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The main objective of this work was to determine the significant physicochemical and bioactive parameters of honeys originating from Iraqi Kurdistan. For this purpose, honey samples (n = 16) were taken directly from Kurdish beekeepers from different places of Dohuk and Erbil Governorate in 2018 and 2022. The following parameters were analyzed: moisture content, electrical conductivity, diastase activity, hydroxymethylfurfural content, pH, free acidity, content of saccharides, total phenolic content, total flavonoid content, color, color intensity and DPPH, FRAP. Another objective of this work was to compare the properties of Kurdistan honeys with the requirements of European Union law and with the honeys of Central Europe. A total of 48 honey samples were included in the comparison. It was detected that the honeys produced in Iraqi Kurdistan met the strict quality criteria set by European law, which is important information for local beekeepers and experts in relation to honey production and an opportunity to set local limits of honey quality. Despite the different climatic and topographical conditions, the available flora, and the different species of bees, the properties of Iraqi Kurdistan honeys were similar to the properties of honeys from the Czech and Slovak Republics. [ABSTRACT FROM AUTHOR]

We aimed to evaluate the effect of freeze-drying and vacuum-drying on moisture, water activities (aw), total soluble solid (TSS), hydroxymethylfurfural (HMF), diastase activity, total phenolic content (TPCs), and antioxidant activities (ABTS, DPPH, FRAP, ORAC) of longan (Dimocarpus longan Lour.) blossom honey and Siam weed (Chromolaena odorata Lour.) honey. The fresh longan blossom honey and Siam weed honey were collected from a local apiarist in Northern Thailand. Freeze-drying at 0.013 kPa, −54℃ for 72 h or vacuum-drying at 2.5 kPa at 60 ℃ for 12 h was applied to dehydrate fresh honey. The moisture of freeze-dried samples was 10.10% for longan blossom honey and 11.50% for Siam weed honey, and the aw of both freeze-dried honeys was 0.43. Freeze- and vacuum-dried produced more TSS than fresh honey did (p ≤ 0.05). However, the amounts of TSS derived freeze-dry and vacuum-dry were not significantly different. Freeze-dried honey contained the highest HMF and the lowest diastase activity regardless of honey origins (p ≤ 0.05). Drying processes significantly increased the TPCs levels of honey (approximately 2 folds by freeze-drying method). The antioxidant activity of dried honey was significantly higher than that of fresh honey. It was observed that the freeze-drying method tended to better preserve the antioxidant activity of honey compared to vacuum-drying methods in both types of honey. The results indicated that drying processes significantly affect the quality of dried honey, including TSS, HMF, diastase activity, TPCs, and antioxidant activity. In this study, freeze-drying emerged as the relatively low temperature drying method that can preserve the quality of honey, especially in terms of TPCs and antioxidant activity.

The thermal treatment of honey is used to prevent honey crystallization which is one of the main problems that face beekeepers. In this study three samples of honey were heated at 40, 60, 80 and 100 °C, as a function of time in hours (h). Heating the samples at 40 °C did not show any significant effect on hydroxymethylfurfural (HMF) production or diastase enzyme activity up to 95 hours. Heating to higher temperatures 60, 80 and 100 °C resulted in a regular increase in HMF content and drop-off in diastase activity as a function of time. The HMF content reached 40 mg/kg after 80, 12.5 and 6 hours. For the three samples at 60, 80 and 100 °C respectively. Conversely, diastase enzyme activity reached close to 8 IU after 96, 12.5 and 5 hours. For the following temperatures 60, 80 and 100 °C respectively. The results showed that heating temperatures up to 40 °C is safe for long-term storage, while heating at 60 °C could be used but for a shorter treatment time. Results showed that the must temperature does not exceed 60 °C for 5 hours or 80 °C for one hour to preserve the honey's quality. The reaction rate constants and activation energy Ea of HMF formation in three samples were found 83.07, 91.79 and 89.57 kJ.mol-1 respectively. Therefore, honey can be preserved in this way, while at the same time the HMF remains below the permissible values, and the enzymatic activity remains at its highest level.

