Development of Novel Methods to Determine Crystalline Glucose Content of Honey Based on DSC,HPLC, and Viscosity Measurements,and Their Use to Examine the Setting Propensity of Honey

Crystallization must occur in honey in order to produce set or creamed honey; however, the process must occur in a controlled manner in order to obtain an acceptable product. As a consequence, reliable methods are needed to measure the crystal content of honey (? expressed as kg crystal per kg honey), which can also be implemented with relative ease in industrial production facilities. Unfortunately, suitable methods do not currently exist. This article reports on the development of 2 independent offline methods to measure the crystal content in honey based on differential scanning calorimetry and high‐performance liquid chromatography. The 2 methods gave highly consistent results on the basis of paired t‐test involving 143 experimental points (P > 0.05, r² = 0.99). The crystal content also correlated with the relative viscosity, defined as the ratio of the viscosity of crystal containing honey to that of the same honey when all crystals are dissolved, giving the following correlation: . This correlation can be used to estimate the crystal content of honey in industrial production facilities. The crystal growth rate at a temperature of 14 °C—the normal crystallization temperature used in practice—was linear, and the growth rate also increased with the total glucose content in the honey.     

Application of Selected Ion Flow Tube Mass Spectrometry Coupled with Chemometrics to Study the Effect of Location and Botanical Origin on Volatile Profile of Unifloral American Honeys

Abstract: Ten Ohio and Indiana honey samples from star thistle (Centaurea Americana), blueberry (Vaccinium spp.), clover (Trifolium spp.), cranberry (Vaccinium spp.), wildflower, and an unknown source were collected. The headspace of these honeys was analyzed by selected ion flow tube mass spectrometry and soft independent modeling of class analogy (SIMCA). SIMCA was utilized to statistically differentiate between honeys based on their composition. Ohio honeys from star thistle, blueberry, and clover were similar to each other in volatile composition, while Ohio wildflower honey was different. Indiana honeys from star thistle, blueberry, and wildflower were different from each other in volatile composition, while clover and cranberry honeys were similar. Honeys from Ohio and Indiana with the same floral origins were different in volatile composition. Furfural, 1‐octen‐3‐ol, butanoic, and pentanoic acids were the volatiles with the highest discriminating power between types of floral honey. Methanol and ethanol followed by acetic acid were at the highest levels in most honeys, though furfural was at the highest concentration in Indiana blueberry honey, while 1‐octen‐3‐ol was at the highest concentration in Indiana wildflower honey. The highest concentration of volatile compounds was in Indiana wildflower honey followed by Ohio wildflower honey, while the lowest concentration of volatile compounds was observed in Ohio clover honey followed by Indiana clover honey. Practical Application: Using chemometrics, concentrations of volatile compounds in different honeys can be used to determine the influence of botanical and geographical origins on aroma, which is important for the quality of honey. Characterization of volatile compounds can also be a useful tool for assessing honey quality.     

Stingless bee honey: Quality parameters,bioactive compounds,health-promotion properties and modification detection strategies

BackgroundHoney is a natural product produced and marketed worldwide by stingless bees and Apis bees. Both these types of honey contain unique and distinct compounds of variable nutritional and biological importance. Stingless bee honey is popular for its distinct sweetness, mixed with an acidic taste, and fluid texture; it has higher added value than Apis mellifera honey. Due to the relatively low output of stingless bee honey compared to Apis mellifera honey, comprehensive data regarding the former is limited. This complex, natural product requires official, international methodologies and standards to be established to serve as a reference for quality control, to prevent adulteration, and to aid marketing purposes.Scope and approachThe article summarises the existing literature regarding the physicochemical parameters, chemical composition, bioactive constituents, biological properties, and modification detection strategies of honey originated from 478 honey samples from 66 different stingless bee species produced worldwide.Key findings and conclusionsStingless bee honey is one of the most complex natural foodstuffs. This type of honey quantitatively possesses a higher moisture content, greater acidity, a slightly lower level of total carbohydrates, and higher levels of antioxidant and biological activities than Apis mellifera honey. This review emphasises that stingless bee honey represents an important innovation for the food, pharmaceutical and cosmetic industries, due to its positive health effects and market potential.     

