Month: December 2022

Khatun, Habiba published the artcileCharacterization of freeze-dried, oven-dried and blanched house crickets (Acheta domesticus) and Jamaican field crickets (Gryllus assimilis) by means of their physicochemical properties and volatile compounds, Computed Properties of 110-42-9, the main research area is volatile compound Achete Gryllus freeze oven drying blanching.

Edible insects are repeatedly being considered as underutilized food candidate due to their high nutritional value. Although frequent acceptance of whole insects to consumer is still challenging, incorporation of insects in food as powder or paste has been suggested to increase their acceptability. Hence, Acheta domesticus and Gryllus assimilis were subjected to freeze drying, oven drying, and blanching to acquire a clear insight on the impact of the processing methods on the nutritional and phys. properties of both species. Result showed that these three methods had limited effects on the proximate composition, fatty acid and amino acid profile but had significant impact on other parameters for both species. Vitamin B12 in A. domesticus did not change but G. assimilis changed due to the treatment. Freeze drying showed better lightness (L* value) and lower browning index for both cricket species. Oven drying and blanching resulted in lower lipid oxidation values than freeze drying for both cricket species; though lipid oxidation was in all cases well below the rejection limit. Esters were the predominant group of volatile compound in freeze and oven-dried cricket while least amount of volatiles were found in blanched cricket. The volatiles resulted from fatty acid oxidation were higher in freeze-dried crickets, while Maillard reaction products were found in oven-dried samples. Although freeze drying showed higher color quality, oven drying exerted superior effect in terms of nutritional and flavor characteristics followed by blanching treatment.

European Food Research and Technology published new progress about Acheta domesticus. 110-42-9 belongs to class esters-buliding-blocks, name is Methyl decanoate, and the molecular formula is C11H22O2, Computed Properties of 110-42-9.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Stevenson, Keisean A. J. M. published the artcileThermodynamics-based modelling of gas chromatography separations across column geometries and systems, including the prediction of peak widths, Recommanded Product: Methyl decanoate, the main research area is thermodn modeling gas chromatog separation across column geometries system; peak width prediction; retention prediction; thermodynamic modeling.

Thermodn.-based models have been demonstrated to be useful for predicting retention time and peak widths in gas chromatog. and two-dimensional gas chromatog. separations However, the collection of data to train the models can be time consuming, which lessens the practical utility of the method. In this contribution, a method for obtaining thermodn.-based data to predict peak widths in temperature-programmed gas chromatog. is presented. Exptl. work to collect data for peak width prediction is identical to that required to collect data for retention time prediction using approaches that we have presented previously. Using this combined approach, chromatograms including retention times and peak widths are predicted with very high accuracy. Typical errors in retention time are < 0.5%, while errors in peak width are typically < 5% as demonstrated using polycycic aromatic hydrocarbons and a mixture containing compounds with aldehyde, ketone, alkene, alkane, alc., and ester functionalities. Journal of Separation Science published new progress about Gas chromatography. 110-42-9 belongs to class esters-buliding-blocks, name is Methyl decanoate, and the molecular formula is C11H22O2, Recommanded Product: Methyl decanoate.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Ng, Felicia published the artcileCharacterization of volatile compounds in Ylang-Ylang essential oils from Comoros and Madagascar by gas chromatography and principal component analysis, Quality Control of 140-11-4, the main research area is Ylang essential oil gas chromatog volatile compound.

Chem. composition of ylang-ylang essential oil is affected by the geog. origins of flowers used for extraction This study aimed to determine the compositional difference between the extra, first and third grades of ylang-ylang essential oil from Comoro Islands and Madagascar. The oils were characterized by both gas chromatog.-mass spectrometry (GC-MS) and gas chromatog.-flame ionization detector (GC-FID) in conjunction with principal component anal. (PCA). A total of 124 volatile compounds were identified and quantified by GC-MS and GC-FID. Twenty-two compounds that made up 85% to 90% of the oils were shortlisted to compare across grades and geog. origins. The PCA showed that the ylang-ylang essential oils are clustered according to grade and origin based on their compositions Anal. of variance was performed to determine the statistical significance of the differences between each compound across extra, first and third grades of ylang-ylang essential oil from Madagascar and Comoros. The oils of Madagascar are dominating in geranyl acetate, cis-α-farnesene, benzyl benzoate, humulene and caryophyllene, while in those of Comoros, cinnamyl acetate, benzyl salicylate, trans-farnesyl acetate and α-farnesene are found to be higher. It is possible to verify the origin and grade of an unspecified source of ylang-ylang essential oil from the biplot of the 22 compounds