The main objective of this work was to determine the significant physicochemical and bioactive parameters of honeys originating from Iraqi Kurdistan. For this purpose, honey samples (n = 16) were taken directly from Kurdish beekeepers from different places of Dohuk and Erbil Governorate in 2018 and 2022. The following parameters were analyzed: moisture content, electrical conductivity, diastase activity, hydroxymethylfurfural content, pH, free acidity, content of saccharides, total phenolic content, total flavonoid content, color, color intensity and DPPH, FRAP. Another objective of this work was to compare the properties of Kurdistan honeys with the requirements of European Union law and with the honeys of Central Europe. A total of 48 honey samples were included in the comparison. It was detected that the honeys produced in Iraqi Kurdistan met the strict quality criteria set by European law, which is important information for local beekeepers and experts in relation to honey production and an opportunity to set local limits of honey quality. Despite the different climatic and topographical conditions, the available flora, and the different species of bees, the properties of Iraqi Kurdistan honeys were similar to the properties of honeys from the Czech and Slovak Republics.

Copyright of Food Science & Engineering Research is the property of Ataturk University Coordinatorship of Scientific Journals and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The thermal treatment of honey is used to prevent honey crystallization which is one of the main problems that face beekeepers. In this study three samples of honey were heated at 40, 60, 80 and 100 °C, as a function of time in hours (h). Heating the samples at 40 °C did not show any significant effect on hydroxymethylfurfural (HMF) production or diastase enzyme activity up to 95 hours. Heating to higher temperatures 60, 80 and 100 °C resulted in a regular increase in HMF content and drop-off in diastase activity as a function of time. The HMF content reached 40 mg/kg after 80, 12.5 and 6 hours. For the three samples at 60, 80 and 100 °C respectively. Conversely, diastase enzyme activity reached close to 8 IU after 96, 12.5 and 5 hours. For the following temperatures 60, 80 and 100 °C respectively. The results showed that heating temperatures up to 40 °C is safe for long-term storage, while heating at 60 °C could be used but for a shorter treatment time. Results showed that the must temperature does not exceed 60 °C for 5 hours or 80 °C for one hour to preserve the honey's quality. The reaction rate constants and activation energy Ea of HMF formation in three samples were found 83.07, 91.79 and 89.57 kJ.mol-1 respectively. Therefore, honey can be preserved in this way, while at the same time the HMF remains below the permissible values, and the enzymatic activity remains at its highest level. [ABSTRACT FROM AUTHOR]

The honey quality can vary based on various factors such as plant origin, geographical area, production method and storage. By determining the quality characteristics of honey, it is possible to ensure the quality level as well as the existence of fraud in it. In this study, some physico-chemical, rheological and microbiological characteristics of 14 types of honey of Sistan and Baluchestan and Qazvin provinces (six natural honey samples and one counterfeit honey sample from each province) were investigated. The results indicated that there was no significant difference between amounts of reducing sugar of natural honey samples. The highest significant sucrose value belonged to the counterfeit samples and Diyalabad Qazvin and Ziziphus honey of Chabahar had the lowest values. Moisture content of samples varied from 12.5 to 17.21%. Diastasis activity of counterfeit samples was zero and Astragalus-Thymus of Tarom Qazvin with 08.09 DN had the lowest diastase activity among the natural honey samples. HMFcontent of natural samples was in the range of 3.9 to 7.80 mg/kg whereas for Zabol and Qazvin counterfeit honey was measured 341 and 280 mg/kg respectively. The highest and lowest fructose to glucose ratio was obtained for the samples of Ziziphus of Chabahar (1.22) and Alhagi honey of Zabol (0.69). In general, Sistan and Baluchestan samples had the higher viscosity compared to Qazvin provine’s ones. Furthermore, the highest contamination of osmophilic yeasts and mold belonged to counterfeit honeys. According to the results of this study, the quality of honey can vary significantly depending on the geographical location and plant origin. Also, some quality indicators of honey, especially the amount of sucrose, diastase activity and hydroxymethylfurfural content can be used as useful tools to detect the adulteration of the product. [ABSTRACT FROM AUTHOR]

Honey is used for centuries both as nutrient and in medicine, being an exhaustless source of benefic factors for health and also for different biotechnological processes. This is a complex matrix which possesses antioxidant and antimicrobial properties due to its peroxidic activity and bioactive compounds. A fully validated approach for the determination of sugars, hydroxymethylfurfural content and diastase activity in honey samples were presented in accordance with the official methods from the International Honey Commission. Spectrophotometric method was used for diastazic activity determination and chromatographic determinations for HMF content (photodiode array detection) and sugars (refractive index detection). The limits of detection and quantification were calculated. Accuracy, precision and uncertainty were determined in the spectrophotometric and chromatographic techniques using the certified reference material. Diastase activity, sucrose content and hydroxymethylfurfural (HMF) content were easily differentiated and these parameters were used for indication of a possible adulteration of the honey. The present study confirms that, in order to have an authentic honey sample, diastazic activity must be above 8 DN (diastazic number) and HMF content less than 40 mg/kg. Sugar spectrum is different for every honey type. Consequently, physico-chemical analysis should be combined for the determination of authentic honey and proper labeling.

