molecules-logo

Journal Browser

Journal Browser

Progress in Analytical Methods for the Characterization, Quality and Safety of the Beehive Products

A special issue of Molecules (ISSN 1420-3049). This special issue belongs to the section "Analytical Chemistry".

Deadline for manuscript submissions: closed (31 May 2021) | Viewed by 48689

Printed Edition Available!
A printed edition of this Special Issue is available here.

Special Issue Editors


E-Mail Website
Guest Editor
Department of Chemical, Physical, Mathematical and Natural Sciences, University of Sassari, Via Vienna, 2, 07100 Sassari, Italy
Interests: analytical chemistry; validation of analytical methods; chemometrics and data analysis; environmental chemistry and monitoring; food chemistry and analysis; speciation analysis; science of materials; electroanalytical methods; sensors and biosensors; modification of electrode surfaces; gas-chromatography; liquid chromatography; hyphenated methods; ICP-MS methods; FT-IR methods; determination of trace analytes in foods; food georeferencing and traceability; bioaccumulation of toxic elements in cereals; synthesis and characterization of conductive polymers; biomedical analysis in dental research; studies of equilibria in solution between metal ions and ligands of biological interest; ability of vegetal biomasses in removal of organic pollutants by wastewaters
Special Issues, Collections and Topics in MDPI journals

E-Mail Website
Guest Editor
Dipartimento di Chimica e Farmacia, Università degli Studi di Sassari, Sassari, Italy
Interests: analytical chemistry; validation of analytical methods; chemometrics and data analysis; food chemistry and analysis; liquid chromatography; gas-chromatography; HPLC methods; GC methods; LC-MS; LC-MS/MS; GC-MS; SPME methods; extraction and characterization of bioactive compounds; determination of trace analytes in foods; food authentication and traceability
Special Issues, Collections and Topics in MDPI journals

E-Mail Website
Guest Editor
1. CIBER Epidemiology and Public Health (CIBERESP), Madrid, Spain
2. Food and Environmental Safety Research Group, Department of Preventive Medicine and Public Health, Food Science, Toxicology and Legal Medicine, University of Valencia, Avda. Vicente Andrés Estellés s/n, 46100 Burjassot, Valencia, Spain
3. Research Center on Desertification (CIDE, UV-CSIC-GV), Carretera Moncada-Náquera, 46113 Moncada, Valencia, Spain
Interests: development of new analytical methods to determine organic contaminants in food and the environment, identification of metabolites, degradation products and unknown compounds by liquid chromatography-mass spectrometry; environmental risk assessment; environmental and food safety; application of “omics” techniques to environmental problems; development of environmental forensic approaches
Special Issues, Collections and Topics in MDPI journals

E-Mail Website
Guest Editor
Department of Chemistry and Pharmacy, Sassari University, Sassari, Italy
Interests: analytical chemistry; development and validation of analytical methods (liquid- and gas-chromatography, spectroscopic methods, HPLC-ICP-MS, electroanalytical methods); food chemistry and analysis; environmental chemistry; speciation analysis; sensors and biosensors; synthesis and characterization of conductive polymers; studies of equilibria in solution between metal ions and ligands of biological interest; characterization of different components in biomasses
Special Issues, Collections and Topics in MDPI journals

E-Mail Website
Guest Editor
Department of Life and Environmental Sciences, Università degli studi di Cagliari, Cagliari, Italy
Interests: food chemistry and analysis; natural bioactive compounds; antioxidants; phenolic compounds; beehive products; analytical chemistry; validation of analytical methods; extraction techniques; liquid-chromatography; gas-chromatography; hyphenated methods; chemometrics and data analysis; agro-food quality control; by-product valorization
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Although beehive products have been known for millennia by humankind, their relevance in contemporary society is continuously growing. The most popular of them, honey, already used by the Neolithic man as a sweetener and medicament, is the object of thousands of published contributions. In addition, scientists also show an untiring interest towards other beehive products like beeswax, pollen, propolis, and royal jelly. The reasons for this success are several: Alongside the growing awareness of consumers that the biological and health properties of beehive foods strongly depend on factors like freshness, quality, safety, and origin, the scientific and technologic evolution of the analytical approaches is reflected in the improvement of specificity, sensitivity, accuracy, and robustness of the methods used for their characterization. Hence, this Special Issue of Molecules will be mainly addressed to collect original articles, reviews, and technical notes providing the most recent and performing methods aimed to characterize, in terms of both quality and safety, beehive and beehive-derived products. Emphasis will be devoted to original, fully validated methods, as well as to new chemometric procedures aimed at maximizing the information contained in analytical data.

Dr. Gavino Sanna
Dr. Marco Ciulu, PhD
Dr. Yolanda Picò
Dr. Nadia Spano, PhD
Prof. Dr. Carlo I.G. Tuberoso
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Molecules is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Beehive products
  • Honey
  • Propolis
  • Beeswax
  • Royal jelly
  • Pollen
  • Nectar
  • Bee venom
  • Food traceability
  • Food quality
  • Food safety
  • Spectroscopy
  • Chromatography
  • Electroanalysis
  • Mass spectrometry
  • Hyphenated methods
  • Chemometrics
  • Saccharides
  • Lipids
  • Proteins
  • Amino acids
  • Polyphenols
  • Flavonoids
  • Vitamins
  • Trace compounds
  • Volatile compounds
  • Contaminants

Published Papers (15 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

16 pages, 1670 KiB  
Article
Multi-Elemental Analysis as a Tool to Ascertain the Safety and the Origin of Beehive Products: Development, Validation, and Application of an ICP-MS Method on Four Unifloral Honeys Produced in Sardinia, Italy
by Andrea Mara, Sara Deidda, Marco Caredda, Marco Ciulu, Mario Deroma, Emanuele Farinini, Ignazio Floris, Ilaria Langasco, Riccardo Leardi, Maria I. Pilo, Nadia Spano and Gavino Sanna
Molecules 2022, 27(6), 2009; https://doi.org/10.3390/molecules27062009 - 21 Mar 2022
Cited by 11 | Viewed by 2272
Abstract
Despite unifloral honeys from Sardinia, Italy, being appreciated worldwide for their peculiar organoleptic features, their elemental signature has only partly been investigated. Hence, the principal aim of this study was to measure the concentration of trace and toxic elements (i.e., Ag, As, Ba, [...] Read more.
Despite unifloral honeys from Sardinia, Italy, being appreciated worldwide for their peculiar organoleptic features, their elemental signature has only partly been investigated. Hence, the principal aim of this study was to measure the concentration of trace and toxic elements (i.e., Ag, As, Ba, Be, Bi, Cd, Co, Cr, Cu, Fe, Hg, Li, Mn, Mo, Ni, Pb, Sb, Sn, Sr, Te, Tl, V, and Zn) in four unifloral honeys produced in Sardinia. For this purpose, an original ICP-MS method was developed, fully validated, and applied on unifloral honeys from asphodel, eucalyptus, strawberry tree, and thistle. Particular attention was paid to the method’s development: factorial design was applied for the optimization of the acid microwave digestion, whereas the instrumental parameters were tuned to minimize the polyatomic interferences. Most of the analytes’ concentration ranged between the relevant LoDs and few mg kg−1, while toxic elements were present in negligible amounts. The elemental signatures of asphodel and thistle honeys were measured for the first time, whereas those of eucalyptus and strawberry tree honeys suggested a geographical differentiation if compared with the literature. Chemometric analysis allowed for the botanical discrimination of honeys through their elemental signature, whereas linear discriminant analysis provided an accuracy level of 87.1%. Full article
Show Figures

Figure 1

12 pages, 972 KiB  
Article
An Analytical Method for the Biomonitoring of Mercury in Bees and Beehive Products by Cold Vapor Atomic Fluorescence Spectrometry
by Maria Luisa Astolfi, Marcelo Enrique Conti, Martina Ristorini, Maria Agostina Frezzini, Marco Papi, Lorenzo Massimi and Silvia Canepari
Molecules 2021, 26(16), 4878; https://doi.org/10.3390/molecules26164878 - 12 Aug 2021
Cited by 15 | Viewed by 2961
Abstract
Bees and their products are useful bioindicators of anthropogenic activities and could overcome the deficiencies of air quality networks. Among the environmental contaminants, mercury (Hg) is a toxic metal that can accumulate in living organisms. The first aim of this study was to [...] Read more.
Bees and their products are useful bioindicators of anthropogenic activities and could overcome the deficiencies of air quality networks. Among the environmental contaminants, mercury (Hg) is a toxic metal that can accumulate in living organisms. The first aim of this study was to develop a simple analytical method to determine Hg in small mass samples of bees and beehive products by cold vapor atomic fluorescence spectrometry. The proposed method was optimized for about 0.02 g bee, pollen, propolis, and royal jelly, 0.05 g beeswax and honey, or 0.1 g honeydew with 0.5 mL HCl, 0.2 mL HNO3, and 0.1 mL H2O2 in a water bath (95 °C, 30 min); samples were made up to a final volume of 5 mL deionized water. The method limits sample manipulation and the reagent mixture volume used. Detection limits were lower than 3 µg kg−1 for a sample mass of 0.02 g, and recoveries and precision were within 20% of the expected value and less than 10%, respectively, for many matrices. The second aim of the present study was to evaluate the proposed method’s performances on real samples collected in six areas of the Lazio region in Italy. Full article
Show Figures

Graphical abstract

14 pages, 2172 KiB  
Article
Electrochemical Determination of the “Furanic Index” in Honey
by Severyn Salis, Nadia Spano, Marco Ciulu, Ignazio Floris, Maria I. Pilo and Gavino Sanna
Molecules 2021, 26(14), 4115; https://doi.org/10.3390/molecules26144115 - 6 Jul 2021
Cited by 9 | Viewed by 1937
Abstract
5-(hydroxymethyl)furan-2-carbaldehyde, better known as hydroxymethylfurfural (HMF), is a well-known freshness parameter of honey: although mostly absent in fresh samples, its concentration tends to increase naturally with aging. However, high quantities of HMF are also found in fresh but adulterated samples or honey subjected [...] Read more.
5-(hydroxymethyl)furan-2-carbaldehyde, better known as hydroxymethylfurfural (HMF), is a well-known freshness parameter of honey: although mostly absent in fresh samples, its concentration tends to increase naturally with aging. However, high quantities of HMF are also found in fresh but adulterated samples or honey subjected to thermal or photochemical stresses. In addition, HMF deserves further consideration due to its potential toxic effects on human health. The processes at the origin of HMF formation in honey and in other foods, containing saccharides and proteins—mainly non-enzymatic browning reactions—can also produce other furanic compounds. Among others, 2-furaldehyde (2F) and 2-furoic acid (2FA) are the most abundant in honey, but also their isomers (i.e., 3-furaldehyde, 3F, and 3-furoic acid, 3FA) have been found in it, although in small quantities. A preliminary characterization of HMF, 2F, 2FA, 3F, and 3FA by cyclic voltammetry (CV) led to hypothesizing the possibility of a comprehensive quantitative determination of all these compounds using a simple and accurate square wave voltammetry (SWV) method. Therefore, a new parameter able to provide indications on quality of honey, named “Furanic Index” (FI), was proposed in this contribution, which is based on the simultaneous reduction of all analytes on an Hg electrode to ca. −1.50 V vs. Saturated Calomel Electrode (SCE). The proposed method, validated, and tested on 10 samples of honeys of different botanical origin and age, is fast and accurate, and, in the case of strawberry tree honey (Arbutus unedo), it highlighted the contribution to the FI of the homogentisic acid (HA), i.e., the chemical marker of the floral origin of this honey, which was quantitatively reduced in the working conditions. Excellent agreement between the SWV and Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC) data was observed in all samples considered. Full article
Show Figures

Figure 1

15 pages, 1296 KiB  
Article
Characterizing the Volatile and Sensory Profiles, and Sugar Content of Beeswax, Beebread, Bee Pollen, and Honey
by Małgorzata Starowicz, Paweł Hanus, Grzegorz Lamparski and Tomasz Sawicki
Molecules 2021, 26(11), 3410; https://doi.org/10.3390/molecules26113410 - 4 Jun 2021
Cited by 22 | Viewed by 4459
Abstract
Bee products are a well-known remedy against numerous diseases. However, from the consumers’ perspective, it is essential to define factors that can affect their sensory acceptance. This investigation aimed to evaluate the volatile and sensory profiles, and sugar composition of beeswax, beebread, pollen, [...] Read more.
Bee products are a well-known remedy against numerous diseases. However, from the consumers’ perspective, it is essential to define factors that can affect their sensory acceptance. This investigation aimed to evaluate the volatile and sensory profiles, and sugar composition of beeswax, beebread, pollen, and honey. According to the HS-SPME/GC-MS results, 20 volatiles were identified in beeswax and honey, then 32 in beebread, and 33 in pollen. Alkanes were found to dominate in beeswax, beebread, and pollen, while aldehydes and monoterpenes in honey. In the case of sugars, a higher content of fructose was determined in beebread, bee pollen, and honey, whereas the highest content of glucose was assayed in beeswax. In the QDA, the highest aroma intensity characterized as honey-like and sweet was found in honey, while the acid aroma was typical of beebread. Other odor descriptors, including waxy, pungent, and plant-based aromas were noted only in beeswax, honey, and pollen, respectively. Full article
Show Figures

Figure 1

14 pages, 3191 KiB  
Article
LC-ESI/LTQ-Orbitrap-MS Based Metabolomics in Evaluation of Bitter Taste of Arbutus unedo Honey
by Paola Montoro, Gilda D’Urso, Adam Kowalczyk and Carlo Ignazio Giovanni Tuberoso
Molecules 2021, 26(9), 2765; https://doi.org/10.3390/molecules26092765 - 8 May 2021
Cited by 7 | Viewed by 2888
Abstract
Strawberry tree honey is a high-value honey from the Mediterranean area and it is characterised by a typical bitter taste. To possibly identify the secondary metabolites responsible for the bitter taste, the honey was fractionated on a C18 column and the individual fractions [...] Read more.
Strawberry tree honey is a high-value honey from the Mediterranean area and it is characterised by a typical bitter taste. To possibly identify the secondary metabolites responsible for the bitter taste, the honey was fractionated on a C18 column and the individual fractions were subjected to sensory analysis and then analysed by liquid chromatography coupled with high-resolution tandem mass spectrometry in negative ion mode, using a mass spectrometer with an electrospray source coupled to a hybrid high resolution mass analyser (LC-ESI/LTQ-Orbitrap-MS). A chemometric model obtained by preliminary principal component analysis (PCA) of LC-ESI/LTQ-Orbitrap-MS data allowed the identification of the fractions that caused the perception of bitterness. Subsequently, a partial least squares (PLS) regression model was built. The studies carried out with multivariate analysis showed that unedone (2-(1,2-dihydroxypropyl)-4,4,8-trimethyl-1-oxaspiro [2.5] oct-7-en-6-one) can be considered responsible for the bitter taste of strawberry tree honey. Confirmation of the bitter taste of unedone was obtained by sensory evaluation of a pure standard, allowing it to be added to the list of natural compounds responsible for giving the sensation of bitterness to humans. Full article
Show Figures

Graphical abstract

16 pages, 749 KiB  
Article
Mining the Royal Jelly Proteins: Combinatorial Hexapeptide Ligand Library Significantly Improves the MS-Based Proteomic Identification in Complex Biological Samples
by Eliza Matuszewska, Joanna Matysiak, Grzegorz Rosiński, Elżbieta Kędzia, Weronika Ząbek, Jarosław Zawadziński and Jan Matysiak
Molecules 2021, 26(9), 2762; https://doi.org/10.3390/molecules26092762 - 7 May 2021
Cited by 7 | Viewed by 2503
Abstract
Royal jelly (RJ) is a complex, creamy secretion produced by the glands of worker bees. Due to its health-promoting properties, it is used by humans as a dietary supplement. However, RJ compounds are not fully characterized yet. Hence, in this research, we aimed [...] Read more.
Royal jelly (RJ) is a complex, creamy secretion produced by the glands of worker bees. Due to its health-promoting properties, it is used by humans as a dietary supplement. However, RJ compounds are not fully characterized yet. Hence, in this research, we aimed to broaden the knowledge of the proteomic composition of fresh RJ. Water extracts of the samples were pre-treated using combinatorial hexapeptide ligand libraries (ProteoMinerTM kit), trypsin-digested, and analyzed by a nanoLC-MALDI-TOF/TOF MS system. To check the ProteoMinerTM performance in the MS-based protein identification, we also examined RJ extracts that were not prepared with the ProteoMinerTM kit. We identified a total of 86 proteins taxonomically classified to Apis spp. (bees). Among them, 74 proteins were detected in RJ extracts pre-treated with ProteoMinerTM kit, and only 50 proteins were found in extracts non-enriched with this technique. Ten of the identified features were hypothetical proteins whose existence has been predicted, but any experimental evidence proves their in vivo expression. Additionally, we detected four uncharacterized proteins of unknown functions. The results of this research indicate that the ProteoMinerTM strategy improves proteomic identification in complex biological samples. Broadening the knowledge of RJ composition may contribute to the development of standards and regulations, enhancing the quality of RJ, and consequently, the safety of its supplementation. Full article
Show Figures

Figure 1

15 pages, 964 KiB  
Article
The Comparison of Physicochemical Parameters, Antioxidant Activity and Proteins for the Raw Local Polish Honeys and Imported Honey Blends
by Michał Miłek, Aleksandra Bocian, Ewelina Kleczyńska, Patrycja Sowa and Małgorzata Dżugan
Molecules 2021, 26(9), 2423; https://doi.org/10.3390/molecules26092423 - 21 Apr 2021
Cited by 17 | Viewed by 2788
Abstract
Many imported honeys distributed on the Polish market compete with local products mainly by lower price, which can correspond to lower quality and widespread adulteration. The aim of the study was to compare honey samples (11 imported honey blends and 5 local honeys) [...] Read more.
Many imported honeys distributed on the Polish market compete with local products mainly by lower price, which can correspond to lower quality and widespread adulteration. The aim of the study was to compare honey samples (11 imported honey blends and 5 local honeys) based on their antioxidant activity (measured by DPPH, FRAP, and total phenolic content), protein profile obtained by native PAGE, soluble protein content, diastase, and acid phosphatase activities identified by zymography. These indicators were correlated with standard quality parameters (water, HMF, pH, free acidity, and electrical conductivity). It was found that raw local Polish honeys show higher antioxidant and enzymatic activity, as well as being more abundant in soluble protein. With the use of principal component analysis (PCA) and stepwise linear discriminant analysis (LDA) protein content and diastase number were found to be significant (p < 0.05) among all tested parameters to differentiate imported honey from raw local honeys. Full article
Show Figures

Graphical abstract

18 pages, 728 KiB  
Article
Multielemental Analysis of Bee Pollen, Propolis, and Royal Jelly Collected in West-Central Poland
by Eliza Matuszewska, Agnieszka Klupczynska, Krzysztof Maciołek, Zenon J. Kokot and Jan Matysiak
Molecules 2021, 26(9), 2415; https://doi.org/10.3390/molecules26092415 - 21 Apr 2021
Cited by 27 | Viewed by 4697
Abstract
Beehive products possess nutritional value and health-promoting properties and are recommended as so-called “superfoods”. However, because of their natural origin, they may contain relevant elemental contaminants. Therefore, to assess the quality of bee products, we examined concentrations of a broad range of 24 [...] Read more.
Beehive products possess nutritional value and health-promoting properties and are recommended as so-called “superfoods”. However, because of their natural origin, they may contain relevant elemental contaminants. Therefore, to assess the quality of bee products, we examined concentrations of a broad range of 24 selected elements in propolis, bee pollen, and royal jelly. The quantitative analyses were performed with inductively coupled plasma-mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP-OES) techniques. The results of our research indicate that bee products contain essential macronutrients (i.e., K, P, and S) and micronutrients (i.e., Zn and Fe) in concentrations depending on the products’ type. However, the presence of toxic heavy metals makes it necessary to test the quality of bee products before using them as dietary supplements. Bearing in mind that bee products are highly heterogenous and, depending on the environmental factors, differ in their elemental content, it is necessary to develop standards regulating the acceptable levels of inorganic pollutants. Furthermore, since bees and their products are considered to be an effective biomonitoring tool, our results may reflect the environment’s condition in west-central Poland, affecting the health and well-being of both humans and bees. Full article
Show Figures

Figure 1

9 pages, 1056 KiB  
Article
Classification of Unifloral Honeys from SARDINIA (Italy) by ATR-FTIR Spectroscopy and Random Forest
by Marco Ciulu, Elisa Oertel, Rosanna Serra, Roberta Farre, Nadia Spano, Marco Caredda, Luca Malfatti and Gavino Sanna
Molecules 2021, 26(1), 88; https://doi.org/10.3390/molecules26010088 - 27 Dec 2020
Cited by 16 | Viewed by 2947
Abstract
Nowadays, the mislabeling of honey floral origin is a very common fraudulent practice. The scientific community is intensifying its efforts to provide the bodies responsible for controlling the authenticity of honey with fast and reliable analytical protocols. In this study, the classification of [...] Read more.
Nowadays, the mislabeling of honey floral origin is a very common fraudulent practice. The scientific community is intensifying its efforts to provide the bodies responsible for controlling the authenticity of honey with fast and reliable analytical protocols. In this study, the classification of various monofloral honeys from Sardinia, Italy, was attempted by means of ATR-FTIR spectroscopy and random forest. Four different floral origins were considered: strawberry-tree (Arbutus Unedo L.), asphodel (Asphodelus microcarpus), thistle (Galactites tormentosa), and eucalyptus (Eucalyptus calmadulensis). Training a random forest on the infrared spectra allowed achieving an average accuracy of 87% in a cross-validation setting. The identification of the significant wavenumbers revealed the important role played by the region 1540–1175 cm−1 and, to a lesser extent, the region 1700–1600 cm−1. The contribution of the phenolic fraction was identified as the main responsible for this observation. Full article
Show Figures

Figure 1

10 pages, 2605 KiB  
Article
Determination of Ascorbic Acid, Total Ascorbic Acid, and Dehydroascorbic Acid in Bee Pollen Using Hydrophilic Interaction Liquid Chromatography-Ultraviolet Detection
by Meifei Zhu, Jian Tang, Xijuan Tu and Wenbin Chen
Molecules 2020, 25(23), 5696; https://doi.org/10.3390/molecules25235696 - 3 Dec 2020
Cited by 19 | Viewed by 2982
Abstract
Ascorbic acid (AA) is one of the essential nutrients in bee pollen, however, it is unstable and likely to be oxidized. Generally, the oxidation form (dehydroascorbic acid (DHA)) is considered to have equivalent biological activity as the reduction form. Thus, determination of the [...] Read more.
Ascorbic acid (AA) is one of the essential nutrients in bee pollen, however, it is unstable and likely to be oxidized. Generally, the oxidation form (dehydroascorbic acid (DHA)) is considered to have equivalent biological activity as the reduction form. Thus, determination of the total content of AA and DHA would be more accurate for the nutritional analysis of bee pollen. Here we present a simple, sensitive, and reliable method for the determination of AA, total ascorbic acids (TAA), and DHA in rape (Brassica campestris), lotus (Nelumbo nucifera), and camellia (Camellia japonica) bee pollen, which is based on ultrasonic extraction in metaphosphoric acid solution, and analysis using hydrophilic interaction liquid chromatography (HILIC)-ultraviolet detection. Analytical performance of the method was evaluated and validated, then the proposed method was successfully applied in twenty-one bee pollen samples. Results indicated that contents of AA were in the range of 17.54 to 94.01 µg/g, 66.01 to 111.66 µg/g, and 90.04 to 313.02 µg/g for rape, lotus, and camellia bee pollen, respectively. In addition, percentages of DHA in TAA showed good intra-species consistency, with values of 13.7%, 16.5%, and 7.6% in rape, lotus, and camellia bee pollen, respectively. This is the first report on the discriminative determination between AA and DHA in bee pollen matrices. The proposed method would be valuable for the nutritional analysis of bee pollen. Full article
Show Figures

Figure 1

20 pages, 1882 KiB  
Article
Effectiveness of Different Sample Treatments for the Elemental Characterization of Bees and Beehive Products
by Maria Luisa Astolfi, Marcelo Enrique Conti, Elisabetta Marconi, Lorenzo Massimi and Silvia Canepari
Molecules 2020, 25(18), 4263; https://doi.org/10.3390/molecules25184263 - 17 Sep 2020
Cited by 24 | Viewed by 3225
Abstract
Bee health and beehive products’ quality are compromised by complex interactions between multiple stressors, among which toxic elements play an important role. The aim of this study is to optimize and validate sensible and reliable analytical methods for biomonitoring studies and the quality [...] Read more.
Bee health and beehive products’ quality are compromised by complex interactions between multiple stressors, among which toxic elements play an important role. The aim of this study is to optimize and validate sensible and reliable analytical methods for biomonitoring studies and the quality control of beehive products. Four digestion procedures, including two systems (microwave oven and water bath) and different mixture reagents, were evaluated for the determination of the total content of 40 elements in bees and five beehive products (beeswax, honey, pollen, propolis and royal jelly) by using inductively coupled plasma mass and optical emission spectrometry. Method validation was performed by measuring a standard reference material and the recoveries for each selected matrix. The water bath-assisted digestion of bees and beehive products is proposed as a fast alternative to microwave-assisted digestion for all elements in biomonitoring studies. The present study highlights the possible drawbacks that may be encountered during the elemental analysis of these biological matrices and aims to be a valuable aid for the analytical chemist. Total elemental concentrations, determined in commercially available beehive products, are presented. Full article
Show Figures

Graphical abstract

12 pages, 1112 KiB  
Article
Grouping, Spectrum–Effect Relationship and Antioxidant Compounds of Chinese Propolis from Different Regions Using Multivariate Analyses and Off-Line Anti-DPPH Assay
by Xiasen Jiang, Linchen Tao, Chunguang Li, Mengmeng You, George Q. Li, Cuiping Zhang and Fuliang Hu
Molecules 2020, 25(14), 3243; https://doi.org/10.3390/molecules25143243 - 16 Jul 2020
Cited by 12 | Viewed by 2372
Abstract
49 samples of propolis from different regions in China were collected and analyzed for their chemical compositions, contents of total flavonoids (TFC), total phenolic acid (TPC) and antioxidant activity. High-performance liquid chromatography (HPLC) analysis identified 15 common components, including key marker compounds pinocembrin, [...] Read more.
49 samples of propolis from different regions in China were collected and analyzed for their chemical compositions, contents of total flavonoids (TFC), total phenolic acid (TPC) and antioxidant activity. High-performance liquid chromatography (HPLC) analysis identified 15 common components, including key marker compounds pinocembrin, 3-O-acetylpinobanksin, galangin, chrysin, benzyl p-coumarate, pinobanksin and caffeic acid phenethyl ester (CAPE). Cluster analysis (CA) and correlation coefficients (CC) analysis showed that these propolis could be divided into three distinct groups. Principal component analysis (PCA) and multiple linear regression analysis (MLRA) revealed that the contents of isoferulic acid, caffeic acid, CAPE, 3,4-dimethoxycinnamic acid, chrysin and apigenin are closely related to the antioxidant properties of propolis. In addition, eight peak areas decreased after reacting with 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radicals, indicating that these compounds have antioxidant activity. The results indicate that the grouping and spectrum–effect relationship of Chinese propolis are related to their chemical compositions, and several compounds may serve as a better marker for the antioxidant activity of Chinese propolis than TFC and TPC. The findings may help to develop better methods to evaluate the quality of propolis from different geographic origins. Full article
Show Figures

Figure 1

17 pages, 6319 KiB  
Article
The Use of Fluorescence Spectrometry to Determine the Botanical Origin of Filtered Honeys
by Aleksandra Wilczyńska and Natalia Żak
Molecules 2020, 25(6), 1350; https://doi.org/10.3390/molecules25061350 - 16 Mar 2020
Cited by 10 | Viewed by 3170
Abstract
The aim of this study was to determine whether fluorescence spectrometry can be used to identify the botanical origin of filtered honeys. Sixty-two honey samples with different botanical origins, both filtered and unfiltered, were investigated in order to examine their fluorescence spectra. The [...] Read more.
The aim of this study was to determine whether fluorescence spectrometry can be used to identify the botanical origin of filtered honeys. Sixty-two honey samples with different botanical origins, both filtered and unfiltered, were investigated in order to examine their fluorescence spectra. The results showed that individual honey varieties have different fluorescence spectra, and the filtration process had no impact on these spectra. The results suggest that fluorescence spectroscopy may be a useful method to identify the botanical origin of filtered honeys. Full article
Show Figures

Figure 1

10 pages, 2151 KiB  
Article
Honey as Source of Nitrogen Compounds: Aromatic Amino Acids, Free Nucleosides and Their Derivatives
by Piotr M. Kuś
Molecules 2020, 25(4), 847; https://doi.org/10.3390/molecules25040847 - 14 Feb 2020
Cited by 8 | Viewed by 3170
Abstract
The content of selected major nitrogen compounds including nucleosides and their derivatives was evaluated in 75 samples of seven varieties of honey (heather, buckwheat, black locust, goldenrod, canola, fir, linden) by targeted ultra-high performance liquid chromatography-diode array detector - high-resolution quadrupole time-of-flight mass [...] Read more.
The content of selected major nitrogen compounds including nucleosides and their derivatives was evaluated in 75 samples of seven varieties of honey (heather, buckwheat, black locust, goldenrod, canola, fir, linden) by targeted ultra-high performance liquid chromatography-diode array detector - high-resolution quadrupole time-of-flight mass spectrometry (UHPLC-DAD-QqTOF-MS) and determined by UHPLC-DAD. The honey samples contained nucleosides, nucleobases and their derivatives (adenine: 8.9 to 18.4 mg/kg, xanthine: 1.2 to 3.3 mg/kg, uridine: 17.5 to 51.2 mg/kg, guanosine: 2.0 to 4.1 mg/kg; mean amounts), aromatic amino acids (tyrosine: 7.8 to 263.9 mg/kg, phenylalanine: 9.5 to 64.1 mg/kg; mean amounts). The amounts of compounds significantly differed between some honey types. For example, canola honey contained a much lower amount of uridine (17.5 ± 3.9 mg/kg) than black locust where it was most abundant (51.2 ± 7.8 mg/kg). The presence of free nucleosides and nucleobases in different honey varieties is reported first time and supports previous findings on medicinal activities of honey reported in the literature as well as traditional therapy and may contribute for their explanation. This applies, e.g., to the topical application of honey in herpes infections, as well as its beneficial activity on cognitive functions as nootropic and neuroprotective, in neuralgia and is also important for the understanding of nutritional values of honey. Full article
Show Figures

Figure 1

26 pages, 2821 KiB  
Article
Effectiveness of Different Analytical Methods for the Characterization of Propolis: A Case of Study in Northern Italy
by Radmila Pavlovic, Gigliola Borgonovo, Valeria Leoni, Luca Giupponi, Giulia Ceciliani, Stefano Sala, Angela Bassoli and Annamaria Giorgi
Molecules 2020, 25(3), 504; https://doi.org/10.3390/molecules25030504 - 23 Jan 2020
Cited by 32 | Viewed by 5014
Abstract
Propolis is used as folk medicine due to its spectrum of alleged biological and pharmaceutical properties and it is a complex matrix not still totally characterized. Two batches of propolis coming from two different environments (plains of Po Valley and the hilly Ligurian–Piedmont [...] Read more.
Propolis is used as folk medicine due to its spectrum of alleged biological and pharmaceutical properties and it is a complex matrix not still totally characterized. Two batches of propolis coming from two different environments (plains of Po Valley and the hilly Ligurian–Piedmont Apennines) of Northern Italy were characterized using different analytical methods: Spectrophotometric analysis of phenols, flavones and flavonols, and DPPH radical scavenging activity, HPLC, NMR, HSPME and GC–MS and HPLC–MS Orbitrap. Balsam and moisture content were also considered. No statistical differences were found at the spectrophotometric analysis; balsam content did not vary significantly. The most interesting findings were in the VOCs composition, with the Po Valley samples containing compounds of the resins from leaf buds of Populus nigra L. The hills (Appennines) samples were indeed characterize by the presence of phenolic glycerides already found in mountain environments. HPLC–Q-Exactive-Orbitrap®–MS analysis is crucial in appropriate recognition of evaluate number of metabolites, but also NMR itself could give more detailed information especially when isomeric compounds should be identified. It is necessary a standardized evaluation to protect and valorize this production and more research on propolis characterization using different analytical techniques. Full article
Show Figures

Figure 1

Back to TopTop