A new derivatizing reagent for the determination of 5-nitro-2-furaldehyde in trout muscle by liquid chromatography-tandem mass spectrometry.

The 5-nitro-2-furaldehyde (5-NF) is an aldehyde aromatic organic compound that has been envisaged as an alternative marker for detecting nitrofurazone treatment abuse and to avoid the false positive results induced by the semicarbazide. Analyzing 5-NF presents challenges, and its derivatization reaction with hydrazine reagents is required to enhance the capability of its detection and its identification. This study aims at developping an analytical method for 5-NF determination in trout muscle samples based on chemical derivatization prior to analysis by liquid chromatography-tandem mass spectrometry. Four commercially available hydrazine reagents, namely: N,N-Dimethylhydrazine (DMH), 4-Hydrazinobenzoic acid (HBA), 2,4-Dichlorophenylhydrazine (2,4-DCPH) and 2,6-Dichlorophenylhydrazine (2,6-DCPH) were proposed for the first time as derivatizing reagents in the analysis of 5-NF. The derivatization reaction was simultaneously performed along with the extraction method in acidic condition using ultrasonic assistance and followed by liquid extraction using acetonitrile. The efficiency of the chemical reaction with 5-NF was examined and the reaction conditions including the concentration of hydrochloric acid, pH, temperature, reaction time and the concentration of the derivatizing reagents were optimized. Experiments with fortified samples demonstrated that 2,4-DCPH derivatizing reagent at 20 mM for 20 min of ultrasonic treatment under acidic condition (pH 4) gave an effective sample derivatization method for 5-NF analysis. Under the optimized conditions, the calibration curves were linear from 0.25 to 2 µg kg-1 with coefficient of determination >0.99. The recoveries ranged from 89 % to 116 % and precision was less than 13 %. The limit of detection and quantification were 0.1 and 0.2 µg kg-1, respectively.

Volatile profile of bee bread.

Bee bread is one of the least studied bee products. In this study, ten bee bread samples were characterized using palynology and HS-SPME-GC-MS (headspace solid-phase microextraction gas chromatography-mass spectrometry). In total, over one hundred different volatile components were identified, belonging to different chemical groups. Only ten common components were detected in all the samples. These volatiles were ethanol, ethylene chloride, ethyl acetate, acetic acid, α-pinene, furfural, nonane, nonanal, n-hexane and isovaleric acid. Several other components were commonly shared among various bee bread samples. Over sixty detected compounds have not been previously reported in bee bread. The analysis required a mild extraction temperature of 40 °C, as higher temperatures resulted in the Maillard reaction, leading to the production of furfural. The profile of volatile compounds of the tested bee pollen samples was complex and varied. Some relationships have been shown between botanical origin and volatile organic compound profile.

Açai Seeds (Euterpe oleracea Mart) Are Agroindustrial Waste with High Potential to Produce Low-Cost Substrates after Acid Hydrolysis.

Açai seeds have been discarded improperly around the Amazonia region, but they can be seen as promising low-cost substrates for fermentation processes. The structural carbohydrates and physicochemical characterization of açai seeds from the Amazonia were assessed followed by the determination of the optimal hydrolysis conditions using H3PO4 (phosphoric acid) and H2SO4 (sulfuric acid) to obtain a liquor with high contents of simple carbohydrates and low levels of potential microbial inhibitors usually generated during acid hydrolysis of carbohydrates. A central composite rotational design was carried out varying the concentrations of diluted acid (0-5%, w/v), solids (0.1-25%, w/v), and hydrolysis time (9.5-110 min). Acid hydrolysis with H2SO4 was more effective in producing reducing sugars (15.9-103.1 g/L) than H3PO4 (2.9-33.9 g/L) during optimization. The optimal hydrolysis conditions with H2SO4 were 3.5% of acid (w/v), 25% of solids during 70 min at 121 °C, which provided a liquor with 55 g/L of reducing sugars and low levels of microbial inhibitors: acetic acid (1.8 g/L), hydroxymethyl furfural (338 mg/L), and furfural (10 mg/L). Thus, açai seeds were characterized as promising agroindustrial waste with high potential to be used as a low-cost substrate in biotechnological processes, comprising relevant environmental and bioeconomic aspects for the development of the Amazonia.