In this study, three parameters (hydroxymethylfurfural, diastase activity and invertase activity) were used to evaluate the quality of twenty samples of multifloral honey from northern Algeria heated by a traditional method (conventional heating in a water bath at 100 °C) for five treatment periods (2, 4, 6, 8 and 16 min). The assay was carried out with honey samples whose initial HMF, diastase activity and invertase activity values were within the recommended food authority limit. HMF was determined by HPLC, diastase was measured with Phadebas and invertase was determined using the Siegenthler method. During heating, it was observed an increase in the HMF related to an increase in temperature, but still below the international standard limit (40 mg.kg-1 ). Diastase activity and invertase activity also decreases during heating. However, invertase is more heat-sensitive and heating time than diastase and HMF, and it's an important parameter to determine if honey has been submitted to heating. Therefore to liquefy honey we can use this method but with a low temperature and a short time because time has a deep impact on the quality of heating treatment of honey. [ABSTRACT FROM AUTHOR]

The present study was done to optimize the power ultrasound processing for maximizing diastase activity of and minimizing hydroxymethylfurfural (HMF) content in honey using response surface methodology. Experimental design with treatment time (1-15 min), amplitude (20-100 %) and volume (40-80 mL) as independent variables under controlled temperature conditions was studied and it was concluded that treatment time of 8 min, amplitude of 60 % and volume of 60 mL give optimal diastase activity and HMF content, i.e. 32.07 Schade units and 30.14 mg/kg, respectively. Further thermal profile analyses were done with initial heating temperatures of 65, 75, 85 and 95 ºC until temperature of honey reached up to 65 ºC followed by holding time of 25 min at 65 ºC, and the results were compared with thermal profile of honey treated with optimized power ultrasound. The quality characteristics like moisture, pH, diastase activity, HMF content, colour parameters and total colour difference were least affected by optimized power ultrasound treatment. Microbiological analysis also showed lower counts of aerobic mesophilic bacteria and in ultrasonically treated honey than in thermally processed honey samples complete destruction of coliforms, yeasts and moulds. Thus, it was concluded that power ultrasound under suggested operating conditions is an alternative nonthermal processing technique for honey.

The activities of enzymes are the basis of evaluating the quality of honey. Beekeepers usually use concentrators to process natural honey into concentrated honey by concentrating it under high temperatures. Active enzymes are very sensitive to high temperatures and will lose their activity when they exceed a certain temperature. The objective of this work is to study the kinetic mechanism of the temperature effect on diastase activity and to develop a nondestructive approach for quick determination of the diastase activity of honey through a heating process based on visible and near-infrared (Vis/NIR) spectroscopy. A total of 110 samples, including three species of botanical origin, were used for this study. To explore the kinetic mechanism of diastase activity under high temperatures, the honey of three kinds of botanical origins were processed with thermal treatment to obtain a variety of diastase activity. Diastase activity represented with diastase number (DN) was measured according to the national standard method. The results showed that the diastase activity decreased with the increase of temperature and heating time, and the sensitivity of acacia and longan to temperature was higher than linen. The optimum temperature for production and processing is 60 °C. Unsupervised clustering analysis was adopted to detect spectral characteristics of these honeys, indicating that different botanical origins of honeys can be distinguished in principal component spaces. Partial least squares (PLS) and least squares-support vector machine (LS-SVM) algorithms were applied to develop quantitative relationships between Vis/NIR spectroscopy and diastase activity. The best result was obtained through Gaussian filter smoothing-standard normal variate (GF-SNV) pretreatment and the LS-SVM model, known as GF-SNV-LS-SVM, with a determination coefficient (R2) of prediction of 0.8872, and root mean square error (RMSE) of prediction of 0.2129. The overall results of this paper showed that the diastase activity of honey can be determined quickly and non-destructively with Vis/NIR spectral methods, which can be used to detect DN in the process of honey production and processing, and to maximize the nutrient content of honey.

