Valorization of the honeys from the Molise region through physico-chemical, organoleptic and nutritional assessment

Low Heating Effects on The Total Microbial Activity and Physico-Chemical Properties of Stingless Bee (Heterotrigona itama) Honey

The high moisture content of stingless bee honey (SBH) is a worrisome problem and heat treatment is used to reduce the moisture and maintain the honey’s quality by destroying the microorganisms that affect the physico-chemical properties of honey during storage. Low heat treatment (45 °C) for 0, 30, 60, 90, and 120 min were conducted to determine the total microbial activity using fluorescein diacetate hydrolysis (FDA). The total microbial population that subsequently affected the physico-chemical properties was also analyzed. The total microbial activities of SBH were significantly reduced after thermal treatment at 45 °C for 90 min (63.76 µg FDA/g/h) and 120 min (62.43 µg FDA/g/h) compared with control (67.127 µg FDA/g/h). Also, the moisture content, electrical conductivity (EC), pH, and free acidity of the heat-treated SBH at all durations were significantly reduced compared with the control. The total microbial activity was detected as significantly correlated to bacterial and fungal populations, moisture content, EC, pH, and free acidity of low heat-treated SBH. Low heat treatment at 45 °C for 120 min was efficient to reduce the total microbial activity, and total acidity, and increasing the pH of SBH. Prolonging the heating duration is suggested to further reduce the water content, and total microbial activity and further increase the shelf life of SBH.

Monofloral honey from a medical plant, Prunella Vulgaris, protected against dextran sulfate sodium-induced ulcerative colitis via modulating gut microbial populations in rats

Honeys produced from medicinal plants hold great promise for human health. Herein, we determined the chemical composition and gastrointestinal protective effects of a novel monofloral honey from Prunella vulgaris (PVH). The physicochemical parameters (moisture, sugars, pH, protein content, diastase activity, and hydroxymethylfurfural) of the PVH samples met the criteria specified in European Union regulations and Chinese National Standards. Fifteen phenolic compounds were identified and quantified via high-performance liquid chromatography with a diode array detector and with time of flight tandem mass spectrometry detection (HPLC-DAD/Q-TOF-MS). Rosmarinic acid was found to be a potential marker for PVH identification. Using a dextran sulfate sodium (DSS)-induced acute colitis model, we demonstrated that the administration of PVH (5 g per kg b.w., p.o.) significantly decreased the disease activity index and mitigated colonic histopathological changes in rats. PVH also modulated the gut microbiota composition in the colitic rats, reversing the increase in the Bacteroidetes/Firmicutes ratio and restoring Lactobacillus spp. populations in DSS-challenged rats. The results of this study provide fundamental data on PVH, supporting its future application in the prevention of colitis.

Consumer sensory evaluation of honey across age cohorts in Slovakia

The growing popularity of honey among consumers has caused many frauds and cases when honey of high quality is adulterated by cheap imported honey of very low quality. The aim of this research paper was to study consumer perception of honey quality based on sensory attributes such as taste, aroma, colour and consistency. The primary research comprised the sensory blind test conducted as a part of questionnaire survey at selected shopping mall and at university. Research sample reached 400 respondents living in the Nitra region between 18 and 70 years. Respondents tested sensory attributes of two samples. Sample A represented Slovak honey from a local beekeeper and sample B was honey purchased from selected supermarket with country of origin „blend of EU and non - EU honeys" and represented imported honey. Besides descriptive statistics, the following statistical tests were applied: Fisher's Exact Test, Chi-Square Test of Independence, Cramer´V coefficient and Mann-Whitney U test. Results showed significant differences in perception of honey quality across age cohorts. Respondents older than 40 years (Generation X and Babyboomers) evaluated better the local honey from a beekeeper (sample A) than younger generations (Generation Y and Generation Z). Imported honey from selected supermarket (sample B) obtained the best evaluation in case of colour in both age cohorts while sample A obtained it in terms of aroma. The majority of respondents in both age cohorts mostly decided their preference according to taste, however there exist some differences. While Generation X and Baby boomers took into consideration also aroma, the generations Y and Z considered consistency. More interesting observation appealed in case of aroma where more than 90% of respondents, who decided according to aroma, preferred sample A - local Slovak honey. According to physico-chemical analysis, both samples fulfilled standard of EU legislation, however better parameters were reached in sample A. All in all, better perception of honey quality through sensory attributes in older age cohorts could be caused by the deeper experience in honey consumption as well as due to the fact that younger cohorts consume more semiproducts and industrial food products characterised by intensive, sweet taste which could confuse their assessments.