Furfural Derivatives and Phenolic Constituents in Stemona tuberosa Lour.

Chemical investigation on the water-soluble constituents of Stemona tuberosa Lour. resulted in the isolation of a previously undescribed furfural derivative namely (S)-5-((R)-hydroxy(5-(hydroxymethyl)furan-2-yl)methyl)-5-methylfuran-2(5H)-one and twenty-five known compounds from the water decoction of the dried root tubers. Their structures were determined by analysis of the extensive spectroscopic data, including 1D/2D NMR, HR-ESI-MS, and ORD, as well as the ECD simulation and comparison. Most of them were phenolic and among them, four compounds were isolated from Stemona plants for the first time. This study uncovers diverse constituents from water decoction of S. tuberosa dedicated for its quality control and allows for the exploitation of chemical markers with potential significance for discrimination of Stemona plants.

Study of Brewer's Spent Grain Environmentally Friendly Processing Ways.

BACKGROUND: This article is devoted to the study of the effect of electrochemically activated water (catholyte with pH 9.3) on organic compounds of the plant matrix of brewer's spent grain in order to extract various compounds from it. METHODS: Brewer's spent grain was obtained from barley malt at a pilot plant by mashing the malt followed by filtration and washing of the grain in water and storing it at (0 ± 2) °C in craft bags. For the organic compound quantitative determination, instrumental methods of analysis (HPLC) were used, and the results were subjected to mathematical analysis. RESULTS: The study results showed that at atmospheric pressure, the alkaline properties of the catholyte showed better results compared to aqueous extraction with respect to ß-glucan, sugars, nitrogenous and phenolic compounds, and 120 min was the best period for extraction at 50 °C. The excess pressure conditions used (0.5 ÷ 1 atm) revealed an increase in the accumulation of non-starch polysaccharide and nitrogenous compounds, while the level of sugars, furan and phenolic compounds decreased with increasing treatment duration. The waste grain extract ultrasonic treatment used revealed the effectiveness of catholyte in relation to the extraction of ß-glucan and nitrogenous fractions; however, sugars and phenolic compounds did not significantly accumulate. The correlation method made it possible to reveal the regularities in the formation of furan compounds under the conditions of extraction with the catholyte: Syringic acid had the greatest effect on the formation of 5-OH-methylfurfural at atmospheric pressure and 50 °C and vanillic acid under conditions of excess pressure. Regarding furfural and 5-methylfurfural, amino acids had a direct effect at excess pressure. It was shown that the content of all furan compounds depends on amino acids with thiol groups and gallic acid; the formation of 5-hydroxymethylfurfural and 5-methylfurfural is influenced by gallic and vanillic acids; the release of furfural and 5-methylfurfural is determined by amino acids and gallic acid; excess pressure conditions promote the formation of furan compounds under the action of gallic and lilac acids. CONCLUSIONS: This study showed that a catholyte allows for efficient extraction of carbohydrate, nitrogenous and monophenolic compounds under pressure conditions, while flavonoids require a reduction in extraction time under pressure conditions.

Eu3+-Functionalized MOFs for the simple and rapid 5-Hydroxymethylfurfural determination in food.

5-Hydroxymethylfurfural (5-HMF) is an important product of the Maillard reaction and can be used as a quality indicator of food. 5-HMF has been found in studies to be harmful to human health. In this study, a highly selective and anti-interference fluorescent sensor Eu@1 is constructed based on Eu3+-functionalized Hf-based MOF for monitoring 5-HMF in a variety of food products. Eu@1 shows high selectivity, low LOD (8.46 µM), fast response time, and repeatability for 5-HMF. More importantly, after adding 5-HMF to milk, honey and apple juice samples, the probe Eu@1 is proved to be successfully in sensing 5-HMF in the above food samples. Therefore, this study provides a dependable and efficient alternative for the detection of 5-HMF in food samples.

Mechanism of sugar degradation product 5-hydroxymethylfurfural reducing the stability of anthocyanins.