The present study was done to optimize the power ultrasound processing for maximizing diastase activity of and minimizing hydroxymethylfurfural (HMF) content in honey using response surface methodology. Experimental design with treatment time (1-15 min), amplitude (20-100 %) and volume (40-80 mL) as independent variables under controlled temperature conditions was studied and it was concluded that treatment time of 8 min, amplitude of 60 % and volume of 60 mL give optimal diastase activity and HMF content, i.e. 32.07 Schade units and 30.14 mg/kg, respectively. Further thermal profile analyses were done with initial heating temperatures of 65, 75, 85 and 95°C until temperature of honey reached up to 65°C followed by holding time of 25 min at 65°C, and the results were compared with thermal profile of honey treated with optimized power ultrasound. The quality characteristics like moisture, pH, diastase activity, HMF content, colour parameters and total colour difference were least affected by optimized power ultrasound treatment. Microbiological analysis also showed lower counts of aerobic mesophilic bacteria and in ultrasonically treated honey than in thermally processed honey samples complete destruction of coliforms, yeasts and moulds. Thus, it was concluded that power ultrasound under suggested operating conditions is an alternative nonthermal processing technique for honey. [ABSTRACT FROM AUTHOR]

Com o objetivo de verificar as características físico-químicas de amostras de méis coletadas em cidades do Estado do Ceará (Araripe, Santana do Cariri, Assaré, Iguatu, Crato, Missão Velha e Pacajús), foram determinados no Laboratório de Apicultura do Departamento de Entomologia, Fitopatologia e Zoologia Agrícola da Escola Superior de Agricultura "Luiz de Queiroz", USP: açúcares totais, açúcares redutores, sacarose aparente, umidade, atividade diastásica, hidroximetilfurfural, proteína, cinzas, pH, acidez, índice de formol, condutividade elétrica, viscosidade e cor de 20 amostras de méis Apis mellifera L., 1758, coletadas entre março de 2002 e agosto de 2002. A maioria das amostras de méis analisadas (65%) encontra-se dentro das especificações brasileiras para as características físico-químicas, com exceção das características sacarose aparente (10% das amostras), umidade (10% das amostras), atividade diastásica (35% das amostras) e HMF (20% das amostras). Os resultados indicaram condutividade elétrica e a sacarose aparente como as características que mais influenciaram no agrupamento das amostras.This research was aimed at to determining physico-chemical characteristics honey samples collected in cities of Ceara States (Araripe; Santana do Cariri 1 sample; Assaré 1 sample; Iguatu 8 samples; Crato 4 samples; Missão Velha 2 samples and Pacajús 3 samples), they were determined at the laboratory of Apiculture in the "Escola Superior de Agricultura Luiz de Queiroz" (ESALQ) University of São Paulo, in Piracicaba, São Paulo State: total sugar, reducing sugars, apparent sucrose, humidity, diastase activity, hydroxymethylfurfural (HMF), protein, ash, pH, acidity, formol index, electrical conductivity, viscosity and color of 20 samples of Apis mellifera L., 1758 honey collected between March of 2002 and August of 2002. Most of the samples of honey analyzed (65%) are inside of the Brazilian specifications for the characteristics physical-chemistries except for the characteristics apparent sucrose (10% of the samples), humidity (10% of the samples), diastase activity (35% of the samples) and HMF (20% of the samples). The results showed electrical conductivity and apparent sucrose as characteristics that most influenced grouping samples.

The physicochemical properties, colour characteristics and dynamic viscosity of fresh rapeseed honey (control, CON) and those stored for 18 months at room temperature (RT) or in freezer (FRO) were compared. The significant decrease of pH after storage was found. Honey stored at RT showed an increase of 5-hydroxymethylfurfural (HMF) (+543.0 %) and decrease of diastase activity (−24.4 %), while in FRO samples the decreasing course (−50.5 and −7.3 %, p > 0.05) were found in comparison with CON samples (3.07 and 28.37 mg kg). The negative correlation between HMF content and diastase activity was found. The temperature of storage significantly influenced colour parameters, however, RT differentiated colour of honey to a greater extent (ΔE = 20.37) than FRO (ΔE = 8.07). The lightness (L*), hue (h°), whiteness index (WI) and colour intensity (ABS) of CON honey samples were similar to honey from FRO. The dynamic viscosity was significantly higher in honey stored in FRO in comparison to CON honey and honey stored at RT. However, in comparison with CON honey, higher (almost twice) viscosity for honey stored at RT was observed. [ABSTRACT FROM AUTHOR]

