Linden Honey Research Articles

Polish honeys exhibit activity against Pseudomonas aeruginosa isolated from wounds

Pseudomonas aeruginosa is recognized as an opportunistic pathogen and a common contributor to wound infections. This study focused on evaluating the antibacterial activity of selected Polish honeys against P. aeruginosa. Six bacterial strains isolated from wounds and four types of honeys (multifloral, linden, buckwheat, and heather) were utilized. The minimal inhibitory concentrations (MIC) were determined through the micro-dilution method employing 96-well plates, while antibiofilm activity was assessed using fluorescence microscopy after a 4-hour incubation period with the honeys. Results indicated diverse antibacterial efficacy among honeys, with linden and heather honeys demonstrating the most potent activity. Linden honey displayed an average MIC of 20.8%, while heather honey exhibited an MIC of 25%. Both honeys significantly reduced biofilm formation, with linden honey achieving a reduction of 54-67% and heather honey of 45-58%. Buckwheat and multifloral honeys exhibited lower activity, demonstrating average MIC levels of 37.5% and 41.7%, respectively, and a biofilm reduction below 20%. Conclusively, Polish honeys exhibited promising activity against both planktonic and biofilm forms of P. aeruginosa. These findings suggest potential applications in wound healing treatments, emphasizing the need for further research in this area. The study contributes valuable insights to the limited literature on the antibacterial activity of Polish honeys.

Analysis of Free Amino Acid Composition and Honey Plant Species in Seven Honey Species in China.

Honey is well-known as a food product that is rich in active ingredients and is very popular among consumers. Free amino acids (FAAs) are one of the important nutritional components of honey, which can be used not only as a nutritional indicator of honey but also as an indicator of plant source identification. In this study, the contents of 20 FAAs in seven types of honey from 11 provinces in China were examined for the first time. The 20 FAAs were analyzed by ultra-performance liquid chromatography-mass spectrometry/mass spectrometry (UPLC-MS/MS). By analyzing 93 honey samples from seven types of honey, the FAAs were found to range from 394.4 mg/kg (linden honey) to 1771.7 mg/kg (chaste honey). Proline ranged from 274.55 to 572.48 mg/kg, and methionine was only present in some of the linden honey, chaste honey, acacia honey, and rape honey. Evaluated by amino acid principal component analysis, multifloral grassland honey had the highest overall evaluation score, acacia and jujube honey were the most similar, while chaste honey was the least similar to the other types of honey. In addition, DNA was extracted from 174 Xinjiang grassland honey samples and different plant leaves for PCR and sequencing to identify the species of nectar plants. As a result, 12 families and 25 species of honey plants were identified. The results confirmed the diversity of FAAs in dissimilar types and sources of honey. This study provides a reference for expanding honey quality standards and verifying the authenticity of honey.

Pesticide residues in different honey types and public health risk assessment

Honeybees and humans are endangered by pesticides in daily agricultural production. The aim of this research was to investigate pesticide residues in different honey types and to assess the risk to public health. A total of 88 honey samples originating from pine, multifloral, sunflower, acacia, linden, and canola were collected and analysed by a QuEChERS method. The hazard quotient (HQ) was used to evaluate the risk of detected pesticide residues. Analysis of pine honey did not detect any residue of investigated pesticides. The most frequently detected pesticides in the honey samples were chlorpyrifos ranging between 15.1 µg/kg (linden honey) to 22.3 µg/kg (multifloral honey), clothianidin ranging between 12.0 µg/kg (acacia honey) to 22.0 µg/kg (canola honey), dimethoate ranging between 8.9 µg/kg (multifloral honey) to 18.9 µg/kg (canola honey), and thiamethoxam ranging between 4.2 µg/kg (linden honey) to 15.6 µg/kg (canola honey), respectively. The lowest estimated daily intake (EDI) of 128 × 10-3 μg/kg of body weight per day was found in acacia honey, and the highest EDI of 265 × 10-3 μg/kg of body weight per day was found in canola honey. Similar values of EDI were determined for multifloral, sunflower, and linden honey (186 × 10-3, 187 × 10-3, and 183 × 10-3), respectively. The HQ value for pine honey was 0 indicating that this honey is the safest for consumption, however, the other types of honey investigated in this study posed no risk to humans after potential consumption.

