Antibacterial and antioxidant potency of floral honeys from different botanical and geographical origins

In order to assess their physicochemical and antioxidant properties as well as their antimicrobial potency, four varieties of honey from different botanical and geographical origins were used. The agar incorporation method was used to determine the antimicrobial potency of honeys. The total phenol content was determined by a modified Folin-Ciocalteu method and the free radical scavenging activity by the Fe³⁺ reducing power (FRAP) assay. Manuka honey was the most effective against Staphylococcus aureus Oxa R and S. aureus Oxa S with a Minimum Inhibitory Concentration (MIC) of 6% and 7%, respectively, whereas wild carrot honey was the most effective against Pseudomonas aeruginosa, with a MIC of 12%. Lavender honey was the least effective against all tested strains, even though was found to have the lowest pH and water content. Manuka honey had the highest content of polyphenols, with 899.09 ± 11.75 mg gallic acid/kg, whereas lavender honey had the lowest, with 111.42 ± 3.54 mg gallic acid/kg. A very significant correlation (r value was 0.9079 at P < 0.05) was observed between the total polyphenolic content and the Fe²⁺ content formed in the presence of the honey antioxidants. The differences between honey samples in terms of antibacterial and antioxidant activity could be attributed to the natural variations in floral sources of nectar and the different locations.     

菀葆牌硒蜜康对酒精性肝损伤保护作用的实验研究

为研究菀葆牌硒蜜康对小鼠酒精性肝损伤的保护作用,将动物随机分成溶剂对照组、溶剂模型组、蜂蜜对照组、蜂蜜模型组及低、中、高3个样品剂量组,共7组,每组10只,3个样品剂量组每天给予硒蜜康1667、3333、6667mg／（kg·d）,连续给予小鼠灌胃30d后,模型对照组和样品剂量组最后一次给予受试物后20min,按体质量计一次灌胃给予50％乙醇10mL／kg,对照组给双蒸水,禁食12h后处死,取动物肝脏,测定肝匀浆液MDA、GSH、TG含量;肝脏冰冻切片,进行病理组织学检查。结果表明,与蜂蜜模型组比较,中、低剂量组的GSH含量升高,各剂量组的TG含量降低,各剂量组冰冻病理学组织切片观察到脂肪变性评分低于模型对照组,差异均有显著性。可见菀葆牌硒蜜康对酒精性肝损伤具有辅助保护作用。     

Characterization of Polish rape and honeydew honey according to their mineral contents using ICP-MS and F-AAS/AES

In this work twelve elements (Al, B, Ca, Cr, Cu, Fe, K, Mg, Mn, Na, Ni and Zn) were determined in 30 honey samples from various locations within Poland and in two different types of honey--rape and honeydew. Trace elements (Al, B, Cr, Mn and Ni) were determined by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), however, major elements (Ca, K, Mg, Na) and Cu, Fe, Zn were determined by Flame Atomic Absorption Spectrometry (F-AAS). Cluster analysis of honey data revealed that the origin of honey samples correlated with their chemical composition. It was shown that rape honey includes lower amounts of manganese than honeydew honeys. Also honeydew honey includes much higher concentrations of Al, Cu, K, Fe and Ni in comparison with rape honey. Moreover honeydew honey was found to have a higher mineral content, which reflects sources from which the honey is composed. Trace element analysis showed that the differences in the values found in honey samples could be used as evidence of the quality of honey samples.     

蜂蜜中果糖和葡萄糖近红外检测的差异性分析及优化研究

采集了来自全国20种单植物源和其它多植物源的101份的蜂蜜样品,分别运用傅立叶型近红外光谱仪采用光纤透反射(800～2500nm,2mm光程)和透射(800～1370nm,20mm光程)采集方式获得近红外光谱,来预测蜂蜜中结构和含量都很相近的果糖和葡萄糖含量。结果发现,两种测量方式下果糖、葡萄糖的预测准确度存在着较大的差异。为了分析这种差异产生的原因,采用支持向量机分析其非线性信息,采用遗传算法分析其特征波长,结果表明:这种差异主要来自两种糖分特征波长分布不同所导致。通过对两种糖分的检测方案进行优化,得出在利用近红外光谱技术检测蜂蜜中葡萄糖成分含量时应尽量采集短波区、长光程的光谱,或者对全谱区、短光程的光谱,进行特征波长的提取,避开水分的干扰,从而提高其预测精度;而对于果糖,则应尽量采集全谱区、短光程的光谱;采用常用线性定量建模方法PLSR就可以得到很好的预测模型,非线性的支持向量机模型未能明显提升模型性能。     

