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Following years of its exploitation from only wild colonies, the stingless bee (Meliponula bocandei Spinola, 1853) was recently domesticated in Uganda. Products currently harvested by the beekeepers are honey and propolis. Studies from other countries have shown that stingless bees produce honey that is distinct in physicochemical properties. Therefore, in an effort to lay a foundation for the development of quality standards for stingless bee honey in Uganda, we collected M. bocandei honey from the Western Highlands and Lake Victoria Crescent agroecological zones. A selected set of physicochemical properties (moisture content, viscosity, water activity, electrical conductivity and HMF) of the honey were determined. Results reveal the following means of the physicochemical properties: moisture content (26.45 ± 3.9%), viscosity (38.32 ± 2.25 Pa.s), water activity (0.71 ± 0.04%), electrical conductivity (0.229 ± 86.91 mS/cm), pH (4.15 ± 0.68), and HMF (5.42 ± 4.78 mg kg−1), The low mean HMF reveals that stingless bee honey from these two agroecological zones is of good quality. Overall, the mean values of the physicochemical parameters measured are within the figures in the East African Community standards for stingless bee honey. We recommend investigations to establish the diversity of forage plant resources used by the stingless bee M. bocandei in order to boost meliponiculture. [ABSTRACT FROM AUTHOR]

Honey is an excellent alternative to be used in different applications by the food, pharmaceutical, and cosmetics industries. However, the use of honey in its liquid form can present several disadvantages due to its high viscosity and density. In addition, honey can naturally crystallize during storage time, limiting its application in new products by industries. Thus, an alternative to using liquid honey in industry is the powder form. The objective of this study was to obtain honey powder by spray drying using a plant-based protein as a carrier. The honey used as raw material showed acceptable physicochemical parameters by the legislation of honey quality control, such as pH of (4.0 ± 0.1), the water content of (20.70 ± 0.3) g/100 g, ash of (0.48 ± 0.02) g/100 g, the fructose content of (35.42 ± 0.14) g/100 g, (43.05 ± 0.46) g/100 g for glucose, (0.56 ± 0.02) g/100 g for sucrose, and 5-hydroxymethylfurfural (HMF) value of (37.47 ± 1.04) mg/kg of honey, leading to the production of the honey powder. The mixture of fresh honey and plant-based protein was made with dispersions of 15, 16 and 18 g/100 g of honey using isolated rice protein as a carrier (total solid at 30 g/100 g d.b.). Finally, the honey powder produced was physicochemically characterized. The dispersion with 16 g/100 g of honey achieved an intermediary sugar/honey recovery of 35.93 ± 0.82% and 68.54 ± 2.16% of total protein recovery, and the spray drying yield was satisfactory > 50%. The overall results suggested that this dispersion is the ideal formulation when commercialization of the honey powder as an ingredient is intended. [ABSTRACT FROM AUTHOR]

With an increasing demand for safe and natural products from both industries and consumers, paired with the recent ban of decried molecules (i.e. octinoxate, avobenzone or octocrylene) due to their high negative impact on humans and the environment (i.e. endocrine disruption, coral bleaching), safe bio-based alternatives are a necessary and promising surrogate to substitute current commercialized petroleum-based UV filters. In this context, a class of bio-based molecules, displaying interesting UV-B filtering properties and great photostability were developed from furfural and 5-hydroxymethylfurfural (HMF), using the Knoevenagel condensation with a set of green conditions to minimize the impact on environment. Furthermore, those furfural- and HMF-based molecules demonstrated antimicrobial properties as secondary activity, highly sought by industries. Some furan derivatives being recognized to exhibit toxicological risks, in silico and in vitro assays were conducted and demonstrated the absence of endocrine disruption activity for these new molecules. [ABSTRACT FROM AUTHOR]