Sensitive immunoenzyme assay for the detection of antibiotic flumequine in honey.

Fluoroquinolone antibiotics are used to cure and protect bees and apiaries from infections. Consequently, they may contaminate honey and other products of beekeeping. In this study, a highly sensitive immunoenzyme assay (EIA) was for the first time developed for the determination of a fluoroquinolone flumequine (FLU) in honey. The EIA was carried out in an indirect competitive format with colorimetric detection. The analysis was characterized by a low limit of detection of 30 pg mL-1. The polyclonal antibodies used showed no cross-reactivity with 24 other (fluoro)quinolones; the assay was highly specific only toward FLU. Different coating FLU-protein conjugates were tested to achieve the most sensitive competitive immunodetection. A highly simplified and rapid (3-5 min) sample preparation was proposed based on the 100-300 times dilution of honey by a buffer. The developed EIA has been tested to detect FLU in honey of different origins, namely acacia, flower, buckwheat, chestnut, and linden honey. It has been demonstrated that 76.2-115.9% of FLU could be determined by the assay. The versatility, simplicity, and rapidity of the EIA enable us to propose this method as an effective tool to control the contamination of honey.

Radioprotective effects of linden honey in rat peripheral blood

Radiotherapy affects not only malignant, but also a healthy tissue adjacent to tumor by increasing reactive oxygen species generation, with consequent damage to biomolecules, such as the oxidation of membrane lipids, known as lipid peroxidation. The end product of lipid peroxidation is malondialdehyde. Radioprotectors are compounds that could significantly protect normal cells from radiation, without changing the tumor cell radiosensitivity. Synthetic radioprotectors usually have side effects and are toxic. Natural radioprotectors exert protection without adverse effects. In this study, we examined the radioprotective ability of linden honey in rat blood, by detecting alterations in the activities of antioxidant enzymes catalase and glutathione peroxidase and malondialdehyde concentration after the exposure to a therapeutic dose of gamma rays. Sixteen rats were randomly divided into Control and Honey groups. Honey group received honey (1.5 mL(kgd-1)) orally for four weeks, while at the same time Control group were given distilled water. After four weeks, blood was sampled from all animals. Samples were halved, and one series of samples were gamma irradiated (2 Gy). Radiation induced decreased glutathione peroxidase activity and increased malondialdehyde level, while honey treatment attenuated those alterations, keeping glutathione peroxidase and malondialdehyde at physiological levels. These findings confirm radioprotective properties of linden honey.

Antioxidant Status in the Blood of Psychosocially Stressed Rats Treated with Honey

Abstract Linden honey represents a unique honey variety valued for its nutritional benefits, distinctive taste and aroma. Phenols, polyphenols, flavonoids, ascorbic acid and phenolic acids in honey have antioxidant activities. This study aimed to investigate the effects of linden honey on the activities of antioxidant enzymes catalase (CAT) and glutathione peroxidase (GPx), as well as on the concentration of malondialdehyde (MDA) in individually housed animals. The investigated parameters were quantified using spectrophotometric method for determination of enzyme activities and MDA concentration in the blood. We found that treatment with linden honey in the socially isolated animals significantly increased the enzyme activities of CAT and GPx, and significantly decreased the concentration of MDA. The modulation of CAT and GPx activities in socially isolated animals treated with linden honey may be very important for understanding the role of honey in the capacity of antioxidant defense system to increase and maintain its stability in psychosocial stress conditions. Our results may be important in biomedical research for understanding the role of honey in the amelioration of oxidative stress.

Characterization of Italian honeys: integrating volatile and physico-chemical data

