Shanghai Tobacco Group Co., Ltd.

To explore the variation in adaptability to fluctuating light environments, the non-photochemical quenching (NPQ) characteristics of a local tobacco variety Xiaofeng 8 and a foreign introduced variety K326, under both constant and fluctuating light conditions were examined. The field experiment demonstrated that Xiaofeng 8 exhibited significantly stronger growth compared to K326, with the dry weight per plant and leaf area of Xiaofeng 8 increased by 28.26 % and 32.85 % compared with those of K326, respectively. Further, a distinct activation pattern of NPQ was detected in both varieties during the transition from dark to high light. Building on this finding, our subsequent tests proved that, in the high light intensity segments of a fluctuating light environment, Xiaofeng 8 exhibited a higher NPQ value compared to K326, indicating an enhanced capacity for dissipating excess light energy as thermal energy and mitigating the potential risk of photodamage. Subsequent analysis of the contents of violaxanthin (V), antheraxanthin (A), and zeaxanthin (Z) within the two varieties after high - light treatment has proved that Xiaofeng 8 has a superior ability to dissipate excess absorbed light energy under high - light conditions. This ability may contribute to its better growth under fluctuating light environments. Mutants defective in violaxanthin de-epoxidase (VDE) and zeaxanthin epoxidase (ZEP) were employed to examine their involvement in regulating plants growth under fluctuating light condition. The results showed that defects in these enzymes affected the NPQ response and reduced the growth rate of the mutants under fluctuating light conditions, suggesting its pivotal role of xanthophyll in regulating plant growth and adaptation to variable light environments. Collectively, these findings emphasize the importance of exploring genetic resources improving plant NPQ under fluctuating light conditions from both domestic and imported varieties, thereby providing promising targets for selecting and breeding new crop varieties with improved yield.

Polycyclic aromatic hydrocarbons (PAHs), carcinogenic persistent organic compounds, require ultrasensitive detection for health risk assessment of tobacco products. While traditional cigarette smoke contains FDA-monitored PAHs (e.g., benzo [a]pyrene) at ng/cigarette (cig) levels, heated tobacco aerosols exhibit 1-2 orders of magnitude lower PAH concentrations (<0.1 ng/cig), demanding advanced analytical methods. Current approaches involve laborious pretreatment (multi-step purification, solvent concentration) and suffer from matrix interference and insufficient sensitivity. Existing large-volume injection techniques face limitations in aerosol analysis due to matrix complexity or analyte loss. This study introduces a novel large volume thermal injection-column internal evaporation concentration and gas chromatography-triple quadrupole mass spectrometry (LVI-CIEC-GC-MS/MS) platform. Optimized injection parameters enabled direct introduction of 200 μL aerosol extract into a 300°C inlet, coupled with pre-column dynamic condensation equilibration and solvent venting, eliminating tedious pretreatment while enhancing sensitivity. Using Multiple Reaction Monitoring (MRM) mode, the method achieved excellent linearity (R² >0.996) for 16 PAHs, with LOQs of 0.003-0.023 ng/cig (1-2 orders lower than conventional methods), spiked recoveries of 84.6-113.2%, and relative standard deviations (RSDs) <2.8%. Applied to commercial heated tobacco products, PAH levels were quantified at 0.0154-10.035 ng/cig, demonstrating robustness against complex matrices. By integrating large-volume injection, in-column enrichment, and high-selectivity MS/MS, this method overcomes critical challenges in ultra-trace PAH analysis, offering a streamlined, and high-sensitivity platform for evaluating tobacco product risks.

Puff-by-puff release stability is critical for heated tobacco product (HTP) quality and user experience, yet existing methods lack dynamic puff-by-puff evaluation. Here, we develop a novel stability index (SI) using the "modulus of the sum vector of two evaluation dimensions" algorithm to quantify puff-by-puff release consistency and interpuff variability. In addition, the algorithm has been validated through practical product applications. Compared with traditional methods, SI significantly enhances the differentiation and accuracy of stability evaluation. Under a 10% relative deviation in the release amount measurement, the deviation of the stability index (SI) is maintained at 10.6%, demonstrating precision. The SI is applicable to reconstituted tobacco sheets, HTP sticks, and final products, enabling quantitative stability assessment. As a key screening tool, it streamlines HTPs development by identifying inconsistent formulations early.