Flavour and Fragrance Journal published new progress about Gas chromatography. 140-11-4 belongs to class esters-buliding-blocks, name is Benzyl acetate, and the molecular formula is C9H10O2, Quality Control of 140-11-4.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Wei, Zheng published the artcileVolatile aroma compounds in wines from Chinese wild/hybrid species, Safety of Methyl decanoate, the main research area is volatile aroma compound wine; Chinese wild/hybrid species; HS-SPME/GC-MS; PCA; volatile compounds; wines.

The volatile aroma compounds in wines produced from Chinese wild/hybrid species were investigated in comparison to wines from European grapes. Volatiles were extracted by headspace solid-phase micro-extraction and identified by gas-chromatog./mass-spectrometry. The identification of analyte was performed by a combination of the linear retention index approach with the comparison of the obtained mass spectra. A total of 98 peaks were tentatively assigned as wine aroma components, and 15 odorants can be found at concentrations above their odor threshold among the odor activity values (OAVs) of 46 compounds evaluated in all of the wines. The “”OAVsâ€?aroma wheels”” showed that the classes of aromatic series are first fruity, next herbaceous and roasty and no spicy and caramelized notes. Via principal component anal., all the grape germplasm studied could be divided into four groups: “”Jingsheng-1,”” “”Cabernet Gernischt,”” “”Beibinghong,”” and others, which exhibited distinctive aroma features, resp. Practical applications Chinese wild grape species have many desirable properties for wine grape breeding such as possessing strong resistant genes to fungal diseases and cold condition, especially after hybridization with European grapes. As an emerging wine country, wines from Chinese wild/hybrid species have achieved much success in the last few years. The chem. content and biol. properties have been studied extensively in many but there are a few studies in our knowledge about the wine tastes of these species. In this paper, the key odorants in wines produced from the Chinese grape species of V. amurensisRupr., V. davidiiFoex., and V. quinquangularisRehd. and its hybrids were characterized in comparison to wines produced from European grapes (V. vinifera). The findings will help to the further understanding of the key aroma components in the different Chinese grapevine germplasm, and make further efforts to enrich the wine types in the marketplace.

Journal of Food Biochemistry published new progress about Gas chromatography. 110-42-9 belongs to class esters-buliding-blocks, name is Methyl decanoate, and the molecular formula is C11H22O2, Safety of Methyl decanoate.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Kfoury, Miriana published the artcileContribution of headspace to the analysis of cyclodextrin inclusion complexes, Category: esters-buliding-blocks, the main research area is cyclodextrin inclusion complex headspace.

Headspace technol. is a sampling method of a gas, which has been previously in contact with a liquid or a solid matrix from which volatiles were released into the gaseous phase. It is generally coupled to a subsequent gas chromatog. anal. The headspace anal. can be carried out either as a one-step extraction (static or equilibrium headspace) or as a continuous extraction (dynamic headspace). The static headspace gas chromatog. (SH-GC) is gaining an increasing interest for the study of cyclodextrin (CD) inclusion complexes with volatile compounds CDs are natural supermol. hosts able to encapsulate volatile compounds and improve their functionalities (e.g. solubility, stability, retention, controlled release). Herein, the application of the SH-GC in the CD field will be reviewed. This paper will focus on the characterization of the inclusion complexes via the SH-GC, mainly aiming at the determination of formation constant (Kf) and encapsulation efficiency (EE%) values. Moreover, it will review the application of the SH-GC to monitor the properties of volatile compounds upon encapsulation (e.g. retention, controlled release).

