GNS Science Quantitative pollen analysis technique for New Zealand honey J.I. Raine, S. Fry, R. Tremain, D.C. Mildenhall GNS Science, PO Box 30368 Lower Hutt ([email protected]) REFERENCES Jones, G.; Bryant, V. 2001:Alcohol dilution of honey. . American Association of Stratigraphic Palynologists Foundation, pp. 453-458. Louveaux, J.; Maurizio, A.; Vorwohl, G. 1978: Methods of melissopalynology. : 139-157. Maher, L.J. 1971: Nomograms for computing 0.95 confidence limits of pollen data. : 85-93. Moar, N.T. 1985: Pollen analysis of New Zealand honey. : 39-70. Mosimann, J.E. 1965: Statistical methods for the pollen analyst: multinomial and negative multinomial techniques. In: B. Kummel and D. Raup (editors), . Freeman, SanFrancisco, California, pp. 636-673. Proceedings of the 9th International Palynological Congress, 1996, Houston, Texas, U.S.A Bee world 59 Review of palaeobotany and palynology 13 New Zealand Journal of Agricultural Research 28 Handbook of Palaeontological Techniques GNS SERVICES · routine honey pollen analyses for quality control using the technique described above, results provided as a standard report (left) verification of botanical and geographical origin of honeys, e.g. those of foreign origin · INTRODUCTION Analysis of the pollen content of honey has long been used to investigate provenance and provide a quantitative measure of floral origin (e.g. manuka pollen percentage) for use in commerce. To fully characterize pollen content, not only the botanical species present but their relative abundance and concentration should be obtained. The last is critical when honeys with different pollen profiles are blended, so that a blend may have a predictable percentage of characteristic pollen. However, accurate measurement can be time-consuming and expensive. For routine analysis of New Zealand honeys, GNS Science has developed a simple technique based on the standard European method of Maurizio described by Louveax et al. (1978). SOME CHARACTERISTIC NZ HONEY POLLEN Leptospermum type manuka/kanuka Metrosideros type rata/pohutukawa Knightia excelsa rewarewa Trifolium clover type Weinmannia kamahi Lotus Lamiaceae pennyroyal, thyme Echium type bugloss Taraxacum type dandelion Apiaceae fennel family Plantago rumex, dock (nectarless) HDE honey-dew fungi etc. acetolysed pollen, scale bars 10 m μ TECHNIQUE 10 g of honey is diluted with hot water and ethanol, and pollen concentrated by centrifugation (1-3). Use of ethanol reduces loss of pollen by flotation (Jones & Bryant 2001), and removes interfering wax particles. The pollen concentrate is resuspended in 1.0 ml of water, and a measured aliquot (typically 10 or 20 μl) of suspension mounted in glycerol jelly with Safranin stain on a microscope slide using a 22 x 22 mm coverslip (4-8). After sealing edges, these permanent slides are suitable for archiving and later re-examination. If needed, fuller botanical characterization is assisted by acetolysis (chemical clearing) of the pollen concentrate before mounting. Under the microscope, a pattern of regularly spaced traverses across the mount are examined and pollen grains of the various plant groups tallied (9). FUTURE DIRECTIONS training, advice and quality control for honey industry members seeking to establish their own laboratories production of technical manuals including a New Zealand honey pollen atlas research into pollen-based standards for honey description, extending the work of Moar (1985) · · · CALCULATION To provide suitable statistical precision, relative percent abundances are based on a total count of at least 500 pollen grains, and two standard deviation limits calculated (Mosimann 1965; Maher 1971). Pollen of nectarless plants (e.g. grass) and of honeydew elements are excluded from the total, and their relative abundance expressed as percentages of the total of nectar- bearing plant pollen. Absolute concentration, expressed as pollen grains per 10 g of honey, is calculated from the pollen count, the area of slide traversed, sample dilution, and aliquot volume. Honey Pollen Analysis Paleontology and Environmental Change Section Resources Group GNS Science PO Box 30368, 1 Fairway Avenue, Lower Hutt, New Zealand Telephone (04) 570 1444, Facsimile (04) 570 4600 Client: GNS Test Sample: GNS T10-C053 Analysis date: GNS laboratory number: L24903 Pollen concentration: pollen grains per 10 g honey Pollen type % mean min max manuka/kanuka 45.3 41.6 49.0 lotus 23.4 20.3 26.7 Apiaceae 6.6 4.9 8.7 clover 6.0 4.4 8.0 kamahi 4.5 3.2 6.4 other nectar-bearing plant pollen 14.3 11.9 17.1 0 0.0 0.0 0.0 0 0.0 0.0 0.0 0 0.0 0.0 0.0 0 0.0 0.0 0.0 nectarless plant pollen 0.4 % honey-dew elements (HDE) 0.9 % based on a total pollen count of pollen of nectar-bearing plants Palynological Classification: manuka multifloral Notes: other nectar-bearing plant pollen includes dandelion, rata, rewarewa. Technician: Sonja Fry Pollen analyst: Sonja Fry 95% limits 685 4/06/2010 746,000 1 2 3 4 5 6 7 8 9