The coexistence of anthocyanin with the sugar degradation product 5-hydroxymethylfurfural (5-HMF) is inevitable during the processing and storage of anthocyanin-rich juices. It was determined from our study that lower concentrations of 5-HMF have little effect on the stability of Cyanidin-3-O-glucoside (C3G), and even cause a slight increase for a short period of time. As the concentration of 5-HMF increased, the retention of C3G decreased and the color of the solution changed from orange-red to purple-red. The reaction sites of 5-HMF and C3G in its hemiketal form were predicted by quantum chemical calculations in order to investigate the pathways of action of the two. The degradation mechanism of 5-HMF on anthocyanin was verified by Ultraviolet and Visible spectrophotometer and Ultra performance liquid chromatography-mass spectrometry. Therefore, this article provides further theoretical support for the study of the effect of furfural compounds, which are sugar degradation products, on the stability of anthocyanins.

Aroma generation in sponge cakes: The influence of sucrose particle size and sucrose source.

The influence of sucrose source and particle size was investigated in relation to the volatile and aromatic properties of sponge cakes. Six sponge cake formulations were studied using two sucrose sources (sugarbeet and sugarcane), at two particle sizes (large and small) with controls. Volatiles profiles and odour active compounds were identified by gas chromatography mass spectrometry and olfactometry. Sixty two volatile compounds were identified, incorporating twenty five odour active compounds/co-eluting compounds, with 5 odours perceived without any corresponding volatile. Particle size had the greatest impact on volatile abundance, with particle size especially influencing pyrazine abundance. Five odour active volatiles (methional, furfural, 2,3-dimethylpyrazine, heptanal and (E)-2-octenal) contributed most to the aroma of these sponge cakes. Small particle size particularly from sugarbeet yielded higher levels of some Maillard and caramelisation reaction compounds, such as furfural (spicy/ bready), where larger particle size supressed volatile abundance in comparison to the control.

Concentration of pomegranate juice by forward osmosis or thermal evaporation and its shelf-life kinetic studies.

Pomegranate (Punica grantum L.) fruit juice was concentrated by forward osmosis or thermal evaporation and the samples were stored at ambient (25 °C) and accelerated (37 °C) storage conditions. The anthocyanin content of raw, reconstituted forward osmosis as well as reconstituted thermally evaporated pomegranate juice were 421.1, 414.4 and 357.2 mg/kg respectively. The physicochemical attributes of pomegranate juice concentrate such as anthocyanin content, antioxidant activity, browning index, and hydroxymethyl furfural showed that the quality of the concentrate was markedly affected by storage conditions. Based on the hydroxymethyl furfural content (≤25 mg/kg), it was concluded that the forward osmosis concentrated juices could be stored at ambient and accelerated conditions for ∼101 and ∼66 days, respectively. While, thermally concentrated juice could only be stored for less ∼31 and ∼3 days, respectively. Forward osmosis could be a method to concentrate pomegranate juice with minimum effect on quality attributes with extended shelf life.

A Comprehensive HPTLC-Based Analysis of the Impacts of Temperature on the Chemical Properties and Antioxidant Activity of Honey.

Honeys are commonly subjected to a series of post-harvest processing steps, such as filtration and/or radiation treatment and heating to various temperatures, which might affect their physicochemical properties and bioactivity levels. Therefore, there is a need for robust quality control assessments after honey processing and storage to ensure that the exposure to higher temperatures, for example, does not compromise the honey's chemical composition and/or antioxidant activity. This paper describes a comprehensive short-term (48 h) and long-term (5 months) study of the effects of temperature (40 °C, 60 °C and 80 °C) on three commercial honeys (Manuka, Marri and Coastal Peppermint) and an artificial honey, using high-performance thin-layer chromatography (HPTLC) analysis. Samples were collected at baseline, at 6 h, 12 h, 24 h and 48 h, and then monthly for five months. Then, they were analysed for potential changes in their organic extract HPTLC fingerprints, in their HPTLC-DPPH total band activities, in their major sugar composition and in their hydroxymethylfurfural (HMF) content. It was found that, while all the assessed parameters changed over the monitoring period, changes were moderate at 40 °C but increased significantly with increasing temperature, especially the honeys' HPTLC-DPPH total band activity and HMF content.

Nutrient and Maillard reaction product concentrations of commercially available pet foods and treats.