This article focuses on the comprehensive characterization of Italian honeys using various physico-chemical analyses and their volatile organic compounds (VOCs) fingerprint obtained through the PTR-ToF-MS technology. Honey characteristics, including pH, electrical conductivity, moisture content, hydroxymethylfurfural (HMF), and sugar content, were analyzed to assess their quality and origin. Honey samples from different flowers, including acacia, chestnut, citrus, linden, and multifloral, were collected and investigated. Furthermore, a few aged honeys were collected and analyzed and compared with the fresh ones. Physico-chemical analysis revealed that chestnut honey is characterized by high pH and EC values. Acacia honey has a higher fructose content, while aging appears to influence HMF levels, a vital indicator of honey quality, with aged samples exhibiting significant increases in HMF content. The VOC profiles have been found to vary among different honey types, suggesting that VOCs could be used as indicators of honey origin. Multivariate statistical analyses, such as partial least squares discriminant analysis (PLS-DA), have been applied to the VOCs data to differentiate honey types based on their volatile profiles. Acacia honey exhibited different physicochemical parameters but on the contrary, in the VOCs analysis, it displayed similarities with the linden honey due to their shared low emissions of volatile compounds. Citrus honey had similar chemical parameters to linden and multifloral honeys, but its distinctive VOCs emission allowed for a more accurate identification. In conclusion, the analysis performed with the PTR-ToF-MS was successful in obtaining specific volatile fingerprints of those samples and was effective for improving the characterization of honeys.

The Study of Consumer Behaviour in the Honey Market with Emphasizing Quality and Nutritional Value

The paper presents an interdisciplinary study involving consumer research complemented by analytical research. The research aim is to identify the mineral content of 5 different types of monofloral honey produced in Slovakia as well as the behaviour of Slovak honey consumers (n=600), but mainly their preferences and awareness of honey quality and its nutritional value. The results showed that honey produced by Slovak beekeepers contained trace and major minerals such as K, Ca, Mg, Na, Mn, Al, Fe, Ba, Sr, Li, Zn. The highest mineral content was identified in honeydew honey and linden honey while the lowest content was in acacia honey and rapeseed honey. Consumer research revealed that most consumers were not able to list nutritional values or specific minerals which are found in honey. The antibacterial activity was indicated by the majority of respondents as the most frequent positive effect of honey. The most preferred monofloral honey was honeydew honey followed by acacia honey and linden honey.

EFFECT OF THE PEROXIDE ACTIVITY OF BASHKIR LINDEN HONEY ON ANTIBACTERIAL ACTIVITY

Bashkir linden honey is known not only for its unique aroma and delicate taste, but also for its medicinal antibacterial properties. One of the components responsible for the bactericidal properties of honey is hydrogen peroxide, which is formed as a result of enzymatic oxidation of glucose to gluconic acid by glucose oxidase, the enzyme produced by bees. However, there are no data in the literature on the studies of the peroxide antibacterial properties of Bashkir honey. The present study deals with the quantitative determination of the hydrogen peroxide content in Bashkir linden honey collected from various natural and agricultural zones of the Republic of Bashkortostan. According to the results of the melissopalinological analysis, all the studied 39 honey samples are floral monofloral linden honey. The concentration of hydrogen peroxide in all samples ranges within 0-51.97 mg/kg•h. The high diversity in the sensitivity of the investigated strains of opportunistic microorganisms Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa to the tested samples of linden honey suggests the presence of both peroxide and non-peroxide mechanisms of antibacterial activity. Non-peroxide antibacterial activity can be represented by the honey components of bee, plant and microbial origin: organic acids, antimicrobial proteins and peptides, as well as bacteriocins.

Survay Study of Antimicrobial Activities of Different Region Honeys in Turkey

Honey is a functional food with high nutritional properties and rich in bioactive components. The fact that the biological activity of honey differs according to botanical origin, geography and climatic characteristics necessitates a comprehensive consideration of monofloral and multifloral honeys produced in Turkey. The adoption of the understanding of replacing natural preservatives with synthetic products enables the search for alternative uses of honey. For this purpose, the antimicrobial activities of linden, rhododendron, chestnut and multifloral honeys were determined in this study and their antimicrobial activities were compared. Obtained zone diameters were statistically compared with the IBM SPSS version 22.0 statistical program. According to the results, it was determined that in general, multifloral honey has higher antimicrobial activity than monofloral honey, rhododendron honey from monofloral honeys shows strong inhibition against the tested microorganisms, and Yalova linden honey has the weakest antibacterial effect. It was determined that the antimicrobial activity in all honey varieties was generally bacteria > yeast > mold respectively.

Simultaneous qualitative and quantitative analyses of volatile components in Chinese honey of six botanical origins using headspace solid-phase microextraction and gas chromatography-mass spectrometry.

Honey aroma is one of its most important properties and it depends on the qualitative and quantitative composition of the volatile compounds. The volatile profile of honey could reveal its botanical origin to avoid a false characterization. Thus, it is of great significance to honey authentication. This study developed and validated a headspace solid-phase microextraction and gas chromatography-mass spectrometry (HS-SPME-GC-MS) method for simultaneous qualitative and quantitative analyses of 34 volatile components in honey. The developed method was applied to 86 honey samples from six different botanical origins, including linden honey, rape honey, jujube honey, vitex honey, lavender honey and acacia honey. The volatile fingerprints and quantitative results were simultaneously obtained by using the SCAN+SIM mass spectrometry scanning mode. The limits of quantifications (LOQs) and limits of detections (LODs) of 34 volatile compounds were in the ranges of 1-10 ng/g and 0.3-3 ng/g, respectively. And the spiked recoveries ranged between 70.6% and 126.2%, with the relative standard deviations (RSDs) not higher than 45.4%. A total of 98 volatile compounds were found with relative contents determined, and the 34 volatile compounds were determined with absolute concentrations. Based on the volatile fingerprints and the contents of volatile compounds, honey samples from six botanical origins were well classified by principal component analysis and orthogonal partial least-squares discrimination analysis. The HS-SPME-GC-MS method was successfully applied to achieve the volatile fingerprints of six types of honey and to absolute quantitative analyze of 34 volatile compounds with satisfying sensitivity and accuracy. Chemometrics analysis showed significant correlations between honey types and volatiles. These results reveal the characteristics of volatile compounds in six types of unifloral honey and provide some supports for honey authentication. This article is protected by copyright. All rights reserved.

Lime tree honey resources in Eurasia

The genus Tilia, commonly known as linden, basswood (North America) or lime tree (Eurasia), was investigated as a resource for honey. This article describes the results of melissopalynological analysis of the role of lime tree (Tilia spp.) in honey from Eurasia. From a review of published palynological characteristics and using independently discovered data from lime tree honey in Europe and Asia, five resource zones were identified where lime tree honey is produced. The lowest levels of Tilia pollen grains (0–44%) are typical for samples of lime honey from western and southern Europe (henceforth resource zone 1, RZ 1). In central European countries (RZ 2), honey with similar characteristics was reported (10–41% of Tilia pollen). The content of Tilia pollen grains in monofloral linden honeys from RZ 3, which includes the territory of south-eastern Europe, the south of central and eastern Europe, and the southern part of European Russia, was higher than in the previous zones (25–88%). Even higher rates (30–99%) were typical for linden honey samples extracted from the north of eastern Europe and European Russia (RZ 4). The regions in the Russian Far East (Primorye Krai) and the northeast China have been allocated to RZ 5. Here, we noted lime honey samples had the highest proportion of Tilia pollen (50–99%). An analysis of the features of the pollen spectra of all Eurasian linden honeys allowed the zones to be combined and be identified into two major groups: southern and northern.

Botanical Origin Influence on Some Honey Physicochemical Characteristics and Antioxidant Properties.

Five types of honey (multifloral, sunflower, linden, rapeseed, and acacia), from Southern Romania, were classified using chemometrics methods coupled with IR spectroscopy. The botanical origin's effect on the physicochemical characteristics of honey was studied to highlight the most valuable plant source of honey. Except for antioxidant activity, the moisture, ash, electrical conductivity (EC), pH, free acidity (FA), total sugar content (TSC), hydroxymethylfurfural (HMF), total phenolic (TPC), tannin (TTC), and flavonoid content (TFC) were significantly influenced by the botanical origin of the honey. The results showed that sunflower honey had the highest moisture (15.53%), free acidity (16.67 mEq kg-1), electrical conductivity (483.92 µS cm-1), phenolics (167.59 mg GAE 100 g-1), and flavonoids (19.00 mg CE 100 g-1), whereas multifloral honey presented the highest total sugar content (69.64 g Glu 100 g-1). The highest HMF content was found in linden honey (33.94 mg kg-1). The HMF contents of all tested honey were within the standard recommended limit, and they confirmed that the tested honey was free of any heat treatment. All five types of tested honey presented a safe moisture content for storage and consumption (12.21-18.74%). The honey's free acidity was in the range of 4.00 to 25.00 mEq kg-1; this indicated the freshness of the samples and the absence of any fermentation processes in the tested honey. Honey with a total sugar content over 60% (except for linden honey, with 58.05 g glucose 100 g-1) showed the characteristic of nectar-derived honey. The elevated antioxidant activity of honey was correlated with its high moisture, flavonoids, and HMF, whereas the tannins and HMF were positively correlated with ash and electrical conductivity. The higher content of phenolics, flavonoids, and tannins was correlated with higher free acidity. The chemometric method, coupled with ATR-FTIR spectra, revealed a clear separation between linden honey from acacia, multifloral, and sunflower honey.