Quality evaluation of Omani honey

This study was intended to evaluate the quality parameters of 58 Apis mellifera honey samples, from different regions in the Sultanate of Oman. Physicochemical analyses were carried out and examined according to the Gulf Standardization Organization (GSO). The results revealed that 64.4% of the samples were failing to meet the GSO standards due to acidity, hydroxyl methyl furfural (HMF), diastase, sucrose, and glucose & fructose. Acidity and HMF were above the limits in 30% and 29% of the failed samples respectively, where diastase and total glucose & fructose were below the limits in 25% and 5% respectively. Sucrose was above the limits in 11% of the failed samples. The unconformity of the analyzed honey samples to GSO standards could be due to stage of harvesting, process and storage conditions. Therefore, it's important to reconsider the whole process of honey production in Oman in order to improve the technology and honey quality.

Physicochemical parameters and sensory properties of honeys from Buenos Aires region

The physicochemical parameters (moisture, hydroxymethyl furfural, colour, electrical conductivity, free acidity, glucose, fructose and sucrose) and the sensory properties(aroma, taste, appeareance, texture) were determined in honeys from apiaries of the agricultural, hills and meadow zones of the south east region of Buenos Aires province (Argentina). The analysis of variance showed significant differences among zones in the mean value of hydroximethyl furfural, colour, electrical conductivity and sucrose content. The principal component analysis explained the 70% of the variance among samples with the first two principal components in both cases. The cluster analysis and linear discriminant analysis showed that samples were grouped in relation to the sampling region coinciding with the results of the principal component analysis. Results suggest that could be possible to classify honeys according to the geographic origin based on the physicochemical parameters; however, the sensory properties were not good predictors.

Nutritional value and antioxidant activity of honeys produced in a European Atlantic area

One hundred eighty-seven honey samples from an Atlantic European area were studied to determine their nutritional compositions and antioxidant capacities, as well as the relationships between them. The results showed that heather, polyfloral, blackberry, and eucalyptus honeys had the highest carbohydrate contents, whereas honeydew and chestnut honeys had the lowest. There were some important differences among the honey types, which were related to the presence of minor components. The protein contents were significantly higher in honeydew and chestnut honeys, and the same results were obtained for mineral contents. Related to the presence of several antioxidant compounds, heather honey had the highest phenolic content, whereas honeydew and chestnut honeys had the highest flavonoid contents. Multivariate analysis showed that some variables, such as the amounts of flavonoids, minerals, proteins, and phenols, were significantly correlated with antioxidant activity. The regression analysis produced a significant model (R(2)=0.716; F=154.680; P<0.001) that related the antioxidant activity and the flavonoids, K, and P contents.

Honey physicochemical properties of three species of the Brazilian Melipona

Physicochemical analyses were carried out to evaluate 27 samples of honeys from three species of the Brazilian genus Melipona (M. capixaba, M. rufiventris and M. mondury) from Espírito Santo and Minas Gerais States. The parameters water activity (Aw), percentage of soluble solids (Brix %), pH, acidity (meq/Kg) and moisture (%) were evaluated. The honey characteristics obtained from these samples were very similar to the ones from other Melipona species. However, regarding the honey from Apis (honey bee), only the pH values were similar. The low pH value and the high acidity detected in Melipona honey are potential factors for increasing the honey shelf life because they do not provide favorable conditions for the microbial development. On the other hand, the high level of water activity favors the growth of microorganisms, especially yeast, which demands a more careful handled and storage. The observed differences between Melipona and Apis honey reinforce the need for specific quality settings for stingless bee honey.

Volatile fraction composition and physicochemical parameters as tools for the differentiation of lemon blossom honey and orange blossom honey

BACKGROUND

Volatile fraction profile and physicochemical parameters were studied with the aim of evaluating their effectiveness for the differentiation between lemon blossom honey (Citrus limon L.) and orange blossom honey (Citrus spp.). They would be useful complementary tools to the traditional analysis based on the percentage of pollen.

RESULTS

A stepwise discriminant analysis constructed using 37 volatile compounds (extracted by purge and trap and analysed by gas chromatography-mass spectrometry), and physicochemical and colour parameters (diastase, conductivity, Pfund colour and CIE L a b) together provided a model that permitted the correct classification of 98.3% of the original and 96.6% of the cross-validated cases, indicating its efficiency and robustness. This model proved its effectiveness in the differentiation of both types of honey with another set of batches from the following year.

CONCLUSION

This model, developed from the volatile compounds, physicochemical and colour parameters, has been useful for the differentiation of lemon and orange blossom honeys. Furthermore, it may be of particular interest for the attainment of a suitable classification of orange honey in which the pollen count is very low. These capabilities imply an evident marketing advantage for the beekeeping sector, since lemon blossom honey could be commercialized as unifloral honey and not as generic citrus honey and orange blossom honey could be correctly characterized.

