Lapsang Souchong black tea enjoys a good reputation in China for its unique smoky flavor. A total of 61 odorants in smoked Lapsang Souchong (SLS) and 49 odorants in the reference sample (non-smoked Lapsang Souchong, NSLS) were identified, respectively. The odorants of tea origin decreased significantly after the smoking process, while the pyrolysis products of pine wood increased markedly. Phenols (66.6%) were the most abundant odorants in SLS, among them, 18 phenols were newly found compared to NSLS. Aroma recombinates of SLS and NSLS proved the successful identification and quantitation of their respective key aroma compounds. The omission and addition tests clearly corroborated 3-ethylphenol, p -cresol, m -cresol, and 2-methoxy-4-methylphenol were the crucial factor for the strong smoky pine aroma characteristics of SLS tea. The findings offer a new insight into the flavor role of phenols to SLS tea, which will help to deeply explore the effect of smoking process on aroma changes during tea production.
β -Carboline heterocyclic amines ( β -CHAs), known for their synergistic neurotoxic and carcinogenic effects, are predominantly produced by humans through cigarette smoke and food and are found particularly in meats cooked at high temperatures. Few studies have explored the differences in the mechanisms of accumulation of β -CHAs in smoked meat and meat processed at high temperatures. In this research, the concentration of β -CHAs in smoked meats prepared using a variety of wood materials was measured using LC MS/MS. Additionally, key volatile organic compound markers associated with β -CHAs accumulation in smoke were identified through GC MS and multivariate statistical analysis and subsequently confirmed in a chemical simulation system. Three types of strainers, each with a distinct aperture size, were used to assess the efficacy of particle filtration in reducing β -CHAs levels in smoked meat. The findings indicated that smoke exposure indeed increases the β -CHAs content of meat. However, only the strainer capable of filtering PM2.5-sized particles reduced the amount of β -CHAs present compared to the control group. In contrast, strainers with larger pore sizes facilitated excessive accumulation of β -CHAs. The presence of aldehydes such as 1 H-pyrrole-2-carboxaldehyde, 5-methylfurfural, benzaldehyde , furfural , and nonanal exhibited a positive correlation with the accumulation of β -CHAs. Conversely, phenolic compounds , including 2-methoxy-4-vinylphenol, 2-methoxy-5-methylphenol, p- cresol, phenol, 2-methoxy-4-(1-propenyl)-, ( Z )-, phenol, 3-ethyl-, and phenol, 4-ethyl-2-methoxy-, showed a negative correlation. Thus, filters made from chelated carbonyl trap materials both chemically and physically disrupt the buildup of β -CHAs in smoked meats. The use of this approach will not only improve the quality of these products but will also contribute to decreasing the amount of inhalation pollutants released into the environment.
Yang Ruilin,Wang Ping,Guan Xinhui,Gu Xiaofei,Qiao Xiaoqiang
Phospholipids have been considered biomarkers for diagnosing many diseases in recent years. However, the isolation and analysis of phospholipids still face many difficulties. Styrene-maleic acid (SMA) copolymer is currently considered suitable for the separation and analysis of phospholipids due to its ability to enhance and improve the solubility of phospholipid bilayers on cell membranes. In this work, metal-free atom transfer radical polymerization was first exploited to graft SMA copolymer onto the surface of silica gel. With glycerol monolaurate (GML) as the derivatization reagent, Sil-SMA-GML polymer-brush silica-based stationary phase was first developed. The chromatographic retention mechanism revealed that the Sil-SMA-GML column is of hydrophilic/reversed-phase mixed-mode retention modes. The chromatographic separation performance evaluation indicated that the Sil-SMA-GML column had excellent separation capabilities for both hydrophilic and hydrophobic compounds. The maximum column efficiency was up to 78,600 N/m. The Sil-SMA-GML column could also achieve simultaneous separation and analysis of different phospholipid classes and species as well as complex phospholipid extracts from human serum and exosomal phospholipid extracts, demonstrating the good potential of the developed stationary phase. Graphical
危险品化学品经营许可证（带存储）