Evaluation of the Phenolic Content,Antiradical, Antioxidant,and Antimicrobial Activity of Different Floral Sources of Honey

Thirty-five honeys were evaluated for total phenolic content by Folin-Ciocalteu method, for potential antioxidant activity using phosphomolibdenum assay and by the 1,1-diphenyl-2-picrylhydrazyl method for antiradical activity. The antimicrobial activity was studied by the agar diffusion method, using 12 bacteria and 2 yeasts. The means of the total phenolic contents of chestnut, honeydew, multifloral, thyme, and astragalus were 47 ± 18, 24.2 ± 0.6, 14 ± 11, 11 ± 6, and 9 ± 7 mg/100 g honey as gallic acid equivalent, respectively. The lowest antioxidant activity was observed in honeydew 70 ± 5 mg ascorbic acid equivalent/g honey while the highest content was observed in astragalus honey 86 ± 16 mg ascorbic acid equivalent/g honey. Correlation between the phenolic content and antioxidant activity were found to be statistically significant. Chestnut honeys (n = 5) exhibited maximum free radical scavenging activity with an average 68 ± 9%. The honey samples showed the highest antimicrobial activity against some microorganisms, especially Escherichia coli O157:H7, Salmonella typhimurium, Staphylococcus aureus, Listeria monocytogenes, and Proteus mirabilis. On the other side, Aeromonas hydrophila, Bacillus subtilis, and E. coli were the most resistant microorganisms. The results revealed that the Turkish honeys studied proved to be a good source of antioxidant and antimicrobial agents that might serve to protect human health.     

Evaluation of the phenolic content,antioxidant activity and colour of Slovenian honey

Honey samples from the seven most common honey types in Slovenia were screened for total phenolic content by the modified Folin–Ciocalteu method, for potential antioxidant activity using the ferric reducing antioxidant power (FRAP) assay and by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method for antiradical activity. In addition the colour characteristics of honey samples were analysed. The results of the study showed that total phenolic content, antioxidant activity and colour parameters differ widely among different honey types. Phenolic content expressed as gallic acid equivalent ranged from 44.8 mg/kg in acacia honey to 241.4 mg/kg in fir honey. Antioxidant activity was the lowest in the brightest acacia and lime honeys and the highest in darker honeys, namely fir, spruce and forest. The colour of the Slovenian honeys, analysed in this study was very variable and ranged from pale yellow to dark brown. Correlations between the parameters analysed were found to be statistically significant (p < 0.05).     

Optimization of the Process Parameters to Establish the Quality Attributes of DPPH Radical Scavenging Activity,Total Phenolic Content,and Total Flavonoid Content of Apple (Malus domestica) Honey Using Response Surface Methodology

The response surface methodology was used to study the combined effect of temperature (60 to 80°C), time (10 to 15 min), and pH (3 to 6) on the antioxidant activity (1,1-diphenyl-2-picrylhydrazyl-radical scavenging activity, total phenolic content, and total flavonoid content) of apple honey. Statistical analysis revealed that all the responses were significantly (p < 0.05) affected by independent process variables. 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity, total phenolic content, and total flavonoid content increased with the increase in time and temperature due to the formation of browning pigments. The antioxidant properties of apple honey significantly (p < 0.05) decreased with increase in pH from 3 to 6. The thermal treatment of apple honey at 80°C was found to be more effective than at 70 and 60°C. The average increase in 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity, total phenolic content, and total flavonoid content of raw apple honey due to combined effect of three process variables was 9.6% ± 1.9, 13.7 ± 2.5 mg gallic acid equivalent/100 g and 49.3 ± 3.3 mg quercetin/100 g, respectively. The results showed that the most desirable optimum conditions for temperature, time and pH for 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity (92.39%), total phenolic content (133.55 mg gallic acid equivalent/100 g of honey), and total flavonoid content (25.82 mg quercetin/100 g of honey) were 80°C, 15 min and 3.01, respectively. The results demonstrated that thermal treatment significantly increased the antioxidant activity of apple honey.     