Journal of Inclusion Phenomena and Macrocyclic Chemistry published new progress about Formation constant. 140-11-4 belongs to class esters-buliding-blocks, name is Benzyl acetate, and the molecular formula is C9H10O2, Category: esters-buliding-blocks.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

do Nascimento, Fernando H. published the artcileFast construction of polymer monolithic columns inside fluorinated ethylene propylene (FEP) tubes for separation of proteins by reversed-phase liquid chromatography, Recommanded Product: Dodecyl 2-methylacrylate, the main research area is polymer monolithic column fluorinated ethylene propylene protein RPHPLC; Egg white; Fluoropolymer tubes; Liquid chromatography; Monolithic columns; Photografting; Urine.

This paper describes the preparation of polymer monolithic columns in the confines of fluorinated ethylene propylene (FEP) tubes. These tubes are cheap, chem. stable, and widely used in flow anal. laboratories UV-initiated grafting with 5% benzophenone in methanol for 1 h activated the internal surface walls, thus enabling the further covalent binding of ethylene glycol dimethacrylate (EDMA) from a 15% solution in methanol, also via photografting. Both steps used 254 nm radiation under a potency of 120 mJ cm2. ATR-FTIR measurements revealed carbonyl, alkyl and vinyl groups in the functionalized FEP. The d. of vinyl groups was high enough to firmly attach a poly(lauryl methacrylate-coethylene glycol dimethacrylate) monolith in 120 × 1.57 mm internal diameter tubes, prepared via photopolymerization The total preparation lasts <2-h. The columns were permeable, (1.58 ± 0.06) x 10-13 m2, providing reproducible chromatog. parameters of retention times, retention factor, selectivity, and resolution The monoliths were stable at flow rates of 500μL min-1, collapsing only at flow rates >700μL min-1, a condition that increased the backpressure over 1000 psi (experiments at the room temperature). The separation of proteins by reversed-phase liquid chromatog. demonstrated the efficiency of the columns. Determination of egg white proteins (ovalbumin and lysozyme) and myoglobin in spiked urine proved the applicability to the anal. of real samples.

Talanta published new progress about Egg white, poultry. 142-90-5 belongs to class esters-buliding-blocks, name is Dodecyl 2-methylacrylate, and the molecular formula is C16H30O2, Recommanded Product: Dodecyl 2-methylacrylate.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Wang, Dong-Hao published the artcileAsymmetric Reductive Amination of Structurally Diverse Ketones with Ammonia Using a Spectrum-Extended Amine Dehydrogenase, Application of Ethyl 4-oxopentanoate, the main research area is asym reductive amination reductive engineered amine dehydrogenase.

Amine dehydrogenase-catalyzed reductive amination of prochiral ketones with ammonia is a promising method for the synthesis of optically pure amines in the pharmaceutical and fine chem. industries. However, previously reported amine dehydrogenases show restricted catalytic capacity toward bulky ketones, which limits their widespread applications toward the production of chiral amines. Herein, we expanded the substrate scope of an engineered amine dehydrogenase GkAmDH from Geobacillus kaustophilus via laboratory evolution for the reductive amination of an extensive set of ketones. Several beneficial mutants were identified with a up to 2.2 U mg-1 activity toward bulky benzylacetone, 110-fold higher than that of M0. Using the engineered M3 and M8, structurally diverse bulky chiral amines could be synthesized with up to >99% conversion, >99% ee, and up to 18,900 TON. Among them, two key chiral intermediates used in the synthesis of the drugs medroxalol and dilevalol were produced on a gram scale in up to 85% yield and >99% ee. Addnl., the engineered enzymes M3 and M8 displayed considerable thermostability with a half-life of more than three days at 50 °C. These results demonstrate that these engineered amine dehydrogenases are promising biocatalysts for the synthesis of chiral amines. Mol. dynamics simulations provide insights into how mutations improve the amination activity toward bulky ketones and the thermostability.

ACS Catalysis published new progress about Directed evolution. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, Application of Ethyl 4-oxopentanoate.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Nedele, Ann-Kathrin published the artcileCharacterization of cheesy odor formed during fermentation of soy drink with Agrocybe aegerita, Computed Properties of 140-11-4, the main research area is cheesy odor fermentation soy drink Agrocybe; Agrocybe aegerita; Cheesy flavor; Fermentation; Short-chain fatty acids; Soy drink.

