High-performance polyethyleneimine/sodium silicate material: one-step strategy at ambient temperature and application in removing heavy metal ion

Journal of Materials Science - Polyethyleneimine (PEI) composites containing silicon have shown extraordinary potential in scavenging heavy metal ions, but usually suffer from difficulty in...     

水酶法提取栀子油工艺优化及其脂肪酸组成

为促进栀子的开发利用,以栀子成熟果实为原料,采用水酶法提取栀子油。采用单因素实验研究酶种类、加酶量、酶解pH、酶解温度、液料比、酶解时间对栀子油得率的影响,在此基础上采用均匀设计实验进行工艺条件优化,并对各种酶提取的栀子油进行脂肪酸组成分析。结果表明：水酶法提取栀子油的最佳工艺条件为采用中性蛋白酶、加酶量0.7%、液料比3∶1、酶解pH 7、酶解温度60℃、酶解时间7 h,在此条件下栀子油得率为7.27%,与空白组（3.34%）相比提高了117.66%;栀子油中亚油酸含量最高,超过56%,不饱和脂肪酸含量为80%左右。不同酶提取栀子油的脂肪酸组成及含量没有显著差异。     

油茶资源利用及产业发展现状

油茶是世界四大木本油料植物之一,也是我国特有的优质木本油料资源.油茶籽油是一种高档植物油,具有丰富的营养物质和保健功效成分.为了促进油茶资源的合理配置,延伸油茶产业链,提高综合效益,本文对油茶资源的分布和总量进行概述;对油茶籽油、油茶果壳、油茶饼粕的功能成分及利用现状进行分析;纵观油茶产业发展历程总结出油茶产业可推广经...     

Efficient one-pot tandem conversion of saccharides to 2,5-dimethylfuran by adjusting the wettability of 2DMOF catalysts

One-pot multiple tandem synthesis of DMF from biomass saccharides including monosaccharides, disaccharides, and polysaccharides is of great importance for biomass fuels and chemicals. Due to the complexity of reactions, current catalytic systems often suffer from inferior activity, low yield, and harsh reaction conditions. Here, a Pd-supported hydrophobic acidic 2DMOF (Pd/NUS-PhSO₃H-Ph) was first prepared by continuous grafting of benzenesulfonic acid and tert-butylbenzene groups followed by Pd impregnation methods. It shows catalytic efficiency for the DMF synthesis from saccharides under the reduction of polymethylhydrosiloxane (PMHS), which are previously unattainable in all reported catalysts. Controlled experiments and detailed characterizations show that hydrophobic 2D nanosheet structure promotes the wettability of feedstocks and intermediates for the active sites. This work proposes a new door toward an efficient and facile synthesis of DMF via designing a powerful 2DMOF-based catalyst with cooperative acid-hydrogenation catalysis.     

生物质耦合燃煤发电经济环境效益评估

建立了生物质直燃、生物质耦合燃煤发电及煤电的经济及环境影响评估模型,对比了四种不同的生物质预处理技术,量化了生物质固体燃料的供应链成本,不同发电策略的度电成本,电力碳排放强度,边际减排成本,以及考虑碳交易情况下的电厂成本收益率。研究发现,生物质耦合燃煤发电较生物质直燃发电是更为低碳的生物质利用路径,且可利用电厂的规模效应,即随着规模增大度电成本降低,成本利润率上升,而直燃发电相反。与煤电相比,耦合发电的度电成本更低,且可受益于碳交易,成本利润率更高。因此,生物质耦合燃煤发电是具有经济与环境效益的煤电淘汰方案。     

Apricot polysaccharides as new carriers to make curcumin nanoparticles and improve its stability and antibacterial activity

Apricot polysaccharides (APs) as new types of natural carriers for encapsulating and delivering active pharmaceutical ingredients can achieve high-value utilization of apricot pulp and improve the solubility, the stability, and the antibacterial activity of insoluble compounds simultaneously. In this research, the purified APs reacted with bovine serum albumin (BSA) by the Maillard reaction, and with d -α-tocopheryl succinate (TOS) and pheophorbide A (PheoA) by grafting to fabricate two materials for the preparation of curcumin (Cur)-encapsulated AP–BSA nanoparticles (CABNs) and Cur-embedded TOS–AP–PheoA micelles (CTAPMs), respectively. The biological activities of two Cur nano-delivery systems were evaluated. APs consisted of arabinose (22.36%), galactose (7.88%), glucose (34.46%), and galacturonic acid (31.32%) after the optimized extraction. Transmission electron microscopy characterization of CABNs and CTAPMs displayed a discrete and non-aggregated morphology with a spherical shape. Compared to the unencapsulated Cur, the release rates of CABNs and CTAPMs decreased from 87% to 70% at 3 h and from 92% to 25% at 48 h, respectively. The antioxidant capacities of CABNs and CTAPMs were significantly improved. The CTAPMs exhibited a better antibacterial effect against Escherichia coli than CABNs due to the synergistic photosensitive effect between Cur and PheoA.     

