Honey moisture reduction using several thermal methods and their effects on its quality

Honey is thermally heated at various methods to decrease the moisture content and prolong the shelf life. The heating methods might decrease the quality of honey's physicochemical and biochemical properties. The present study thermally treated the honey with a pasteurizer, evaporator, and dehumidifier. The most thermally affected to decrease the moisture content were treatment by dehumidifier (14.09%), subsequent evaporation (8.41%), and pasteurization (8.41%). After heating, significant differentiation was also observed in the variation of both HMF (Hydroxymethylfurfural) content and diastase activity according to the botanical origin of the honey sample. In line with the biochemical analysis of honey, total phenolic decreased significantly during the pasteurization treatment. Evaporation was the most resistant thermal treatment due to its ability to maintain the level of HMF and the enzyme diastase as a standard for honey quality. However, changes made in physicochemical and biochemical quality are still in compliance with national and international legal limits.

Comparison of biochemical and antimicrobial activities of different honey samples

Honey, a natural healing agent and a sweet food, has been used since ancient times. A honey sample could possess many biological activities depending on its chemical composition. The amount and the diversity of these minor components of honey mainly depend on the floral sources. That is why the biological activity of the honey sample obtained in a region should be determined. In this study, total phenolic and flavonoid content, antioxidant activity, melissopalynological analyses and antimicrobial activity of twenty honey samples obtained from Doganyol, Malatya, Turkey were examined. In order to determine the in vitro antibacterial activity of honey samples, the agar well diffusion (AWD) method, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays were used. For this purpose, ten Gram-positive bacteria and eight Gram-negative bacteria were used. Total phenolic content was found in the range from 9.68 ± 0.72 to 29.40 ± 1.03 mg GAE g^–1 sample. Antioxidant activity of honey samples varied from 2.21 ± 0.46 to 6.03 ± 1.11 µmol FeSO₄ 7H₂O g^–1. Honey samples showed moderate antimicrobial activity against tested microorganisms, especially against Gram-positive bacteria. It could be concluded from our findings that there is a good correlation between total phenolic content and the biological activity of honey samples.

Proximate, mineral and melissopalynological analyses of honeys produced by Apis mellifera adansonii maintained at the University of Lagos Apiary

This study focused on the management of established Apis mellifera adansonii colonies, and evaluation of the proximate, mineral, and pollen contents of honeys produced by these bees at the University of Lagos apiary. Two newly established bee colonies were managed using modern hive management techniques. Honeys produced by these colonies were subjected to further laboratory analyses. Proximate composition of honey samples was determined based on the official analysis methods from Association of Official Analytical Chemists (AOAC). Mineral composition was determined quantitatively using atomic absorption spectroscopy (AAS). Melissopalynological analysis was conducted to ascertain the amount, type and origin of pollen present in the samples. On the basis of the proximate composition, colony 1 honey had higher carbohydrate (81.29%), crude fibre (1.43%) and ash contents (0.70%) while colony 2 honey recorded higher protein (2.72%), crude fat (0.17%), moisture content (17.32%) and pH (4.6). Result of the mineral analysis showed that potassium was the most abundant element, while manganese was the least present trace element in both honeys. Investigated honey samples contained 8609 pollen and spore types belonging to 27 families and 29 species. Colony 1 honey had the highest pollen diversity, while colony 2 honey recorded the highest abundance. Hippocratea sp. was the predominant pollen type in colony 1 honey sample while Phyllantus sp. was the secondary dominant species in colony 2 honey. Celastraceae and Rubiaceae were the most dominant families recorded in the investigated honey samples. Investigated honey samples were multifloral, rich in minerals, and met the standard requirements of good honey as recommended by International Honey Commission. The study provided the basis for identification of major plants visited by Apis mellifera honeybees within the apiary. There is a need to conserve the existing flora within the study location, especially those found to be rewarding to Apis mellifera adansonii.