The market for plant protein-based substitutes for cheeses is growing, but the sensory properties are distinctively different from the original products. Hence, natural and vegan cheesy flavors are needed to aromatize the products. A cheesy, sweaty and parmesan-like aroma was produced by fermentation of soy drink with Agrocybe aegerita. Aroma dilution anal. revealed short-chain fatty acids (SCFAs) as main influencing cheesy odorants analyzed by gas chromatog.-mass spectrometry-olfactometry. In comparison to the five cheese varieties, the SCFA profile of the fermented soy drink revealed similarities with Parmesan and Emmental cheese. Meanwhile, principal component anal. showed an approximation of the aroma profile after fermentation with A. aegerita to those of cheeses. 3-Methylbutanoic acid was synthesized from the protein fraction, while the oil fraction contributed to the formation of unbranched SCFAs like butanoic acid. Accordingly, the production of these compounds can be increased by addition of the fractions.

Food Chemistry published new progress about Cyclocybe aegerita. 140-11-4 belongs to class esters-buliding-blocks, name is Benzyl acetate, and the molecular formula is C9H10O2, Computed Properties of 140-11-4.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Duan, Bobo published the artcileAccess to α,α-dithioketones through direct di-sulfenylation of methyl ketones mediated by KOH-DMSO system, Recommanded Product: Benzyl acetate, the main research area is ketone alkylthio arylthio preparation; methyl ketone sulfenylation selenylation disulfide diselenide superbase system.

A direct di-sulfenylation of Me ketones R1C(O)Me (R1 = Me, i-Pr, cyclopropyl, Ph, 2-thienyl, 2-pyridyl, etc.) with disulfides R2SSR2 [R2 = Me, Ph, 4-MeC6H4, Et2NC(S), 2-pyridyl, etc.] mediated by KOH-DMSO superbase system has been developed. This method provides an efficient route to α,α-dithioketones R1C(O)CH(SR2)2 and has the advantages of readily available non-prefunctionalized substrates, good functional group tolerance, excellent yields as well as high selectivity. In a single operation, two C-S bonds are simultaneously built on the same carbon atom under mild reaction conditions. The procedure was extended to the reaction of acetophenone with di-Ph diselenide which afforded the keto bis(selenide) PhC(O)CH(SePh)2 in 81% yield.

Tetrahedron Letters published new progress about C-S bond formation. 140-11-4 belongs to class esters-buliding-blocks, name is Benzyl acetate, and the molecular formula is C9H10O2, Recommanded Product: Benzyl acetate.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Gao, Guoming published the artcileCrystal facet-dependent activity of h-WO3 for selective conversion of furfuryl alcohol to ethyl levulinate, HPLC of Formula: 539-88-8, the main research area is crystal facet WO3 furfuryl alc ethyl levulinate.

The use of WO3 as an acid catalyst has received extensive attention in recent years. However, the correlation between the catalytic activity and the predominantly exposed surface with varied acidic sites needs further understanding. Herein, the effects of the Bronsted and Lewis acid sites of different crystal facets of WO3 on the catalytic conversion of furfuryl alc. (FA) to Et levulinate (EL) in ethanol were investigated in detail. A yield of EL up to 93.3% over WO3 with the (110) facet exposed was achieved at 170°C, while FA was mainly converted to polymers over (001) faceted nanosheets and nanobelts with exposed (002) and (100) facets. This was attributed to the different distribution of the acidic sites on different exposed crystal facets. The (110) faceted WO3 possessed abundant and strong Bronsted acid sites, which favored the conversion of FA to EL, while the (100) faceted WO3 with stronger Lewis acid sites and weaker Bronsted acid sites mainly led to the formation of polymers. In addition, the (110) faceted WO3 showed excellent sustainability in comparison with the (100) faceted counterpart.

Physical Chemistry Chemical Physics published new progress about Crystal morphology. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, HPLC of Formula: 539-88-8.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics