The R-Values of Honey: Pollen Coefficients

Abstract

One of the goals of melissopalynology is to determine the floral sources utilized by honeybees in the production of honey. Because some types of commercial honey are preferred over others, the preferred types are in high demand and are sold at much higher prices. Verification of these preferred (premium) types of honey is often difficult because many of them come from plant sources that are either weak pollen producers or have pollen that is underrepresented in honey. In an effort to verify these premium honey types, researchers developed various methods for correcting the pollen data. These methods produce what are known as pollen coefficient (PC) values. Pollen coefficient values are used to verify honey types produced from floral sources that are over or under-represented in the relative pollen counts of a honey sample. We examine the historical development of PC values, the reliability of PC data, the flaws inherent in the development of various types of PC data, and the steps needed to formulate new types of PC values that would become universally accepted for the verification of honey types.

Pollen analyses of honey from Finland

“…Pollen analyses do not reveal all aspects of the botanical origin of honey, because the pollen grains found in honey samples rarely correspond one-to-one to the vegetation composition around the apiaries or the floral types they represent (Bryant & Jones, 2001). For example, Myosis spp., with its minute and numerous pollen grains, and Brassicaceae pollen are known to be over-represented in honey samples ( Van der Ohe et al, 2004).…”

“…On the other hand, pollen of Epilobium spp. and Calluna vulgaris seems to be under-represented in honey samples (Van der Ohe et al, 2004;Bryant & Jones, 2001). In many areas of eastern and northern Finland, bees produce large amounts of honey collected from Calluna vulgaris and Epilobium angustifolium.…”

“…However, pollen from these taxa occurs in small amounts even in unifloral honey (Ruottinen, 2005). The structure of the Epilobium angustifolium flowers is such that bees are able to collect nectar without touching the pollen bearing anthers, and the pollen grains are so large that bees are easily able to 1960, 1962, 1963, 1977and 1978(Varis et al, 1982, 2003 filter them out from the nectar (Bryant & Jones, 2001). The pollen content of these unifloral honeys requires further investigation.…”

Fluorescence spectroscopy coupled with PARAFAC and PLS DA for characterization and classification of honey

“…According 30 to botanical origin, honeys are classified into two groups: polyfloral that contains 31 nectar or honeydew from different plant species and monofloral with more than 45% 32 of pollen concentration from a single species (Bryant & Jones, 2001). Over the years, 33 numerous methods and analyses were proposed in order to describe the chemical 43 In recent years, the presence of fake honey in markets all over the world has become 44 an increasing problem.…”

The use of ETOH for the dilution of honey

“…Although pollen coefficient values were not the initial goal of Todd and Vansell (1942), their pioneering effort led others to compile lists of plants that are over or underrepresented by their relative pollen counts in honey samples (Berner 1952, Deans 1957, Demianowicz 1961, 1964Maurizio 1949Maurizio , 1955Maurizio , 1958Pritsch 1956, Sawyer 1988). The benefits and problems of using pollen R-values or pollen coefficient values have been discussed by various authors (Bryant & Jones 2001, Jones & Bryant 1992, 1996, Moar 1985, Sawyer 1981, 1988While et al 1962While et al , 1991. Regardless of the controversy over R-values and pollen coefficient values, all authors agree that pollen analysis is an essential tool to assess the botanical and geographical origin of honey (Agwu & Akanbi 1985, Barth 1990, Crane 1975Feller-Demalsy et al 1987a, 1989Lieux 1972Lieux , 1980Lieux , 1981Louveaux et al 1970, Maurizio 1951Moar 1985).…”