Antioxidant Activity of Artisanal Honey From Tabasco,Mexico

Potential claims for honey, floral variety and their health properties are relevant for small farmers and artisan producers. The antioxidant activity of honey samples from cacao farms, mangrove, citrus, and coconut groves from Mexico was established by applying a multiple-method approach, which included determination of the level of total phenolic compounds and total flavonoids. Total phenolics and total flavonoids ranged from 51 to 134 mg gallic acid equivalents (GAE)/100 g honey and from 29.6 to 187.1 mg rutin equivalents/100 g honey respectively. Methanolic and aqueous solutions had similar profiles for inhibition of 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical (range from 33 to 85%) but the aqueous solutions tended to show lower radical scavenging properties. Linear correlations were established between flavonoids contents and percentage inhibition of DPPH, but phenolics contents were not well correlated (R² = 0.68) to the ferric reducing antioxidant power (FRAP) values which showed wide ranges from 48 to 152 mg Trolox/100 g honey. No patterns could be found in relation to antioxidant activities and the agrifood system of origin, floral availability, collection location, or season. Artisan honey samples from Tabasco were highly variable in their antioxidant properties, possibly because of the biodiversity and seasonal variations, which contribute to their unique nature. The antioxidant tests used in this study could be useful to verify the antioxidant function of honey.     

不同种类蜂蜜总酚酸含量测定和抗氧化作用的研究

本文测定了槐花蜜、黄芪蜜、苹果蜜、荞麦蜜、枸杞蜜、山楂蜜、山花蜜、五味子蜜、菊花蜜和油菜蜜等十种蜂蜜的总酚酸含量和抗氧化活性。结果表明,十种蜂蜜的总酚酸含量在13.30±0.92mg/100g蜂蜜到148.46±2.34mg/100g蜂蜜之间,其中荞麦蜜的总酚酸含量远高于其它种类的蜂蜜。应用黄嘌呤-黄嘌呤氧化酶体系产生的超氧阴离子自由体系和FeSO4诱导的脂质过氧化模型,研究了稀释蜂蜜的抗氧化活性,结果表明,十种蜂蜜均有抑制超氧阴离子自由基和抗脂质过氧化的作用,呈现量效关系。其中荞麦蜜的抗氧化活性最强。本研究还观察到,蜂蜜中总酚酸的含量与其抗氧化活性成正相关,表明蜂蜜的抗氧化活性可能与其所含的总酚酸有关。十种中国蜂蜜中含有酚酸类抗氧化剂可能是其发挥保健功能的有效成分之一。     

Phenolic profile and antioxidant properties of Polish honeys

The phenolic components of honeys have great participation in their nutritional value and antioxidant activity. Moreover, phenolic components are promising markers for the determination of botanical and geographical origin of honey. The purpose of the present work was to study the antioxidant activity and profiles of phenolic acids and flavonoids of honeys of various origins. The total phenolic content of honeys varied from 4.46 to 15.04 mg of gallic acid equivalents per 100 g of product and the total phenolic acid content determined chromatographically varied from 201.05 to 2089.08 μg per 100 g of product. Buckwheat honey exhibited the highest antioxidant activity and contained the highest total phenolic amount, whereas rape honey exhibited the lowest values in this respect. Moreover, the buckwheat honey contained the highest amount of phenolic acids. There were significant linear correlations between total phenolic content and antioxidant activity of honey extracts in the reaction with DPPH^? (1,1‐diphenyl‐2‐picrylhydrazyl) and ABTS^{? +} (2,2′‐azinobis‐(3‐ethylbenzothiazoline‐6‐sulfonic acid)) free radicals. In most samples, p‐coumaric acid was the dominant phenolic acid (39.1–677.2 μg per 100 g). The honeys also contained considerable amount of gallic acid (6.0–913.8 μg per 100 g). Among flavonoids naringenin was predominant in the most studied honey samples.     

