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The current study investigated the effect of different thermal and non-thermal procedures for the estimation of the optimum conditions of treatment of different honey types (erica, cotton, thyme, eucalyptus and pine honey) to avoid or delay crystallization without losing the nutritional benefits of honey. Different physicochemical parameters, such as pollen analysis, hydroxymethylfurfural (HMF), diastase activity, acidity, and total phenolic compounds were used as quality indicators. The different treatment procedures were evaluated in different honey types and in different time periods. It was proved that to achieve a non-crystallised product that lasts over a year, samples must be heated at 72 oC or stored at -18 °C. However, only by storing samples at -18 °C kept the nutritional benefits of honey and provide similar results with the fresh unheated samples. All procedures were examined in a long-term period (one year) in order to have a complete and accurate result., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

A new original application for a polyacrylic film based on the monomers 2-(dimethylamino)ethyl methacrylate (NNDA), 2-hydroxyethyl acrylate (2HEA) and methylmethacrylate (MMA) as a starch azure container has been set up for a simple determination of honey diastase activity. The proposed method is based on the correlation of reducing sugars generated during the enzymatic process with the Schade reference assay. The polyacrylic film is charged with starch azure acting as a container for this substance; thus, the starch does not interfere in the measurement of reducing sugars, so that the diastase activity is easily calculated. The method has been contrasted with Schade method, showing good correlation and differences under 0.4% between methods in some honey samples. The polyacrylic film has great potential for the routine honey diastase activity assessment in small laboratories, dramatically reducing analysis time and cost., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

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 ( R ²) 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., Competing Interests: The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.

Honey is a food of high importance due to its nutritional value. The effect of late harvest and pollen composition on honey quality and antimicrobial activity was studied. Different physicochemical parameters were determined as quality indicators. The HMF content, diastase activity, sugar content, antimicrobial activity, and hydrogen peroxide content were selected in current work as the crucial parameters for evaluation. The results proved that the late harvested honey sample showed a vast number of pollens from different blossom periods. The hydrogen peroxide content and antimicrobial activity of late harvested honey was significantly increased (proved by t-test), whereas the honey seems to be affected significantly from weather conditions since the HMF content was also increased. The diastase activity was proved to be lower than the respective in fresh honey, whereas no difference was observed on the sugar content. Finally, the effect of origin and processing in late harvested honey was discussed., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

A fully validated approach for the determination of diastase activity and hydroxymethylfurfural content in honeys were presented in accordance with the official methods. Methods were performed in real honey sample analysis and due to the vast number of collected data sets reliable conclusions about the correlation between the composition and the quality criteria were exported. The limits of detection and quantification were calculated. Accuracy, precision and uncertainty were estimated for the first time in the kinetic and spectrometric techniques using the certified reference material and the determined values were in good accordance with the certified values. PCA and cluster analysis were performed in order to examine the correlation among the artificial feeding of honeybees with carbohydrate supplements and the chemical composition and properties of the honey. Diastase activity, sucrose content and hydroxymethylfurfural content were easily differentiated and these parameters were used for indication of the adulteration of the honey., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

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.)

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.

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.

Physicochemical and microbiological parameters of Turkish blossom honey after cold atmospheric gliding arc discharge (GAD) plasma, non-thermal ultrasound, and low-temperature oven treatments were investigated. For this purpose, a full-factorial design method was employed to optimize plasma and ultrasound treatment conditions on 5-hydroxymethyl-2-furfural (HMF) reduction in honey. Results showed that air-GAD plasma operated at 0.3 mL/min of gas flow rate (GF) with a 0.3 cm copper electrode tip distance (ED) for 30 min, nitrogen-GAD plasma operated at 0.4 mL/min of GF with 0.5 cm ED for 30 min, and non-thermal ultrasound operated at 40% amplitude for 5 min significantly decreased HMF in honey samples (p < 0.05). The optimal conditions for non-thermal ultrasound, nitrogen-GAD and air-GAD plasma treatments reduced HMF by 19%, 32%, and 37%, respectively (p < 0.05) while low-temperature oven treatment at 55 °C for 7 h caused no significant change in HMF compared to untreated honey (control) (p > 0.05). On the other hand, diastase activity was significantly increased after non-thermal ultrasound and oven treatments by up to 47–57% (p < 0.05) compared to control. Nitrogen-GAD plasma is recommended over other treatments not only because it was effective in decreasing HMF (32%), free acidity (22%), moisture (41%) value, and osmophilic yeast count (100%) and increasing maltose (31 %) and L* (40) values but also because it maintained diastase and antiradical activities, soluble phenolic content, glucose, fructose, pH, and a* and b* values of the honey. [ABSTRACT FROM AUTHOR]