Chemical Analyses and Antimicrobial Activity of Nine Kinds of Unifloral Chinese Honeys Compared to Manuka Honey (12+ and 20+)

Honey has good antimicrobial properties and can be used for medical treatment. The antimicrobial properties of unifloral honey varieties are different. In this study, we evaluated the antimicrobial and antioxidant activities of nine kinds of Chinese monofloral honeys. In addition, headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS) technology was used to detect their volatile components. The relevant results are as follows: 1. The agar diffusion test showed that the diameter of inhibition zone against Staphylococcus aureus of Fennel honey (21.50 ± 0.41 mm), Agastache honey (20.74 ± 0.37 mm), and Pomegranate honey (18.16 ± 0.11 mm) was larger than that of Manuka 12+ honey (14.27 ± 0.10 mm) and Manuka 20+ honey (16.52 ± 0.12 mm). The antimicrobial activity of Chinese honey depends on hydrogen peroxide. 2. The total antioxidant capacity of Fennel honey, Agastache honey, and Pomegranate honey was higher than that of other Chinese honeys. There was a significant positive correlation between the total antioxidant capacity and the total phenol content of Chinese honey (r = 0.958). The correlation coefficient between the chroma value of Chinese honey and the total antioxidant and the diameter of inhibition zone was 0.940 and 0.746, respectively. The analyzed dark honeys had better antimicrobial and antioxidant activities. 3. There were significant differences in volatile components among Fennel honey, Agastache honey, Pomegranate honey, and Manuka honey. Hexanal-D and Heptanol were the characteristic components of Fennel honey and Pomegranate honey, respectively. Ethyl 2-methylbutyrate and 3-methylpentanoic acids were the unique compounds of Agastache honey. The flavor fingerprints of the honey samples from different plants can be successfully built using HS-GC-IMS and principal component analysis (PCA) based on their volatile compounds. Fennel honey, Agastache honey, and Pomegranate honey are Chinese honey varieties with excellent antimicrobial properties, and have the potential to be developed into medical grade honey.     

Determination of B-group vitamins in Turkish honey using ultra-performance liquid chromatography with electrospray ionization coupled to tandem mass spectrometry

A rapid and sensitive ultra-performance liquid chromatography–tandem mass spectrometry method with electrospray ionization (UPLC–ESI–MS/MS) for analysis of B-group vitamins in honey has been presented. Aim of this study is the characterization of different types of Turkish honeys according to B-group vitamins. Vitamins were determined in 17 different types of Turkish honey samples by UPLC–ESI–MS/MS. Heather honey samples were distinguished among the studied honeys with the richest vitamin content with 286.10?mg/kg, and it is followed by sunflower honey and thyme honey with the total vitamin contents of 206.01 and 163.27?mg/kg, respectively. The presence of vitamin B₁ (thiamine), vitamin B₂ (riboflavin), vitamin B₃ (nicotinamide, B₃N and nicotinic acid, B₃H), vitamin B₆ (pyridoxine), and vitamin B₉ (folic acid) was detected in all the honey samples analyzed. Moreover, vitamin B₅ (pantothenic acid) was observed in most of them. Vitamin B₁₂ (cyanocobalamin) and vitamin B₇ (biotine) were not detected in the studied honey samples. Turkish honey samples showed efficacious vitamin content for the consumers.     

Rapid honey characterization and botanical classification by an electronic tongue

In this paper a commercial electronic tongue (αAstree, Alpha M.O.S.) was applied for botanical classification and physicochemical characterization of honey samples. The electronic tongue was comprised of seven potentiometric sensors coupled with an Ag/AgCl reference electrode. Botanical classification was performed by PCA, CCA and ANN modeling on 12 samples of acacia, chestnut and honeydew honey. The physicochemical characterization of honey was obtained by ANN modeling and the parameters included were electrical conductivity, acidity, water content, invert sugar and total sugar. The initial reference values for the physicochemical parameters observed were determined by traditional methods. Botanical classification of honey samples obtained by ANN was 100% accurate while the highest correlation between observed and predicted values was obtained for electrical conductivity (0.999), followed by acidity (0.997), water content (0.994), invert sugar content (0.988) and total sugar content (0.979).All developed ANN models for rapid honey characterization and botanical classification performed excellently showing the potential of the electronic tongue as a tool in rapid honey analysis and characterization. The advantage of using such a technique is a simple sample preparation procedure, there are no chemicals involved and there are no additional costs except the initial measurements required for ANN model development.     

Conventional and Organic Honeys as a Source of Water- and Ethanol-Soluble Molecules with Nutritional and Antioxidant Characteristics

The benefits of natural honeybee products (e.g., honey, royal jelly, beeswax, propolis, beevenom and pollen) to the immune system are remarkable, and many of them are involved in the induction of antibody production, maturation of immune cells and stimulation of the immune system. The type of plants in the geographical area, climatic conditions and production method have a significantly influence on the nutritional quality of honey. However, this variability can influence consumer liking by the sensory attributes of the product. The aim of this work was to compare the most popular honeys from Poland in terms of nutritional value, organoleptic properties and antioxidant activity. In the study, five varieties of honey (honeydew, forest, buckwheat, linden and dandelion) from conventional and organic production methods were tested. The nutritional characteristics of honey samples included acidity, content of water, sugars, vitamin C, HMF and phenolics (total and flavonoids), while honey color, taste, aroma and consistency were investigated in the organoleptic characteristics. The antioxidant activity was determined in water- and ethanol-soluble honey extracts using DPPH and ORAC tests. The results showed that organoleptic and nutritional characteristics of popular Polish honeys differ significantly in relation to plant source and production method. The significant effect of honey variety on the content of HMF, saccharose and phenolics, as well as acidity and antioxidant capacity were noted. The impact of variety and variety × production method interaction was significant in the case of the content of vitamin C, glucose and fructose. A visible difference of buckwheat and forest honeys from other samples was observed. The highest content of total phenolics with antioxidant activity based on the SET mechanism was found in buckwheat honeys, while forest honeys were richer in flavonoids.     

Quality Assessment of Honey Using Modern Analytical Tools

The quality of eighteen honey samples collected from the Western district of Saudi Arabia was assessed according to the International Honey regulatory standards using modern analytical methods. A number of quality criteria were measured to determine the botanical and geographical origin of honey. Hydroxymethylfurfural (HMF) as an adulteration marker was analyzed and detected quantitatively via high performance liquid chromatography (HPLC). The moisture content was assessed by Karl Fisher coulometric method using an automatic potentiometric titrator. While, mineral content and toxic heavy metal ions were determined using an inductively coupled plasma-atomic emission spectrometry (ICP-AES) technique after microwave digestion. All the investigated honey samples were of good quality. The elements with the highest frequency were K, Se, and Cd. High content of Cd and Se were found in samples (7 and 9). The maximum residues limit of the most dangerous metal for the human health lead was below European Standards.     

蜂蜜中外源性γ-淀粉酶残留量的测定

采用液相色谱-同位素质谱联用法(LC-IRMS)建立了测定蜂蜜中外源性γ-淀粉酶残留量的方法。先采用凝胶色谱柱对蜂蜜样品进行预分离,将样品中所含的酶与糖分离开。根据γ-淀粉酶可将底物麦芽糖酶解为葡萄糖的原理,在55 ℃、pH 4.5的0.03 mol/L磷酸盐缓冲液中将γ-淀粉酶与麦芽糖反应48 h后,采用LC分离麦芽糖和葡萄糖,以IRMS测定酶解产物葡萄糖的含量来确定γ-淀粉酶的残留量。本方法的线性范围为5～200 U/kg,定量限为5 U/kg,回收率为89.6%～108.2%,相对标准偏差为3.3%～4.9%。采用本方法对市售蜂蜜和大米糖浆共38个样本进行了考察,γ-淀粉酶的检出率为76.3%。为了进一步验证本方法的检测能力,测定了掺入15%(质量分数)大米糖浆的蜂蜜样品,测得γ-淀粉酶的含量为10.2 U/kg。本方法能够有效地从酶学的角度鉴定蜂蜜中是否含有大米糖浆。     

Direct Electrochemical Determination of Hydroxymethylfurfural (HMF) and its Application to Honey Samples

Abstract

In this work an electrochemical method is evaluated for direct hydroxymethylfurfural (HMF) content determination in untreated honey samples. The HMF presented a single, well‐defined reduction signal at ?1100 mV vs. Ag/AgCl. Borate was confirmed as being the most suitable supporting electrolyte for determining HMF content in honey because it allowed better definition and selectivity of the HMF reduction signal. The detection limit for the differential pulse polarography method was 48 ppb and it was successfully applied to three samples of Mexican honey, using the standard addition method.     

Chromatographic-based methods for pesticide determination in honey: An overview

Nowadays the control of pesticides in honey is an issue of primary health importance as consequence of the increasing content of these chemicals in the aforementioned matrix. This poisoning has led to the worldwide increasing loss of bees since 1995. From Europe to Canada, scientist, beekeepers and chemical companies disagree about the reasons that have led to colony losses higher than 50% in some areas. This problem has become a public health issue due to the high honey worldwide consumption. The presence of pesticides in honey has been directly related to bees’ mortality by some researchers through pesticide presence in (1) pollen, (2) honeycomb walls, (3) own bees and (4) honey. In this work we describe the actual state-of-the-art for pesticides determination in honey along with a review in this subject focused on sample treatments and instrumentation. Finally, future trends are also commented.     

The Use of HPTLC and SDS-PAGE Methods for Coniferous Honeydew Honey Fingerprinting Compiled with Mineral Content and Antioxidant Activity

Fir honeydew honey is a uniquely beneficial product which is often subjected to adulteration; however, pollen analysis is not useful to verify this honey type. Fourteen samples of EU protected designation of origin fir honeydew honey gathered directly from apiaries were studied. Standards of legal requirements and additional parameters, i.e., specific optical rotation, mineral content, and antioxidant activity, were tested. Five nectar honeys of different varieties were used as a comparative material. HPTLC and SDS-PAGE methods were used to fingerprint the honey types. All honeys tested fulfilled the quality requirements in terms of water content, pH, total acidity, conductivity, HMF, and diastase number. They were defined as dark amber on the Pfund scale and exhibited positive specific rotation (+2.5 to 25). Honeydew honey surpassed the tested nectar honeys in terms of mineral content and antioxidant activity as well as total polyphenolic content, except for buckwheat honey. The sugar and polyphenolic profile obtained by HPTLC allowed to distinguish honeydew from nectar honeys. The same was achieved by SDS-PAGE protein profiling. Both techniques seem to be cheap and quick tools for precisely distinguishing honeydew honey.     

Antimicrobial activity and pollen composition of honey samples collected from different provinces in Turkey

The antibacterial activity of honey samples from different sources were collected and investigated against Bacillus cereus, Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 27736, Morganella morganii, Micrococcus luteus NRRL B-4375, Escherichia coli ATCC 35218, and Candida albicans. Pathogens exhibited different sensitivities towards the honey samples. The results showed that majority of the honey samples (75%) generally inhibitied the bacteria tested. The honey samples which were obtained from Izmir (samples 1 and 2) proved more effective as inhibitors against P. aeruginosa, E. coli, and S. aureus. The honey which was obtained from Mu?la (sample 5) exhibited high anticandidal activity on C. albicans. A comparison of the honey samples on the basis of pollen content revealed that they were heterofloral, and samples which had highest antibacterial activity against P. aeruginosa, E. coli, and S. aureus were dominated by pollen from Chenopodiaceae/Amaranthaceae (sample 1), and Trifolium, Trigonella, Cyperaceae, Zea mays and Anthemis taxa (sample 2). The honey proved more effective on bacteria than antibiotics.     

Botanical Origin Differentiation of Malaysian Stingless Bee Honey Produced by Heterotrigona itama and Geniotrigona thoracica Using Chemometrics

Stingless bee honey, specifically honeydew honey, is generally valued for its better health benefits than those of most blossom types. However, scientific studies about the differentiation of stingless bee honey based on honeydew and blossom origins are very limited. In this study, ¹³C NMR spectroscopy was employed to quantify the seven major sugar tautomers in stingless bee honey samples, and the major sugar compositions of both honeydew and blossom types were found not significantly different. However, several physicochemical properties of honeydew honey including moisture content, free acidity, electrical conductivity, ash content, acetic acid, diastase, hydrogen peroxide, and mineral elements levels were significantly higher; while total soluble solid, proline, and hydroxymethylfurfural were significantly lower than blossom honey. Greater antioxidant capacity in honeydew honey was proven with higher total phenolic compounds, ABTS, DPPH, superoxide radical scavenging activities, peroxyl radical inhibition, iron chelation, and ferric reducing power. Using principal component analysis (PCA), two clusters of stingless bee honey from the honeydew and blossom origin were observed. PCA also revealed that the differentiation between honeydew and blossom origin of stingless bee honey is possible with certain physicochemical and antioxidant parameters. The combination of NMR spectroscopy and chemometrics are suggested to be useful to determine the authenticity and botanical origin of stingless bee honey.     

The Comparison of Physicochemical Parameters,Antioxidant Activity and Proteins for the Raw Local Polish Honeys and Imported Honey Blends

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.     

Assessment of the Botanical Origin of Polish Honeys Based on Physicochemical Properties and Bioactive Components with Chemometric Analysis

Is it possible to characterize the types of honey based on their chemical composition, their content of bioactive substances, and their physicochemical properties? The objective of this study was a comparative analysis of four types of honey from the Carpathian Foothills area, located in south-east Poland, based on the content of the main phenolic acids and proline, the mineral composition, and selected physicochemical properties. Most analyses, such as those of phenolic acids, sugars, and proline content, in honey samples were performed using chromatographic methods. These experiments demonstrated that honeydew honeys were the richest in phenolic acids, minerals, as well as oligosaccharides, compared to other honeys. Dark-colored honeys were characterized by the highest proline content. The dominant elements in all types of honey were potassium and calcium. The results of the present study show that analyses of specific phenolic acids, minerals, proline, and sugar content, in combination with chemometrics analysis, may successfully differentiate between the biological origins of honey samples and allow the preliminary verification of the samples before performing time-consuming pollen analysis.     

Determination of trace elements in bee honey,pollen and tissue by total reflection and radioisotope X-ray fluorescence spectrometry

Multielemental determinations in samples of various types of bee honey, pollen and bee tissue have been carried out using total reflection X-ray fluorescence spectrometry (TXRF) and radioisotope excited X-ray fluorescence spectrometry (XRF). The objective was to establish whether the elemental content of bee honey, in particular, correlates with any useful information about the environment, variety of honey, etc. An attempt has also been made to determine the X-ray techniques' ability to compete with atomic absorption spectrometry (AAS) and inductively coupled plasma-atomic emission spectrometry (ICP-AES), with regard to elemental sensitivity, accuracy, sample preparation procedures, and in particular, economic performance, which is very important in selecting an appropriate technique for the analysis of large numbers of samples. The results confirm the advantages of the TXRF method for trace element analysis, but only when utilising monochromatic excitation and selecting a proper sample preparation procedure. The radioisotope XRF technique, which does not require any sample preparation, is still very competitive in analysis of elements with concentrations above a few ten ppm. Preliminary results also confirm some correlations between the elemental content of honey and the status of the environment, and encourage further work in this direction     

Australian Honeypot Ant (Camponotus inflatus) Honey—A Comprehensive Analysis of the Physiochemical Characteristics,Bioactivity, and HPTLC Profile of a Traditional Indigenous Australian Food

Despite its cultural and nutritional importance for local Aboriginal people, the unusual insect honey produced by Western Australian honeypot ant (Camponotus inflatus) has to date been rarely investigated. This study reports on the honey’s physicochemical properties, its total phenolic, major sugars and 5-hydroxymethylfurfural contents, and its antioxidant activities. The honey’s color value is 467.63 mAU/63.39 mm Pfund, it has a pH of 3.85, and its electric conductivity is 449.71 µSiemens/cm. Its Brix value is 67.00, corresponding to a 33% moisture content. The total phenolics content is 19.62 mg gallic acid equivalent/100 g honey. Its antioxidant activity measured using the DPPH* (2,2-diphenyl-1-picrylhydrazyl) and FRAP (ferric reducing–antioxidant power) assays is 1367.67 µmol Trolox/kg and 3.52 mmol Fe⁺²/kg honey, respectively. Major sugars in the honey are glucose and fructose, with a fructose-to-glucose ratio of 0.85. Additionally, unidentified sugar was found in minor quantities.