Today, sustainable chemistry is a key trend in the chemical manufacturing industry due mainly to concerns over the global environment and resource security. In sustainable chemical manufacture, the choice of a bio-based feedstock plays a pivotal pillar. In terms of feedstock utilization for producing HMF, which is a multivalent platform intermediate easily convertible to valuable chemical products; biopolymers, biofuels, and other important chemicals, seagrass biomasses can be more favorable feedstocks compared with land plant resources due primarily to easy availability and no systematic farming. Moreover, seagrass feedstocks could contribute cost-effectively and sustainably producing HMF by exploiting the beach-cast seagrasses on seagrass-prairies with no feedstock cost, indicating that seagrass biomasses could be a most promising biofeedstock source for sustainable HMF production. We afford a platform bioprocessing technology that has not been attempted before for sustainable HMF production using raw seagrass biomass. This bioprocess can be operated by simple reaction conditions using inorganic Brønsted acids (mainly HCl) and ionic liquid solvents at relatively low temperatures (120–130 °C). In addition, some bioengineering strategies for improving the growth of seagrass biomass and the quantity/quality of nonstructural carbohydrates (starch, sucrose) that can be used as the feeding substrates for HMF production are also discussed. The main aim of this review is to provide some important information about breakthrough bio/technologies conducive to cost-effective and sustainable HMF production. [ABSTRACT FROM AUTHOR]

This work assessed the effect of formulation and heat treatment on the formation of HMF, non-enzymatic browning and rheology of dulce de leche (DL). Laboratory scale trials were developed with different DL formulas: whole powdered milk, skimmed milk, and lactose-free skimmed milk, and added sucrose, subjected to different processing temperatures (110°C, 120°C, and 130°C). Additionally, an alternative formulation was designed in which half the sucrose was replaced by 50% tagatose. DL samples were compared with three commercial products in terms of water activity, soluble solids content, pH, colour, apparent viscosity, and HMF concentration. HMF formation in DL was mitigated (35%) in a lactose-free formulation by lowering the process temperature. Moreover, HMF formation was reduced up to 80% replacing sucrose by tagatose without affecting the quality parameters (pH, soluble solids, colour, and apparent viscosity). Decrease in processing temperature and the use of tagatose are viable alternatives for HMF mitigation in DL. [ABSTRACT FROM AUTHOR]

Nobiletin is an abundant phytoconstituent having multiple pharmacological activities. Various citrus species like orange (Citrus sinensis), lemon (Citrus limon), grapefruit (Citrus paradisi) and tangerine (Citrus tangirina) having flavanones, flavones, flavon aglycon, and Polymethoxyflavones (Nobiletin & Tangeretin). Nobiletin (HMF); Hexamethoxyflavone {2-(3, 4)-dimethoxyphenyl)-5,6,7,8-tetramethoxychromen-4-one}is extracted from non-edible orange peel rich in polymethoxyflavones (PMFs). Many are suggesting Nobiletin as chemo-sensitizing agent induces nuclear retention of tumor suppressor protein and Tyrosinase inhibitor, inhibiting hepatitis B virus replication. It is also proposed that 2-aryl-4H-chromen-4-one derivative may be effective in Chikungunya Virus, and other suggested multiple activities. Citrus species are traditionally used in Ayurveda as immune modulator which is effective in viral disease because of their antioxidant properties. To study the ability as drug of an independent phyto-active Nobiletin (HMF) is under consideration, HMF is lipophilic in nature, its physiochemical properties may by enhanced by increasing water solubility for more bioavailable, and prospective as a therapeutic agent or as broad-spectrum antiviral. [ABSTRACT FROM AUTHOR]

Synthesis of 5-hydroxymethylfurfural (HMF) was studied using Cr-montmorillonite and Cr-bentonite catalysts. Catalysts were characterized by Brunauer–Emmett–Teller surface area analyzer, X-ray diffraction (XRD), infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The effects of temperature and time on the conversion of glucose to HMF were investigated with different solvent-catalyst systems. HMF yield (45%) was obtained at 140 °C for 20 min using Cr-montmorillonite in 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) ionic liquid. The 62.6% HMF yield was efficiently achieved at 150 °C for 10 min in [BMIM]Cl using Cr-bentonite. Cr-bentonite catalyst has good reusable properties in dimethyl sulfoxide (DMSO). The 94% of catalytic efficiency was maintained at the end of fifth use in DMSO. [ABSTRACT FROM AUTHOR]

Apple sour is a traditional product of Kastamonu, Turkey. It is consumed by spreading on bread or drinking after diluting with water. The aim of this study was to determine patulin (PAT) and 5-hydroxymethylfurfural (HMF) in apple sour. This study is the first to evaluate the occurrence of PAT and HMF in apple sour. The samples were extracted with ethyl acetate using liquid-liquid extraction technique. PAT and HMF were determined by HPLC with UV detection. PAT was detected in all samples, and the PAT level in 94.9% of samples was found to be equal or greater than the legal limit for juice concentrates. The mean value for PAT was found to be 284 ± 307 μg kg−1. PAT levels in 13 of 39 samples were in the range of 100 ≤ x < 200 μg kg−1, two samples were in the range of 0 ≤ x < 50 μg kg −1 and two samples were in the range of 1000 ≤ x < 1500 μg kg1. HMF levels of all samples were above the legal limit for solid molasses. The mean value for HMF was found to be 16215 ± 13317 mg kg−1. HMF levels of 10 of 39 samples were determined to be in the range of 10000 ≤ x < 20000 mg kg−1, eight samples were in the range of 20000 ≤ x < 30000 mg kg−1 and only three samples were in the range of 100 ≤ x < 1000 mg kg−1. There was a significant and inverse relationship between HMF and pH of the samples. These results indicate that consumption of apple sour is a considerable risk in terms of HMF and PAT toxicity. [ABSTRACT FROM AUTHOR]

The purpose of this study was to measure acrylamide (AA) levels and selected parameters of different traditional Turkish coffees. AA, 5-hydroxymethylfurfural (HMF), total reducing sugar, protein, pH, moisture, dry matter (DM) as well as ash, caffeine and soluble solids content (SSC) in DM, L*, a*, b* colour parameters of coffee samples were determined and the correlation between AA level and these parameters were investigated. A total of 36 coffee samples (20 Turkish, 8 Dibek and 8 Terebinth coffee) from the Turkish market were examined. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was validated for the detection and quantitation of AA in coffee samples. The calibration curve was linear (R2 ≥ 0.999) over the range of 30–1000 μg kg−1. The limit of detection (LOD) and limit of quantification (LOQ) were found as 4.6 μg kg−1 and 15.5 μg kg−1, respectively. The amounts of AA in analysed coffee samples were in the range 31.1 ± 0.6 to 323.4 ± 5.4 µg kg−1. The highest mean AA levels were found in Terebinth coffees (240.3 μg kg−1) followed by Turkish coffees (204.3 µg kg−1) and then Dibek coffees (78.6 µg kg−1). No tested Turkish coffee samples had an AA concentration above the indicative value (450 µg kg−1) for roast coffee recommended by the European Commission (EC) in 2011. In addition, a strong positive correlation was found between HMF values and AA amounts of selected coffee types. [ABSTRACT FROM AUTHOR]

In this study, CrCI3, H–Y, Cr–Y and calcined CrOx–Y zeolites were studied in the liquid phase heterogeneous catalytic conversion of glucose to HMF in ionic liquids. Characterization of catalysts was done in XPS, XRD and NH3-TPD. Both glucose conversion and HMF yield decreased with the addition of chromium (III) chloride impregnated catalysts in comparison to the homogeneous CrCI3–[BMIM]CI system. High glucose and HMF yields were obtained with heterogeneous calcined CrOx–Y zeolite. Best HMF yield achieved was 52.8%. [ABSTRACT FROM PUBLISHER]