Geographical classification of honey samples by near-infrared spectroscopy: a feasibility study

The potential of near-infrared (NIR) spectroscopy to determine the geographical origin of honey samples was evaluated. In total, 167 unfiltered honey samples (88 Irish, 54 Mexican, and 25 Spanish) and 125 filtered honey samples (25 Irish, 25 Argentinean, 50 Czech, and 25 Hungarian) were collected. Spectra were recorded in transflectance mode. Following preliminary examination by principal component analysis (PCA), modeling methods applied to the spectral data set were partial least-squares (PLS) regression and soft independent modeling of class analogy (SIMCA); various pretreatments were investigated. For unfiltered honey, best SIMCA models gave correct classification rates of 95.5, 94.4, and 96% for the Irish, Mexican, and Spanish samples, respectively; PLS2 discriminant analysis produced a 100% correct classification for each of these honey classes. In the case of filtered honey, best SIMCA models produced correct classification rates of 91.7, 100, 100, and 96% for the Argentinean, Czech, Hungarian, and Irish samples, respectively, using the standard normal variate (SNV) data pretreatment. PLS2 discriminant analysis produced 96, 100, 100, and 100% correct classifications for the Argentinean, Czech, Hungarian, and Irish honey samples, respectively, using a second-derivative data pretreatment. Overall, while both SIMCA and PLS gave encouraging results, better correct classification rates were found using PLS regression.

Characterization of microorganisms in Argentinean honeys from different sources

Seventy polyfloral honeys including commercial samples obtained from supermarkets, harvested from apiaries and purchased in bulk were initially examined for total antibacterial activity. From each sample, numbers of aerobic mesophilic bacteria, total coliforms, moulds and yeasts were determined and the presence of Salmonella spp., Shigella spp., Clostridium sulfite-reducers, Paenibacillus larvae and Bacillus spp. was investigated. Moisture content, pH and total acidity were also determined for all samples. Any honey diluted to concentrations from 75% to 1% (w/v) of full-strength honey showed total antibacterial activity. The numbers of aerobic mesophilic bacteria, moulds and yeasts were less than 10(3) cfu/g for all 70 samples. Faecal coliforms, Escherichia coli, Salmonella spp., Shigella spp. and Clostridium sulfite-reducers were not detected but P. larvae subspp. larvae, Bacillus cereus, Bacillus pumilus and Bacillus laterosporus were found among samples. For commercial, apiary and bulk honey the mean values for moisture content, pH and acidity, respectively, were 17.50%, 17.40% and 17.50%; 4.60, 4.10 and 4.20; and 18.30, 20.60 and 21 meq NaOH/kg. P. larvae was recovered from 35% of apiaries including hives in which the bees did not display symptoms of American foulbrood disease.

Significance of nonaromatic organic acids in honey

Although organic acids represent < 0.5% of honey's constituents, they make important contributions to the organoleptic, physical, and chemical properties of honey. To date, approximately 30 nonaromatic organic acids have been identified in honey, but relatively little attention has been paid to these components. This article reviews the current literature related to the significance of nonaromatic organic acids in honey; it was written with a goal of attracting researchers to study these interesting honey components. Previous research contributions on nonaromatic organic acids in honey may be classified into five main areas: (i) the antibacterial activities of these acids, (ii) the antioxidant activities of these acids, (iii) the use of these acids as possible indicators of incipient fermentation, (iv) the use of these acids for treatment of Varroa infestation, and (v) the use of these acids as factors for the characterization of both botanical and geographical origins of honeys. We conclude that nonaromatic organic acids are of interest for diverse reasons and that there is a particular need for studies regarding their possible antibacterial and antioxidant activities.

High-performance liquid chromatographic determination of methyl anthranilate, hydroxymethylfurfural and related compounds in honey

A high-performance liquid chromatographic method for determining 5-hydroxymethyl-2-furaldehyde (hydroxymethylfurfural), 2-furaldehyde (furfural), furan-2-carboxylic acid (2-furoic acid), furan-3-carboxylic acid (3-furoic acid), furan-3-carboxaldehyde (3-furaldehyde) and 2-aminobenzoic acid methyl ester (methyl anthranilate) in honey and honeydew samples is described. To prevent matrix interference and to isolate the compounds, a clean-up step which implies a solid-phase extraction on polymeric cartridges and an elution with 0.5 ml methanol is recommended. The compounds are separated on a reversed-phase column with a gradient of (A) 1% aqueous acetic acid-acetonitrile (97:3, v/v) and (B) acetonitrile-water (50:50, v/v), with UV detection at 250 nm. The method is applied to the analysis of samples from different botanical origin.