Estimation of the honeydew ratio in honey samples from their physicochemical data and from their volatile composition obtained by SPME and GC‐MS

Differentiation of nectar and honeydew honeys is difficult, not only because of the wide variability in composition and organoleptic properties among samples from the same source, but also because of the frequent existence of honeys resulting from a blend of nectar and honeydew. A mathematical expression to evaluate the relative presence of honeydew in a honey sample (HD) has been developed from relevant physicochemical properties of honey samples selected as highly representative of both honey types on the basis of their physico‐chemical and melissopalynological analysis. As honey aroma depends on its volatiles composition, GC‐MS analysis of the volatile fraction obtained by SPME has been carried out in order to evaluate its usefulness in honey source differentiation. Stepwise regression from multicomponent volatiles data was used for the estimation of HD and for determining which volatile compounds were related to the different honey sources. Copyright © 2004 Society of Chemical Industry     

An innovative method for preventing honey crystallization

The paper aims to promote a new method to prevent honey crystallization by using trehalose, a disaccharide found in all types of honey in different proportions. Two batches of samples, a control one and a trehalose-added one, were analyzed. In each sample with the addition of trehalose were added between 0.0701 and 0.087 mmol of trehalose per 100 g honey. The two batches of samples were compared after 12 months of storage under the same conditions. All the physico-chemical parameters of honey samples with the addition of trehalose remained constant during storage, while in the case of the control samples some parameters had small variations (acidity, HMF, diastase activity). The added-trehalose samples maintained their color and retained their initial liquid state, while the control ones began to crystallize from the first month. The texture analyses performed on the two batches of samples showed that the samples with trehalose maintain all the sizes on the Texture Profile Analysis curve (TPA), while the control samples without trehalose underwent changes, due to the crystallization of glucose. Differential scanning calorimetry (DSC) analysis revealed the absence of crystallization process in trehalose-added honey samples at a wide range of temperatures, including also normal storage temperatures. Thus, the addition of trehalose prevented the crystallization process, honey maintaining its liquid state, its texture and its initial color as well.Industrial relevanceThe results of the determinations carried out with the addition of trehalose are so far the most advanced ones, easy to use and available to producers. The addition can be made by any manufacturer, at the place of production, does not require special equipment, a lot of work and special knowledge to apply. It has the advantage that storage temperature does not require to be carefully monitored, knowing that its low variations can make crystals appear. The addition of trehalose solution is done at usual temperature, so that the enzymatic activity of the product is not affected as it happens in the case of heating honey to dissolve the formed crystals.     

Chemical and molecular dynamics analysis of crystallization properties of honey

Honey crystallization is a natural phenomenon commonly found in honey products. To better understand the characteristics of honey crystallization, the concentrations of the four major compositions (namely glucose, fructose, sucrose, and maltose) were determined in the liquid, crystal, and mixed forms of honey. Our study revealed the contents of glucose and fructose in three forms varied significantly (p < 0.05). Molecular dynamics simulation was performed to investigate honey crystallization process. All the simulation systems had a tendency to form a cubic crystal. When the ratio of glucose/fructose is 2.5:1, which is the same as the crystal found in honey, a shorter time and lower root-mean-square deviation were found compared to the ratios at 2:1, 1:1, and pure glucose. It infers that glucose/fructose at 2.5:1 is the most stable honey crystallization, relatively. The morphology of crystals found in honey, which was observed under an environment scanning electron microscope, looked like sticky balls with indistinct edges, different from that plates or granule of glucose crystal with flattened edges. These results indicated that the relative content of glucose and fructose had a significant effect on the crystallization of honey. The glucose/fructose at 2.5:1 probably is the critical ratio of honey crystallization, at which honey can form stable crystalline deposit speedily.     

Production and characterization of mead from the honey of Melipona scutellaris stingless bees

Mead is a traditional alcoholic beverage obtained by fermenting must and can offer a solution to honey over‐production and a way of valorizing honey of lower quality. The purpose of this study was to produce and characterize mead with different levels of sugars and alcohol obtained from honey from Melipona scutellaris. The honey used for mead preparation was analysed in order to ensure that it met the required quality standards. It was found that the alcoholic content and volatile acidity were outwith the limits established by Brazilian law. Mead legislation is based on the product obtained from Apis mellifera (‘honey bee’) honey and these results indicate the need to re‐evaluate the standards established for this product in order to incorporate mead produced from honey from stingless bees of the genus Melipona. Copyright © 2018 The Institute of Brewing & Distilling     

Characterization of monofloral honeys with multivariate analysis of their chemical profile and antioxidant activity