A Comparative Analytical Study of Fresh Honey Collected from Honey Comb of Apis Mellifera and Market Samples of Honey

Honey is a natural product which was known to ancient seers of Ayurveda since Veda period. The nutritional and therapeutic benefits of honey were well known and also documented in authentic texts of Ayurveda. However the abundant availability of honey has gone decreasing since industrialization and deforestation. It has resulted in artificial culture and marketing of honey. The quality of such honey is matter of concern as it is easy to adulterate honey but is very hard to find out the difference between natural and adulterated honey. Considering this issue, present work has been planned to compare freshly collected natural honey and marketed samples of honey. For the comparative analytical study four different samples were collected. Three samples of three different pharmacies were procured from market (honey of branded Ayurvedic companies) and compared with collected honey sample from honeycomb of Apis mellifera. The collected four samples of honey have almost similar organoleptic characters i.e. colour, odour, taste and touch. Considerable differences are detected in physico-chemical analysis, nutritional value and HMF value. The observations are within normal range however the differences are suggestive of need of establishing quality control parameters based on source of honey, collection season, temperature and storage condition and also providing these details while labelling the samples. Finding of present study revealed that freshly collected natural honey have best desired attributes compared all three marketed samples.

In Vitro Antibacterial and Antibiofilm Activity of Hungarian Honeys against Respiratory Tract Bacteria

Honey is a rich source of carbohydrates, while minor compounds such as amino acids and polyphenols contribute to its health-promoting effects. Honey is one of the oldest traditional remedies applied for microbial infections, due to its antibacterial, anti-inflammatory, and antioxidant properties. The aim of this study was to investigate the antibacterial and antibiofilm effects of Hungarian black locust, linden, and sunflower honeys against the most common biofilm-forming respiratory tract pathogens Haemophilus spp., Pseudomonas aeruginosa, and Streptococcus pneumoniae. The unifloral character of all three honey types was confirmed by melissopalynological analysis. The antibacterial activity of each honey sample against each bacterium strain was proven with agar well diffusion assay and thin layer chromatography—direct bioautography. Kinetics and mechanisms of antibacterial action were clarified with time-kill assay and membrane degradation study. The anti-biofilm activity was evidenced using crystal violet assay. In each assay, linden honey was the most effective, followed by sunflower and black locust honey. In addition, each honey sample had greater potential to suppress respiratory tract bacteria, compared to major sugar components. In conclusion, honey in general and linden honey in particular, can have a role in the treatment of respiratory tract infections caused by biofilm-forming bacteria.

Investigasi pengaruh pengenceran sampel madu pada proses klasifikasi madu menggunakan uv spectroscopy dan kemometrika

One form of honey adulteration is label adulteration for some premium honey such as uniflora honey from the honeybee species Trigona sp. One of the analytical methods that are currently developing and have the potential to perform the classification of premium honey in Indonesia is the UV spectroscopy method. In this study, an investigation was carried out on the effect of dilution on the performance of UV spectroscopy in the process of classifying Indonesian honey with different honeybees. A total of 4 types of honey samples with 10 samples each were used in this study. The honey sample was then diluted using distilled water. Each type of honey was given two dilution treatments, namely 1:20 (volume: volume) dilution of 5 samples and 1:40 (volume: volume) dilution of 5 samples. Spectral data were taken using a UV-visible spectrometer with a wavelength of 190-1100 nm (Genesys™ 10S UV-Vis, Thermo Scientific, USA) using the transmittance mode. The results of spectra analysis generally show that the sample with a 1:20 dilution has a higher absorbance intensity for both the original and modified spectra. The PCA results for each dilution showed that the honey samples could be separated into four different clusters for both 1:20 and 1:40 dilutions. The results of PCA analysis using all samples showed that the honey samples were classified into eight different clusters showing a significant effect of differences in honey sample dilution on the classification process of honey samples based on differences in the types of honeybees.