Antioxidant activity of Portuguese honey samples: Different contributions of the entire honey and phenolic extract

The antioxidant activity of Portuguese honeys was evaluated considering the different contribution of entire samples and phenolic extracts. Several chemical and biochemical assays were used to screen the antioxidant properties of entire honeys with different colour intensity and phenolic extracts: reducing power, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging capacity, and inhibition of lipid peroxidation using the β-carotene linoleate model system and the thiobarbituric acid reactive substances (TBARS) assay. The amounts of phenols, flavonoids, ascorbic acid, β-carotene, lycopene and sugars present in the samples were also determined. The highest antioxidant contents and the lowest EC₅₀ values for antioxidant activity were obtained in the dark honey. An analysis of variance was carried out to evaluate the influence of the colour intensity and extraction method in the antioxidant properties and phenolic contents. A discriminant analysis was also performed, giving satisfactory results once the six samples were clustered in six individual groups obtained through the definition of two discriminant analysis dimensions.     

Total phenolic content,antiradical, antioxidant and antimicrobial activities of Rhododendron honeys

Fifty Rhododendron honey samples obtained from Black Sea Region of Turkey were screened for total phenolic content by the modified Folin–Ciocalteu method, for potential antioxidant activity using phosphomolybdenum assay and by the 1,1-diphenyl-2-picryl hydrazyl (DPPH) method for antiradical activity. The antimicrobial activity was studied by the agar diffusion method, using eleven bacteria and two yeasts.     

A comparative study on phenolic profile,vitamin C content and antioxidant activity of Italian honeys of different botanical origin

The aim of our study was to identify and quantify the phenolic acids, flavonoids and vitamin C and to evaluate the antioxidant activity in ninety Italian honeys of different botanical origins (chestnut, sulla, eucalyptus, citrus and multifloral). The results showed that total phenolic and flavonoid contents varied from 11.08 to 14.26 mg GAE per 100 g honey and from 5.82 to 12.52 mg QE per 100 g honey, respectively. HPLC–UV analysis showed a similar but quantitatively different phenolic profile of the studied honeys. Vitamin C is present in all samples. Multifloral honey showed the highest amount of the detected total phenolic compounds and the highest vitamin C content. The DPPH value varied from 55.06 to 75.37%. Among the unifloral honeys, chestnut honey presented the highest levels of phenolic acids, flavonoids and vitamin C, which are closely associated with its high antioxidant activity. The results show that honey contains high amount of biologically active compounds, which play an important role in defining the nutraceutical quality of the product, and that the distribution of these compounds is influenced by the botanical origin.     

黑色小扁豆中不同结合态酚类含量、花青素组成及其抗氧化活性研究

黑色小扁豆因含有丰富的营养素、微量营养素和植物化学物成分而受到研究者的关注。为深入了解小扁豆的营养价值,对小扁豆中不同结合形态的酚类化合物含量及其抗氧化活性(亚铁离子还原能力、DPPH自由基清除能力、ABTS自由基清除能力)进行测定。结果表明,黑色小扁豆中不同存在形式的酚类提取物含量差异显著。酯键合态酚类提取物中含有较高的酚酸含量(1.61 mg/g),碱水解结合态酚类提取物具有较高的黄酮含量(1.07 mg/g)及抗氧化活性【亚铁离子还原能力(43.80 mmol/g)、DPPH自由基清除能力(2.13 mg/g)、ABTS清除能力(3.92 mg/g)】。对黑色小扁豆中存在的花青素进行提取和分析鉴定,其含有的花青素主要为飞燕草-3-O-(2-O-β-D-吡喃葡萄糖基-α-L-吡喃阿拉伯糖苷)和矢车菊素衍生物。     