Thermal processing is used to produce most commercial pet foods and treats to improve safety, shelf life, nutritional characteristics, texture, and nutrient digestibility. However, heat treatments can degrade protein quality by damaging essential amino acids, as well as contribute to the Maillard reaction. The Maillard reaction forms melanoidins that favorably improve food qualities (e.g., color, flavor, aroma), but also form Maillard reaction products (MRP) and advanced glycation end-products that may negatively affect health. Because commercial pet diets are frequently fed to domestic cats and dogs throughout their lifetimes, it is critical to quantify MRP concentrations and understand the variables that influence their formation so future diets may be formulated with that in mind. Because few research studies on MRP in pet diets have been conducted, the goals of this study were to measure the MRP in commercial pet foods and treats, estimate pet MRP intake, and correlate MRP with dietary macronutrient concentrations. Fifty-three dry and wet dog foods, dog treats, and cat foods were analyzed for dry matter, organic matter, crude protein, acid-hydrolyzed fat, total dietary fiber, and gross energy using standard techniques. MRP were analyzed using high-performance liquid chromatography and gas chromatography-mass spectrometry. Data were analyzed using the Mixed Models procedure of SAS 9.4. Dry foods had lower reactive lysine concentrations and reactive lysine: total lysine ratios (indicator of damage) than wet foods. Wet foods had more fructoselysine (FRUC) than dry foods; however, dry dog treats contained more FRUC than wet dog treats. The greatest 5-hydroxymethyl-2-furfural (HMF) concentrations were measured in dry and wet dog foods, whereas the lowest HMF concentrations were measured in dry and wet cat foods. Based on dietary concentrations and estimated food intakes, dogs and cats fed wet foods are more likely to consume higher carboxymethyllysine and FRUC concentrations than those fed dry foods. However, dogs fed wet foods are more likely to consume higher HMF concentrations than those fed dry foods. In cats, those fed dry foods would consume higher HMF concentrations than those fed wet foods. We demonstrated that pet foods and treats contain highly variable MRP concentrations and depend on diet/treat type. In general, higher MRP concentrations were measured in wet pet foods and dry treats. While these findings are valuable, in vivo testing is needed to determine if and how MRP consumption affect pet health.

When heat is applied to food, the structure of sugars and proteins are rearranged. Some of the newly formed compounds are Maillard reaction products (MRP). The Maillard reaction can form melanoidins that improve color, flavor, and aroma, but can also lead to the loss of essential amino acids and the formation of advanced glycation end-products that may negatively affect animal health. Most commercial pet foods and treats are heated to improve safety, shelf life, nutritional characteristics, texture, and nutrient digestion, but MRP formation can be a problem. Because commercial pet foods are fed to domestic cats and dogs throughout their entire lives, quantifying MRP and understanding the variables that influence their formation is critical. The goals of this study were to determine the amount of MRP in commercial pet foods and treats, estimate MRP ingestion in pets, and correlate MRP with dietary macronutrient concentrations. Wet foods and dry treats contained more fructoselysine than dry foods, while dry foods contained more 5-hydroxymethyl-2-furfural. According to our findings, wet diets will result in higher total MRP, carboxymethyllysine, and fructoselysine intake than dry diets. While these findings are valuable, in vivo testing is needed to determine if and how MRP consumption affect pet health.

[Identification and chromatemass- spectrometry quantification of toxic chemicals (N-nitrosamines, phthalates) in baby foods].