Physicochemical and antibacterial activities of Apis honey types derived from Coorg, Karnataka, India

Natural honey has various ingredients in it that contribute to its incredible properties. The aim of this investigation was to evaluate the physicochemical and antibacterial activity of various Apis honey from Coorg, Karnataka. Four samples of Apis honey viz., A. florea, A. mellifera, A. cerana and A. dorsata were collected from various regions of Coorg, Karnataka. The honey samples' physicochemical properties and antibacterial activities against Streptococcus sp., Staphylococcus aureus, Bacillus subtilis and Enterococcus sp were determined in vitro. The moisture and ash content varied from 13.6 - 17.2% and 0.32 – 0.49%, respectively. Hydroxy methyl furfurals) content of A. dorsata honey samples was highest with 9.2±0.5 mg/Kg and least was recorded with 6.8±0.4 mg/Kg for A. florae honey. The reducing sugar content of A. florea honey sample was highest with 87.5±3.2 (%) and the peroxide levels were in the range of 10.2 – 14.9 µg/g/h at 20°C. The antibacterial assay revealed that S. aureus, Enterococcus sp and Streptococcus sp were most susceptible against the honey varieties tested and minimum inhibitory concentration (MIC) values between 25-6.5 (%v/v) were determined. In conclusion, honey varieties from Coorg could be used in specific antibacterial prophylaxis as the activity depends on the honey bee species, their metabolism and floral sources in specific geographical regions.

Melittopalynological studies of Apis dorsata honey samples from Kolar District, Karnataka, India

Honeybees, while foraging for nectar on flowers, also gather some pollen which retains in the honey even after extraction. Pollen grains are the essential tools in the analysis of honey. The aim of the present report was to find the Apis dorsata honey floral resources in Kolar district state Karnataka. In the present study, the pollen content of 28 A. dorsata honey samples were collected from 5 different locations of Kolar district, Karnataka, India. Samples were subjected to Melittopalynological studies to identify their honey plant resources and colour, optic density and collection places were documented. A wide variety of pollen types represent their plant sources and their frequency classes were recognized in each honey sample. Among 28 honey samples analysed, 10 samples were identified as multifloral, 18 unifloral with predominant pollen types such as Syzygium cumini, Pongamia pinnata, Eucalyptus sp, Guizotia abyssinica, Psidium guajava and Coriandrum sativum, each count was found above 45%. Pollen spectra indicated a total of 56 pollen types belonging to 27 plant families. Fabaceae was represented as the largest family with 14 species contributing honey production. Among the habit, tree was dominant with 51.78%, followed by herbs (32.14%) and shrubs (16.07%). The economic importance of identified plants with apiculture importance was categorized as medicinal, ornamental, vegetable, timber and oil yielding, weeds, fruits and nuts. A. dorsata depends on wild trees and cultivated plants bloom throughout the year as pollen and nectar source. From the results, it is evident that there is a lot of potential in establishing beekeeping industries in the study area.

A Rheological Analysis of Biomaterial Behaviour as a Tool to Detect the Dilution of Heather Honey

Heather honey is a valuable and rheologically special type of honey. Its above-average selling price may motivate its intentional violation with a mixture of honey from another botanical origin, the price of which is lower on the market. This work deals with the rheological properties of such devalued heather honey in order to determine the changes in the individual rheological parameters depending on the degree of dilution of the heather honey. For this purpose, a differently diluted heather honey sample series was created and the following rheological parameters were determined: hysteresis area, n-value, yield stress (τ0), parameter B (Weltman model), parameter ϕ, or parameter C (model describing the logarithmic dependence of the complex viscosity on the angular frequency). Part of the work was research into whether the set parameters can be used as comparative parameters. It was found that the hysteresis area does not appear to be a suitable relative comparison parameter due to the high variability. The parameters that appear to be suitable are the relative parameters n-value and the parameter ϕ, which showed the greatest stability. The change in the determined rheological parameters is, depending on the degree of dilution, non-linear with a step change between the samples containing 40% (w/w) and 60% (w/w) of a heather honey.

Quantification of Hydrogen Peroxide in Cretan Honey and Correlation with Physicochemical Parameters

The aim of the present study is to quantify hydrogen peroxide, generated from various types of honey produced in Crete, as a potent antimicrobial agent, and establish any correlation with their physicochemical parameters. The basic physicochemical parameters (diastase activity, HMF content, moisture, electrical conductivity, color, and sugars) of 30 authentic honey samples were determined. The concentration of hydrogen peroxide in all samples was found to be within the range 0.010–0.092 mM. The known correlation between the electrical conductivity and the color of honey was confirmed in this study. Univariate and multivariate statistics applied to the results indicate that the results can be used to discriminate honey sample groups of different botanical origins.