8 research outputs found
HYGIENIC WATER SUPPLY FOR THE BEES
Za pravilan razvoj i opstanak pÄelama je neophodno osigurati kontinuiranu i dostatnu opskrbu kvalitetnom vodom. Ima raznih vrsta pojilica kojima se koriste pÄelari. Kako u praksi gotovo svaka od njih ima nedostataka (nedostatna zapremina, otežana kontinuirana opskrba vodom, nedovoljna higijena), razvijena je nova higijenska pojilica od nehrÄajuÄeg lima. U uvjetima 6 izoliranih pokusnih pÄelinjaka na otoku Unije praÄena je djelotvornost novog modela higijenske pojilice glede kontinuirane opskrbe, higijenske ispravnosti i potroÅ”nje vode. Tijekom cijelog trajanja pokusa
snaga pÄelinjih zajednica bila je ujednaÄena. U razdoblju od 26. srpnja do 29. rujna 2006. godine 83 zajednice su potroÅ”ile ukupno 374,10 litara vode. ProsjeÄna potroÅ”nja vode za promatrano razdoblje po zajednici bila je 5,19Ā±2,88 litara vode. ProsjeÄna dnevna potroÅ”nja vode po zajednici iznosila je 0,12Ā±0,07 litara vode.The bees must have continuous and adequate supply of good quality water for normal development and survival. In their work, the beekeepers use various water supply containers that usually have many disadvantages ( inadequate loading capacity, inconstant supply of water, unsatisfactory sanitary conditions). In order to study permanency, consumption and hygiene of water supply, a new model of hygienic water supply container has been constructed
and applied in the experiment on the island of Unije. The trial took place from 26 July to 29 September 2006 and it included six isolated apiaries of equal strength of colonies. During that period, 83 beehives consumed 374,10 litters of water, the average water consumption per beehive being 5,19 Ā± 2,88 liters. The average daily water consumption per beehive was 0,12 Ā± 0,07 liters
STANJE PÄELARSTVA U REPUBLICI HRVATSKOJ
In this paper analysis of beekeeping conditions, number and distribution of beekeepers and honeybee colonies, annual colony losses as well as honey production, export, import and consumption are given. Beekeeping in Croatia has a long tradition. In comparison to pasture potential and necessity for pollination of cultivated
and wild plants, present beekeeping is inadequately developed and distributed in different regions. According to data of the Croatian Livestock Center (2008) there are 313 978 honeybee colonies registered in the 2007 in Croatia on professional and sideline apiaries. The majority of honeybee colonies is placed in Pannonian region with 238 300 (76%), second in representation is in Mediterranean region with 59 763 (19%) and less represented is in
Mountain region with 15 915 (5%) honeybee colonies. Yearly honey production is approximately 5 000 t and 2 000 t of national honey consumption (0.4 kg per capita) gives possibility for honey export. Croatia exported 1 051 in 2003, but 274 t of honey in 2007, which indicates on significant export decreasing trend. Normal 10 % of winter colony losses till 2007 increased in 2007/2008 on 55 615 (41.71 %) in Pannonian region, 13 892 (37.46 %) in Mediterranean and 5 359 (32.71 %) in Mountain region. There is a need to make beekeeping much more flexible to fit into an integrated agricultural system, as well as more oriented to the consumersā demands, to be able to increase competitiveness.U ovom je radu prikazana analiza stanja pÄelarstva u Republici Hrvatskoj, broj i raspodjela pÄelara i pÄelinjih zajednica, godiÅ”nji gubitci pÄelinjih zajednica, kao i analiza proizvodnje i potroÅ”nje meda, te uvoza i izvoza meda. PÄelarstvo u Hrvatskoj ima dugu tradiciju. U odnosu na paÅ”ne potencijale i potrebu za opraÅ”ivanjem kultiviranog i samoniklog bilja, sadaÅ”nje je pÄelarstvo nedekvatno razvijeno i raspodjeljeno u razliÄitim regijama. Prema podatcima Hrvtaskog stoÄarskog centra (2008.), u Hrvatskoj je 2007. godine registrirano 313.978 pÄelinjih zajednica [2]. VeÄina pÄelinjih zajednica, odnosno 238.300 (76 %) smjeÅ”teno je u panonskoj regiji. Druga po zastupljenosti je mediteranska regija sa 59.763 pÄelinjih zajednica (19 %), a najmanji broj zajednica, odnosno 15.915
(5 %) nalazi se u gorskoj regiji. U Hrvatskoj se godiÅ”nje proizvede približno 5.000 tona meda [8], a potroÅ”i tek 2.000 t. PotroÅ”nja meda u Hrvatskoj je vrlo niska, samo 0,4 kg po stanovniku godiÅ”nje. Takav omjer proizvodnje i potroÅ”nje meda pruža moguÄnost za
izvoz. Hrvatska je u 2003. godini izvezla 1.051 t meda, a u 2007. godini 274 t, Å”to ukazuje na znaÄajan opadajuÄi trend izvoza meda. Normalnih 10 % zimskih gubitaka pÄelinjih zajednica u Hrvatskoj do 2007. godine, poraslo je u razdoblju 2007./2008. na 55.615 (41,71 %) u panonskoj regiji, 13.892 (37,46 %) u mediteranskoj i 5.359 (32,71 %) u gorskoj regiji. PÄelarstvo bi u Hrvatskoj trebalo biti fleksibilnije kako bi se uklopilo u integrirani poljiprivredni sektor, te usmjerenije zadovoljavanju potreba potroÅ”aÄa sa ciljem postizanja bolje konkurentnosti
POLLEN SPECTRUM AND VOLATILE COMPOUNDS IN THE HONEY SAC CONTENT AND MINT (MENTHA SPP.) HONEY
