5-hydroxymethylfurfural and 1-1-diphenyl-2-picrylhydrazyl

Fructose and its polysaccharides are widely found in fruits and vegetables, with the Maillard reaction of fructose affecting food quality. This study aimed to investigate the Maillard reaction of fructose using a fructose⁻histidine model system. The reaction process was characterized using fluorescence spectroscopy and ultraviolet spectroscopy. The effects of temperature, initial reactant concentration, initial fructose concentration, initial histidine concentration, and initial pH value on the different stages of the Maillard reaction were studied. Reactant reduction, ultraviolet and fluorescence spectra, acetic acid content, 5-hydroxymethylfurfural (5-HMF) content, and browning intensity were evaluated. The results showed that increasing the temperature and reactant concentration promoted the condensation reaction of fructose and amino acid in the early stage, the formation of intermediate products with ultraviolet absorption and fluorescence in the intermediate stage, and the formation of pigment in the final stage. The 5-HMF concentration decreased with increasing histidine concentration and initial pH value. Changes in the shape of ultraviolet and fluorescence spectra showed that the initial pH value affected not only the reaction rate, but also the intermediate product types. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging rate of the Maillard reaction products increased with increasing temperature, reactant concentration, and initial pH value.

Topics: Acetic Acid; Antioxidants; Biphenyl Compounds; Free Radical Scavengers; Fructose; Furaldehyde; Histidine; Hydrogen-Ion Concentration; Maillard Reaction; Models, Biological; Picrates; Spectrometry, Fluorescence; Spectrophotometry, Ultraviolet; Temperature

Seven commercial Moroccan honeys were considered for chemical characterisation. Volatile fraction, total polyphenols content, antioxidant and antiradical activities were evaluated by employing different analytical methodologies. Several physical parameters such as refractive index, pH, water content, solids content and colour were measured. Volatile fraction revealed an abundant presence of cis- and trans-linalool oxide in the seven studied samples. The presence of high levels of compounds related to the Maillard reaction, like furfural and hydroxymethylfurfural, could be the result of thermal treatments used to liquefy commercial honeys or of long storage times. The CIE L*a*b*C*(ab)h°(ab) chromatic coordinates confirmed the advanced stage of the Maillard reaction, showing L* values lower than the common values found for honey of similar typologies.

Topics: Acyclic Monoterpenes; Antioxidants; Biphenyl Compounds; Color; Cyclohexanols; Furaldehyde; Honey; Hydrogen-Ion Concentration; Monoterpenes; Morocco; Oxidation-Reduction; Picrates; Polyphenols; Solid Phase Microextraction; Trityl Compounds; Water

Sugar beet molasses is a raw material with high potential to be a functional ingredient in baked goods. This paper investigated the nutritional and functional properties of gluten-free cookies enriched with sugar beet molasses. At all enrichment levels and forms tested (liquid and dry), the addition of beet molasses improved the micronutrient pattern and antioxidative status of gluten-free cookies. The cookies prepared with molasses were significantly higher in potassium, magnesium, calcium, iron, betaine, total phenolics and DPPH radical scavenging abilities. Molasses contributed to wider spectra of phenolic compounds. The dominating phenolic compounds in the molasses-enriched cookies were catechin, ferulic, syringic and vanillic acid. Molasses also contributed to the presence of p-hydroxybenzoic acid in the cookies. Addition of molasses increased the content of hydroxymethyfurfural in the cookies, but not above values commonly reported for this product type. Molasses addition improved the overall acceptance of gluten-free cookies up to 30% enrichment level.

Topics: Adult; Beta vulgaris; Biphenyl Compounds; Cooking; Furaldehyde; Glutens; Humans; Middle Aged; Molasses; Nutritive Value; Oxidoreductases; Picrates; Taste

To investigate the effects of isorhamnetin 3,7-di-O-beta-D-glucopyranoside (isorhamnetin diglucoside), a major flavonoid compound of mustard leaf, on oxidative stress due to diabetes mellitus, in vivo and in vitro studies were carried out. Oral administration of isorhamnetin diglucoside (10 or 20 mg/kg of body weight/day for 10 days) to rats with streptozotocin-induced diabetes significantly reduced serum levels of glucose and 5-(hydroxymethyl)furfural (5-HMF), which is glycosylated with hemoglobin and is an indicator of oxidative stress. After intraperitoneal administration, isorhamnetin diglucoside did not show these activities. In addition, after oral administration, the thiobarbituric acid-reactive substance levels of serum, and liver and kidney mitochondria declined significantly compared with the control group in a dose-dependent manner, whereas after intraperitoneal administration these levels fell only slightly. On the basis of the oral and intraperitoneal results, it was hypothesized that isorhamnetin diglucoside was converted to its metabolite in vivo, and its conversion to its aglycone, isorhamnetin, by beta-glucosidase was confirmed; isorhamnetin acted as an antioxidant. Moreover, it was observed that isorhamnetin diglucoside had no effect on the 1,1-diphenyl-2-picrylhydrazyl radical, whereas isorhamnetin showed a potent antioxidant effect in vitro. In addition, intraperitoneal administration of isorhamnetin reduced serum glucose and 5-HMF levels. Furthermore, lipid peroxidation in blood, liver, and kidney associated with diabetes mellitus declined after the administration of isorhamnetin. These results suggest that isorhamnetin diglucoside is metabolized in vivo by intestinal bacteria to isorhamnetin and that isorhamnetin plays an important role as an antioxidant.

Topics: Animals; Antioxidants; Biphenyl Compounds; Blood Glucose; Brassica; Diabetes Mellitus, Experimental; Flavonols; Free Radical Scavengers; Furaldehyde; Glucosides; Glycated Hemoglobin; Kidney; Male; Mitochondria; Mitochondria, Liver; Picrates; Plant Leaves; Quercetin; Rats; Rats, Wistar; Thiobarbituric Acid Reactive Substances