Currently, assessing exposure to toxic chemicals detected in foodstuffs is a vital issue, especially regarding foods for babies and toddlers. The research goal was to identify and quantify toxic chemicals (N-nitrosamines, phthalates) in baby foods. Material and methods. Our research objects were 21 samples of canned meat and vegetable purees; 30 samples of juices. All samples were bought in retail outlets. We applied solid phase extraction to prepare the samples for the chromatographic analysis. Chemicals were identified in samples by a hybrid technique, gas chromatography and quadrupole mass spectrometry (GC-MS). The components were classified by comparing the mass spectra we obtained with spectra of specific chemicals and data from the following libraries: NIST 08.L, WILEY275.L and PMW_TOX2.L, AMDIS, USEPA (US Environmental Protection Agency) database with identification numbers of environmental pollutants; libraries containing mass spectra of narcotics, drugs, toxic pollutants and pesticides. Quantitative determination of phthalates in juice products by HPLC/MS was performed. Results. We identified three toxic chemicals in the analyzed canned meat and vegetable purees for babies. They belonged to the 1-3 hazard category and to different classes of organic compounds. Specifically, we identified nitrogen-containing chemicals (N-nitrosamines within a range of concentrations being 0.00077-0.0015 mg/kg with a 73% probability that a mass spectrum would match one taken from a library) in 52.9% of samples. These chemicals are not allowed in canned meat purees for babies by the Technical Regulations TR CU 021/2011 (<0.001 mg/kg). Next, we identified dibutyl phthalate and diethyl phthalate in 30.0% of samples; contents of these organic compounds in canned meat purees for babies are not stipulated by the TR CU 021/2011. We also identified an aromatic compound, namely furfural in 21.7% of samples, and a food additive, 2-butenoic acid (E570) in 5.3% of samples; their contents are regulated by the Technical Regulations TR CU 029/2012. Three toxic chemicals were identified in the analyzed juice samples. First, N-nitrosodiethylamine and N-nitrosodimethylamine were identified in 56.7% of samples (with a 73% probability that a mass spectrum would match one taken from a library, over a concentration range of 0.00045- 0.00077 mg/kg). Second, we identified phthalates (dibutyl phthalate, diethyl phthalate, and diisobutyl phthalate) in 30% of samples (in the concentration range from 0.4 to 59.26 mg/l). The contents of these compounds in juices for babies are not regulated by the TR CU 021/2011. We also detected furfural in 56.7% of samples (with a value of the coefficient of coincidence with library data of 90%), the use of which is regulated in TR CU 029/2012. Conclusion. We have developed and experimentally substantiated an algorithm of an analytical study with its focus on preparing food samples for further identification of chemicals in them. The algorithm involves using a complex technique that combines distillation, solid phase extraction, gas chromatography and mass spectrometry. This technique provides an opportunity to identify a component structure of complex chemical mixtures in food samples with high probability and reliability. It also provides solid evidence that organic compounds occur in food samples based on comparing analytical mass spectra with those taken from mass spectral libraries.

The role of 5-hydroxymethylfurfural in food and recent advances in analytical methods.

The thermal processing, storage, and transportation of foodstuffs (e.g., fruit juices, coffee, honey, and vinegar) generate 5-hydroxymethylfurfural (HMF). The food industry uses this compound as a quality marker, thus increasing the demand for fast and reliable analytical methods for its determination. This review focuses on the formation of HMF in food, its desirable and toxic effects, and recent advances in analytical methods for its determination in foodstuffs. The advantages and limitations of these analytical approaches are discussed relative to the main analytical features.

A quick and simple paper-based method for detection of furfural and 5-hydroxymethylfurfural in beverages and fruit juices.

Improper storage and transportation of non-alcoholic beverages can, over longer periods, induce Maillard reaction, degrading nutritional components and generating genotoxic and carcinogenic by-products such as furfural and 5-hydroxymethylfurfural (HMF), rendering products unsafe for human consumption. Here, we describe a rapid quantitative solution-based method and test-strips for detection of furfural and HMF. The standard spectroscopic method indicated an LOD of 0.006 ±â€¯0.003% (v/v) and 0.005 ±â€¯0.002% (v/v) for furfural and HMF, respectively in fruit juice samples. The novel chromogenic test-strip has sensitivity of 0.008% (v/v) and 0.004% (v/v) for furfural and HMF, respectively in the same samples of fruit juice. Thus, the developed method and test-strips were specific for furfural and HMF and can be used to help ensure food safety and quality in various industrial applications.

Analysis of the evolution of potential and free furfural compounds in the production chain of infant formula and risk assessment.

Furfural compounds are produced during infant formula production when heat treatment is involved. In this study, a robust method was established for determining potential and free furfural compounds (furfural, 5-methyl-2-furfural, 2-acetylfuran and 5-hydroxymethyl-2-furfural) using a modified QuEChERS technique coupled with GC-MS/MS. Further, 36 samples of two batches, covering the whole infant formula production chain were analyzed by the method to investigate how furfurals evolved during process. Then risk assessment was conducted using the Toxtree and T.E.S.T. software and evaluated by hazard quotient. Results showed the contents of bound and free 5-hydroxymethyl-2-furfural demonstrated largest increase during spray-drying (6-11 times) and homogenization stages (12-33 times), respectively. As the sum up of bound and free 5-hydroxymethyl-2-furfural, potential 5-hydroxymethyl-2-furfural was found can cause safety risks in the production chain due to the high hazard quotient value (3.11), indicating it should be controlled in homogenization and spray-drying stages.

Maillard reaction products and guaiacol as production process and raw material markers for the authentication of sesame oil.

BACKGROUND: Sesame oil has an excellent flavor and is widely appreciated. It has a higher price than other vegetable oils because of the high price of its raw materials, and different processing techniques also result in products of different quality levels, which can command different prices. In the market, there is a persistent problem of adulteration of sesame oil, driven by economic interests. The screening of volatile markers used to distinguish the authenticity of sesame oil raw materials and production processes is therefore very important. RESULTS: In this work, six markers related to the production processes and raw materials of sesame oil were screened by gas chromatography-tandem mass spectrometry (GC-MS/MS) combined with chemometric analysis. They were 3-methyl-2-butanone, 2-ethyl-5-methyl-pyrazine, guaiacol, 2,6-dimethyl-pyrazine, 5-methyl furfural, and ethyl-pyrazine. The concentration of these markers in sesame oil is between 10 and1000 times that found in other vegetable oils. However, only 3-methyl-2-butanone and 2-ethyl-5-methyl-pyrazine differed significantly as the result of the use of different production processes. Except for guaiacol, which was mainly derived from raw materials, the other five compounds mentioned above all result from the Maillard reaction during thermal processing. The six compounds mentioned above are sufficient to distinguish fraud involving sesame oil raw materials and production processes, and can identify accurately adulteration levels of 30% concentration. CONCLUSION: In this study, the classification markers can identify the adulteration of sesame oil accurately. These six compounds are therefore important for the authenticity of sesame oil and provide a theoretical basis for the rapid and accurate identification of the authenticity of sesame oil. © 2021 Society of Chemical Industry.

Reduction of 5-Hydroxymethylfurfural and 1,2-Dicarbonyl Compounds by Saccharomyces cerevisiae in Model Systems and Beer.

Glycation and caramelization reactions in malt lead to the formation of 1,2-dicarbonyl compounds, which come in contact with yeast during fermentation. In the present study, the metabolic fate of 5-hydroxymethylfurfural (HMF) and 1,2-dicarbonyl compounds (3-deoxyglucosone, 3-deoxygalactosone, 3-deoxypentosone, 3,4-dideoxyglucosone-3-ene) was assessed in the presence of Saccharomyces cerevisiae. HMF is degraded very fast by yeast with the formation of 2,5-bis(hydroxymethyl)furan (BHMF). By contrast, only 7-30% of 250 µM dicarbonyl compounds is degraded within 48 h. The respective deoxyketoses, 3-deoxyfructose (3-DF), 3-deoxytagatose, 3-deoxypentulose, and 3,4-dideoxyfructose, were identified as metabolites. While 17.8% of 3-deoxyglucosone was converted to 3-deoxyfructose, only about 0.1% of 3-deoxypentosone was converted to 3-deoxypentulose during 48 h. Starting with the parent dicarbonyl compounds, the synthesis of all deoxyketose metabolites was achieved by applying a metal-catalyzed reduction in the presence of molecular hydrogen. In a small set of commercial beer samples, BHMF and all deoxyketoses were qualitatively detected. 3-DF was quantitated in the four commercial beer samples at concentrations between 0.4 and 10.1 mg/L.

Influence of Sargassum pallidum and the synergistic interaction mechanism of 6-gingerol and poricoic acid A on inhibiting ovalbumin glycation.

