Tag: M.W=100-150

Frauendorfer, Felix published the artcileKey aroma compounds in fermented Forastero cocoa beans and changes induced by roasting, Safety of 2,3,5-Trimethylpyrazine, the main research area is Forastero cocoa bean favor dilution.

The influence of the roasting procedure on the composition of key aroma compounds in fermented Forastero cocoa beans was investigated. For this purpose, the volatile fractions from the unroasted, fermented and the roasted cocoa were isolated by extraction/SAFE distillation, and the odor-active constituents were characterised by gas chromatog.-olfactometry in combination with an aroma extract dilution anal. A total of 41 aroma compounds in the flavor dilution (FD) factor range of 2-8192 were identified in the unroasted and 42 compounds with FD factors of 2-8192 in the roasted cocoa beans. Qual., the set of aroma compounds was nearly identical in both samples; however, differences in the flavor dilution factors were observed 2- and 3-Me butanoic acid (sweaty) and acetic acid (vinegar-like, sour) showed the highest FD factors in the unroasted beans, while 3-methylbutanal (malty), 4-hydroxy-2,5-dimethyl-3(2H)-furanone (caramel-like) and 2- and 3-Me butanoic acid (sweaty) were detectable by GC/O in the highest dilutions in the roasted seeds. Quantitation of the most odor-active compounds by means of stable isotope dilution assays, followed by calculation of odor activity values (OAV, ratio of concentration to odor threshold), revealed concentrations above the threshold level for 20 compounds in the unroasted and 24 compounds in the roasted beans. The roasting procedure led to a strong increase, in particular, in the concentrations of the two Strecker aldehydes 3-methylbutanal (malty) and phenylacetaldehyde (honey-like) as well as 4-hydroxy-2,5-dimethyl-3(2H)-furanone (caramel-like).

European Food Research and Technology published new progress about Cocoa beans. 14667-55-1 belongs to class pyrazines, name is 2,3,5-Trimethylpyrazine, and the molecular formula is C7H10N2, Safety of 2,3,5-Trimethylpyrazine.

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Scalone, Gustavo Luis Leonardo published the artcileCocoa-specific flavor components and their peptide precursors, COA of Formula: C7H10N2, the main research area is cocoa flavor peptide pepsin chromatog; Cocoa flavor; Globular storage protein; Mass spectrometry; Peptides; Volatile compounds; in-vitro proteolysis.

Essential precursors of the cocoa-specific roasting-flavor notes were formed during proteolysis of the cocoa vicilin-class(7S) globulin by a mixture of cocoa aspartic protease and carboxypeptidase. These could be partially purified by ligand-exchange chromatog. Many constituents of this peptide fraction were destroyed by post-treatment with pepsin, but the cocoa-specific flavor-precursor peptides were largely resistant against pepsin treatment. However, these peptides were not generated when the cocoa vicilin-class(7S) globulin was digested with a mixture of pepsin and carboxypeptidase. By nano-liquid chromatog. mass spectrometry, the peptide composition of these peptide fractions were compared in order to identify the putative precursors of the cocoa-specific flavor components. These peptides were assigned to five regions of the cocoa vicilin-class(7S) globulin. Analyzing the roasting products of the different protein fractions by headspace solid-phase microextraction, followed by gas chromatog. mass spectrometry, eight volatile compounds were detected, whose occurrence correlated with the sensory detection of cocoa-specific flavor notes.

Food Research International published new progress about Cocoa beans. 14667-55-1 belongs to class pyrazines, name is 2,3,5-Trimethylpyrazine, and the molecular formula is C7H10N2, COA of Formula: C7H10N2.

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Schafer, Gabriel published the artcileScalable Synthesis of Trifluoromethylated Imidazo-Fused N-Heterocycles Using TFAA and Trifluoroacetamide as CF3-Reagents, Computed Properties of 39204-49-4, the main research area is heterocyclic benzylamine trifluoroacetic anhydride dehydrative cyclization; trifluoromethylated imidazo fused nitrogen heterocycle preparation.

