In this paper, HACC modified with (5-Carboxypentyl) (triphenyl) phosphonium bromide (HA-CS-NP) was synthesized. Then, a multifunctional food packaging composite film with good thermal stability and antibacterial functions was fabricated by HA-CS-NP and poly (vinyl alcohol) (PVA). The tensile strength and elongation at break of HA-CS-NP/PVA composite film at the weight ratio of 3/7 were 20.32 ± 1.02 MPa and 65.73 ± 3.29%, respectively. And, the inhibition rates of HA-CS-NP (0.5%) on Mango C. lagenarium and Papaya C. gloeosporioides on day 6 were up to 80.92 ± 4.12%. Compared with CK group, the weight loss of experimental groups were 23.96 ± 2.46 g/206 ± 7.25 g (mangoes) and 59.45 ± 3.06 g/496 ± 6.37 g (papaya), reduced by 35.76 ± 1.15%. Moreover, the final hardness value of the fruits coated with composite films was 4.94 ± 0.23 kg/cm 3 and increased by 20.79 ± 1.04%, and the rot index was reduced by 71.43 ± 3.24%. The multifunctional HA-CS-NP/PVA coating has broad prospects in the application of food packaging.
Lu Yan,Chang Zhaosen,Zhang Shizhen,Wang Shunli,Chen Qi,Feng Lijuan,Sui Zhuyin
Abstract Cycloaddition reaction using CO 2 as a starting material to form a cyclic carbonate has been applied to chemical fixation of CO 2 . In order to further increase the reaction efficiency, herein, a bifunctional catalyst ( CPBrs ) containing metalloporphyrin and quaternary phosphonium salt groups was prepared, and the related catalytic performance for CO 2 conversion was also studied. The catalytic system possesses multiple active sites of zinc porphyrin (Lewis acids) and quaternary phosphonium bromide salts (nucleophilic reagents), which can cooperatively work together to enhance the efficiency of cycloaddition reaction. At the same time, CPBrs ( CPBr-1 and CPBr-2 ) are microporous polymers with permanent microporous pore structure and high specific surface areas (342–370 m 2 g −1 ). Their moderate capacities (5.76 and 8.81% at 1 bar/273 K) to capture carbon dioxide were also beneficial for CO 2 conversion. The activity of the bifunctional catalyst is higher than that of the catalyst with a single component. The corresponding highest yield to catalyze cycloaddition reaction between methyl substituented propylene oxide and CO 2 is up to 95% (2.5 MPa, 90 °C). What is more, the porous nature of catalysts provides the recoverability of the catalyst, and the efficiency of the catalyst CPBr-2 remains high (above 90% yield) after five catalytic recycle. Graphic abstract
Zhi Mei,Yuhao Fu,Fang Wang,Leilei Xiang,Fang Hu,Jean Damascene Harindintwali,Mingyi Wang,Marko Virta,Syed A. Hashsham,Xin Jiang,James M. Tiedje
Antibiotic resistance genes (ARGs) and human pathogenic bacteria (HPB) in leafy vegetable is a matter of concern as they can be transferred from soil, atmosphere, and foliar sprays, and poses a potential risk to public health. While traditional disinfection technologies are effective in reducing the presence of ARGs and HPB in soil. A new technology, foliar spraying with magnetic biochar/quaternary ammonium salt (MBQ), was demonstrated and applied to the leaf surface. High-throughput quantitative PCR targeting 96 valid ARGs and 16 S rRNA sequencing were used to assess its efficacy in reducing ARGs and HPB. The results showed that spraying MBQ reduced 97.0 ± 0.81% of “high-risk ARGs”, associated with seven classes of antibiotic resistance in pakchoi leaves within two weeks. Water washing could further reduce “high-risk ARGs” from pakchoi leaves by 19.8%− 24.6%. The relative abundance of HPB closely related to numerous ARGs was reduced by 15.2 ± 0.23% with MBQ application. Overall, this study identified the potential risk of ARGs from leafy vegetables and clarified the significant implications of MBQ application for human health as it offers a promising strategy for reducing ARGs and HPB in leafy vegetables.
危险品化学品经营许可证（带存储）