Whey protein improves survival and release characteristics of bacteriophage Felix O1 encapsulated in alginate microspheres

Bacterial contamination is a major cause of food poisoning in humans worldwide. Phage therapy is a potential alternative to antibiotics in food animal production. Gastric acidity has been shown to compromise the viability of phage in vitro, hence, may affect the effectiveness of the phage treatment. Microencapsulation of bacteriophage in alginate microspheres protected phage against gastric acids; however, the release rate of phage was too slow when applied in chicks. The current study investigated the in vitro protection and release characteristics of alginate–whey protein microspheres (AWM) containing phage Felix O1 prepared by an extrusion method. Free phage was completely inactivated within minutes in simulated gastric fluid (SGF) at pH 2.0 and pH 2.5, while phage encapsulated in AWM mostly retained their viability after 2.0 h incubation. Encapsulated phage was completely released from the AWM in simulated intestinal fluid (SIF) within 3 h. Moreover, addition of maltodextrin to the encapsulation formula improved phage stability during air drying and storage. Our results show that addition of whey to alginate microsphere improved phage protection against acidic conditions and accelerated the release rate in SIF. AWM could be more suitable for oral phage therapy in chickens.     

Composites from biodegradable and biocompatible methylcellulose,poly(d,l-lactide-co-glycolide) and poly(1,4-butylene succinate) with enhanced properties

Polymer materials based on fossil resources have brought great convenience to various industries. However, environmental pollution is becoming increasingly conspicuous due to their difficult degradation in nature. Therefore, biodegradable composites are highly desired. In the present work, a simple and feasible preparation approach was presented to fabricate biodegradable and biocompatible composite films including methylcellulose/poly(d ,l -lactide-co-glycolide) (MC/PLGA) and methylcellulose/poly(1,4-butylene succinate) (MC/PBS). The effects of MC/PLGA and MC/PBS mass ratios on the morphology, crystalline state, mechanical properties and thermal stability of the composite films were systematically investigated. At the same time, the influence of thermal compression treatment on mechanical properties (tensile strength and elongation) and the cyclic utilization of the composite films were also estimated. The composite films displayed enough good mechanical properties, re-usability and thermal stability.     

Antimicrobial activity of Pistacia lentiscus and Satureja montana essential oils against Listeria monocytogenes CECT 935 using laboratory media: Efficacy and synergistic potential in minced beef

The aim of this study was to optimize the antimicrobial efficacy of plant essential oils (EOs) for control of Listeria monocytogenes (L. monocytogenes) serovar 4b CECT 935 using laboratory media and minced beef stored at 5 ± 1 °C. Commercial EOs obtained from leave parts of Mediterranean Pistacia lentiscus (P. lentiscus) and Satureja montana (S. montana) were analyzed by gas chromatography–mass spectrometry (GC–MS). The main components of EOs obtained were β-myrcene (15.18%) and carvacrol (29.19%), respectively for P. lentiscus and S. montana. The in vitro antimicrobial activity of both EOs was evaluated against L. monocytogenes using the agar diffusion technique, the minimum inhibitory concentrations (MIC) were also determined against the same microorganism using the broth microdilution method. According to the diameters of inhibition, S. montana EO had more antibacterial effects than that from P. lentiscus. MICs showed a range of 0.03 and 0.10% (vol/vol) respectively for S. montana and P. lentiscus. S. montana and P. lentiscus EOs were added respectively in minced beef (twofold MIC values) at 0.06 and 0.20%, experimentally inoculated with L. monocytogenes at a level of 3 × 10⁵ CFU/g and stored at 5 ± 1 °C during one week. S. montana EO was the more effective (P < 0.05) against target bacteria. P. lentiscus EO also demonstrated antibacterial effect against the same bacterium. EO combinations were also investigated in minced beef and P. lentiscus combined with S. montana had synergistic effects. This work shows that the combined EOs might be more effective against L. monocytogenes when applied to minced beef at the ratio of 1/1 to 2/2 according to the MIC values. Sensory evaluation revealed that minced beef treated with EOs was acceptable by panelists at the levels used.