Characteristics and potential biomarkers of flavor compounds in four Chinese indigenous chicken breeds

Chinese indigenous chickens have a long history of natural and artificial selection and are popular for their excellent meat quality and unique flavor. This study investigated six meat quality-related traits in Ningdu yellow, Baier yellow, Kangle, and Shengze 901 chickens. Two-dimensional gas chromatography-time-of-flight mass spectrometry was used to detect unique flavors in 24 breast muscle samples from the same phenotyped chickens. Overall, 685, 618, 502, and 487 volatile organic compounds were identified in Ningdu yellow, Baier yellow, Kangle, and Shengze 901 chickens, respectively. The flavor components were separated into eight categories, including hydrocarbons and aldehydes. Multivariate analyses of the identified flavor components revealed some outstanding features of these breeds. For example, the hydrocarbons (22.09%) and aldehydes (14.76%) were higher in Ningdu yellow chickens and the highest content of N, N-dimethyl-methylamine was in Ningdu yellow, Baier yellow, and Shengze 901 chickens, indicating the maximum attribution to the overall flavor (ROAV = 439.57, 289.21, and 422.80). Furthermore, we found that 27 flavor compounds differed significantly among the four Chinese breeds, including 20 (e.g., 1-octen-3-ol), two (e.g., 2-methyl-naphthalene), four (e.g., 2,6-lutidine), and one (benzophenone) flavor components were showed significant enrichment in Ningdu yellow, Baier yellow, Kangle, and Shengze 901 chickens, respectively. The flavor components enriched in each breed were key biomarkers distinguishing breeds and most were significantly correlated with meat quality trait phenotypes. These results provide novel insights into indigenous Chinese chicken meat flavors

An ONIOM Study of Thiophene Cracking in a Bronsted Acidic Zeolite

An ONIOM study at B3LYP and M05-2X level was carried out to investigate thiophene cracking in a Bronsted acidic zeolite and the effect of the zeolite framework on the geometry, electronic structure, and energy of the intermediates. The zeolite framework stabilized positively charged transition states and lowered the reaction barriers. The newly developed M05-2X functional performed much better than the popular B3LXP functional for describing non-bonded interactions between the reactants and the zeolite framework, which gave more accurate electronic structures and energy barriers. The rate determining barrier was that for electrophilic aromatic substitution (122.4 kJ/mol), while the subsequent C-S bond dissociation has a lower barrier (75.5 kJ/mol)

Polyurethane Foam-Based Ultramicroporous Carbons for CO₂ Capture

A series of sustainable porous carbon materials were prepared from waste polyurethane foam and investigated for capture of CO₂. The effects of preparation conditions, such as precarbonization, KOH to carbon precursor weight ratio, and activation temperature, on the porous structure and CO₂ adsorption properties were studied for the purpose of controlling pore sizes and nitrogen content and developing high-performance materials for capture of CO₂. The sample prepared at optimum conditions shows CO₂ adsorption capacities of 6.67 and 4.33 mmol·g^–1 at 0 and 25 °C under 1 bar, respectively, which are comparable to those of the best reported porous carbons prepared from waste materials. The HCl treatment experiment reveals that about 80% of CO₂ adsorption capacity arises from physical adsorption, while the other 20% is due to the chemical adsorption originated from the interaction of basic N groups and CO₂ molecules. The relationship between CO₂ uptake and pore size at different temperatures indicates that the micropores with pore size smaller than 0.86 and 0.70 nm play a dominant role in the CO₂ adsorption at 0 and 25 °C, respectively. It was found that the obtained carbon materials exhibited high recyclability and high selectivity to adsorption of CO₂ from the CO₂ and N₂ mixture