单花蜂蜜多酚类物质的抗氧化活性

以5种中国单花原蜜,不同产地的42个样本通过Amberlite XAD-2吸附树脂得到的多酚提取物为原料,采用分光光度法,测定总酚酸和总黄酮含量、还原能力、抗氧化活性(清除DPPH自由基、O2－ ·能力),评估蜂蜜多酚类物质抗氧化活性及蜂蜜品种、颜色和地域差异对清除自由基的影响。结果表明：样本总黄酮含量为(9.41±0.18)～(92.76±0.13)mg/kg;总酚酸含量为(9.10±0.05)～(149.57±0.14)mg/100g;深色枣花蜜抗氧化能力最强,对DPPH自由基、O2－ ·清除作用分别为EC50＝(0.042±0.014)g/mL和EC50＝(0.038±0.009)g/mL。提示蜂蜜的多酚类物质影响抗氧化活性,酚酸、黄酮含量与抗氧化能力呈现正相关系;色深原蜜的酚酸、黄酮含量高于色浅原蜜,抗氧化能力也强于浅色原蜜。     

Antioxidant activity,color chromaticity coordinates,and chemical characterization of monofloral honeys from Morocco

The bioprospecting of several monofloral Moroccan honeys was carried out. The antiradical activity expressed as mmol Trolox equivalents/kg of honey and evaluated by 2,2-diphenyl-1-picrylhydrazyl assay, ranged from 0.15 for euphorb honey to 1.08 for citrus honey. The antioxidant activity expressed as mmol Fe²⁺/kg and evaluated by ferric ion reducing antioxidant power assay, ranged from 0.96 for euphorb honey to 4.74 for orange honey. The total phenol content was evaluated by colorimetric assay, while the color attributes were evaluated as transmittance data. Significant Pearson correlation factors were found between total polyphenol amount and antioxidant activity and between color attributes and antioxidant activity. Furthermore the chemical composition of volatile organic compounds was determined. The volatile organic compounds chemical composition of the studied honeys was mainly represented by terpene and benzene derivatives, Maillard reaction products, isoprenoids, and hydrocarbons. The volatiles fingerprint, as well as a targeted high-performance liquid chromatography analysis of the polar components, was used to tentatively confirm the declared botanical origin of the samples studied.     

Antioxidant activity of yogurt made from milk characterized by different casein haplotypes and fortified with chestnut and sulla honeys

The aim of this work was to evaluate the antioxidant activity of yogurt made from milk characterized by different casein (CN) haplotypes (α_s1-, β-, κ-CN) and fortified with chestnut and sulla honeys. The CN haplotype was determined by isoelectric focusing, whereas antioxidant activity of yogurt was measured using 2,2’-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid and ferric-reducing antioxidant power. The statistical analysis showed a significant effect of the studied factors. The results showed that chestnut honey presented the highest phenolic acid and flavonoid contents, which are closely associated with its high antioxidant activity. The antioxidant activity of fortified yogurt samples was affected both by different CN haplotypes and by type of honey added. Yogurts fortified with chestnut honey showed higher antioxidant activity than those fortified with sulla honey. The different behavior observed among the fortified yogurts led us to hypothesize that the effects of protein-polyphenol complex on antioxidant activity are interactive. The results suggest that milk proteins polymorphism and polyphenols play different roles in affecting the bioavailability and the antioxidant activity of yogurt.     

Metal content of southern Italy honey of different botanical origins and its correlation with polyphenol content and antioxidant activity

Seventy‐eight samples of southern Italy honey from five different floral origins (chestnut, eucalyptus, citrus, multifloral and sulla) were screened to quantify the polyphenol and metal contents, evaluate the antioxidant activity and determine the correlations between the parameters analysed. The average polyphenol content was 12.06 mg gallic acid equivalent per 100 g honey and 7.92 mg quercetin equivalent per 100 g honey, for total phenolic and flavonoid contents, respectively. The antioxidant activity ranged from 58.40% (eucalyptus honey) to 60.42% (chestnut honey) in the ABTS assay, from 152.65 μm Fe (II) (citrus honey) to 881.34 μm Fe (II) (chestnut honey) in the FRAP assay, and from 54.29% (citrus honey) to 78.73% (chestnut honey) in the DPPH assay. Fe and Zn were the most abundant among the tested metals, while Cd, Co and Mo were those less present. Chestnut honey presented the highest polyphenol content, antioxidant activity and metal content. The correlations between the analysed parameters were statistically significant (P < 0.05). The correlations between metal content and both total phenolic and antioxidant activities were particularly interesting, suggesting a relationship between metal and polyphenol contents in honey.     