Study on the quality of honey from different botanical sources and one re-gional origin

Research on honey is important from the standpoint of product quality and consumer protection. According to legislation in many countries, including Ukraine, honey is considered a food product and is subject to mandatory certification and labeling. Research on the physicochemical properties of honey is important for determining its quality and detecting falsification. This article is dedicated to the study of the quality of honey from various botanical and one regional source. Organoleptic and physicochemical properties of the honey were determined, as well as a comparison with a falsified sample. The results of the analysis showed that different varieties of honey have different physicochemical properties. The highest diastase number was found in buckwheat honey, while the lowest was found in linden honey. The mass fraction of sucrose was highest in buckwheat honey and lowest in sunflower honey. The water content was in the range of 18.4–21 %, with buckwheat and sunflower honey having similar values. The pH value was lowest in buckwheat honey and highest in linden honey. Research on the organoleptic properties showed that buckwheat honey has a dark brown color, pleasant aroma and taste without foreign flavors, and a viscous consistency. Sunflower honey has a golden-yellow color, bright and delicate aroma, sweet taste without foreign flavors, and a viscous consistency. Linden honey has a pale yellow color, pleasant and delicate aroma, sweet taste without foreign flavors, and a viscous consistency. Flower honey has a light brown color, pleasant aroma and taste without foreign flavors, sweet and tart, and a viscous consistency. The results of the comparison of buckwheat honey with falsified honey showed that the diastase number, mass fraction of sucrose and water, as well as the pH value in the honey were within normal range, while in the falsified sample the values of these indicators were different. These results indicate that falsified honey based on sugar syrup can be detected using physicochemical analysis. Therefore, a study of honey from various botanical and one regional origin showed that its physicochemical properties differ depending on the variety. Comparison of buckwheat honey with counterfeit honey based on sugar syrup has shown that the counterfeit can be detected by physicochemical analysis.

Main indicators of honey quality and their relationships

Harmonization of product quality requirements contributes to increasing the competitiveness of domestic honeys on foreign markets. The purpose of the research was to establish the main quality indicators of honey samples of various botanical origins in accordance with the requirements of national regulatory documents. The material of the research was 115 samples of acacia, linden, buckwheat honey, sunflower and various herb honey. Sampling of honey and analysis of organoleptic indicators, honey color and moisture content, diastase and proline content, acidity was carried out in accordance with DSTU 4497: 2005. According to the results of organoleptic tests, it was found that in terms of color, taste, aroma, consistency, all samples met the requirements of regulatory documentation, as well as in terms of physicochemical parameters: the average values of the mass fraction of water for acacia honey 17.7 ± 1.2 %, linden – 17.5 ± 1.0 %, buckwheat honey – 18.6 ± 0.5 %, sunflower honey – 17.1 ± 3.5 %, herb honey – 17.8 ± 1.0 %; the value of the diastase number in different types of honey is from 5.05 to 57.3 Goethe units. Among the analyzed honey samples, 7 samples of acacia honey had the lowest enzymatic activity (from 5.05 to 11.92 units Goethe); content electrical conductivity of acacia honey 0.1 ± 0.01 mS/cm, linden – 0.5 ± 0.1 mS/cm, buckwheat honey – 0.4 ± 0.1 mS/cm, sunflower honey – 0.3 ± 0.0 mS/cm, honey from different herbs – 0.3 ± 0.0 mS/cm; the content of free acids was: acacia honey – 25.4±5.8 meq/kg, linden honey – 26.4 ± 3.9 meq/kg, buckwheat honey – 33.1 ± 3.0 meq/kg, sunflower honey – 26.5 ± 5.3 meq/kg, honey from different herbs – 26,7 ± 5.9 meq/kg. The results of the study of 115 samples of honey of different botanical origin according to organoleptic and physicochemical indicators meet the requirements of regulatory documents.

Antibacterial and Antibiofilm Effect of Unifloral Honeys against Bacteria Isolated from Chronic Wound Infections.

Honey is known as an alternative remedy for the treatment of wounds. To evaluate the potential of five Hungarian honey types against wound-associated bacteria, in vitro microbiological assays were conducted on Pseudomonas aeruginosa, Staphylococcus epidermidis and methicillin-resistant Staphylococcus aureus (MRSA). Minimum inhibitory concentration (MIC) was determined with the broth macrodilution method, and biofilm degradation capacity was tested with a crystal violet assay. To understand the underlying mechanisms, the effects of honey treatments were assessed on bacterial membrane integrity and quorum sensing (QS). The highest antibacterial activity, indicated by the lowest MIC values, as well as the highest biofilm inhibition rates and membrane disruption, was displayed by chestnut and linden honeys. The most sensitive bacterium was S. epidermidis. Bacterial membrane degradation took place 40 min after treatment with honey solutions of at least a 40% concentration. Each honey sample exhibited anti-QS activity, which was most pronounced in the case of chestnut honey. It was concluded that the antibacterial, biofilm-inhibiting and anti-QS activities of linden and chestnut honeys were superior to those of acacia, goldenrod and milkweed honeys. In addition to the floral source, the antibacterial effect of honey is influenced by the microbial species treated. The use of honey in wound treatment can be justified by its diverse antibacterial mechanisms.

Sensorium

Sensorium

Detection of Low-Level Adulteration of Hungarian Honey Using near Infrared Spectroscopy

Honey adulteration is a worldwide problem; however, its detection is a challenge for researchers and authorities. There are numerous ways of honey counterfeiting; amongst them, direct adulteration is one of the most common methods. Correlative techniques, such as near-infrared spectroscopy (NIRS), are useful tools in the detection of honey adulteration; however, this method has not been applied to Hungarian honeys. The aim of this research was to investigate the performance of NIRS for the detection of sugar syrup addition to Hungarian honeys at lower concentration levels (<10% w/w). Acacia, rape, forest, sunflower, and linden honeys were mixed with high-fructose-content sugar syrup, rice syrup, or self-made glucose fructose syrup in 3%, 5%, and 10% w/w. NIRS analysis was performed in the spectral range of 950–1650 nm. Principal component analysis was coupled with linear discriminant analysis and partial least square regression models were built for the classification and prediction of adulteration levels, respectively. Our results showed that the performance of NIRS highly depends on both type of syrup and honey. PCA-LDA models provided the 100% correct classification of control in the case of all the models, while PLSR results could predict the added sugar syrup content in the case of rice and F40 syrup models, obtaining >2.2 RPDCV value.

RELATIONSHIP BETWEEN PHYSICOCHEMICAL PARAMETERS AND ANTIMICROBIAL ACTIVITY OF MOLDAVIAN HONEY

Six samples of Moldavian honey from different regions were analyzed, physical and chemical parameters, the content of macro-, microelements, and aminoacids were determined, as well as antibacterial and antifungal activity. The antibacterial and antifungal properties were determined using the double serial dilution method. It was established that all of the samples of acacia, linden, and sunflower honey possess high antibacterial activity. The bioactivity of the samples of honey was proven to be dependent on the type and origin of honey. Sunflower honey has higher antibacterial potency than linden, but linden honey is more active than acacia. Both Gram-positive and Gram-negative bacterial species proved to be susceptible to Moldavian honey. Acacia, linden, and sunflower honey, possess high antibacterial potency against S. aureus and P. aeruginosa even at a dilution of 1:16 (2.5%). The studied samples showed weak antifungal activity against Candida albicans, with the MIC determined at 1:2 dilution (20%). For linden and sunflower honey, the antifungal activity was higher than for acacia honey. The samples with the best bioactivity (sunflower honey) contain a higher amount of free acids, had lower pH values of the honey solution, and these samples also have the highest content of OMF.

In Vitro Antibacterial Efficacy of Different Natural Linden Honeys against Some Gram-Positive and Gram-Negative Strains

In Vitro Antibacterial Efficacy of Different Natural Linden Honeys against Some Gram-Positive and Gram-Negative Strains