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]

Copyright of Folia Pomeranae Universitatis Technologiae Stetinensis Agricultura Alimentaria Piscaria et Zootechnica is the property of West Pomeranian University of Technology in Szczecin 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 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]

This research intends to reveal the effects of different storage temperatures on the HMF amounts and diastase activities of strained flower honey and honeydew honey samples produced by different companies in Turkey. In this context, the initial HMF values and diastase activities of the strained flower honey and honeydew honey samples belonging to five different companies, collected at the date of filling, were examined with defined quality criteria (moisture, sugar, pH, acidity, electrical conductivity and ash). Samples were stored at certain temperatures (10±2 °C, 22±2 °C, 35±2 °C), and were analyzed at the end of each of the threemonth periods (3rd, 6th, 9th and 12th months) regarding HMF and diastase activity. According to the results, average HMF values of the flower honey and honeydew honey samples stored at 10±2 °C and 22±2 °C for one year did not exceed 40 mg/kg, which is given as the limit HMF value in the Turkish Food Codex (TFC) Directive on honey, while it rapidly increased in the samples stored at 35±2 °C, and was determined to be over 40 mg/kg as of 6th month onwards. In addition, average diastase activities of the samples at 10±2 °C and 22±2 °C did not drop below the limit value of 8 in TFC, though it was determined to be below 8 as of 6th month onwards, for the flower honey stored at 35±2 °C. To conclude, decrease in diastase activity shortens the shelf lives set by the firms. By providing proper production and storage conditions, all quality criteria should be ensured to remain consistent with the TFC Directive on honey. [ABSTRACT FROM AUTHOR]

The effect of heat treatment (75 °C) and spray drying with the addition of Arabic gum (inlet/outlet air temperature 180/75 °C), on the diastase activity of multifloral honey (MH) and rape honey (RH) was investigated. The physical properties of the powders (particle size and morphology, water content and activity, bulk loose and tapped density, angle of repose, hygroscopicity) directly after drying and after 12 weeks of storage were studied. During heat treatment, diastase activity decreased gradually, to decline below limit values after 180 min. Diastase activity in the powders was lower than in fresh honeys, but it was concluded that temperature was not the only factor affecting this decrease. Powders were characterized by low water content and medium flowability, which was improved after storage due to particle size increase. Diastase activity in powders was stable during storage. [ABSTRACT FROM AUTHOR]

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]

Abstract: The present study was undertaken to determine the physico-chemical parameters of honey samples obtained from retailers in Marmara Region (Site 1) and East Anatolia (Site 2) of Turkey. The 70 samples were analysed for parameters including moisture, total acidity, diastase activity, hydroxymethylfurfural (HMF), invert sugar, sucrose, ash, commercial glucose and starch. 10 of 70 (14.3%) honey samples were of unacceptable quality based on recommended criteria of moisture (3 of 70, 4.29%), diastase activity (3 of 70, 4.29%), HMF (2 of 70, 2.86%), invert sugar (4 of 70, 5.71%) and sucrose (2 of 70, 2.86%) by Turkish Food Codex and European Commission Regulation. The results of study indicated that 85.7% of honey samples were at good quality. It is important that the essential precautions should be taken to ensure standardisation and rationalisation of beekeeping techniques, manufacturing procedures and storing processes to improve honey quality. [Copyright &y& Elsevier]

Thermal processing of honey eliminates the microorganisms responsible for spoilage. Microwave heating, infrared heating, ultrasound processing, and membrane processing have been explored as alternatives to conventional heat processing. Microwave heating provides a rapid method for achieving the desired level of yeast reduction with reduced thermal damage. Infrared heating is not as rapid as microwave heating but desired results are achieved in a relatively shorter duration (3 to 4 minutes) compared to the conventional method. Membrane processing is an athermal process and very effective in the complete removal of yeast cells from honey. Microfiltration and ultrafiltration could be employed to produce enzyme-enriched honey besides clarified honey. [ABSTRACT FROM AUTHOR]

Attempts were made to examine the rejection of enzymes in honey (50% diluted with water) with various molecular weight cutoff (MWCO) ultrafiltration (UF) membranes and the effectiveness of these membranes in eliminating yeast cells. The permeates of 25 000, 50 000 and 100 000 MWCO membranes did not show any diastase activity indicating that these UF membranes completely rejected amylases. The average permeate flux obtained with these membranes was between 0.90 and 1.15 kg/(m2 h). Membrane processing completely removed yeast cells that would result in improved stability of the processed honey. These studies also revealed that it is possible to produce clarified honey and enzyme enriched honey using a combination of microfiltration and UF membranes in the process. [Copyright &y& Elsevier]

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]