ANTIOXIDANT ACTIVITY AND PHENOLIC ACID CONSTITUENTS OF CHESTNUT (CASTANIA SATIVA MILL.) HONEY AND PROPOLIS

This study describes the constituents of phenolic acids and antioxidant activities of chestnut ( Castania sativa Mill.) honeys and propolis in Turkey. Antioxidant activity of the chestnut honeys and propolis were examined by three different methods, namely scavenging of free radical 2, 2-diphenyl-1-picrylhydrazyl, FRAP, and cupric reducing antioxidant power. Total phenolic contents were determined by using Folin–Ciocalteu reagent as GA equivalent. The phenolic constituents were also determined by HPLC. The antioxidant activities were compared with standard antioxidants such as catechin, BHT and Trolox. The antioxidant activities of all the samples were found high and related to the sample concentrations. The ethanolic propolis extracts showed the highest antioxidant activity. The major phenolic acids of the chestnut honeys and propolis identified by HPLC with PDA detection were coumaric acid, FA, cinnamic acid, CA and ChA.

PRACTICAL APPLICATIONS

In this study, some phenolic acid components and antioxidant capacity of chestnut ( Castania sativa Mill.) honey and propolis were measured. The comparative findings from antioxidant activities and phenolic acid analyses of honey and propolis samples of chestnut origin provide important criteria for considering their nutritional and nutraceutical potentials. Comparison of our results with literature data also ranks the chestnut honey and propolis as better sources of antioxidants among those from other floral origins.     

Evaluation of antioxidant activity and total phenolics of selected Czech honeys

Honey serves as a good source of natural antioxidants, which are effective in reducing the risk occurrence of heart disease, cancer, cataracts, different inflammatory processes and immune-system decline. In the fresh selected Czech honey samples originated mainly from the region North Moravia antioxidant activity and total polyphenol content were determined. A total of 40 honey samples (multifloral, lime, rape, raspberry, mixture and honeydew honeys) native to different stations gained in the period from May by August year 2006 were analysed. Total phenolics (TP) content was determined by the modified Folin-Ciocalteau method [TP was expressed as mg of gallic acid equivalent (GA eq.) per kg of honey]. For evaluation of the antioxidant activity (AOA) three different methods were used, the ferric reducing antioxidant power (FRAP) assay, the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay and the 2,2′-azinobis(3-ethylbenzothiazolin)-6-sulfphonate (ABTS) assay. AOA was expressed in mg ascorbic acid equivalent (AA eq.) per kg of honey. The results indicated that TP and AOA in Czech honey varied greatly between the honey kinds, location and time of the harvest. Average TP ranged from 89.9 mg GA eq. kg^-1 in lime honey to 215.2 mg GA eq. kg⁻¹ in honeydew honey. Antioxidant activity determined by the DPPH, ABTS and FRAP methods was lowest in floral honeys. The highest values were obtained for honeydew and mixture honeys. ABTS and FRAP assays have been shown to be the optimal methods for AOA determination in honey. A positive linear correlation between AOA and TP was observed (in FRAP assay R² = 0.852). It indicates that phenolics are one of the main components responsible for antioxidant behaviour of honey. The obtained results support and extend complete knowledge about the content of bioactive phenolics and antioxidant activity in the Czech honeys.     

