A comparison of methods, two based upon 5-hydroxymethylfurfural determination (colorimetric using a semi-automated procedure and HPLC) and ion exchange chromatography (HbA1 using BioRad method) was performed. The influence of variables on 5-hydroxymethylfurfural determination is reported. The dialysis step appears to be essential for an accurate determination of 5-hydroxymethylfurfural released...

Portuguese honeys (n = 15) from different botanical and geographical origins were analysed regarding their quality parameters (diastase activity, hydroxymethylfurfural content, moisture and pH), colour (L*, a*, b*) and antioxidant profile (total phenolics content, total flavonoids content, DPPH• scavenging activity, and ferric reducing power). The samples were analysed fresh and after 4-years o...

Oxidation of 5-hydroxymethylfurfural into 2,5-furandicarboxylic acid is an important transformation for the production of bio-based polymers. Carbon-supported gold catalysts hold great promise for this transformation. Here we demonstrate that the activity, selectivity, and stability of the carbon-supported gold nanoparticles in the oxidation of 5-hydroxymethylfurfural strongly depend on the sur...

This colorimetric assay for glycosylated hemoglobin can be performed in 120 min with equipment available in most clinical laboratories. The glucose moiety of glycosylated hemoglobin is converted to 5-hydroxymethylfurfural by heating with oxalic acid for 60 min is an autoclave at 124 degrees C and 124 kPa (18 lb/in.2). The adduct formed by reacting 2-thiobarbituric acid with hydroxymethylfurfura...

this study was intended to evaluate the quality of 30 honey samples, in terms of physicochemical properties such as moisture content, electrical conductivity, ash content, reducing sugars and sucrose, free acidity, ph, diastase activity, and hydroxymethylfurfural (hmf) content. moreover, three methods recommended by the international honey commission for the determination of hmf, including 1) h...

Hydroxymethylfurfural is a product of food deterioration and is still under investigation for possible toxic effects. It can also be used to monitor food quality. A sensitive and selective LC/MS method for monitoring this compound is presented. The method can quantitatively determine hydroxymethylfurfural in food with a detection limit of 0.005 μg/g. Sample preparation and analytical conditions...

Objective: Fake honeys from the Ecuadorian market were collected and analyzed with the quality indicators of the Venezuelan honey norm and a simple test. Method: Ash, free acidity, moisture, reducing sugars, apparent sucrose, qualitative diastase activity, qualitative hydroxymethylfurfural, and a simple test based on the number of phases formed after shaking honey water dilutions with diethyl e...

The incompletely coordinated zinc ions in the concentrated aqueous ZnCl(2) solution catalyze the direct conversion of carbohydrates into 5-hydroxymethylfurfural, and a moderate HMF yield up to 50% can be achieved.

Hot pressurized liquid extraction has been used to obtain polyphenols; however, its operating conditions can generate hydroxymethylfurfural, a potential human carcinogen. The addition of ethanol can reduce process temperatures and retain extraction efficiencies, but the ethanol may reduce the recovery of polyphenols in the subsequent purification stage, affecting the antioxidant properties of t...

The bio-based substrate and target product 2,5-bishydroxymethylfuran (BHMF) demonstrated to influence the reaction kinetics in the homogeneous reduction of 5-hydroxymethylfurfural (HMF) catalyzed by the Ru-based Shvo's catalyst. A combined experimental and computational study supports an important role of the -CH2OH moiety which may be involved in the catalytic cycle toward the formation of dif...