This study aimed to investigate the antiglycation capacity of Sargassum pallidum extract on ovalbumin (OVA) glycation, and the interaction mechanism of its active compounds, including 6-gingerol (6G) and poricoic acid A (PA). The results showed that Sargassum pallidum extract, PA and 6G had excellent suppression on the formation of fructosamine, 5-hydroxymethylfurfural (5-HMF), acrylamide and advanced glycation end products (AGEs), which was higher than aminoguanidine (AG). The combination of PA and 6G showed good synergistic effect on inhibiting the formation of AGEs. PA exhibited the strongest inhibition activity for protein glycation products, and the content of 5-HMF and acrylamide decreased from 277.44 and 10.60 µg mL-1 to 208.37 and 5.46 µg mL-1, respectively, at 30.08 × 10-5 M compared with the control group. 6G and PA quenched the fluorescence of OVA with a static mechanism, and enhanced the hydrophilic microenvironment of the tyrosine (Tyr) and tryptophan (Trp) residues. The binding of 6G and PA with OVA was spontaneous and driven by hydrogen bonds and van der Waals interactions. Molecular docking indicated that 6G and PA entered the hydrophobic cavity of OVA, and formed hydrogen bonds with Ser103, Leu101 and Thr 91. These findings suggested that Sargassum pallidum extract, PA and 6G have great potential as antiglycation inhibitors to treat diabetes complications in healthy food.

Electrochemical Determination of the "Furanic Index" in Honey.

5-(hydroxymethyl)furan-2-carbaldehyde, better known as hydroxymethylfurfural (HMF), is a well-known freshness parameter of honey: although mostly absent in fresh samples, its concentration tends to increase naturally with aging. However, high quantities of HMF are also found in fresh but adulterated samples or honey subjected to thermal or photochemical stresses. In addition, HMF deserves further consideration due to its potential toxic effects on human health. The processes at the origin of HMF formation in honey and in other foods, containing saccharides and proteins-mainly non-enzymatic browning reactions-can also produce other furanic compounds. Among others, 2-furaldehyde (2F) and 2-furoic acid (2FA) are the most abundant in honey, but also their isomers (i.e., 3-furaldehyde, 3F, and 3-furoic acid, 3FA) have been found in it, although in small quantities. A preliminary characterization of HMF, 2F, 2FA, 3F, and 3FA by cyclic voltammetry (CV) led to hypothesizing the possibility of a comprehensive quantitative determination of all these compounds using a simple and accurate square wave voltammetry (SWV) method. Therefore, a new parameter able to provide indications on quality of honey, named "Furanic Index" (FI), was proposed in this contribution, which is based on the simultaneous reduction of all analytes on an Hg electrode to ca. -1.50 V vs. Saturated Calomel Electrode (SCE). The proposed method, validated, and tested on 10 samples of honeys of different botanical origin and age, is fast and accurate, and, in the case of strawberry tree honey (Arbutus unedo), it highlighted the contribution to the FI of the homogentisic acid (HA), i.e., the chemical marker of the floral origin of this honey, which was quantitatively reduced in the working conditions. Excellent agreement between the SWV and Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC) data was observed in all samples considered.

Headspace Solid-Phase Microextraction Analysis of Volatile Components in Peanut Oil.

Peanut oil is favored by consumers due to its rich nutritional value and unique flavor. This study used headspace solid-phase microextraction (HS-SPME) combined with gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) to examine the differences in the peanut oil aroma on the basis of variety, roasting temperatures, and pressing components. The results revealed that the optimal conditions for extracting peanut oil were achieved through the use of 50/30 µm DVB/CAR/PDMS fibers at 60 °C for 50 min. The primary compounds present in peanut oil were pyrazines. When peanuts were roasted, the temperature raised from 120 °C to 140 °C and the content of aldehydes in peanut oil increased; however, the content of aldehydes in No. 9 oil at 160 °C decreased. The components of peanut shell oil varied depending on the peanut variety. The most marked difference was observed in terms of the main compound at the two roasting temperatures. This compound was a pyrazine, and the content increased with the roasting temperature in hekei oils. When the roasting temperature was lower, No. 9 oil contained more fatty acid oxidation products such as hexanal, heptanal, and nonanal. When the roasting temperature increased, No. 9 oil contained more furfural and 5-methylfurfural. Heren oil was easier to oxidize and produced nonanal that possessed a fatty aroma.