Bioraznolikost medonosnih biljnih vrsta iz razliÄitih klimatsko-zemljopisnih podruÄja
Hrvatske pruža veliki potencijal za proizvodnju specifiÄnih vrsta meda. MeÄutim, peludni
spektar, kao i kemijske znaÄajke veÄine hrvatskih vrsta meda nedovoljno su poznati. U
jednu od vrsta meda, koja nije sustavno istraživana, ubraja se i med od metvice (Mentha
spp.). Stoga je cilj istraživanja bio utvrditi botaniÄko podrijetlo i profil isparljivih spojeva iz
sadržaja mednog mjehura u odnosu na med od metvice te skupljaÄku aktivnost pÄelinje
zajednice na paŔi metvice. Istraživanje je bilo provedeno na pokusnoj lokaciji Mahovo
(podruÄje Parka prirode Lonjsko polje) na pet pokusnih pÄelinjih zajednica sive pÄele (Apis
mellifera carnica Pollmann, 1879), gdje je praÄena skupljaÄka aktivnost pÄelinje zajednice
i posjeÄenosti pÄela na paÅ”i metvice. Analiza sadržaja mednog mjehura i peludnog tereta
provedena je prema metodi Soehngen i Jay (1974). Na prikupljenim je uzorcima meda,
zatim, sadržaju mednog mjehura i peludnom teretu provedena kvalitativna
melisopalinoloÅ”ka analiza. Od fizikalno-kemijskih analiza bilo je provedeno utvrÄivanje
udjela vode, elektriÄne provodnosti i pH vrijednosti. Analiza isparljivih spojeva provedena
je pomoÄu mikroekstrakcije vrÅ”nih para na krutoj fazi (HS-SPME) i ultrazvuÄne ekstrakcije
organskim otapalima (USE) na uzorcima meda i sadržaju mednih mjehura. Od
analiziranih skupljaÄica najveÄi je udio bio onih koje su skupljale nektar (1 774), zatim one
koje su skupljale pelud (1 190), a najmanje onih kod kojih je utvrÄen puni medni mjehur i
peludni teret. U ranim popodnevnim satima (14:00) je utvrÄen statistiÄki znaÄajno veÄi broj
skupljaÄica s punim mednim mjehurom, kao i s peludnim teretom u usporedbi sa
skupljaÄicama prikupljenim u 9:00 i 18:00. ProsjeÄna se masa sadržaja mednog mjehura
kretala od 9,58 do 12,22 mg s rasponom od 0,20 do 50,60 mg. U uzorcima pÄela
skupljenih u 9:00 sati bila je utvrÄena statistiÄki znaÄajno niža prosjeÄna masa sadržaja
mednog mjehura (9,02 mg) u odnosu na uzorke prikupljene u 18:00 (11,06 mg) i one
prikupljene u 14:00 (12,04 mg). ProsjeÄna se masa peludnog tereta kretale od 4,77 mg do
9,60 mg, a raspon se kretao od 0,10 mg do 31,70 mg. U uzorcima pÄela skupljenih u 9:00
sati utvrÄena je statistiÄki znaÄajno niža masa peludnog tereta (7,73 mg) u odnosu na
uzorke prikupljene u 14:00 (8,63 mg), dok izmeÄu skupljaÄica prikupljenih u 9:00 i 18:00 te
14:00 i 18:00 nije bila utvrÄena statistiÄki znaÄajna razlika. Obzirom na posjeÄenost pÄela
paÅ”i metvice utvrÄeno je da je statistiÄki znaÄajno manji broj pÄela bio utvrÄen u 18:00 sati
(20,08) u odnosu na broj pÄela u 10:00 (30,22) i 13:00 sati (36,50). Prema utvrÄenom
peludnom spektru u analiziranim uzorcima meda, uz mirisnu metvicu (M. pulegium), kao
prateÄe biljne vrste bile su utvrÄene zlatoÅ”ipka (S. gigantea), amorfa (A. fruticosa), pitomi
kesten (C. sativa) i smiljkita (L corniculatus). Iz analiziranih uzoraka skupljaÄica utvrÄeno
je da je u njihovim peludnim teretima utvrÄen udio od 37,82% metvice, od kojih je veÄi
udio bio podrijetlom od mirisne metvice (20,42%) u odnosu na samo 1,93% peludi od
vodene metvice (M. aquatica). U uzorcima meda, prosjeÄni je udio vode iznosio 17,3 % s
rasponom od 14,5 do 18,8%, zatim je elektriÄna provodnost iznosila 0,62 mS/cm s
rasponom od 0,37 do 0,75 mS/cm te se je pH vrijednost kretala u rasponu od 3,52 do 4,15
s prosjekom od 3,80. Na osnovu analize isparljivih spojeva u uzorcima meda su po
intenzitetu izdvojeni metil-siringat i vomifoliol, dok je u ekstraktu mednih mjehura, uz
navedene spojeve, utvrÄen joÅ” i 3,7-Dimetilokta-1,5-dien-3,7-diol (terpendiol I). TakoÄer,
analizom vrÅ”nih para, kao najzastupljeniji spojevi, utvrÄeni su hotrienol, 2-metoksi-4metilfenol,
cis- i trans-linalol oksidi, linalol i nerol oksid.Nectariferous plants biodiversity from different climatic and geographical areas of Croatia
(Pannonian, Mountain and Adriatic) offers a great potential for the production of specific
types of honey. The diversity that we have in climazonal and biocenological schedule
represents a unique national treasure that is in Europe rarely found. However, due to nonsystematic
research, pollen spectrum and chemical properties of most Croatian honeys
are poorly understood. One of the honey types which is not systematically researched is
mint (Mentha spp.). According to available literature on European unifloral honeys, mint
honey belongs to rare types. Therefore the aim of this study was to characterize the mint
honey through determination of botanical origin (pollen spectrum) and content of the
honey sac and certain physical and chemical parameters (water content, electrical
conductivity and pH value). The second goal was to determine the profile of volatile
compounds in the honey sac content, as well as the end product, honey. At the same
time, one of the study goals was to investigate the behaviour of bees on mint nectar flow
through the foraging activity of bee colonies.
