Palyno–morphological and isotopic characterization of monofloral and multifloral honeys from Lucknow, India

Abstract

We describe and illustrate the detailed palyno–morphological attributes, based on light microscopy (LM) and field emission scanning electron microscopy (FESEM), as well as characterize the carbon stable isotopic (δ13C) values of filtered and unfiltered natural and commercial honey samples from Lucknow, India. The principal objective behind conducting the melissopalynological investigation is to gather relevant information about the pollen and nectar sources, foraged by honey bees in an area, which is a decade–old expansion of the city on an arable land. The pollen assemblages revealed one monofloral and two multifloral honey samples, ultimately provide insights into the variety of plants foraged by honey bees in an urban set–up, and is a potential archive for observing decadal changes in plant diversity. The carbon stable isotopic (δ13C) values of all the natural honeys varied from ~ –25 to –26‰, which relates to the regional vegetation types and environmental conditions. The difference between the filtered (without pollen) and unfiltered honey is ≤ 1.00‰. The δ13C values of the three commercial honey, which are filtered /without pollen are same i.e. –27‰. Hence, it is suggested that honey with pollen of diverse flora of the study area should be preferred by the consumers as a pure and also as a clinically safe food product.