This study reports on a rapid method for the determination of levulinic acid (LA) and 5-hydroxymethylfurfural (HMF) in acid hydrolyze system of glucose based on UV spectroscopy. It was found that HMF and LA have a maximum absorption at the wavelengths of 284 nm and 266 nm, respectively, in a water medium, and the absorptions of HMF and LA at 284 nm and 266 nm follow Beer's law very well. Howeve...

The molecular origin of the photoluminescence of carbon dots (CDs) is not known. This restricts the design of CDs with desired optical properties. We have synthesized CDs starting from carbohydrates by employing a simple synthesis method. We were able to demonstrate that the CDs are composed of aggregated hydroxymethylfurfural (HMF) derivatives. The optical properties of these CDs are quite uni...

In this study, we investigated the effects of various temperatures between 140 to 260 degrees C during sub-critical water extraction of residual green tea in making a roasted green tea-like extract, a popular beverage in Japan. Each residual green tea extract was analyzed for sensory properties and antioxidative activities, and this revealed 140 degrees C to be the best extraction temperature. ...

The maturation of Madeira wines usually involves exposure to relatively high temperatures and humidity levels >70%, which affect the aroma and flavor composition and lead to the formation of the typical and characteristic bouquet of these wines. To estimate the levels of sotolon [3-hydroxy-4,5-dimethyl-2(5H)-furanone] and their behavior over time, 86 aged Madeira wines samples (1-25 years old),...

Objective. To develop a quantitative analysis of multicomponents by single-marker (QAMS) method for the simultaneous determination of polar active components in Fructus Corni. Methods. Loganin was selected as the internal reference, and the relative correction factors (RCFs) of gallic acid, 5-hydroxymethyl-2-furfural, morroniside, sweroside, cornin, 7α-O-methylmorroniside, 7β-O-methylmorronisid...

The highly efficient and selective production of 5-hydroxymethylfurfural (HMF) from sucrose has been achieved in the presence of metal chlorides and ammonium halides under mild conditions. Notably, an 87% yield of HMF from sucrose was obtained with a catalyst system composed of CrCl(3) and NH(4)Br at 100°C for 1.0 h in N,N-dimethylacetamide (DMAc) solvent. The effect of the reaction temperature...

Acid catalyzed decomposition of C5 and C6 sugars has been considered an important source of biomass derived chemicals. An essential step in this process is the extraction of furfural, hydroxymethylfurfural and levulinic acid from aqueous phase. In this work, a computational screening of 178 organic solvents for simultaneous extraction of these chemicals from aqueous phase has been done with the...

HPLC methods are described for the determination of furanic compounds (hydroxymethylfurfural and furfural) in enteral formulas prepared with dextrinomaltose and milk proteins, and in model systems enclosing these ingredients. These compounds were extracted in aqueous solution, purified with organic solvents, and separated in a reversed-phase C18 column with water-acetonitrile (95:5 v/v). Averag...

Browning is a major quality deterioration process affecting both visual colour and nutritional value of guava leather. The aim the study was to determine role different sugars viz., sucrose, fructose, glucose sorbitol in non-enzymatic browning antioxidant activity fruit total free amino acids, ascorbic acid activities were at significantly lower levels fructose treated leather, while added samp...