The research was conducted at the experimental site Mahovo, which is located in the
Lonjsko Polje Nature Park. Five experimental colonies of Carniolan (Apis mellifera carnica
Pollmann, 1879) bees in standard Langstroth-Root (LR) colonies were located at the
selected location. Gathering activity of honey bee colonies was conducted by sampling
from each colony three times a day (9:00, 14:00 and 18:00) for six days. Monitoring of the
foraging on the mint field was conducted on the five separate plots of 1 m2 by counting
bees for 1 min on the either side of the plot three times a day (10:00, 13:00, and 18:00) for
30 minutes during six days. Analysis of the honey-sac content and pollen loads was
carried out according to the method of Soehngen and Jay (1974). Qualitative
melisopalinological analysis of collected samples of honey, honey-sac content and the
pollen loads was conducted according to the methodology of von der Ohe et al. (2004).
From the physicochemical analyses, water content, electrical conductivity and pH were
performed. Analysis of volatile compounds was performed using solvent-free headspace
solid-phase microextraction (HS-SPME) and ultrasonic solvent extraction (USE) in the
honey samples and the honey sac content.
From the totally analysed 8 721 workers, 2 992 have brought nectar, pollen, or both, while
5 471 returned to the hive without load. From analysed foragers that delivered load, the
main portion was of those who have gathered nectar (1 774), then those who have
gathered pollen (1 190), but the least those with honey and pollen load, which implies that
most foragers are specialized in collecting either nectar or pollen. Statistically higher
number of foragers with nectar or pollen load were determined in the early afternoon
(14:00) compared with foragers collected in 9:00 and 18:00.
The average weight of honey-sac content ranged from 9.58 to 12.22 mg with a range of
0.20 to 50.60 mg. Significantly lower average weight of honey-sac content (9.02 mg) was
determined in collected samples of bees at 9:00 oāclock compared to samples collected at
18:00 (11.06 mg) and 14:00, when average weight of 12.04 mg was determined. In the
largest group of foragers weight load was ā¤ 10 mg, followed with group with load from 11
to 20 mg, and at the least number of bees collected ā„ 31 mg load.
Average weight of pollen load was from 4.77 to 9.60 mg, with range of 0.10 to 31.70 mg.
In the group of foragers collected at 9:00 oāclock statistically lower pollen load weight (7.73
mg) was determined in comparison to samples collected at 14:00 (8.63 mg). Contrary,
between groups collected at 9:00 and 18:00 as well as at 14:00 and 18:00 oāclock
difference was not significant.
Regarding attendance of bees to mint flowers, statistically lowest number of bees was
determined at 18:00 oāclock (20.08) in comparison to count at 10:00 (30.22) and 13:00
knowledge of the behaviour of bees foraging on mint. In addition to the scientific value of
the results, this study provides a contribution in practical terms, because they indicate
preliminary actions to be undertaken for the timely preparation of colonies for the main
pasture. At the same time, the original data on the profile of mint honey volatile
compounds can be used as potential biomarkers to determine its botanical origin.
Keywords: honeybee colony foraging activity, honey sac, pollen load, mint (Mentha spp.)
honey, pollen spectrum, volatile compounds
(36.50) oāclock.
According to pollen spectrum, accompanying plants to Mentha pulegium were Solidago
gigantea, Amorfa fruticosa, Castanea sativa and Lotus corniculatus.
From pollen loads of collected foragers it was determined that 37.82% samples contain
mint pollen, from which most part (20.42%) is from pennyroyal (M. pulegium) in
comparison to 1.93% of water mint (M. aquatica). Apart from mint pollen, additional 13
plant species were determined in the pollen loads, and the most frequent were Daucus
carota, Salvia spp, Ranunculus spp., Inula britanica, Plantago lanceolata, Solidago
gigantea, Amorfa fruticosa and Centaurea spp.
The average water content was 17.3% with a range from 14.5 to 18.8%. Electrical
conductivity was 0.62 mS/cm and the range from 0.37 to 0.75 mS/cm. pH value was in
range from 3.52 to 4.15 with the average of 3.80.
Based on the volatile compounds analysis of the honey-sac content, the most intensive
were 3 compounds: 3.7-dimethylocta-1.5-dien-3.7-diol (terpendiol I), followed by methyl
syringate and vomifoliol. In the extract of analysed honey samples were also 3.7dimethylocta-1.5-dien-3.7-diol
(terpendiol I). Also, by the analysis of major honey
headspace compounds hotrienol, cis- and trans-linalool oxides, linalool and neroloxide
were determined.
Valuable scientific contribution of the dissertation results from the first time connection of
the honey-sac content and the end product of honey, from monitoring of pollen spectrum
changes and the knowledge of volatile compounds fate. Analysis of mint honey was
performed using two complementary techniques, namely solvent-free headspace solidphase
microextraction (HS-SPME) and ultrasonic solvent extraction (USE). It was found
that both methods are suitable, since did not cause the formation of thermal artefacts
during the extraction of volatile compounds. Also, these methods are complementary
because the HS-SPME method enables extraction of the most volatile compounds which
are in equilibrium with a honey solution, while the USE method allows the isolation of
volatile and semi-volatile compounds. These methods are applied to mint honey for the
first time and enabled the preparation of chemical profiles, which represents an original
contribution to this work. The organic extract of the foragersā honey sac content on mint
nectar flow was analysed for the first time and methyl-siringat, terpendiol I and vomifoliol
found that can be attributable to plant origin. The other major compounds analysed in the
honey sac content were close to the part of cuticular waxes and less to bee pheromones.
Methyl syrnigate was the most common compound in ultrasonic assisted organic honey
extracts together with vomifoliol. Comparison of the organic honey extracts and extracts of
the honey sac content indicated that the methyl-syringate and vomifoliol are transferred to
honey, while terpendiol was partially transformed into hotrienol during maturation of
honey, which is also the original contribution to knowledge about the transport of volatile
compounds in relation nectar - honey sac - honey. Also, study results, based on exact
data, represent scientific contribution related to the biology of honeybee colony, i.e.,
knowledge of the behaviour of bees foraging on mint. In addition to the scientific value of
the results, this study provides a contribution in practical terms, because they indicate
preliminary actions to be undertaken for the timely preparation of colonies for the main
pasture. At the same time, the original data on the profile of mint honey volatile
compounds can be used as potential biomarkers to determine its botanical origin
POLLEN SPECTRUM AND VOLATILE COMPOUNDS IN THE HONEY SAC CONTENT AND MINT (MENTHA SPP.) HONEY
Bioraznolikost medonosnih biljnih vrsta iz razliÄitih klimatsko-zemljopisnih podruÄja
Hrvatske pruža veliki potencijal za proizvodnju specifiÄnih vrsta meda. MeÄutim, peludni
spektar, kao i kemijske znaÄajke veÄine hrvatskih vrsta meda nedovoljno su poznati. U
jednu od vrsta meda, koja nije sustavno istraživana, ubraja se i med od metvice (Mentha
spp.). Stoga je cilj istraživanja bio utvrditi botaniÄko podrijetlo i profil isparljivih spojeva iz
sadržaja mednog mjehura u odnosu na med od metvice te skupljaÄku aktivnost pÄelinje
zajednice na paŔi metvice. Istraživanje je bilo provedeno na pokusnoj lokaciji Mahovo
(podruÄje Parka prirode Lonjsko polje) na pet pokusnih pÄelinjih zajednica sive pÄele (Apis
mellifera carnica Pollmann, 1879), gdje je praÄena skupljaÄka aktivnost pÄelinje zajednice
i posjeÄenosti pÄela na paÅ”i metvice. Analiza sadržaja mednog mjehura i peludnog tereta
provedena je prema metodi Soehngen i Jay (1974). Na prikupljenim je uzorcima meda,
zatim, sadržaju mednog mjehura i peludnom teretu provedena kvalitativna
melisopalinoloÅ”ka analiza. Od fizikalno-kemijskih analiza bilo je provedeno utvrÄivanje
udjela vode, elektriÄne provodnosti i pH vrijednosti. Analiza isparljivih spojeva provedena
je pomoÄu mikroekstrakcije vrÅ”nih para na krutoj fazi (HS-SPME) i ultrazvuÄne ekstrakcije
organskim otapalima (USE) na uzorcima meda i sadržaju mednih mjehura. Od
analiziranih skupljaÄica najveÄi je udio bio onih koje su skupljale nektar (1 774), zatim one
koje su skupljale pelud (1 190), a najmanje onih kod kojih je utvrÄen puni medni mjehur i
peludni teret. U ranim popodnevnim satima (14:00) je utvrÄen statistiÄki znaÄajno veÄi broj
skupljaÄica s punim mednim mjehurom, kao i s peludnim teretom u usporedbi sa
skupljaÄicama prikupljenim u 9:00 i 18:00. ProsjeÄna se masa sadržaja mednog mjehura
kretala od 9,58 do 12,22 mg s rasponom od 0,20 do 50,60 mg. U uzorcima pÄela
skupljenih u 9:00 sati bila je utvrÄena statistiÄki znaÄajno niža prosjeÄna masa sadržaja
mednog mjehura (9,02 mg) u odnosu na uzorke prikupljene u 18:00 (11,06 mg) i one
prikupljene u 14:00 (12,04 mg). ProsjeÄna se masa peludnog tereta kretale od 4,77 mg do
9,60 mg, a raspon se kretao od 0,10 mg do 31,70 mg. U uzorcima pÄela skupljenih u 9:00
sati utvrÄena je statistiÄki znaÄajno niža masa peludnog tereta (7,73 mg) u odnosu na
uzorke prikupljene u 14:00 (8,63 mg), dok izmeÄu skupljaÄica prikupljenih u 9:00 i 18:00 te
14:00 i 18:00 nije bila utvrÄena statistiÄki znaÄajna razlika. Obzirom na posjeÄenost pÄela
paÅ”i metvice utvrÄeno je da je statistiÄki znaÄajno manji broj pÄela bio utvrÄen u 18:00 sati
(20,08) u odnosu na broj pÄela u 10:00 (30,22) i 13:00 sati (36,50). Prema utvrÄenom
peludnom spektru u analiziranim uzorcima meda, uz mirisnu metvicu (M. pulegium), kao
prateÄe biljne vrste bile su utvrÄene zlatoÅ”ipka (S. gigantea), amorfa (A. fruticosa), pitomi
kesten (C. sativa) i smiljkita (L corniculatus). Iz analiziranih uzoraka skupljaÄica utvrÄeno
je da je u njihovim peludnim teretima utvrÄen udio od 37,82% metvice, od kojih je veÄi
udio bio podrijetlom od mirisne metvice (20,42%) u odnosu na samo 1,93% peludi od
vodene metvice (M. aquatica). U uzorcima meda, prosjeÄni je udio vode iznosio 17,3 % s
rasponom od 14,5 do 18,8%, zatim je elektriÄna provodnost iznosila 0,62 mS/cm s
rasponom od 0,37 do 0,75 mS/cm te se je pH vrijednost kretala u rasponu od 3,52 do 4,15
s prosjekom od 3,80. Na osnovu analize isparljivih spojeva u uzorcima meda su po
intenzitetu izdvojeni metil-siringat i vomifoliol, dok je u ekstraktu mednih mjehura, uz
navedene spojeve, utvrÄen joÅ” i 3,7-Dimetilokta-1,5-dien-3,7-diol (terpendiol I). TakoÄer,
analizom vrÅ”nih para, kao najzastupljeniji spojevi, utvrÄeni su hotrienol, 2-metoksi-4metilfenol,
cis- i trans-linalol oksidi, linalol i nerol oksid.Nectariferous plants biodiversity from different climatic and geographical areas of Croatia
(Pannonian, Mountain and Adriatic) offers a great potential for the production of specific
types of honey. The diversity that we have in climazonal and biocenological schedule
represents a unique national treasure that is in Europe rarely found. However, due to nonsystematic
research, pollen spectrum and chemical properties of most Croatian honeys
are poorly understood. One of the honey types which is not systematically researched is
mint (Mentha spp.). According to available literature on European unifloral honeys, mint
honey belongs to rare types. Therefore the aim of this study was to characterize the mint
honey through determination of botanical origin (pollen spectrum) and content of the
honey sac and certain physical and chemical parameters (water content, electrical
conductivity and pH value). The second goal was to determine the profile of volatile
compounds in the honey sac content, as well as the end product, honey. At the same
time, one of the study goals was to investigate the behaviour of bees on mint nectar flow
through the foraging activity of bee colonies.
The research was conducted at the experimental site Mahovo, which is located in the
Lonjsko Polje Nature Park. Five experimental colonies of Carniolan (Apis mellifera carnica
Pollmann, 1879) bees in standard Langstroth-Root (LR) colonies were located at the
selected location. Gathering activity of honey bee colonies was conducted by sampling
from each colony three times a day (9:00, 14:00 and 18:00) for six days. Monitoring of the
foraging on the mint field was conducted on the five separate plots of 1 m2 by counting
bees for 1 min on the either side of the plot three times a day (10:00, 13:00, and 18:00) for
30 minutes during six days. Analysis of the honey-sac content and pollen loads was
carried out according to the method of Soehngen and Jay (1974). Qualitative
melisopalinological analysis of collected samples of honey, honey-sac content and the
pollen loads was conducted according to the methodology of von der Ohe et al. (2004).
From the physicochemical analyses, water content, electrical conductivity and pH were
performed. Analysis of volatile compounds was performed using solvent-free headspace
solid-phase microextraction (HS-SPME) and ultrasonic solvent extraction (USE) in the
honey samples and the honey sac content.
From the totally analysed 8 721 workers, 2 992 have brought nectar, pollen, or both, while
5 471 returned to the hive without load. From analysed foragers that delivered load, the
main portion was of those who have gathered nectar (1 774), then those who have
gathered pollen (1 190), but the least those with honey and pollen load, which implies that
most foragers are specialized in collecting either nectar or pollen. Statistically higher
number of foragers with nectar or pollen load were determined in the early afternoon
(14:00) compared with foragers collected in 9:00 and 18:00.
The average weight of honey-sac content ranged from 9.58 to 12.22 mg with a range of
0.20 to 50.60 mg. Significantly lower average weight of honey-sac content (9.02 mg) was
determined in collected samples of bees at 9:00 oāclock compared to samples collected at
18:00 (11.06 mg) and 14:00, when average weight of 12.04 mg was determined. In the
largest group of foragers weight load was ā¤ 10 mg, followed with group with load from 11
to 20 mg, and at the least number of bees collected ā„ 31 mg load.
Average weight of pollen load was from 4.77 to 9.60 mg, with range of 0.10 to 31.70 mg.
In the group of foragers collected at 9:00 oāclock statistically lower pollen load weight (7.73
mg) was determined in comparison to samples collected at 14:00 (8.63 mg). Contrary,
between groups collected at 9:00 and 18:00 as well as at 14:00 and 18:00 oāclock
difference was not significant.
Regarding attendance of bees to mint flowers, statistically lowest number of bees was
determined at 18:00 oāclock (20.08) in comparison to count at 10:00 (30.22) and 13:00
knowledge of the behaviour of bees foraging on mint. In addition to the scientific value of
the results, this study provides a contribution in practical terms, because they indicate
preliminary actions to be undertaken for the timely preparation of colonies for the main
pasture. At the same time, the original data on the profile of mint honey volatile
compounds can be used as potential biomarkers to determine its botanical origin.
Keywords: honeybee colony foraging activity, honey sac, pollen load, mint (Mentha spp.)
honey, pollen spectrum, volatile compounds
(36.50) oāclock.
According to pollen spectrum, accompanying plants to Mentha pulegium were Solidago
gigantea, Amorfa fruticosa, Castanea sativa and Lotus corniculatus.
From pollen loads of collected foragers it was determined that 37.82% samples contain
mint pollen, from which most part (20.42%) is from pennyroyal (M. pulegium) in
comparison to 1.93% of water mint (M. aquatica). Apart from mint pollen, additional 13
plant species were determined in the pollen loads, and the most frequent were Daucus
carota, Salvia spp, Ranunculus spp., Inula britanica, Plantago lanceolata, Solidago
gigantea, Amorfa fruticosa and Centaurea spp.
The average water content was 17.3% with a range from 14.5 to 18.8%. Electrical
conductivity was 0.62 mS/cm and the range from 0.37 to 0.75 mS/cm. pH value was in
range from 3.52 to 4.15 with the average of 3.80.
Based on the volatile compounds analysis of the honey-sac content, the most intensive
were 3 compounds: 3.7-dimethylocta-1.5-dien-3.7-diol (terpendiol I), followed by methyl
syringate and vomifoliol. In the extract of analysed honey samples were also 3.7dimethylocta-1.5-dien-3.7-diol
(terpendiol I). Also, by the analysis of major honey
headspace compounds hotrienol, cis- and trans-linalool oxides, linalool and neroloxide
were determined.
Valuable scientific contribution of the dissertation results from the first time connection of
the honey-sac content and the end product of honey, from monitoring of pollen spectrum
changes and the knowledge of volatile compounds fate. Analysis of mint honey was
performed using two complementary techniques, namely solvent-free headspace solidphase
microextraction (HS-SPME) and ultrasonic solvent extraction (USE). It was found
that both methods are suitable, since did not cause the formation of thermal artefacts
during the extraction of volatile compounds. Also, these methods are complementary
because the HS-SPME method enables extraction of the most volatile compounds which
are in equilibrium with a honey solution, while the USE method allows the isolation of
volatile and semi-volatile compounds. These methods are applied to mint honey for the
first time and enabled the preparation of chemical profiles, which represents an original
contribution to this work. The organic extract of the foragersā honey sac content on mint
nectar flow was analysed for the first time and methyl-siringat, terpendiol I and vomifoliol
found that can be attributable to plant origin. The other major compounds analysed in the
honey sac content were close to the part of cuticular waxes and less to bee pheromones.
Methyl syrnigate was the most common compound in ultrasonic assisted organic honey
extracts together with vomifoliol. Comparison of the organic honey extracts and extracts of
the honey sac content indicated that the methyl-syringate and vomifoliol are transferred to
honey, while terpendiol was partially transformed into hotrienol during maturation of
honey, which is also the original contribution to knowledge about the transport of volatile
compounds in relation nectar - honey sac - honey. Also, study results, based on exact
data, represent scientific contribution related to the biology of honeybee colony, i.e.,
knowledge of the behaviour of bees foraging on mint. In addition to the scientific value of
the results, this study provides a contribution in practical terms, because they indicate
preliminary actions to be undertaken for the timely preparation of colonies for the main
pasture. At the same time, the original data on the profile of mint honey volatile
compounds can be used as potential biomarkers to determine its botanical origin
POLLEN SPECTRUM AND VOLATILE COMPOUNDS IN THE HONEY SAC CONTENT AND MINT (MENTHA SPP.) HONEY
Bioraznolikost medonosnih biljnih vrsta iz razliÄitih klimatsko-zemljopisnih podruÄja
Hrvatske pruža veliki potencijal za proizvodnju specifiÄnih vrsta meda. MeÄutim, peludni
spektar, kao i kemijske znaÄajke veÄine hrvatskih vrsta meda nedovoljno su poznati. U
jednu od vrsta meda, koja nije sustavno istraživana, ubraja se i med od metvice (Mentha
spp.). Stoga je cilj istraživanja bio utvrditi botaniÄko podrijetlo i profil isparljivih spojeva iz
sadržaja mednog mjehura u odnosu na med od metvice te skupljaÄku aktivnost pÄelinje
zajednice na paŔi metvice. Istraživanje je bilo provedeno na pokusnoj lokaciji Mahovo
(podruÄje Parka prirode Lonjsko polje) na pet pokusnih pÄelinjih zajednica sive pÄele (Apis
mellifera carnica Pollmann, 1879), gdje je praÄena skupljaÄka aktivnost pÄelinje zajednice
i posjeÄenosti pÄela na paÅ”i metvice. Analiza sadržaja mednog mjehura i peludnog tereta
provedena je prema metodi Soehngen i Jay (1974). Na prikupljenim je uzorcima meda,
zatim, sadržaju mednog mjehura i peludnom teretu provedena kvalitativna
melisopalinoloÅ”ka analiza. Od fizikalno-kemijskih analiza bilo je provedeno utvrÄivanje
udjela vode, elektriÄne provodnosti i pH vrijednosti. Analiza isparljivih spojeva provedena
je pomoÄu mikroekstrakcije vrÅ”nih para na krutoj fazi (HS-SPME) i ultrazvuÄne ekstrakcije
organskim otapalima (USE) na uzorcima meda i sadržaju mednih mjehura. Od
analiziranih skupljaÄica najveÄi je udio bio onih koje su skupljale nektar (1 774), zatim one
koje su skupljale pelud (1 190), a najmanje onih kod kojih je utvrÄen puni medni mjehur i
peludni teret. U ranim popodnevnim satima (14:00) je utvrÄen statistiÄki znaÄajno veÄi broj
skupljaÄica s punim mednim mjehurom, kao i s peludnim teretom u usporedbi sa
skupljaÄicama prikupljenim u 9:00 i 18:00. ProsjeÄna se masa sadržaja mednog mjehura
kretala od 9,58 do 12,22 mg s rasponom od 0,20 do 50,60 mg. U uzorcima pÄela
skupljenih u 9:00 sati bila je utvrÄena statistiÄki znaÄajno niža prosjeÄna masa sadržaja
mednog mjehura (9,02 mg) u odnosu na uzorke prikupljene u 18:00 (11,06 mg) i one
prikupljene u 14:00 (12,04 mg). ProsjeÄna se masa peludnog tereta kretale od 4,77 mg do
9,60 mg, a raspon se kretao od 0,10 mg do 31,70 mg. U uzorcima pÄela skupljenih u 9:00
sati utvrÄena je statistiÄki znaÄajno niža masa peludnog tereta (7,73 mg) u odnosu na
uzorke prikupljene u 14:00 (8,63 mg), dok izmeÄu skupljaÄica prikupljenih u 9:00 i 18:00 te
14:00 i 18:00 nije bila utvrÄena statistiÄki znaÄajna razlika. Obzirom na posjeÄenost pÄela
paÅ”i metvice utvrÄeno je da je statistiÄki znaÄajno manji broj pÄela bio utvrÄen u 18:00 sati
(20,08) u odnosu na broj pÄela u 10:00 (30,22) i 13:00 sati (36,50). Prema utvrÄenom
peludnom spektru u analiziranim uzorcima meda, uz mirisnu metvicu (M. pulegium), kao
prateÄe biljne vrste bile su utvrÄene zlatoÅ”ipka (S. gigantea), amorfa (A. fruticosa), pitomi
kesten (C. sativa) i smiljkita (L corniculatus). Iz analiziranih uzoraka skupljaÄica utvrÄeno
je da je u njihovim peludnim teretima utvrÄen udio od 37,82% metvice, od kojih je veÄi
udio bio podrijetlom od mirisne metvice (20,42%) u odnosu na samo 1,93% peludi od
vodene metvice (M. aquatica). U uzorcima meda, prosjeÄni je udio vode iznosio 17,3 % s
rasponom od 14,5 do 18,8%, zatim je elektriÄna provodnost iznosila 0,62 mS/cm s
rasponom od 0,37 do 0,75 mS/cm te se je pH vrijednost kretala u rasponu od 3,52 do 4,15
s prosjekom od 3,80. Na osnovu analize isparljivih spojeva u uzorcima meda su po
intenzitetu izdvojeni metil-siringat i vomifoliol, dok je u ekstraktu mednih mjehura, uz
navedene spojeve, utvrÄen joÅ” i 3,7-Dimetilokta-1,5-dien-3,7-diol (terpendiol I). TakoÄer,
analizom vrÅ”nih para, kao najzastupljeniji spojevi, utvrÄeni su hotrienol, 2-metoksi-4metilfenol,
cis- i trans-linalol oksidi, linalol i nerol oksid.Nectariferous plants biodiversity from different climatic and geographical areas of Croatia
(Pannonian, Mountain and Adriatic) offers a great potential for the production of specific
types of honey. The diversity that we have in climazonal and biocenological schedule
represents a unique national treasure that is in Europe rarely found. However, due to nonsystematic
research, pollen spectrum and chemical properties of most Croatian honeys
are poorly understood. One of the honey types which is not systematically researched is
mint (Mentha spp.). According to available literature on European unifloral honeys, mint
honey belongs to rare types. Therefore the aim of this study was to characterize the mint
honey through determination of botanical origin (pollen spectrum) and content of the
honey sac and certain physical and chemical parameters (water content, electrical
conductivity and pH value). The second goal was to determine the profile of volatile
compounds in the honey sac content, as well as the end product, honey. At the same
time, one of the study goals was to investigate the behaviour of bees on mint nectar flow
through the foraging activity of bee colonies.
The research was conducted at the experimental site Mahovo, which is located in the
Lonjsko Polje Nature Park. Five experimental colonies of Carniolan (Apis mellifera carnica
Pollmann, 1879) bees in standard Langstroth-Root (LR) colonies were located at the
selected location. Gathering activity of honey bee colonies was conducted by sampling
from each colony three times a day (9:00, 14:00 and 18:00) for six days. Monitoring of the
foraging on the mint field was conducted on the five separate plots of 1 m2 by counting
bees for 1 min on the either side of the plot three times a day (10:00, 13:00, and 18:00) for
30 minutes during six days. Analysis of the honey-sac content and pollen loads was
carried out according to the method of Soehngen and Jay (1974). Qualitative
melisopalinological analysis of collected samples of honey, honey-sac content and the
pollen loads was conducted according to the methodology of von der Ohe et al. (2004).
From the physicochemical analyses, water content, electrical conductivity and pH were
performed. Analysis of volatile compounds was performed using solvent-free headspace
solid-phase microextraction (HS-SPME) and ultrasonic solvent extraction (USE) in the
honey samples and the honey sac content.
From the totally analysed 8 721 workers, 2 992 have brought nectar, pollen, or both, while
5 471 returned to the hive without load. From analysed foragers that delivered load, the
main portion was of those who have gathered nectar (1 774), then those who have
gathered pollen (1 190), but the least those with honey and pollen load, which implies that
most foragers are specialized in collecting either nectar or pollen. Statistically higher
number of foragers with nectar or pollen load were determined in the early afternoon
(14:00) compared with foragers collected in 9:00 and 18:00.
The average weight of honey-sac content ranged from 9.58 to 12.22 mg with a range of
0.20 to 50.60 mg. Significantly lower average weight of honey-sac content (9.02 mg) was
determined in collected samples of bees at 9:00 oāclock compared to samples collected at
18:00 (11.06 mg) and 14:00, when average weight of 12.04 mg was determined. In the
largest group of foragers weight load was ā¤ 10 mg, followed with group with load from 11
to 20 mg, and at the least number of bees collected ā„ 31 mg load.
Average weight of pollen load was from 4.77 to 9.60 mg, with range of 0.10 to 31.70 mg.
In the group of foragers collected at 9:00 oāclock statistically lower pollen load weight (7.73
mg) was determined in comparison to samples collected at 14:00 (8.63 mg). Contrary,
between groups collected at 9:00 and 18:00 as well as at 14:00 and 18:00 oāclock
difference was not significant.
Regarding attendance of bees to mint flowers, statistically lowest number of bees was
determined at 18:00 oāclock (20.08) in comparison to count at 10:00 (30.22) and 13:00
knowledge of the behaviour of bees foraging on mint. In addition to the scientific value of
the results, this study provides a contribution in practical terms, because they indicate
preliminary actions to be undertaken for the timely preparation of colonies for the main
pasture. At the same time, the original data on the profile of mint honey volatile
compounds can be used as potential biomarkers to determine its botanical origin.
Keywords: honeybee colony foraging activity, honey sac, pollen load, mint (Mentha spp.)
honey, pollen spectrum, volatile compounds
(36.50) oāclock.
According to pollen spectrum, accompanying plants to Mentha pulegium were Solidago
gigantea, Amorfa fruticosa, Castanea sativa and Lotus corniculatus.
From pollen loads of collected foragers it was determined that 37.82% samples contain
mint pollen, from which most part (20.42%) is from pennyroyal (M. pulegium) in
comparison to 1.93% of water mint (M. aquatica). Apart from mint pollen, additional 13
plant species were determined in the pollen loads, and the most frequent were Daucus
carota, Salvia spp, Ranunculus spp., Inula britanica, Plantago lanceolata, Solidago
gigantea, Amorfa fruticosa and Centaurea spp.
The average water content was 17.3% with a range from 14.5 to 18.8%. Electrical
conductivity was 0.62 mS/cm and the range from 0.37 to 0.75 mS/cm. pH value was in
range from 3.52 to 4.15 with the average of 3.80.
Based on the volatile compounds analysis of the honey-sac content, the most intensive
were 3 compounds: 3.7-dimethylocta-1.5-dien-3.7-diol (terpendiol I), followed by methyl
syringate and vomifoliol. In the extract of analysed honey samples were also 3.7dimethylocta-1.5-dien-3.7-diol
(terpendiol I). Also, by the analysis of major honey
headspace compounds hotrienol, cis- and trans-linalool oxides, linalool and neroloxide
were determined.
Valuable scientific contribution of the dissertation results from the first time connection of
the honey-sac content and the end product of honey, from monitoring of pollen spectrum
changes and the knowledge of volatile compounds fate. Analysis of mint honey was
performed using two complementary techniques, namely solvent-free headspace solidphase
microextraction (HS-SPME) and ultrasonic solvent extraction (USE). It was found
that both methods are suitable, since did not cause the formation of thermal artefacts
during the extraction of volatile compounds. Also, these methods are complementary
because the HS-SPME method enables extraction of the most volatile compounds which
are in equilibrium with a honey solution, while the USE method allows the isolation of
volatile and semi-volatile compounds. These methods are applied to mint honey for the
first time and enabled the preparation of chemical profiles, which represents an original
contribution to this work. The organic extract of the foragersā honey sac content on mint
nectar flow was analysed for the first time and methyl-siringat, terpendiol I and vomifoliol
found that can be attributable to plant origin. The other major compounds analysed in the
honey sac content were close to the part of cuticular waxes and less to bee pheromones.
Methyl syrnigate was the most common compound in ultrasonic assisted organic honey
extracts together with vomifoliol. Comparison of the organic honey extracts and extracts of
the honey sac content indicated that the methyl-syringate and vomifoliol are transferred to
honey, while terpendiol was partially transformed into hotrienol during maturation of
honey, which is also the original contribution to knowledge about the transport of volatile
compounds in relation nectar - honey sac - honey. Also, study results, based on exact
data, represent scientific contribution related to the biology of honeybee colony, i.e.,
knowledge of the behaviour of bees foraging on mint. In addition to the scientific value of
the results, this study provides a contribution in practical terms, because they indicate
preliminary actions to be undertaken for the timely preparation of colonies for the main
pasture. At the same time, the original data on the profile of mint honey volatile
compounds can be used as potential biomarkers to determine its botanical origin
THE STATE OF BEEKEEPING IN CROATIA
In this paper analysis of beekeeping conditions, number and distribution of beekeepers and honeybee colonies, annual colony losses as well as honey production, export, import and consumption are given. Beekeeping in Croatia has a long tradition. In comparison to pasture potential and necessity for pollination of cultivated and wild plants, present beekeeping is inadequately developed and distributed in different regions. According to data of the Croatian Livestock Center (2008) there are 313 978 honeybee colonies registered in the 2007 in Croatia on professional and sideline apiaries. The majority of honeybee colonies is placed in Pannonian region with 238 300 (76%), second in representation is in Mediterranean region with 59 763 (19%) and less represented is in Mountain region with 15 915 (5%) honeybee colonies. Yearly honey production is approximately 5 000 t and 2 000 t of national honey consumption (0.4 kg per capita) gives possibility for honey export. Croatia exported 1 051 in 2003, but 274 t of honey in 2007, which indicates on significant export decreasing trend. Normal 10 % of winter colony losses till 2007 increased in 2007/2008 on 55 615 (41.71 %) in Pannonian region, 13 892 (37.46 %) in Mediterranean and 5 359 (32.71 %) in Mountain region. There is a need to make beekeeping much more flexible to fit into an integrated agricultural system, as well as more oriented to the consumersā demands, to be able to increase competitiveness
Organic Extractives from Mentha spp. Honey and the Bee-Stomach: Methyl Syringate, Vomifoliol, Terpenediol I, Hotrienol and Other Compounds
The GC and GC/MS analyses of the solvent organic extractive from the stomach of the bees, having collected Mentha spp. nectar, revealed the presence of methyl syringate (6.6%), terpendiol I (5.0%) and vomifoliol (3.0%) that can be attributed to the plant origin. Other major compounds from the bee-stomach were related to the composition of cuticular waxes and less to pheromones. Organic extractivesfrom Mentha spp. honey were obtained by solvent-free headspace solid-phase microextraction (HS-SPME) and ultrasonic solvent extraction (USE) and analyzed by GC and GC/MS. The major honey headspace compounds were hotrienol (31.1%ā38.5%), 2-methoxy-4-methylphenol (0.5ā6.0%), cis- and trans-linalool oxides (0.9ā2.8%), linalool (1.0ā3.1%) and neroloxide (0.9ā1.9%). Methyl syringate was the most abundant compound (38.3-56.2%) in the honey solvent extractives followed by vomifoliol (7.0ā26.6%). Comparison of the honey organic extractives with the corresponding bee-stomach extractive indicated that methyl syringate and vomofoliol were transferred to the honey while terpendiol I was partially transformed to hotrienol in ripened honey