An acidic extracellular polysaccharide (EPS) was gained from Stropharia rugosoannulata fermentation broth by the alcohol precipitate method. Sulfated derivatv o EPS (S-EPS) was gained by chlorosulfonic acidAn acidic extracellular polysaccharde (EPS) was gaine d from Stropharia rugosoannulaa fermentation broth pridine method and the conditins were as follows: pyridine as the reaction solvent, temperature 80 degrees C, and by the acohol precipitae method. Sulfated derivative of EPS S-EPS) was gained by chlorosulfonic acidpyridne method and the conditions were as follows: pyridie as the reaction solvent temperature 80 degrees C an reaction time 90 min. The chemical structure and chain conformation of EPS and S-EPS were characterized by FT-IR, NMR and sizexclusion chromatograpy (SEC) coupled with multi-angle laser ligt scatering reaction time 90 min The chemical structure and chan conformation of EPS and S-EPS were characterized by FT-IR, NMR ad size exclusion chromatography (SEC) coupled with muli-ange laser light scattering (MALLS) detection.. FT-IR spectra indicated the sulfated group was linked to the polymer. The EPS mainly consists of mannse, glucose and glucuronic acid, and the glycosidic bon type is mainly (1 -> 4)-linked and (MALLS) detection. FT-IR spectra indicated the sulfaed group was inked to the polymer. The EPS mainly (1 -> 6)-linked. C6 and C2 wre substitted by sulfte groups. The EPS was degraded to smaller molecular consists of mannose glucose and glucuronc acid and the glycosidic bond ype is mainly (1 -> 4)-inked and weight (Mw) polysaccharids with the larger molcular ize (Rg) after sulfation ad S-EPS has bette (1 -> 6)-inked C6 and C2 were subsitut d by sulfate groups The EPS wa degraded into smalle moecular hydrophilicity. Moreover, th sulfated derivative S-EPS was found to have a better scavenging ability on weight (M ) polysaccharides with the larger molecular size (R ) after sulfation and S-EPS has better hydroxyl radicals than EPS. It proved that the chemical modification of S. rugosoannulata polysacchardes by hydrophilicity Moreover, the sulfated derivative S-EPS was found to have a better scavenging ability on hydroxyl radicals than EPS It proved that the chemical sulfation effectively enhanced their antioxidant activity.

The low temperature catalytic pyrolysis performances of heated tobacco sheets by alkali/alkaline earth metal were investigated by TG-FT-IR and Py-GC-MS. Thermogravimetric analysis showed that the maximum weight loss rate temperature of the heated tobacco sheets significantly reduced from 328 degrees C to 292 degrees C catalyzed by alkali metal Na or K catalysts, and the weight loss between 100 and 300 degrees C increased by 48.83% and 40.05% respectively. While alkaline earth metal Mg or Ca catalysts exerted less influence on the maximum weight loss rate temperature and the weight loss between 100 and 300 degrees C reduced slightly. The online infrared absorption band of pyrolysis gas shifted to lower temperature and the concentration of pyrolysis gas increased over Na catalysts, which matched well with TG results. Moreover, the concentration of carbonyl compounds and compounds containing C-O bonds in pyrolysis gas increased significantly. The content of 2-furanmethanol, butyrolactone and megastigmatrienone in pyrolysis gas increased under the assistance of alkali metal Na or K. Model compounds research confirmed that alkali metal could catalyze low temperature pyrolysis of cellulose in heated tobacco sheets. These results demonstrated that the pyrolysis of heated tobacco sheets could be catalyzed by alkali metal catalysts at low temperature, increasing the concentration of pyrolysis gas and aroma substance. This research provided a new idea for the study of aroma and concentration enhancement of heated cigarettes through catalytic technology.

The antibacterial secondary metabolites of the fungus Penicillium chrysogenum associated with the beetle Aspongopus chinensis were investigated through chromatographic fractionation methods of ethyl acetate extracts of the fungal cultures. Five compounds were isolated, and their structures were determined as emodin, 4-(methoxymethyl)benzoic acid, isoochracinic acid, secalonic acid D, and dicerandrol A using mass spectroscopy and nuclear magnetic resonance spectroscopic analyses. Emodin exhibited strong antimicrobial activity, especially against Staphylococcus aureus even when growing on cooked pork, with a minimal inhibitory concentration (MIC) of 6.3 μg/mL. Dimeric tetrahydroxanthones, such as secalonic acid D and dicerandrol A, also exhibited potent activity, with MIC values ranging from 9.5 to 28.5 μg/mL. In summary, P. chrysogenum was isolated as a symbiotic fungus of the beetle A. chinensis for the first time and this strain could generate antibacterial secondary metabolites, which could potently inhibit gram-positive bacteria growth in vitro.

为了制备造纸法薄片料液微胶囊并研究其在加热不燃烧卷烟中的缓释效果,先对料液的挥发性香味成分进行分析,然后采用复凝聚法制备微胶囊及其理化特性的表征,最后研究微胶囊在加热不燃烧卷烟中不同材料段的缓释效果.结果表明:①造纸法薄片料液共有 21种香味挥发性物质,其中有 13种易挥发性,表明料液具有较强挥发性.②红外谱图的峰型表明料液被成功包埋;热重曲线表明,微胶囊中料液快速损失的温度较单独料液提高近170℃,因壁材提高其热稳定性,减少挥发.③微胶囊平均粒径240 nm,包埋率34.11%,放置 7d后的水分质量分数为 9.37%;外观为淡淡的金黄色粉末,由扫描电子显微镜图可知其结构致密,囊壁表面较为光滑,近似椭球状.④加香缓释实验结果表明微胶囊添加在烟草段且添加量为0.015 g/支的效果最好,不仅增加香气量,缓释效果明显,而且刺激性明显降低,劲头提高,余味回甜,为微胶囊技术在加热不燃烧卷烟中的应用提供了理论基础.

以壳聚糖为壁材,柠檬精油为芯材,采用复凝聚法制备柠檬精油亚微米微胶囊.最优制备条件为:壁材量0.27%,芯壁比3.5∶1,乳化剂量0.37%,乳化速率750 r/min.此条件下制备的亚微米微胶囊结构致密,粒径最小,约274 nm,包埋率50.83%,其表面囊壁较为光滑,呈现出近似球状或椭球状.在200℃左右,亚微米微胶囊的精油开始散失,在600℃仍存在少量的精油,说明壁材可有效地控制精油的释放.当微胶囊添加量3%时,制备的香味纸在90℃下可留香2 h,有良好的缓释效果.

Biodegradable polymer materials are attractive in various biomedical applications. Herein, we report a block aliphatic copolymer, polycaprolactone-block-polyglycolide (PCL-b-PGA, denoted as PCLGA), and explored the polymer composition effect on the thermal and degradation behaviors. Three copolymers with different PCL/PGA weight ratios were obtained by a two-step ring opening polymerization. The chemical structures and compositions of copolymers were studied by NMR and FT-IR. The thermal behaviors were investigated by DSC and TGA. The in vitro degradation in phosphate buffer saline and in vivo degradation as an implant in rats were evaluated and the hygroscopic rate and polymer weight loss changes were monitored in an eight-week period. PCLGA with a higher PCL composition showed a slower degradation in vitro and in vivo. These PCLGAs with different degradation rates could be used as biomedical implants for potential application in drug delivery and tissue repair.

为改善香味物质的释放性能,提高电子烟感官评吸品质,研究了薄片料液微胶囊在电子烟烟油中的应用效果.采用复凝聚法将辊压法薄片料液微胶囊化,对其物理化学特性及释放的香味成分进行表征和分析,并将其应用于电子烟烟油中进行感官评价.结果表明:1)微胶囊外观呈近似圆球状或椭球状,结构较致密,平均粒径约为220 nm且大小均匀分布集中,包埋率为 45.68%,常温环境下放置 7 d的含水率为 7.39%,易于运输和储存;料液微胶囊化后热稳定性提高,微胶囊发生最大质量损失率的温度较料液提高约 170℃.2)微胶囊中共检出20 种挥发性香味成分,总含量为 1158.11 μg/g;最主要的香气成分种类为酯类化合物,占化合物总含量的78.71%,对烟草制品香吃味有重要影响.3)添加微胶囊的电子烟烟油评吸效果较好,刺激性减少,香气量增加,在一定程度上提升了逐口抽吸香气的一致性.

为开发新型食用香精,将罗汉果提取物与葡萄糖焦糖化料液掺配后进行加热反应制备罗汉果香料.以感官评分为指标,探究不同反应条件(加热温度、加热时间、体系初始pH、罗汉果提取物与葡萄糖焦糖化料液比)对罗汉果香料的影响,正交试验得到最佳的反应条件为反应时间50 min、反应温度130℃、初始pH 8.0、罗汉果提取物与焦糖化料液比4∶1.在此条件下得到的罗汉果香料感官评分最高,果香、烘烤香、膏香、甜香、药草香都较明显,总体风味较好.该研究为天然植物罗汉果的开发应用提供了理论依据.