A scalable synthesis of trifluoromethylated imidazo-fused N-heterocycles, e.g. I, from heterocyclic benzylamines using TFAA as trifluoromethylating reagent is presented. The reaction proceeds via intermediate benzylic N-trifluoroacetamides followed by dehydrative cyclization to the products. To further broaden the scope and practicality, a new method for the preparation of benzylic N-trifluoroacetamides via alkylation of trifluoroacetamide with benzyl (pseudo)halides was developed. Both methods proceed under mild conditions, and their symbiosis provides access to a wide range of novel CF3-heterocycles.

Organic Letters published new progress about Cyclization. 39204-49-4 belongs to class pyrazines, name is Pyrazin-2-ylmethanamine hydrochloride, and the molecular formula is C5H8ClN3, Computed Properties of 39204-49-4.

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Ontanon, Ignacio published the artcileAir inside a dishwasher: Odour characterization and strategy for measuring odour changes, Related Products of pyrazines, the main research area is dishwasher odor atm sensory analysis.

The use of home appliances can cause various problems. In the case of dishwashers, the generation of bad odours is one of the most serious problems for users. Odours inside dishwashers are mainly caused by the presence of food residues. A study using gas chromatog.-olfactometry (GC-O) has been carried out to establish how different food residues produce differences in the odours found in dishwashers. A total of 49 compounds were identified in the 109 odor zones detected. Di-Me trisulfide and methanethiol/dimethyl sulfide were the most significant compounds in most of the situations studied. Some of these compounds were selected to generate an ‘odorous atm.’ that was subjected to chem. and sensory anal. Treatments for the elimination of odours, designed to alter the odours, were applied to this atm. before performing chem. (GC-MS) and sensory analyses. The sensory anal. was carried out to determine the intensity and hedonic tone of the odorous atm. Differences between treatments were found.

Flavour and Fragrance Journal published new progress about Dishwashers. 14667-55-1 belongs to class pyrazines, name is 2,3,5-Trimethylpyrazine, and the molecular formula is C7H10N2, Related Products of pyrazines.

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Xu, Ziyan published the artcileProcessing of flavor-enhanced oils: optimization and validation of multiple headspace solid-phase microextraction-arrow to quantify pyrazines in the oils, HPLC of Formula: 14667-55-1, the main research area is rapeseed oil flavor pyrazine solid phase microextraction; flavor edible oil; internal standard method; multiple headspace solid-phase microextraction; pyrazine; solid-phase microextraction-arrow.

An efficient and effective multiple headspace-solid phase microextraction-arrow-gas chromatog.-mass spectrometry (MHS-SPME-arrow-GCMS) anal. protocol is established and used to quantify the flavor compounds in oils. SPME conditions, such as fiber coating, preincubation temperature, extraction temperature, and time were studied. The feasibility was compared between SPME-arrow and the traditional fiber by loading different sample amounts It was found that the SPME-arrow was more suitable for the MHS-SPME. The limit of detection (LODs) and limit of quantitation (LOQs) of pyrazines were in the range of 2-60 ng and 6-180 ng/g oil, resp. The relative standard deviation (RSD) of both intra- and inter-day were lower than 16%. The mean recoveries for spiked pyrazines in rapeseed oil were in the range of 91.6-109.2%. Furthermore, this newly established method of MHS-SPME-arrow was compared with stable isotopes dilution anal. (SIDA) by using [2H6 ]-2-methyl-pyrazine. The results are comparable and indicate this method can be used for edible oil flavor anal.

Life (Basel, Switzerland) published new progress about Equilibrium. 14667-55-1 belongs to class pyrazines, name is 2,3,5-Trimethylpyrazine, and the molecular formula is C7H10N2, HPLC of Formula: 14667-55-1.

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Kilgannon, Ashleigh K. published the artcileTemperature-time combination effects on aged beef volatile profiles and their relationship to sensory attributes, Synthetic Route of 14667-55-1, the main research area is volatile organic compound temperature; Accelerated ageing; Ageing period; Eating quality; Holding temperature; Untrained panel; Volatile organic compounds.

