Aldehydes
Mostrando 1-12 de 387 artigos, teses e dissertações.
-
1. Volatile Constituents of Floral Scents from Encyclia cordigera (Kunth) Dressler and E. randii (Barb. Rodr.) Porto & Brade (Orchidaceae)
Encyclia cordigera is native from Central America tropical region, and Encyclia randii occurs at Brazilian Amazon environment domains. Floral concentrates from both Encyclia species were extracted, analyzed by gas chromatography-mass spectrometry, and identified compounds belong to terpenoids, phenylpropanoids, and fatty acid derivatives classes. Primary con
Journal of the Brazilian Chemical Society. Publicado em: 2022
-
2. Volatile Metabolomics from Cashew Leaves: Assessment of Resistance Biomarkers Associated with Black Mold (Pilgeriella anacardii Arx & Müller)
Black mold, a disease caused by the fungus Pilgeriella anacardii Arx & Müller, affects cashews (Anacardium occidentale). Some cashew clones are more resistant to the pathogen; however, little is known about the chemical profile responsible for this trait. The investigation of volatile organic compounds (VOCs) from leaves of dwarf cashew clones resistant (BR
Journal of the Brazilian Chemical Society. Publicado em: 2022
-
3. Ketones as Electrophile in Nitroaldol Reaction: Synthesis of β,β-Disubstituted- 1,3-dinitroalkanes and Allylic Nitro Compounds
Abstract β,β-Disubstituted-1,3-dinitro compounds were obtained exclusively with an overall yield of 83% through a domino nitroaldol/elimination/1,4-addition process, when excess nitromethane was added to cyclohexanone or butanone using DBU (1,8-diazabicyclo[5.4.0]undec-7-ene), as a basic catalyst. On the other hand, β-nitroalcohols could be obtained in 30
J. Braz. Chem. Soc.. Publicado em: 2021-08
-
4. VOLATILE COMPOUNDS IN CACHAÇAS OBTAINED FROM THREE SUGARCANE VARIETIES CULTIVATED UNDER THE MANAGEMENTS: ORGANIC, CONVENTIONAL AND WITHOUT FERTILIZATION
The volatile compounds present in cachaça can derive from the raw material used in the production of the beverage, from the fermentative process, from distillation or aging. The aim of the research was to evaluate the volatile compounds, in the cachaças from stills produced with different sugarcane varieties, under the organic and conventional managements.
Quím. Nova. Publicado em: 2020-09
-
5. EVALUATION OF THE RELATIVE PROTECTION FACTOR OF ROSEMARY EXTRACT IN BIODIESEL IN THE PRESENCE OF TRANSITION METAL IONS
Biodiesel contains unsaturated methyl esters making it susceptible to oxidation reaction. Among the factors that cause oxidative instability is the contamination by transition metal ions that in small quantities catalyze the oxidation reaction. The objective of this work was to evaluate the relative protection factor of rosemary extract, in biodiesel, in the
Quím. Nova. Publicado em: 2020-09
-
6. A Comparative Study on the Groebke-Blackburn-Bienaymé Three-Component Reaction Catalyzed by Rare Earth Triflates under Microwave Heating
Over the last twenty years, the Groebke-Blackburn-Bienaymé (GBB) reaction has been emerged as a powerful tool to access different nitrogen-based heterocycles as privileged scaffolds in medicinal chemistry. This multicomponent reaction is usually catalyzed by ordinary Brønsted or Lewis acid catalysts. Herein, we present a comparative study on the catalytic
J. Braz. Chem. Soc.. Publicado em: 2020-07
-
7. Characterization of volatiles in red- and white-fleshed loquat (Eriobotrya japonica) fruits by electronic nose and headspace solid-phase microextraction with gas chromatography-mass spectrometry
Abstract Aroma differences are generally sensed in white- and red-fleshed loquats. Here, volatile compounds in four white- and three red-fleshed loquat varieties were investigated by headspace solid-phase microextraction and combined analysis of electronic nose (e-nose) and gas chromatography-mass spectrometry (GC-MS). In total, 83 volatile compounds were id
Food Sci. Technol. Publicado em: 2020-06
-
8. Processes for alcohol-free beer production: a review
Abstract Since the invention of beer by the Sumerian people in 5000 BC, alcohol was the main reason of the interest of consumers on beer. Only in the beginning of the 20th century alcohol-free beer was demanded and since then technology has advanced dramatically in the production of those beverages. The aim on alcohol-free beer production is to have products
Food Sci. Technol. Publicado em: 2020-06
-
9. Determination and Risk Assessment of Formaldehyde and Acetaldehyde in the Ambient Air of Gas Stations in Salvador, Bahia, Brazil
Formaldehyde (FA) and acetaldehyde (AA) were determined in the ambient air of five gas stations (GS) in the city of Salvador, Bahia State, Brazil, using three passive samplers exposed simultaneously for 8 h and analysis by high-performance liquid chromatography-ultraviolet detection (HPLC-UV). The concentration ranges found were 3.31-5.78 µg m−3 for FA an
J. Braz. Chem. Soc.. Publicado em: 2020-06
-
10. Optimization of extraction conditions of volatile compounds of roasted beef by solid-phase microextraction
Aroma is one of the most important sensory attributes for acceptance by beef consumers. The first step in analysing the volatile compounds associated with this attribute is their extraction from the food matrix, solid-phase microextraction has been widely used for volatile compound determination in meat. This study aimed to test six different solid-phase mic
Quím. Nova. Publicado em: 2020-04
-
11. Chiral Amino and Imino-Alcohols Based on (R)-Limonene
Derivatives of the natural occurring and inexpensive terpene (R) -limonene were synthetized and completely characterized. Starting from internal olefin epoxidation, followed by epoxide opening with sodium azide and azide reduction with LiAlH4, two chiral amino-alcohols were obtained. The amino-alcohols were reacted with three different aldehydes, generating
J. Braz. Chem. Soc.. Publicado em: 2020-03
-
12. Lipolysis and aroma occurrence in Erzincan Tulum cheese, which is produced by adding probiotic bacteria and ripened in various packages
Abstract This study aimed to investigate the physicochemical, volatile components and fatty acids profile of Erzincan Tulum cheeses, produced using different probiotic bacteria and packaging materials, during the ripening period. Erzincan Tulum Cheese, which is the most popular and highly consumed cheese species in Turkey. Tulum cheese were ripened in skin b
Food Sci. Technol. Publicado em: 2020-03