderate, whereas sunflower, cotton and fir ton honeys have the highest. honeys had a low diastase activity. Finally orange honey had the lowest diastatic value. Diastase activity In a previous study, an average diastase activity of 15.6 DU for thyme honey with the The diastase activity (expressed in dias- minimum value of 4.5 DU was recorded tase units, DU) of all 174 samples exam- (Thrasyvoulou, 1986), which was contra- ined averaged at 23.0 and ranged from a dictory to the high diastase activity of 33.1 minimum of 8.6 DU (orange) to a maximum DU of Italian thyme honey (Persano Oddo et of 51 DU (chestnut). Thymus and chestnut al, 1990). We investigated the possibility of honeys had high values, heather and pine whether beekeeping techniques might have affected the enzymes of this honey. We Proline found that in certain dry, hot islands, beekeepers feed bees with substantial amounts The proline content of the 80 samples taken of to maintain a bee syrup high population. from the 8 different unifloral honeys was This decreased diastase was activity pre- found to have an average of 526 mg/kg, demonstrated Zalewski viously by (1962), with a minimum value of 264 in orange and Kuznetsov and Ermolaeva (1964), Popescu a maximum of 1 205 in thyme (table I). et al (1965), and Zagaevskll and Kra- Thyme and sunflower honeys had high marenko The examined in (1982). samples amounts of proline whereas orange and fir this research had been collected from bee- honeys had the lowest content. keepers that fed no sugar syrup to their bees Proline can be used to distinguish genuine during the The average diastase spring. from adulterated honey, since honey from of those was closer activity samples (32.2) sugar-fed bees has significantly lower levels to the corresponding values for Italian hon- of proline. No sample was found to contain eys. proline near to the 160-200 mg/kg indicator Comparison of our results of diastase level for honey adulteration (White and Rudyj, activity with those previously reported in 1978; Talpay 1985; Dustmann, 1993). the literature, shows that the values for the Greek sunflower and orange honeys (15.9 and 11.7) correspond to those reported by Microscopic characteristics Persano Oddo et al (1990) for Italian hon- and do not eys (16.3 9.8). However, they Predominant pollen was found in the thyme, agree with the 21.8 DU value of orange sunflower, heather and chestnut samples found in Spanish honeys (Serra Bonvehi (table I). Pine and fir honey had a low HDE/P and Gomez Pajuero, 1983). The value of ratio that did not agree with the high value Greek heather honey (27.6) was higher (> 3) of honeydews from other countries than the Italian value (7.8). The DU value in (Louveaux et al, 1978). The presence of fir (18.5) was similar to the Italian (22.9) large fungal spores that characterized the (Persano Oddo et al, 1990) and lower than Greek pine honey (Sawyer, 1988) was not the French honeys (43.0) (Pourtallier and so common in our samples. Taliercio, 1970). The number of pollen types in Greek uni- The wide range of diastase activity floral honeys varied from 24 to 10 (table II). observed in thyme (33.1) and in chestnut High numbers of pollen types (> 20) were honeys (27.1) is not unusual in unifloral hon- found in pine, and thyme honeys, medium eys. Rusakova (1984) found a range of 30.7 number (15-20) in fir, sunflower and heather for lime honey, Persano Oddo et al (1990) honeys and low (10-15) in chestnut, cotton found 32.3 for chestnut and 23.2 DU for Ital- and orange honeys. As the pollen grains ian fir honey, and Serra Bonvehi and Grana- with a frequency < 1 % were not identified, dos Tarres (1993) found 