In Vitro Potential of Ascophyllum nodosum Phenolic Antioxidant-Mediated α-Glucosidase and α-Amylase Inhibition

ABSTRACT: Ascophyllum nodosum is a brown seaweed that grows abundantly in the Northeast coastal region. In this study, the potential of A. nodosum for type 2 diabetes management through antioxidant-mediated α-glucosidase and α-amylase inhibition was investigated. After the initial screening of 4 locally harvested seaweeds, A. nodosum was chosen for its highest phenolic content and was subjected to water extraction. Among extraction ratios of 50 g to 100 to 1000 mL at room temperature, 50 g/400 mL yielded the highest phenolic content of 4.5 mg/g wet weight. For evaluation of extraction temperature ranging from 20 to 80 °C, 50 g/400 mL was chosen as a minimum amount of extractant. Among temperatures studied, extraction at 80 °C resulted in the highest total phenolic contents (4.2 mg/g wet weight). All extracts had similar levels of antioxidant activity in the range of 60% to 70% in terms of 1, 1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity. The 80 °C extract had the highest α-glucosidase and α-amylase inhibitory activity with IC₅₀ of 0.24 and 1.34 μg phenolics, respectively, compared to the IC₅₀ of acarbose, reference inhibitor, being 0.37 and 0.68 μg. The results show that fresh A. nodosum has strong α-glucosidase and mild α-amylase inhibitory activities that correlated with phenolic contents. This study suggests a nutraceutical potential of A. nodosum based on phytochemical antioxidant and antihyperglycemia activities.     

蜂蜜中氨基酸含量对抗氧化能力的影响

以14种中国单花蜜为原料,比较所含有的17种游离氨基酸含量差异,确定样品中主要以脯氨酸为主,占游离氨基酸总量65.27%,平均含游离氨基酸349.829mg/kg。评估14种单花蜜体外抗氧化活性,得到单花蜜对亚硝酸盐抑制能力的EC50值从(0.55±0.021)g/mL到(0.25±0.034)g/mL之间变化,广西的龙眼蜜抑制能力最强;14种单花蜜中脯氨酸、游离氨基酸含量差异分别与对亚硝酸盐抑制能力的相关系数R＝0.7513和R＝0.8051。说明蜂蜜中氨基酸类物质影响抗氧化活性,其含量与对亚硝酸盐的抑制能力呈现正相关关系,蜂蜜作为潜在的功能性食品更应值得关注。     

荞麦蜜酚酸含量的高效液相色谱测定及其抗氧化作用的研究

以中国产荞麦蜜为原料,采用高效液相色谱-电化学检测法(HPLC-ECD)测定其中的原儿茶酸、没食子酸、咖啡酸、丁香酸、p-香豆酸、绿原酸、阿魏酸和鞣花酸等8种酚酸的含量。结果表明,中国荞麦蜜中含有原儿茶酸、没食子酸、咖啡酸、p-香豆酸、阿魏酸等五种酚酸,其含量分别为没食子酸为461μg/100g蜂蜜,p-香豆酸为150μg/100g蜂蜜,咖啡酸为79μg/100g蜂蜜,原儿茶酸为30μg/100g蜂蜜,阿魏酸为39μg/100g蜂蜜。本文还对荞麦蜜酚酸提取物的抗氧化作用进行了研究,结果显示荞麦蜜酚酸提取物对超氧阴离子自由基、羟基自由基、DPPH自由基和脂质过氧化均有抑制作用。     

Determination of the total phenolic,flavonoid and proline contents in Burkina Fasan honey,as well as their radical scavenging activity

Several honey samples (27) from Burkina Faso were analyzed to determine their total phenolic, flavonoid and proline contents as well as their radical scavenging activity. These samples consisted of 18 multifloral, 2 honeydew and 7 unifloral honeys, derived in the latter cases from flowers of Combretaceae, Vitellaria, Acacia and Lannea plant species. The total phenolic contents varied considerably with the highest values obtained for honeydew honey. Similarly, much variation was seen in total flavonoid and proline content, with Vitellaria honey having the highest proline content. Vitellaria honey was also found to have the highest antioxidant activity and content. The correlation between radical scavenging activity and proline content was higher than that for total phenolic compounds. This suggests that the amino acid content of honey should be considered more frequently when determining its antioxidant activity.