Abstract: Various bioactive chemical constituents were quantified for 21 honey samples obtained at Rio de Janeiro and Minas Gerais, Brazil. To evaluate their antioxidant activity, 3 different methods were used: the ferric reducing antioxidant power, the 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical‐scavenging activity, and the 2,2′‐azinobis (3‐ethylbenzothiazolin)‐6‐sulfonate (ABTS) assays. Correlations between the parameters were statistically significant (?0.6684 ≤ r ≤?0.8410, P < 0.05). Principal component analysis showed that honey samples from the same floral origins had more similar profiles, which made it possible to group the eucalyptus, morrão de candeia, and cambara honey samples in 3 distinct areas, while cluster analysis could separate the artificial honey from the floral honeys. Practical Application: This research might aid in the discrimination of honey floral origin, by using simple analytical methods in association with multivariate analysis, which could also show a great difference among floral honeys and artificial honey, indicating a possible way to help with the identification of artificial honeys.     

Improvement of mead fermentation by honey‐must supplementation

Through honey's fermentation, diverse beverages can be obtained, among which is mead, an alcoholic drink with 8 to 18% of ethanol (v/v). Since honey is a matrix with a low nutrient concentration and other unfavourable growth conditions, several problems are usually encountered, namely delayed or arrested fermentations, unsatisfactory quality parameters and lack of uniformity of the final product, as well as unpleasant sensory properties. In this context, the aim of this work was to optimize mead production through honey‐must supplementation with (a) salts, (b) vitamins or (c) salts + vitamins. The effects of the honey‐must formulation on the fermentation kinetics, growth profile and physicochemical characteristics of final meads were evaluated. The results showed minor differences in the fermentation profile and time between fermentations with the different formulations. The growth profile was influenced more by the yeast strain than by the supplements added to the honey‐must. In general, the honey‐must composition did not influence meads’ final characteristics, except regarding the SO₂ concentration of the meads produced using the strain QA23. In summary, the addition of salts and/or vitamins to honey‐must had no positive effects on the fermentation, growth profile or characteristics of the final products. Copyright © 2015 The Institute of Brewing & Distilling     

Descriptive analysis of Rubus honey from the north‐west of Spain

A study of Rubus honey was conducted to determine their sugar composition, physicochemical properties, phenol and flavonoid contents, and sensorial and pollen characteristics. The principal pollen types present in the studied samples were Rubus, Castanea and Cytisus. Other pollen types such as Trifolium, some Erica sp., Eucalyptus or Echium were present in more than 50% of the pollen spectra. The sensorial characteristics of Rubus honey were amber‐to‐amber dark in colour, floral and/or vegetal olfactory perceptions with medium‐to‐low intensity and persistence, medium floral aftertaste and a fruity aroma. Physicochemical analysis showed that the honey had good quality and freshness. Phenol and flavonoid contents varied greatly and were related to the mineral content and colour of the honey. A stepwise regression analysis was performed using colour as the dependent variable, and flavonoid, electrical conductivity, and Rubus pollen as the independent variables.     

Evaluation of physico‐chemical properties,trace metal content and antioxidant activity of Indian honeys

In this study, effect of plant sources viz. Gossypium hirsutum, Coriander sativum, Murraya koenigii and Dalbergia sisso on twelve physico‐chemical properties, phenolic content, flavonoids content as well as on trace mineral (Fe, Cu, Ni, Mn, Cd and Pb) contents of honey were investigated and compared. All the physico‐chemical values were in the range of approved limits of European Commission Regulation and the source of honey had a significant (P < 0.05) effect on physico‐chemical properties, phenol content, flavonoid content and trace mineral content. The results of positive correlations between physico‐chemical properties (colour and antioxidant properties) and compositional components (phenols and flavonoids content) established that antioxidant properties were dependent on source of honey rather than on colour of honey. Pattern recognition methods such as principal component analysis and linear discriminate analysis were performed to classify honey on the basis of physico‐chemical properties, phenolic content, flavonoids content and trace metal content. The variables proline and lead exhibited higher discrimination power.     