55 DU for heather and not all the pollen grains could be iden- honey. This natural variation and the differ- tified to species level, our results are not ences between the same types of honeys directly comparable with the results of other produced in different countries was the rea- authors. The average number of pollen son for a severe criticism of the use of dia- types in Greek honeys does not essentially stase as a criterion of quality evaluation of differ from those reported by Varis et al honey (Schade et al, 1958; Wilson, 1971; (1982) and Seijo et al (1992), but are smaller Rusakova 1984; Thrasyvoulou, 1986; Kim, than those recorded by Serra Bonvehi and 1987; White 1992). Mundo Elias (1988) and Jato et al (1991).

The great number of different pollen types pollen (45-85.1%) and 6 as secondary in pine honey may be explained by contam- pollen (35-45%). Samples with less than ination with foreign pollen. Pollen that had 35% were rejected. The minimum percent- been collected and stored by bees in combs age of Thymus-type pollen in the rejected near brood area during the spring is totally samples was 7.8%. The pollen grains of sealed with pine honey during the heavy Castanea, Cistus, Citrus, Compositae, Bra- honeydew flow. These combs may be sicaceae, Erica spp, Prunus/Pyrus, Robinia, extracted 2 or more times by the beekeepers Taraxacum, Trifolium spp and Vicia form resulting in contamination of pine honey with appear in more than half of the thyme sam- foreign pollen. Floral honey produced in the ples, although in different frequencies. colonies before their removal to pine forest could cause a contamina- secondary pollen Sunflower tion. honey From the of Greek uni- pollen spectrum Although the pollen grains of sunflower are floral in table we can conclude honeys II, under-represented (Sawyer, 1988), we the following: found a range of 21.1 to 81.17% pollen grains of Helianthus. Twelve samples Pine and fir honeys (57.2%) were found with predominant and 9 (42.8%) with secondary pollen. Castanea Secondary and important minor pollen in was the most frequently found pollen type pine honey were usually of chestnut and apart from Helianthus in sunflower hon- heather. The rest were different minor eys. pollen. Important minor pollen grains in fir honey were those of Brassicaceae, Labi- Cotton honey atae and Pyrus/Prunus. Erica spp appeared in 9 of the 16 of fir in minor samples honey Talpay (1985) cited honeydew of cotton as frequency. containing Gossypium only as minor pollen. We found a range between 3 and 45% for Chestnut honey pollen grains of Gossypium in samples examined as cotton honey. Samples that The pollen grains of chestnut were over- had percentages of pollen grains of Gossyp- represented as expected (Louveaux et al, ium less than 20% were rejected. Cotton 1978). The average percentage of pollen honey is not listed by the International grains of Castanea was 90.4 ± 4.5% and Commission for Bee Botany as being the maximum 95%. Four samples with under-represented in pollen of the plant ori- between 85 and 90% pollen grains of Cas- gin (Louveaux et al, 1978). Erica spp was tanea were regarded as being produced the most frequent pollen grain in cotton from Castanea plant, since they had the honey. chemical and organoleptic characteristics of chestnut Other honey. important pollen Heather honey grains were not found. The pollen of Erica spp was predominant Thyme honey in all samples that were examined and occa- sionally reached 90%. Important minor and Fourteen samples of thyme honey out of 20 minor pollens were rare and were mainly were found with Thymus as predominant those of Castanea. Orange honey Résumé — Quelques caractéristiques physico-chimiques et microscopiques Citrus pollen was found in the range of 7.3 de miels grecs unifloraux. Au total, 174 to 14.1 %. Brassicaceae, Erica spp and Tri- échantillons de miels unifloraux ont été ana- folium spp were the most frequent pollen lysés : pin (n = 48), sapin (n = 16), châtai- types that appeared in orange honey. gnier (n = 13), thym (n = 20), bruyère (n = 20), oranger (n =17), tournesol (n = 20) et coton (n = 20). On a déterminé la teneur en CONCLUSIONS eau, en cendres, en HMF, en proline, l’acti- vité enzymatique, la conductibilité électrique, le pH et les caractéristiques microscopiques. This research describes the variability of Tous les échantillons étaient frais, non trai- the physicochemical parameters of 8 Greek tés et stockés au réfrigérateur au préalable. unifloral honeys. The high electrical con- Les teneurs en eau, en cendres, en HMF ash and of fir and chest- ductivity, pH pine, ont été mesurées selon les recommanda- nut honeys are the only variables among tions de la CAC la teneur en pro- those examined with actual (1989), diagnostic line selon la conductibilité The of the other Ough (1969), potential. averages param- électrique selon Louveaux et al (1973), et eters differed between unifloral but honeys l’analyse mélissopalynologique selon Lou- were not representative and do not charac- veaux et al (1978). Le tableau I présente terize a certain of and type honey. Thyme les principaux résultats des analyses phy- chestnut are richer in diastase activ- honeys sico-chimiques, le pourcentage du pollen whereas is low in ity, orange honey pH, ash, principal des miels unifloraux et le rapport diastase and electrical conductiv- proline, HDE/P dans les miellats. Le tableau II pré- Sunflower on the other has ity. honey, hand, sente les résultats des analyses polliniques. a high content of proline but low diastase. Les classes de fréquence des grains de pol- Heather have water content that honey may len se répartissent en : prédominant (P), exceeds the maximum level of permissible secondaire (S), mineur important (IM) et 21 %. Futhermore, all the chestnut samples mineur (M). La majorité des miels avait une do not with CAC standards for ash comply faible teneur en eau (en moyenne 16,7%). content. Pollen analysis along with the Les valeurs maximales étaient inférieures and physicochemical organoleptic param- à ce qui est autorisé par la CAC (21 %). Le eters can be very useful to characterize uni- miel de bruyère présentait la valeur floral those derived from honeys, especially moyenne la plus élevée (18,6%) (2 échan- heather and chestnut thyme, sunflower, tillons avaient une humidité supérieure à blossom. 21 %), tandis que le miel de sapin avait la plus basse (15,2%). Les miels de pin, de sapin et de châtaignier avaient les valeurs ACKNOWLEDGMENTS les plus élevées pour le pH, la teneur en cendres et la conductibilité électrique, tandis We are grateful to Greek beekeepers that col- que le miel d’oranger avait les plus basses. laborated with us in providing samples of honey Tous les échantillons de miels de châtai- and valuable information. We also wish to thank gnier et 2 de sapin dépassaient la tolérance the students of the Aris- Agricultural Faculty, maximale en cendres fixée par la CAC. Une totelian University of Thessaloniki, particularly S corrélation a été observée entre Befa, E Koutis, T Loulou, C Makris, M Dandali, significative and H Tomproukidou for their technical assis- la teneur en cendres et la conductibilité élec- tance. The valuable suggestions and advice of trique (r> 0,97). Pour le miel de châtaignier, 2 referees are acknowledged. la relation n’était pas linéaire (r = 0,41). L’activité enzymatique était élevée pour les (1969) und die Pollenanalyse nach Lou- miels de thym et de châtaignier (respecti- veaux et al (1978) durchgeführt. TabelleI vement 32,5 et 32,2), modérée pour les gibt die mittleren Werte und statistische miels de pin et de bruyère (28,4 et 28,6), Angaben der physikalisch-chemischen Ana- basse pour les miels de sapin, de coton et lysen, sowie den Prozentsatz des Haupt- de tournesol (18,5, 17,6, 15,9) et très basse pollenanteils im Sortenhonig und das HDE/P pour le miel d’oranger (11,7). Les miels de Verhältnis im Honigtauhonig wieder. Tabelle thym et de tournesol avaient une teneur en II zeigt die Pollenanalyse von griechischen proline plus élevée que les autres miels uni- Sortenhonigen. Die Frequenzklassen der floraux. La valeur minimale de 264 mg de Pollenkörner wurden als vorherrschend (P), proline par kg de miel qui a été trouvée dans zweitrangig (S), als wichtige Nebenpollen un échantillon de miel d’oranger était supé- (IM) und unbedeutende Pollen (M) ange- rieure au taux minimum caractéristique geben. Die meisten griechischen Honige d’une altération du miel. Les miels de thym hatten einen geringen Wassergehalt (im et de pin comportaient plus de 20 types dif- Durchschnitt 16,7%). Fast alle Werte waren férents de pollen, les miels de sapin, tour- geringer als das Maximum des nach CAC nesol et bruyère entre 15 et 20, les miels erlaubten Wassergehaltes (21 %); 2 Proben de châtaignier, de coton et d’oranger entre des Heidehonigs hatte über 21 %. Tannen- 10 et 15. Le pollen prédominant a été trouvé honig hatte mit 15,2% den niedrigsten und dans les miels de châtaignier, de thym, de Heidehonig mit 18,6% den höchsten Was- tournesol et de bruyère. Le pollen de sergehalt. Die Werte des pH, der Asche und bruyère a été le pollen le plus fréquent dans der elektrischen Leitfähigkeit waren bei les miels grecs unifloraux. Pinien-, Tannen- und Edelkastanienhonig am höchsten, während sie beim Orangen- miel unifloral / caractéristiques physico- honig am niedrigsten waren. Alle Proben chimiques et microscopiques / Grèce der Edelkastanie und 2 der Tanne (12,5%) überschritten bei den Aschewerten die Tole- ranzgrenze nach CAC (1989). Es wurde ein Zusammenfassung — Einige physika- signifikanter Zusammenhang (r> 0,97) zwi- lisch-chemische und mikroskopische schen Asche und elektrischer Leitfähigkeit Eigenschaften von griechischen Sor- gefunden. Nur im Edelkastanienhonig gab tenhonigen. Wassergehalt, Asche, HMF, es keinen linearen Zusammenhang (r= Diastaseaktivität, elektrische Leitfähigkeit, 0,41). Die Diastaseaktivität war in Honigen pH, Prolin und mikroskopische Eigenschaf- von Thymian (32,5) und Edelkastanien ten von 174 Proben verschiedener Sorten- (32,2) hoch, von Pinien und Heide (28,4 honige wurde analytisch bestimmt. 48 bzw 27,6) mäßig. Bei Tanne, Baumwolle Honigproben stammten von Pinien, 16 von und Sonnenblumen war sie niedrig (18,5, Tannen, 13 von Edelkastanien, 20 von Thy- 17,6 und 15,9) und sehr niedrig im Oran- mian, 20 von Heide, 17 von Orangen, 20 genhonig (11,7). Thymian- und Sonnenblu- von Sonnenblumen und 20 von Baumwolle. menhonige hatten einen signifikant höhe- Die frischen, nicht bearbeiteten Proben ren Prolingehalt als die anderen wurden im Kühlschrank bis zur Analyse auf- Sortenhonige. Der niedrigste Wert, der mit bewahrt. Wassergehalt, Asche, HMF und 264 mg Prolin/kg Honig in einer Probe von Diastaseaktivität wurden entsprechend der Orangenhonig gemessen wurde, lag noch Empfehlungen von CAC (1989) bestimmt. weit über der Grenze (160-200 mg), die als Die Messung der elektrischen Leitfähigkeit Indikator für eine Verfälschung gilt. Pinien- wurde mit Methoden von Louveaux et al und Thymianhonige enthielten mehr als 20 (1973), die von Prolin mit denen von Ough unterschiedliche Pollenarten, Tanne, Son- nenblumen und Heidehonige 15-20, Edel- Kodounis MI (1962) The crystallisation of honey. PhD Baumwoll- und Thesis, Higher School of Agriculture, University of kastanien-, Orangenhonig Athens, 88 p (in Greek) 10-15. Vorherrschende Pollenarten wurden Kuznetsov VA, Ermolaeva PE (1964) The problem of in Honigen von Edelkastanien, Thymian, adulteration of honey in the markets of Ashkhabad. Sonnenblumen und Heide gefunden. Hei- Trudy Turkman Sel Khoz Inst 13, 281-285 (in Rus- depollen war der in griechischen Sortenho- sian) Louveaux Pourtallier Vorwohl G Méthodes nigen am häufigsten gefundene Pollen. J, MP, (1973) d’analyses des miels. Conductivité. Bull Apic 16, 7 p Louveaux Maurizio Vorwohl G Methods of / / J, A, (1978) Honig Sortenhonig physikalisch-che- melissopalynology. Bee World 59, 139-157 mische und mikroskopische Eigen- Mohamed, MA, Ahmed AA, Mazid MM (1982) Studies on schaften / Griechenland Libyan honey. J Food Quality 4, 185-201 Nikolopoulos C (1959) Melliferous flora of Attica. Uni- versity of Athens, Athens, 117 p (in Greek) REFERENCES Ough CS (1969) Rapid determination of proline in grapes and wines. J Food Sci 34, 228-230 Persano Oddo L, Piazza MG, Accorti M (1988) Diagno- Accorti M, Persano Oddo L, Piazza MG, Sabatini AG sis of unifloral honeys. I. Present knowledge and (1986) Schede di caratterizzazione delle principali problems. Apicoltura 4, 1-11 qualità di miele uniflorale italiano. Apicoltura 2, appen- Persano Oddo L, Baldi E, Accorti M Diastasic dice, 36 p (1990). activity in some unifloral honeys. Apidologie 21, 17-24 Accorti M, Piazza MG, Persano Oddo L (1987) La con- Piazza MG, Accorti M, Persano Oddo L (1986) Indagine ductivité électrique et le contenu en cendre du miel. sulle caratteristiche chimico-fisiche dei mieli italiani Apiacta XXII, 19-20 di castagno e di melata. Apic Mod 77, 47-51 Bakandritsos N, Mallios I, Zoutsou P, Manatos N (1993) Piazza MG, Accorti M, Persano Oddo L (1991) Electrical Physico-chemical parameters of Greek honey. In: ash, colour and specific rotatory power Proc National Conferences of Greece about Honey, conductivity, in Italian unifloral honeys. Apicoltura 7, 51-63 Gerakini Chalkidiki, 139-164 (in Greek) Popescu N, Popa C, Popa A, Brinzac B (1965). Contri- Bianchi EM (1992) the mineral (ash%) con- Determining bution à l’étude de la composition physico-chimique tent in honey by conductometric analysis. Apiacta du miel provenant d’abeilles nourries au sirop de VII, 19-24 sucre. Bull Apic 8, 139-146 Bodenheimer FS The Coccoidea of III. (1953) Turkey. Pourtallier J, Taliercio Y (1970) Les caractéristiques Instanbul Univ Fac Sci Rev Ser B, 17, 91-164 physico-chimiques des miels en fonction de leur orig- Codex Alimentarius Commission (1989) Codex stan- ine florale.I. Application à un projet de normes pour dard for honey (worldwide standard). FAO-WHO, les grandes variétés de miels. Bull Apic 13, 58-68 CAC Vol 3, Ed 1 Supp 2, Rome Rodgers PEW (1979) Honey quality control. In: Honey, Crane E (1979) The flowers honey comes from. In: A Comprehensive Survey (E Crane, ed), Heinemann, Honey, A Comprehensive Survey (E Crane, ed), London, 314-325 Heinemann, London, 3-76 Rusakova TM (1984) The diastase number of honeys. Dustmann JH (1993) Honey, quality and its control. Am Pchelovodstvo 10, 22-23 (in Russian) Bee J 133, 648-651 Sabatier S (1988) Les polyphénols des miels de tour- Feinberg B (1951) Ash in honey. Am Bee J 91, 471 nesol. Congrès national des apiculteurs, Toulouse Jato MV, Sala-Llinares A, Iglesias MI, Suarez-Cervera M Sancho MT, Muniategui S, Huidobro JF, Simal-Lozano (1991) Pollens of honeys from north-western Spain. J (1991) Provincial classification of Basque country J Apic Res 30, 69-73 (northern Spain) honeys by their chemical composition. J Apic Res 30, 168-172 Kailidis DS (1965) Monophlebus hellenicus (= Marchalina hellenica) Genn. The pine insect feeder of honey Santas LA, Bikos A (1979) The apicultural flora of bees. Dasika Chronika 81-82, 305-321 (in Greek) Greece. Apiacta XIV, 115-123. Kim JK (1987) Variation and alterations in the chemical Santas LA (1983) Insects producing honeydew exploited composition, diastase number and HMF content of by bees in Greece. Apidologie 14, 93-103 Korean honeys. Korean J Apic 2, 9-66 Sawyer R (1988) Honeydew. In: Honey Identification, Kirkwood KC, Mitchell TJ, Smith D (1960) An examina- Cardiff Academic Press, 30-32 tion of the occurrence of honeydew in honey. Analyst Schade JE, Marsh GL, Eckert JE (1958) Diastase activ- 85, 412-416 ity and hydroxymethylfurfural in honey and their use- fulness in detecting heat alteration. Food Res 23, Thrasyvoulou A, Manikis J (1993) The chemical com- 446-463 position of Greek honey 121-132. Proc National Serra Bonvehi J, Gomez Pajuelo A (1983) Chemical Conferences of Greece about Honey, Gerakini Chalkidiki and physical characteristics of orange, rosemary (in Greek) and honeydews produced in Catalonia, Valence and Varis AL, Helenius J, Koivulehto K (1982) Pollen spec- Estremadura. XXIXth Int Cong Apic Budapest, Hun- trum of Finnish honey. J Sci Agric Soc Finland 54, gary, Apimondia, 378-379 403-420 Serra Bonvehi J, Mundo Elias P (1988) A study of the Vorwohl G (1964) Relations between the electrical con- pollen spectra of ling heather, Calluna vulgaris L (Hull), ductivity of honeys and their botanical origin. Ann honeys produced in Spain. J Apic Res 27, 169-174 Abeille 7, 301-309 Serra Bonvehi J, Granados Tarrès E (1993) Physico- White JW, Riethof ML, Subers MH, Kushnir I (1962) chemical properties, composition and pollen spec- Composition of American honeys. Tech Bull US Dept trum of ling heather (Calluna vulgaris (L) Hull) honey Agric 1261 in 586-596 produced Spain. Apidologie 24, White JW, Rudyj ON (1978) Proline content of United Seijo MC, Aira MJ, Iglesias I, Jato MV (1992) Palyno- States honeys. J Apic Res 17, 89-93 characterization of from la Coruña logical honey White JW (1979) Composition of honey . In: Honey, A Res province (NW Spain). J Apic 31, 149-155 Comprehensive Survey (E Crane, ed), Heinemann, Spettoli P, Bottacin A, Pescia P, Girolami V (1982) Carat- London, 157-206 teristiche fisico-chimiche di mieli di Erica arborea White JW (1992) Quality evaluation of honey: role of toscani. Ind Alim 21, 617-620 HMF and diastase assays. Am Bee J 132, 737-743, Stefanini R (1984). Variability and cluster analysis of 792-794 Italian 109-114 honeys. Apiacta XIX, Wilson RB (1971) Diastase and hydroxymethylfurfural in Talpay B (1985) Spezifikationen für Trachthonige. international honey regulations. XXIII Int Apic Congr, Deutsche Lebensmittel-Rundschau 81, 148-151 Apimondia, 587-588 Thrasyvoulou A (1986) The use of HMF and diastase Zagaevskll IS, Kramarenko VV (1982) Criteria for dif- as criteria of quality of Greek honey. J Apic Res 25, ferentiating between sugar-adulterated and natural 186-195 honey. Voprosy Pitaniya 82, 63-65 (in Russian) Thrasyvoulou A, Bladenopoulou S (1984) A comparative Zalewski W (1962) Determination of the activity of sugar analysis of Greek pine and blossom honey. Nea splitting enzymes in local honeys. Pszczelarstwo 13, Melissa 2, 7-10 (in Greek) 67-69 (in Polish)