Beef ageing (in vacuo) for tenderisation and flavor development may be accelerated by favorable temperature-time combinations (TTCs), however the effect of such manipulations on volatile organic compounds (VOCs) that are generated during cooking, is unknown. We compared VOCs from grilled beef longissimus lumborum muscle samples which had been subjected to different TTCs. The TTCs consisted of combinations of temperatures (∼ 3, 5, or 7°C) and ageing time periods (6, 8, 10 or 12 d); as well as control samples, which were held at 0-2°C for a total of 14 d. Sensory quality attributes of these same samples were measured by untrained consumer panellists. Generally, it was found that TTCs had negligible effects on grilled beef VOCs and were comparable to controls. Furthermore, many VOCs were significantly related to flavor intensity, flavor liking and overall liking. These findings support the use of TTCs as a viable means to accelerate the rate of beef ageing without compromising quality.

Meat Science published new progress about Temperature. 14667-55-1 belongs to class pyrazines, name is 2,3,5-Trimethylpyrazine, and the molecular formula is C7H10N2, Synthetic Route of 14667-55-1.

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Alimoradi, Sirwan published the artcileEffect of temperature on toxicity and biodegradability of dissolved organic nitrogen formed during hydrothermal liquefaction of biomass, Recommanded Product: 2,3,5-Trimethylpyrazine, the main research area is dissolved organic nitrogen biomass hydrothermal liquefaction toxicity biodegradability temperature; HTL wastewater; Heterocyclic N-Containing organic compounds (HNOCs); Hydrothermal liquefaction (HTL); Nitrogen recovery; Non-biodegradable dissolved organic nitrogen (nbDON); Toxicity.

This study investigated the nutrient content and reuse potential of wastewater generated during hydrothermal liquefaction of microalgal biomass. The hydrothermal liquefaction reaction was tested at 270, 300, 330, and 345°C to determine the effect of temperature on the formation of non-biodegradable dissolved organic nitrogen (nbDON). Total nitrogen, ammonium, color, and toxicity were selected as key characteristics for the reuse of hydrothermal liquefaction wastewater. Results indicated that a higher concentration of nbDON5 (nbDON defined with a 5 day growth assay) and more diverse heterocyclic N-containing organic compounds were associated with greater toxicity as measured by a growth rate assay. For the tested temperature ranges, the total nitrogen content of the hydrothermal liquefaction wastewater slightly decreased from 5020 ± 690 mg L-1 to 4160 ± 120 mg L-1, but the percentage nbDON5 fraction increased from 57 ± 3%DON to 96 ± 5%DON. The temperature of hydrothermal liquefaction reactions can be optimized to maximize carbon conversion and nitrogen recovery.

Chemosphere published new progress about Absorption. 14667-55-1 belongs to class pyrazines, name is 2,3,5-Trimethylpyrazine, and the molecular formula is C7H10N2, Recommanded Product: 2,3,5-Trimethylpyrazine.

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Aszyk, Justyna published the artcileConcentration levels of selected analytes in the gas phase of an e-cigarette aerosol, Quality Control of 14667-55-1, the main research area is electronic cigarette gas phase aerosol.

The aerosols generated from e-cigarettes are composed of liquid and gas phases resulting from vaporized e-liquid The apportioning of substances from e-liquid into the liquid and gas phases during e-cigarette use has not been extensively studied. Partitioning of e-liquid components between the gas and the liquid phase of the aerosol influences the substances inhaled and exhaled by the users, leading to second-hand exposure. It seems important to determine which compounds and how much of them are transferred into the gas phase and may immediately enter the bloodstream. For this purpose, a method based on thermal desorption followed by gas chromatog. coupled with tandem mass spectrometry (GC-MS/MS) in electron ionization mode was developed. As in a previous study, an automatic generator of an aerosol from an e-cigarette with a collection tube filled with melt-blown non-woven fabric disks and equipped with Tenax TA sorption tubes was used. The melt-blown non-woven fabric is designed to capture liquid phase compounds, while sorption tubes are meant to sorb compounds in the gas phase of the aerosol. To control the e-liquid mass changes before and after a puff session, quantitation based on the mass change tracking approach (MCT) was applied. Accuracy of the developed method ranged between 91% and 110% regardless of the spiking level, with precision and reproducibility better than 10%. The limits of detection (LODs) ranged from 0.015 to 0.076 ng of substance emitted/mg of consumed e-liquid, while limits of quantitation (LOQs) ranged from 0.045 to 0.23 ng of substance emitted/mg of consumed e-liquid Most of the compounds are deposited in the liquid phase of the aerosol, while only trace levels of some substances may be observed in an actual, non-condensed gas phase.