The impact of ultrasound decrystallization on enzymatic,antioxidant and antibacterial properties of honey

The aim of the research was to assess the impact of liquefying honey by ultrasound processing on its biological activity. Four solid honey samples of different botanical origin were decrystallized by using the ultrasound (sonic bath, 40 kHz, 800 W) and conventional thermal processing (water bath, 40 °C). The biological properties of liquefied and control solid honeys were compared. The ultrasound processing significantly shortened the time of honey liquefaction (from 24 h to 15 min) and delayed of the re-crystallization process compared to conventional method (from 1 to 4 months). Diastase number was comparable in ultrasound and unprocessed honeys, but decreased in conventionally liquefied samples (by 8 to 20.6%) whereas the activity of α-mannosidase and β-galactosidase was insignificantly affected only. Growth inhibition of S. aureus and E.coli by 12.5% water solution of control honey samples was variety-dependent, the lowest for rape (12 and 19%) and the highest for honeydew (32 and 38%, respectively). No significant changes were observed after ultrasound treatment. The antioxidant properties of ultrasound processed honeys were insignificantly reduced up to 8%, while total polyphenols content increased by 3–6% in 75% of tested samples. The hydroxymethylfurfural (HMF) content significantly increased after both treatments (from 31 to 40%), however without exceeding the allowable limit.Industrial relevanceHoney crystallization during storage is natural but undesirable serious problem in processing and marketing of the honey. The ultrasound processing shortened the processing time (saved costs), limited the honey biological activity deterioration, and delayed the re-crystallization of processed honeys. Ultrasound processing is a beneficial non-thermal alternative for conventional liquefying of honey by heating.     

Classification of Honey from Its Bee Origin via Chemical Profiles and Mineral Content

Raw honeys from four different bee species, namely the honey bees and stingless bees, were classified based on its chemical profiles, mineral contents and heavy metals. Chemical profiles including proximate composition, predominant sugars, hydroxymethylfurfural content, and diastase activity were determined following official methods while mineral and heavy metals contents were obtained from atomic adsorption spectrometry (AAS) and inductively coupled plasma-mass spectrometry (ICP-MS) measurements, respectively. Both hierarchical cluster analysis and principal component analysis show high possibility of distinguishing honey by its bee species of honey bees (Apis spp.) and stingless bees (Heterotrigona itama) based on distinctive differences in chemical compositions and mineral contents. Potassium and sodium were the major elements in raw honey samples at average of 904.9 and 617.6 mg/kg, respectively. Honey from stingless bee contained more protein, 0.85 g/100 g and less total sugar of fructose and glucose at 24.99 g/100 g. The information of bee speciation origin of honey bees and stingless bees enhances the identity of honey on the product labelling.     

Quality of honeys influenced by thermal treatment

Honey producers have been heating honeys at mild temperatures below 100 °C chiefly in order to prevent post-bottling crystallization. In this study, we aimed to determine the effects of thermal treatment on the HMF content of honeydew and floral honey during the isothermal heating process at mild temperatures. Water content, formol number, total acidity, pH value and minerals were also determined in both honey types as their characteristics differ with composition, which is able to affect the rate of HMF formation. Potassium content and pH value were found as the distinguishing properties and both were greater in honeydew honey than in floral honey (p<0.01). Honeydew and floral honey samples were heated at 75, 90 and 100 °C for 15-90 min and analysed for HMF content by HPLC-RP. The Arrhenius model was used to calculate reaction rate constants and activation energies which were found to be different for each of the honey types. Heating at 90 °C for up to 90 min in floral honeys and up to 75 min in honeydew honeys did not cause a significant increase of HMF and not exceed the threshold level of 40 mg kg⁻¹. Our results show that the excessive HMF content might be related to primitive storage conditions rather than overheating.     

Fast aroma profiling to detect invert sugar adulteration with zNose™

Rapid aroma profiling of food products is a potential technique for at‐line food quality evaluation. In this work the potential of zNose^?, a surface acoustic wave‐based sensor, was tested for honey quality assessment. Buckwheat honey was purposely adulterated with different levels of beet and cane invert sugar, and its aroma profile was measured after different periods of headspace equilibration. PCA using the relative peak areas as well as the full zNose^? spectra resulted in a clear separation between honey, and beet and cane invert sugar adulterants in the mixtures. PLS models were developed for quantitative estimation of adulterants using the entire spectra as well as the relative peak areas. Better predictions were obtained with the PLS models based on spectra than with those based on relative peak areas. A correlation of validation of 0.98 was obtained between predicted and measured percentage of adulteration. This model was also successfully validated with an external set of honey mixtures, resulting in an average deviation of 3% adulteration between the predicted and reference values. Copyright © 2004 Society of Chemical Industry     