Mulberry pestil and köme are Turkish traditional foods made from herle. Browning leads to quality losses in the herle, and its products. In this study, the effect of thermal treatment on the hydroxymethylfurfural formation and color values in the herle was evaluated. The herle samples were kept at different temperatures (60–110°C) and times (2–6 h). The hydroxymethylfurfural formation was found to increase with increasing time and temperature. The legal limit for hydroxymethylfurfural in the pestil (50 mg/kg) was exceeded at temperatures above 90°C. The lightness (L*value) of the sample decreased with the thermal treatment, indicating browning. [ABSTRACT FROM PUBLISHER]

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]

The alternative feedstock, biomass (particularly lignocelluloses), having the profuse availability, is promising for the synthesis of several value-added chemicals which are currently obtained from fossil feedstock. In this article, the synthesis of two extremely significant furan chemicalsviz.furfural and 5-hydroxymethylfurfural (HMF) are discussed. In the synthesis of furans from biomass, numerous challenges, i.e., use of edible sugars as substrates, selectivity to furans, their isolation in pure form, reuse of catalyst, environmental issues, etc., are perceived and in the recent past researchers tried to resolve those by developing advance methodologies. This article comprehensively summarizes the latest progress made in the above-mentioned areas and also provides commentary on the analyses of results, rationale for observed activity and mechanisms, etc. It also discusses future aspects of this work. [ABSTRACT FROM PUBLISHER]

In this research, the effect of different bicarbonate salts (sodium and ammonium) and their doses (0, 1, 2, and 3 g/100 g raw material) in the coating batter formula use and the sequential use of frying oil (1st, 2nd, 3rd, and 4th) on 5-hydroxymethylfurfural and acrylamide contents in coated fried chicken meat. The addition of sodium bicarbonate was efficient for reducing acrylamide content, but it increased browning and 5-hydroxymethylfurfural content compared to the control. When increasing the doses of sodium and ammonium bicarbonate from 1 to 3 g/100 g of raw material, the acrylamide content of samples did not change significantly, although adding sodium bicarbonate significantly reduced the acrylamide content as a control. These research results showed that using about 1 g/100 g raw material sodium bicarbonate rather than ammonium bicarbonate and as little frying oil as possible use during the production of coated and fried meat results in lower contents of 5-hydroxymethylfurfural and acrylamide. [ABSTRACT FROM PUBLISHER]

A novel CoAl-hydrotalcite catalyst with different Co2+/Al3+ratios was facilely synthesized using a modified coprecipitation method. Different techniques such as X-ray diffraction (XRD), Fourier transform-infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) were used to characterize the resultant CoAl-hydrotalcite. It was indicated that high crystallinity and a single-phase, layered structure with good composition was successfully fabricated. The resultant CoAl-hydrotalcite catalysts and two comparative hydrotalcites (ZnAl-HT and NiAl-HT) were employed for the selective dehydration of D-fructose into platform chemical 5-hydroxymethylfurfural (HMF), which is a versatile intermediate for the production of biofuels and value-added chemicals. It was shown that the metal variation in Co2+/Al3+ratios and reaction temperature display clear influence on the catalytic activities. Furthermore, the spent CoAl-hydrotalcite catalysts were easily recycled and show high catalytic stability over three consecutive runs. [Supplementary materials are available for this article. Go to the publisher's online edition ofChemical Engineering Communicationsfor the following free supplemental resources: Table S1 and Figure S1.] [ABSTRACT FROM PUBLISHER]

The presence of furan in commercial fruit- and vegetable-based jarred baby food was studied. Furan values ranged from 7.7 to 32.1 μg/kg in fruit-based baby food and from 10.9 to 143.0 μg/kg in vegetable-based baby food. The higher furan content in the latter case may be related to either greater ascorbic acid degradation or furfural content in these samples. This could be due to pH and higher temperatures used in sample preparation. Furan intake by Spanish infants ranges from 0.9 to 16.8 μg/day, resulting in exposures of 0.1 to 2.1 μg/kg bw/day. The maximum furan exposure recorded in this study is much lower than the “no observable adverse effect level” of 0.08 mg/kg bw/day determined in experimental animals studies, and is close to the reported acceptable daily intake of 2 μg/kg bw/day. [ABSTRACT FROM PUBLISHER]

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

Glucosylisomaltol (GIM) and hydroxymethylfurfural (HMF) were determined in gluten and gluten-free baby cereals stored under industrial conditions for 1 year and under laboratory conditions for 1 month at Aw = 0.65. In eight mixed cereals, GIM was detected at all times and temperatures assayed, increasing during storage. In rice cereals, GIM was only detected under industrial conditions after 3 and 6 months of storage at 55 and 32 °C, respectively; at Aw = 0.65, GIM was detected after 1 week of storage at 25 and 55 °C. In storage of rice-corn cereals under industrial conditions, GIM was only detected at 55 °C; under laboratory conditions, GIM was detected after 1 week at 55 °C and after 3 weeks of storage at 25 °C. HMF decreased during storage of baby cereals except in rice cereals, the only sample without caramel as an ingredient. HMF only proved to be a useful indicator in rice cereals, whereas GIM was useful in all samples. Glucosilisomaltol (GIM) e hidroximetilfurfural (HMF) fueron determinados en cereales infantiles con gluten y sin gluten almacenados bajo condiciones industriales durante un ano y en laboratorio durante un mes a Aw de 0,65. En la muestra de ocho cereales, GIM fue detectado en todos los tiempos y temperaturas ensayadas, incrementando durante la conservacion. En los cereales de arroz, solo se detecto GIM bajo condiciones industriales tras tres y seis meses a 55 y 32 °C respectivamente; a Aw = 0,65, GIM fue detectado tras una semana a 25 y 55 °C. En los cereales de arroz-maiz, bajo condiciones industriales, GIM fue solo detectado a 55 °C; durante la conservacion en laboratorio, GIM fue detectado tras una semana a 55 °C y tras tres semanas a 25 °C. HMF disminuye durante la conservacion de los cereales, excepto en las muestras de arroz, la unica muestra sin caramelo como ingrediente. HMF solo demostro ser un indicador util en cereales de arroz, mientras que GIM fue util en todas las muestras. [ABSTRACT FROM AUTHOR]

A rapid method for simultaneous determination of furfural and hydroxymethylfurfural (HMF) in the filtrate of an acidic treatment of biomass was developed based on UV spectrophotometer. Interference from acid soluble lignin is alleviated by the use of absorbance difference spectrum before and after reduction with sodium borohydride (NaBH4). The concentrations of furfural and HMF in the filtrate are determined by measuring the absorbance of the difference spectrum at 277 nm and 285 nm, the characteristic absorption maxima for furfural and HMF, respectively. Two simultaneous equations are solved to obtain the concentrations of furfural and HMF in the filtrate. Acid soluble lignin in the solution is determined to cause negligible interference on the analysis. [ABSTRACT FROM AUTHOR]

Ultra-high-pressure homogenization (UHPH) is a technology for continuous treatment of fluid food products and can be applied to avoid thermal treatment of fruit juices. Treatment of fresh apple juice at homogenization pressures from 100 to 300 MPa and inlet temperatures of 4 °C or 20 °C caused important decreases in microbial counts when treatment pressure reached at least 200 MPa. After the treatment, counts were<1 log cfu/ml when homogenization pressure reached at least 200 MPa, and remained stable for more than 2 months at 4 °C. Hydroxymethylfurfural for thermal-treated juice reached values 100-fold higher than for its UHPH-treated or raw counterparts. Browning index was higher in non-thermal-treated juice, and it had an inverse correlation with the severity of UHPH treatment. Part of this browning occurred during Pilot Plant processing, but it kept on browning during preservation in juices in which PPO was not fully inactivated. UHPH treatment of apple juice may be an alternative to conventional thermal processing. [ABSTRACT FROM AUTHOR]

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