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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. [ABSTRACT FROM AUTHOR]

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]

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]

The research project was largely built around the tall traditional cultivars of the predwarfing era, which were known to excel for chapati quality. These included C 306, C 518 and C 273. The few cultivars that had emanated from crosses of these superior chapati quality wheats with dwarf wheats formed another important component of this set and included WG 357, PBW 175, PBW 154, PBW 226, Lok 1 among others. Asecond set of materials, three backcross recombinant populations (BC1F5 generation) derived from C 273/PBW 343//PBW 343 (70 lines), C 306/PBW 534//PBW 534 (70 lines) and C 518/ PBW 343//PBW 343 (80 lines) were also studied to arrive at some conclusion. Various physico-chemical characters(Grain appearance score,Grain hardness,Test weight,1000- grain weight,Yellow berry,Moisture content,Protein content,Gluten content, Gluten index, Sedimentation value, Phenol Test, Carotenoids, Sugar content, Diastatic activity, Falling Number) and chapati-makingscores were evaluated. Grain hardness seems to have a clear role in chapati quality with a correlation coefficient of 0.34, 0.35 and 0.17 observed in different recombinant populations.More consistent correlation was found for grain appearance ranging from 0.26 to 0.36 in the populations.Consistent high positive correlations have showed up for diastase activity, which ranged from 0.32 to 0.46.This consistent behaviour is a strong evidence for the role of this trait in chapati making quality. Diastase activity emerges as a more consistent and stronger contributor to chapati making quality. Phenol score may not serve as a suitable indicator of chapati quality. [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]

Copyright of Veterinary Journal of Ankara University / Ankara Universitesi Veteriner Fakultesi Dergisi is the property of Ankara University 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 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]

The aim of this study was to characterize and classify 10 honey samples collected from different regions of Iran based on their physicochemical properties. Moisture, ash and hydroxymethylfurfural content, pH, electrical conductivity, diastase activity, color, and fructose to glucose ratio were determined. Phenolic and flavonoid compounds, antioxidant activity, and the ability to inhibit enzymatic browning were also evaluated in the samples. Based on diastase activity and hydroxymethylfurfural content, Tamarisk honey showed the best quality. The highest ratio of fructose to glucose (1.5) belonged to Ziziphus. Coriander honey with the lowestL* (18.9) was considered darker than other samples. High correlation coefficients between phenolic, flavonoid compounds, and antioxidant activity indicated that these compounds are mainly responsible for the antioxidant capacity of honey. Based on the first principal component, honey samples were classified into four main groups. The first group included coriander and ziziphus, the second group was dill, the third group contained thyme, parsley, and qanqal, and the fourth group included astragal, alfalfa, tamarisk, and orange blossom. [ABSTRACT FROM PUBLISHER]

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]

Copyright of Proceedings of the Latvian Academy of Sciences. Section B: Natural, Exact & Applied Sciences is the property of Sciendo 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.)

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]

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. [ABSTRACT FROM AUTHOR]