Evaluating the Presence and Contents of Phytochemicals in Honey Samples: Phenolic Compounds as Indicators to Identify Their Botanical Origin

Abstract

Honey is a natural product well known for its beneficial properties. It contains phytochemicals, a wide class of nutraceuticals found in plants, including compounds with highly demonstrated antimicrobial and antioxidant capacities as phenolic compounds and flavonoids. The main goal of this work is the development of a miniaturized and environmentally friendly methodology to obtain the phenolic profile of Galician honeys (Northwest Spain) from different varieties such as honeydew, chestnut, eucalyptus, heather, blackberry and multi-floral. The total phenolic content (TPC) and antioxidant activity (AA) were also evaluated. As regards sample preparation, miniaturized vortex (VE) and ultrasound assisted extraction (UAE) employing aqueous-based solvents were performed. Individual quantification of 41 target phenolic compounds was carried out by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Results revealed the presence of 25 phenolic compounds in the 91 analyzed samples, reaching concentrations up to 252 µg g−1. Statistical tools such as analysis of variance (ANOVA) and principal component analysis (PCA) were employed to obtain models that allowed classifying the different honeys according to their botanical origin. Obtained results, based on TPC, AA and ∑phenolic compounds showed that significant differences appeared depending on the honey variety, being several of the identified phenol compounds being responsible of the main differentiation.

Ultrasound-Assisted Extraction, Identification, and Quantification of Antioxidants from ‘Jinfeng’ Kiwifruit

“…Compound 14 produced the [M–H] − at m/z 179 and generated a secondary fragment at m/z 135 by losing a carboxyl group. Compared with the existing literature, this compound was identified as caffeic acid [ 25 , 54 ]. Compound 12 had the [M–H] − at m/z 341 on the MS with two fragment ions at m/z 179 ([M–H–hexoside] − ) and m/z 135 ([M–H–hexoside–COOH] − ) in the MS 2 spectrum.…”

Calluna vulgaris as a Valuable Source of Bioactive Compounds: Exploring Its Phytochemical Profile, Biological Activities and Apitherapeutic Potential

“…The biologically active compounds found in honey are the substances that are related to the beneficial properties exhibited on human health, with the antioxidant, anti-inflammatory and antibacterial effects [ 221 , 222 , 223 ] being the most common. The majority of these substances are transferred from the plant into the honey through the nectar and thus their composition is correlated with the geographical and botanical origin of the plant source [ 212 , 224 , 225 , 226 ]. Nevertheless, the composition and amount of these bioactive substances can be affected by other external factors such as the season, temperature, storage conditions, harvesting period, etc.…”

“…Another phenolic compound that can be considered a marker for heather honey is 3-hydroxyphenylacetic acid, which was identified in the study of Vazquez et al, 2021 [ 226 ]. This compound had a value ranging from 54 to 242 μg/g for Galician heather honey, being the most predominant phenolic compound in all of the 91 analyzed samples, and thus a specific authenticity marker for this honey variety.…”

Thorough Investigation of the Phenolic Profile of Reputable Greek Honey Varieties: Varietal Discrimination and Floral Markers Identification Using Liquid Chromatography–High-Resolution Mass Spectrometry

“…As we comprehensively discussed in our recent publication [ 3 ], chromatographic and spectroscopic techniques, alongside conventional methods measuring physicochemical properties, such as electrical conductivity or acidity, are commonly applied in the field. Although spectroscopic methods usually provide non-destructive analysis and conventional methods are widely available due to their low-cost, combining chromatography with mass spectrometry (MS) permits the detection of various analyte classes, e.g., pesticide residues (to check bio-production) [ 4 ], sugars (to evaluate quality characteristics towards established regulation, Directive 2001/110/EC) [ 5 ] or phenolic compounds (to estimate geographical, botanical or entomological origin) [ 6 , 7 ]. Importantly, phenolic compounds determination in honey authenticity studies can have a binary character, in detail, both as characteristic markers as well as to evaluate the nutritional value of honey due to their bioactivity [ 8 ].…”