Copyright of Ambiência is the property of Revista Ambiencia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The effect of heating at various temperatures (30, 40, 50, 60, 70 and 80 °C) on dynamic viscosity, colour, 5-hydroxymethylfurfural (5-HMF) concentration and diastase activity of raw rape honey were assessed. In fresh honey, moisture, ash, free acidity, pH and electrical conductivity averaged 185.3 g kg, 1.2 g kg, 18.71 mEq kg, 4.2 and 0.25 mS cm, respectively. Heating significantly ( p ≤ 0.05) increased lightness (L*), yellowness (b*), chroma (C*), hue (h°) values, but decreased redness (a*). The viscosity at 20 °C (33.6 Pa s) differed significantly ( p ≤ 0.01) with those at 30, 40 and 50 °C (8.2, 2.5, and 1.6 Pa s, respectively). Diastase activity decreased concomitant with heating at higher temperatures. Honey heated at 80 °C for 15 min showed the maximum increase of 5-HMF content, with an average of 1.9 mg kg (62 %), compared to unheated samples. Heating for 15 min between 50 °C and 80 °C did not significantly degrade the quality of the honey, but, slightly enhanced formation of 5-HMF and reduced the diastase activity. [ABSTRACT FROM AUTHOR]

Rye (Secale cereale L.) is the most important cereal crop after wheat, rice and maize. A substantial part of the rye yield is used for bread making, especially in European countries. There have been numerous studies on grain enrichment with selenium (Se), as it is known that selenium is a fundamental trace element essential for human health and in the form of selenoproteins plays key structural and enzymic roles. The main aim of this study was to investigate the effect of different selenium concentrations on quality indices of rye malt - the content of malt extract, diastase activity, selenium and total phenol content in malt. Rye grain of 95% viability was soaked and germinated at temperature +6 ± 2 °C for three days +18 ± 2 °C, using sodium selenate Na2SeO4 solutions (Se concentration 3 mg l-1, 5 mg l-1, 10 mg l-1), and dried in an oven for 24 hours at temperature +70 - 112 °C. Germination of grain with deionised water served as a control. The obtained results showed that an increase of selenium concentration caused increase of malt extract concentration (from 74 to 80%), selenium concentration (from 0.0139 to 0.3251 mg kg-1) and total phenol concentration (from 3.13 to 3.63 mg GAE g-1 DW) in rye malt, while diastase activity decreased from 330 to 216. [ABSTRACT FROM AUTHOR]

Honey is a natural product from honeybees Apis mellifera that was found to possess antimicrobial activity. Pseudomonas aeruginosa is opportunistic, nosocomial pathogen that infects urinary and pulmonary tracts, burns, wounds and also causes the other blood infections. The concentration of reducing sugar (any sugar with aldehyde or a ketone group) and sucrose and diastase enzyme were assessed. Because the antimicrobial activity of honeys is related to their geographical regions or from where they are collected, we compared the antibacterial activity of 15 different samples of honeys against Pseudomonas aeruginosa. P. aeruginosa was not inhibited in low concentration of honey while higher concentration of honey affected its growth. The samples of honey without diastase enzyme exhibited antimicrobial activity in high concentrations. [ABSTRACT FROM AUTHOR]

In vitro chemical properties and antioxidant potential and in vivo mutagenic activity of honey-sweetened cashew apple nectar (HSCAN), a beverage produced from the cashew pseudo-fruit (Anacardium occidentale L.) and of its constituents were assessed. Analytical procedures were carried out to investigate the honey used in the HSCAN preparation, and the results observed are in accordance with Brazilian legal regulations, except for diastase number. HSCAN and pulp were investigated for ascorbic acid, carotenoid, anthocyanin and total phenolic contents, and both showed high acid ascorbic concentrations. Antioxidant capacity using 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and/or β-carotene/linoleic acid systems were applied and demonstrated a weak antioxidant capacity of honey and HSCAN, but cashew apple pulp demonstrated high antioxidant capacity. A weakly positive mutagenic effect of cashew pulp 20% was observed using the somatic mutation and recombination test (SMART) in Drosophila melanogaster only in the high-bioactivation (HB) cross. On the contrary, HSCAN was not mutagenic in both standard and high bioactivation crosses. HSCAN exhibited slight antioxidant activity, which could be associated with the high amount of ascorbic acid found in the samples evaluated. The beverage prepared did not induce DNA damage in somatic cells of D. melanogaster, which means that it is neither mutagenic nor recombinagenic in this test system., (Copyright © 2013 Elsevier Ltd. All rights reserved.)