Microchemical Journal published new progress about Adsorption. 14667-55-1 belongs to class pyrazines, name is 2,3,5-Trimethylpyrazine, and the molecular formula is C7H10N2, Quality Control of 14667-55-1.

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Liu, Zeping published the artcileEffect of changing the melanoidins by decoction on the release of volatiles in Zhenjiang aromatic vinegar, COA of Formula: C7H10N2, the main research area is melanoidin decoction zhenjiang aromatic vinegar; Decoction; Melanoidins; Volatiles retention; Zhenjiang aromatic vinegar.

Melanoidins, making general contribution to the food characteristics, are extensively generated in the production of Chinese traditional vinegar; however, their effect on flavor modification remains unknown. This study investigated the changes in the melanoidins of Zhenjiang aromatic vinegar (ZAV) during decoction, and the interactions of crude melanoidins (CM) and pure melanoidins (PM) from decocted and undecocted ZAV with mixed aroma compounds were compared. With the exception of C-N, O-H and C-H, chem. bonds and groups varied among the four types of melanoidins. However, CM and PM, obtained from decocted or undecocted vinegar, displayed generally similar structures, which resulted in their consistent retention of volatiles owning to the overall structure characteristics. Compared to aqueous solution, CM and PM from undecocted vinegar exhibited release, non-influence, or adsorption of flavors. However, melanoidins from decocted vinegar appeared the adsorption for all flavors but 2,3,5,6-Tetramethylpyrazine with weakened release. Free low mol. weight (LMw) compounds would affect the volatiles retention. Total solids (TS) from undecocted vinegar adsorbed volatiles except di-Et succinate; however, TS from decocted vinegar released all flavors significantly. Therefore, the decocted melanoidins were beneficial for the persistence of aroma. This study provided a base for elucidating the formation of melanoidins in decoction procedure and their roles in flavor modification.

Food Research International published new progress about Adsorption. 14667-55-1 belongs to class pyrazines, name is 2,3,5-Trimethylpyrazine, and the molecular formula is C7H10N2, COA of Formula: C7H10N2.

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Barbosa-Pereira, Letricia published the artcileAssessment of volatile fingerprint by HS-SPME/GC-qMS and E-nose for the classification of cocoa bean shells using chemometrics, Application In Synthesis of 14667-55-1, the main research area is Theobroma shell volatile fingerprint headspace SPME GC mass spectrometry; Chemical markers; Cocoa bean shell; Cocoa by-product; Cocoa flavour; E-nose; HS-SMPE/GC-qMS; Principal component analysis; Volatile fingerprint.

The cocoa bean shell (CBS) is a main byproduct of cocoa processing, with great potential to be used as an ingredient for functional foods because of its nutritional and flavor properties. This study aimed to characterize and classify CBSs obtained from cocoa beans of diverse cultivars and collected in different geog. origins through their volatile profile assessed using headspace solid-phase microextraction gas chromatog.-mass spectrometry (HS-SPME/GC-qMS) and E-nose combined with principal component anal. (PCA). The study provides, for the first time in a representative set of samples, a comprehensive fingerprint and semi-quant. data for >100 volatile organic compounds (VOCs), such as aldehydes, ketones, pyrazines, alcs., and acids. Through PCA, a clear separation of the Criollo cultivar from the other cultivars was achieved with both GC-qMS and E-nose anal. techniques because of the high content of key-aroma VOCs. Several biomarkers identified by GC-qMS, such as 2-hepanol, 2-methylpropanoic acid, and 2,3,5-trimethylpyrazine, recognized as key-aroma compounds for cocoa beans, were found suitable for the classification of CBSs according to their quality and origin. GC-qMS and E-nose appeared to be suitable anal. approaches to classify CBSs, with a high correlation between both anal. techniques. The volatile fingerprint and classification of CBSs could allow for the selection of samples with a specific flavor profile according to the food application and, therefore, constitute an interesting approach to valorise this byproduct as a food ingredient.

Food Research International published new progress about Biomarkers. 14667-55-1 belongs to class pyrazines, name is 2,3,5-Trimethylpyrazine, and the molecular formula is C7H10N2, Application In Synthesis of 14667-55-1.

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem