5-hydroxymethylfurfural and 5-methyl-2-furfural

The aim of this study was to develop a multi-analyte UHPLC method for furans and to apply it to commercial coffee samples as well as commercial roasting trials. Furans, as rising time-temperature indicators (TTIs), promised to be an alternative to unsatisfactory roasting temperature measurements. Consequently, a UHPLC-UV method for the determination of 5-hydroxymethyl-2-furfural (HMF), 5-hydroxymethyl-2-furoic acid (HMFA), 2-furfural (F), 5-methylfurfural (MF), 2-furyl methyl ketone (FMC), 2-furoic acid (FA), and for 3-caffeoylquinic acid (3-CQA) was developed and validated. Commercial roasted coffee beans contained 77.7-322 mg/kg HMF, 73.3-158 mg/kg HMFA, 109-200 mg/kg 2-F, 157-209 mg/kg MF, 12.3-32.8 mg/kg FMC, and 137-205 mg/kg FA. Roasting trial samples showed strong rising HMF contents (max.: Arabica: 769 mg/kg, Robusta: 364 mg/kg) followed by a distinct decline. Only MF and FA appeared as steady rising TTIs in the roasting process in Arabica and Robusta beans. 3-CQA fitted well as a decreasing TTI as expected.

Topics: Chlorogenic Acid; Chromatography, High Pressure Liquid; Coffee; Food Analysis; Food-Processing Industry; Furaldehyde; Furans; Hot Temperature; Seeds

Topics: Animals; Dairy Products; Furaldehyde; Furans; Gas Chromatography-Mass Spectrometry; Limit of Detection; Milk; Temperature

The model glycoside compound quercetin-3-O-rutinoside (rutin) was subjected to subcritical water within the temperature range of 120-220 °C, and the hydrothermal degradation products were analyzed. Two kinetic models describing the degradation of this compound in two different atmospheres (N

Topics: Catechols; Furaldehyde; Glycosides; Hot Temperature; Hydrolysis; Hydroxybenzoates; Kinetics; Pressure; Rutin; Water

A fast and simple solvent microextraction technique using salting out-vortex-assisted liquid-liquid microextraction (salting out-VALLME) was developed for the extraction of furfurals (2-furfural (2-F), 3-furfural (3-F), 5-methylfurfural (5-MF) and 5-hydroxymethylfurfural (5-HMF)) and patulin (PAT) in fruit juice samples. The optimum extraction conditions for 5 mL sample were: extraction solvent, 1-hexanol; volume of extractant, 200 µL; vortex time, 45 s; salt addition, 20%. The simultaneous determination of the furfurals and PAT were investigated using high performance liquid chromatography coupled with diode array detector (HPLC-DAD). The separation was performed using ODS Hypersil C18 column (4.6 mm i.d × 250 mm, 5 μm) under gradient elution. The detection wavelengths used for all compounds were 280 nm except for 3-F (210 nm). The furfurals and PAT were successfully separated in less than 9 min. Good linearities (r(2)>0.99) were obtained within the range 1-5000 μg L(-1) for all compounds except for 3-F (10-5000 µg L(-1)) and PAT (0.5-100 μg L(-1)). The limits of detection (0.28-3.2 µg L(-1)) were estimated at S/N ratio of 3. The validated salting out-VALLME-HPLC method was applied for the analysis of furfurals and PAT in fruit juice samples (apple, mango and grape).

Topics: Beverages; Chromatography, High Pressure Liquid; Fruit; Furaldehyde; Hexanols; Limit of Detection; Liquid Phase Microextraction; Malus; Mangifera; Patulin; Salts; Vitis

High fructose corn syrup (HFCS) was added at 5% to 40% to Indiana wildflower honey and added at 40% to Ohio and Indiana honeys from blueberry, star thistle, clover and wildflower, and an unknown source to simulate honey adulteration. Unadulterated honeys were also stored at 37 ºC from 1 to 6 mo. The volatile composition was measured by Selected Ion Flow Tube Mass Spectrometry (SIFT-MS). Most volatiles decreased in concentration with both increasing HFCS and storage time. Furfural significantly increased in concentration in all adulterated honeys and 1,3-butanediol, acetonitrile, and heptane in some adulterated honeys. During storage, the volatiles that increased were maltol, furfural, 5-methylfurfural, and 5-hydroxymethyl furfural in all honeys and also acetic acid and 1-octen-3-ol levels in some honeys. Soft independent modeling by class analogy (SIMCA) was used to differentiate the volatile profiles of adulterated honeys from fresh and stored honeys. The volatile profiles of honeys in accelerated storage for up to 4 mo and the honeys adulterated with 40% HFCS were significantly different. Acetic acid had the most discriminating power in Ohio star thistle and blueberry honeys and unknown honey while furfural had the greatest discriminating power in Indiana blueberry, star thistle, and clover honeys. Adulteration and storage of honey both reduced the volatile levels, but since they changed the volatile composition of the fresh honey differently, SIMCA was able to differentiate adulteration from storage..  Analysis of adulterated and stored honeys determined that both decrease volatile levels, and no clear indicator volatiles were found. However, SIMCA can be used to distinguish the volatile profiles of fresh or stored honeys, from adulterated honeys.

Topics: Acetic Acid; Butylene Glycols; Food Contamination; Food Storage; Fructose; Furaldehyde; Honey; Indiana; Mass Spectrometry; Multivariate Analysis; Octanols; Ohio; Volatile Organic Compounds

Even though the chromogens formed from mannose and galactose showed comparable absorbances at 480 nm in the conventional (developer present during heat of dilution) and modified (developer reacted at room temperature after cooling; epsilon mannose = 13,700, galactose = 14,000) phenol-sulfuric acid reactions, shoulders in the region 420-430 nm were prominent in the former method. Fucose was 10 times less reactive in the modified method (epsilon = 800) than in the conventional method. 2-Formyl-5-furan sulfonic acid reacted equally efficiently in the two methods (epsilon = 40,800). 5-Methyl-2-furaldehyde, unlike the sulfonate derivative or 5-hydroxymethyl-2-furaldehyde, required heat for condensation with phenol. 2-Furaldehyde dimethylhydrazone reacted 25 times better to form a chromogen (epsilon = 40,500) in the modified phenol-sulfuric acid method. The possible roles of intermediates between hexoses and furaldehydes in forming chromogens and the effect of substitution at the 2- and 5-positions of furaldehyde on the rates of condensation with phenol for the observed differences between the conventional and the modified methods are discussed.

Topics: Fucose; Furaldehyde; Furans; Galactose; Hexoses; Hydrazones; Mannose; Phenol; Phenols; Spectrophotometry; Spectrophotometry, Ultraviolet; Sulfuric Acids