Characterization of Botanical Origin of Italian Honey by Carbohydrate Composition and Volatile Organic Compounds (VOCs)

Abstract

Honey is a natural sweetener constituted by numerous macro- and micronutrients. Carbohydrates are the most representative, with glucose and fructose being the most abundant. Minor honey components like volatile organic compounds (VOCs), minerals, vitamins, amino acids are able to confer honey-specific properties and are useful to characterize and differentiate between honey varieties according to the botanical origin. The present work describes the chemical characterization of honeys of different botanical origin (multifloral, acacia, apple–dandelion, rhododendron, honeydew, and chestnut) produced and collected by beekeepers in the Trentino Alto-Adige region (Italy). Melissopalynological analysis was conducted to verify the botanical origin of samples and determine the frequency of different pollen families. The carbohydrate composition (fourteen sugars) and the profile of VOCs were evaluated permitting to investigate the relationship between pollen composition and the chemical profile of honey. Statistical analysis, particularly partial least squares discriminant analysis (PLS-DA), demonstrates the importance of classifying honey botanical origin on the basis of effective pollen composition, which directly influences honey’s biochemistry, in order to correctly define properties and value of honeys.

Selected Characteristics of Multifloral Honeys from North-Eastern Romania

“…Minimum percent of pollen for the characterization of monofloral honey is excepted in Robinia pseudoacacia (Italy-15%; Germany-20%; Croatia-20%; Serbia-20%; Romania-25%), Tilia spp. (Germany-20%; Croatia-25%; Serbia-25%; Romania-30%), and Helianthus annuus (Romania-40%) [3,12]. The differences can be seen in the FTIR spectral analysis, where, after examining sample S1, linden honey (Tillia sp.…”

“…Honey is heavy, with a mean value of specific gravity of 1.4 g/cm 3 . Specific gravity has a practical significance in keeping track of the amount of honey safely stored because it is correlated with moisture content.…”

“…The well-known types of honey produced and marketed in Romania are the common monofloral honeys: acacia; lime; rape; and sunflower. There are regulations established by some European countries regarding the minimum percentage of pollen required for the characterization of monofloral honey [3,12]. Under the limits provided by the legislation, honey is called poly(multi)flora, having as dominant two or more types of different plants' pollen.…”

Sidr Honeys Physical and Chemical Characterization, a Comprehensive Approach through LC-MS/MS, NMR, and GC-MS Analysis

“…The slides were then placed on a hot plate for 10 min. After drying, a drop of glycerin gelatin was dropped into it, which was then covered with a cover slip for identification [47].…”

“…A combination of GC-MS and SPME offers more information, including retention time (R t ), mass fragments for the volatile compounds, and more precise qualitative and quantitative results. The analysis of volatile compounds in foods, including fruits, vegetables, tea, wine, and honey, has been extensively conducted using this technique [47]. In the current study, 37 volatile compounds were identified and grouped into aldehydes (64.67 vs. 32.8%), ketones (16.54 vs. 32.04%), phenols (10.31 vs. 4.45%), acids and esters (7.46 vs. 23.01%), anthraquinone (0 vs. 6.38%), hydrocarbon (0.59 vs. 0%), and nitrogenous compounds (0.37 vs. 1.06%) for honey from Saudi Arabia and Egypt, respectively (Table 3).…”