Honey—its characteristics,sensory aspects,and applications

Abstract

Honey is a natural, sweet, syrupy fluid collected by bees from nectar of flowers. The pleasant aroma and taste of this viscous liquid ranging in color from pale yellow to dark amber varies according to geographical and seasonal conditions. Its use as a sweetener is well known in different parts of the world. In early history, honey occupied a very important place on religious occasions. The high content of sugars, small amounts of amino acids, lipids, along with some vitamins and minerals imparts its high nutritional value. Honey has good medicinal and antimicrobial properties and is used in different cuisines. Proper processing is essential for a product of good sensory qualities. ISI/Agmark specifications for honey, its adulteration and detection of adulteration are well recorded. The application potential in bakery, confectionery, snack foods, fruit and vegetable products and beverages is ever increasing. A bird's‐eye view of these aspects along with possible lines of future research are discussed.     

Simultaneous determination of nine acaricides and two metabolites in comb honey by LC/MS/MS

ABSTRACT

We developed a method for the simultaneous determination of acaricides in comb honey using LC/MS/MS. Because methods for honey analysis had not previously been applied to comb honey, we modified three techniques for sample preparation and LC/MS/MS conditions. First, we used a modified QuEChERS method that changed the extraction solution from ethyl acetate to acetonitrile. Second, we replaced the InertSep® MA-1 (30 mg, 1 ml) clean-up cartridge with an Oasis® HLB (60 mg, 3 ml). Third, we changed the ionisation mode from ESI to atmospheric pressure chemical ionisation (APCI). With these modifications, sample matrices had no effect on the identification and quantification of analytes, using an external solvent calibration curve. We verified this new method with nine acaricides and two metabolites on comb honey and honey samples from three different honey origins. The trueness ranged from 74.0 to 99.4%. The relative standard deviation of repeatability (RSD_r) ranged from 0.8 to 14.8% and that of within-laboratory reproducibility (RSD_WR) ranged from 1.3 to 14.8%. All criteria met Japanese validation guidelines. The LOQ was 1.0 μg kg^–1 for all analytes. We applied this method to 10 comb honey and 31 honey samples commercially available in Tokyo. From the results of the analysis of 41 samples, we observed that amitraz remained as N-(2,4-dimethylphenyl)-N-methylformamidine (DMPF) in 9 comb honey and 23 honey samples and that their residual concentrations were less than 20 μg kg^–1. Using this new method, we improved recovery and precision, which enabled precise quantitative determination. Furthermore, the residual amitraz value in honey determined by both this new and the previous method were in good agreement.     

Determination of physicochemical properties of multifloral honeys stored in different containers

In comparison with the initial values, acidity and 5‐(hydroxy‐methyl)‐2‐furaldehyde (HMF) values of all honey samples increased during storage. The total phenol contents of honey were decreased from 286.2 to 108.6 mg GAE/kg during 9 months of storage in white colored container. In addition, total phenol contents of honey sample stored in tin container ranged from 294.7 to 258.6 mg GAE/kg (p < .05). While radical scavenging activity values of honey samples stored in amber colored container during storage are measured as 78.6 g/L, IC₅₀, 77.9 g/L, IC50, and 76.1 g/L, IC₅₀, these activity values were determined as 84.9 g/L, IC₅₀, 80.7 g/L, IC_50, and 75.2 g/L, IC₅₀ in tin container (p < .05), respectively. While acidity values of honey samples stored in white bottle range from 23.6 (3th month) to 25.7% (9th month), it varied from 20.6 (3th month) to 21.6% (9th month) in honey sample stored in amber colored container during storage.

Practical applications

Different honeys are produced in different parts of Turkey. The known honeys are pine, citrus, and chestnut honey. Various flower honeys are produced in these and other regions. HMF formation is considered as a bed result of storage and heating.     

Sensory attributes of low‐fat strawberry yoghurt as influenced by honey from different floral sources,sucrose and high‐fructose corn sweetener

Low‐fat strawberry yoghurts were prepared with each of five alternative sweeteners: sucrose, high‐fructose corn syrup and honey from three different floral sources. A ninety‐nine‐member consumer panel evaluated the yoghurts for flavour, aroma, sweetness and overall acceptance. Degree of liking was scored by the panellists on a nine‐point hedonic scale. Panellists preferred sucrose‐sweetened yoghurts over those sweetened with high‐fructose corn syrup and honey (P < 0.05). Among the honey‐sweetened yoghurts, sage honey was the most liked (P < 0.05), followed by alfalfa‐ and sourwood‐sweetened yoghurts.