为开发新型食用香精,以广西天然植物罗汉果为原料,将罗汉果提取物与葡萄糖焦糖化料液掺配后进行不同温度的加热反应,制备食用香料,通过GC-MS分析及主成分分析对其挥发性成分进行探索,探讨不同温度样品的差异及特征成分.结合嗅香评价,判断最优的反应条件为天然植物罗汉果的应用提供了数据支持.GC-MS分析发现反应温度为140℃时,样品中挥发性物质的含量最多,反应温度为100℃时,样品中挥发性物质的种类数最多.主成分分析发现5个样品根据距离远近可分为3个区域,3个区域彼此间差异较大.反应温度为140℃时,样品挥发性物质分布较为密集,对其特征香气影响较大的香味物质主要包括2,3-二氢-3,5-二羟基-6-甲基-4H-吡喃-4-酮、5-羟甲基二氢呋喃-2-酮、香草醛等.嗅香分析中发现反应温度为140℃时,样品醇厚感较强,嗅觉层次较丰富,甜香、果香、膏香、药草香明显,感官品质最好.结合上述结果可认为反应温度为140℃时得到的样品具有最佳的风味和感官品质.

为了研究甜茶多糖及其羧甲基化甜茶多糖衍生物的结构和抗氧化活性,通过碱提提取出甜茶中的多糖,并对其进行羧甲基化修饰.通过GC-MS、傅里叶红外光谱分别对甜茶多糖进行结构表征.并对甜茶多糖和羧甲基化甜茶多糖的抗氧化活性进行对比分析.结果表明:①甜茶多糖的提取率为3.48％.②甜茶多糖中单糖主要由葡萄糖和甘露糖两种成分组成,占比分别为59.33％和40.67％;③红外光谱证明甜茶多糖的羧甲基化修饰成功,取代度为0.52;④甜茶多糖和羧甲基化甜茶多糖都具有一定的抗氧化活性,并且羧甲基化甜茶多糖的抗氧化活性优于甜茶多糖.

This research was carried out to determine the influences of cigarette smoking and the hypoglycemic effects of Phellinus vaninii Ljup polysaccharide (PS) on STZ (streptozotocin)-induced severe hyperglycemia maternal rats, as well as the postnatal development of their offspring. The polysaccharide was administered orally and the cigarette smoke (CS) exposure was performed daily for four weeks. The food efficiency ratio, food intake, body weight gain, organ weights, and blood glucose level were tested for the maternal rats, and the body weight and glucose tolerance tests were evaluated for their offspring. It was found that cigarette smoke exposure did not worsen hyperglycemia in maternal rats. In comparison with the control group, P. vaninii Ljup polysaccharide could obviously lower the blood glucose levels and increase the food efficiency ratio of maternal rats, and can help prevent disorders in offspring. In addition, in comparison with the CS exposure group, the polysaccharide also exhibited protective effects that decreased the blood glucose levels and enhanced the food efficiency ratio of maternal rats, which also reduced the blood glucose levels in their offspring at 32 weeks of age. These results suggested that P. vaninii Ljup polysaccharide could be potentially used to treat hyperglycemia in diabetic patients.

为了在加热卷烟调香中更加科学合理地使用烤甜香单体香料,以 自制加热卷烟为载体,采用GC-MS分析方法,测定了 0.01％和0.05％两个添加量下气溶胶中6种烤甜香成分的逐口释放量,揭示了烤甜香单体香料的逐口转移规律.结果表明:①气溶胶中6种烤甜香成分的释放量总体均呈现先升高后降低的趋势;②0.01％和0.05％添加量下,6种烤甜香单体香料的逐口转移率范围分别为0.5％～15.6％和1.0％～9.6％,其最大值均出现在第3 口或第4 口;③各烤甜香单体香料在气溶胶中逐口转移率之和与抽吸口数序号呈良好的线性正相关关系;④两个添加量下,6种烤甜香单体香料在气溶胶中的总转移率分别为34.2％～73.1％和23.3％～63.7％.

采用丙三醇开环聚合左旋丙交酯(L-LA),合成了三臂乳酸预聚物(PLLA 3),通过与封端剂富马酸单乙酯(FAME)的酯化反应,成功地合成光敏性三臂乳酸预聚物(PLLA 3-FAME).将PLLA 3-FAME与反应性稀释剂N-乙烯基吡咯烷酮(NVP)和光引发剂Irgacure 2959,混合调制成光敏性聚(乳酸-乙烯基吡咯烷酮)树脂,经紫外光固化后成功成型,得到聚(乳酸-乙烯基吡咯烷酮)材料,并对材料结构和性能进行了表征测试.结果 表明,较材料PLLA相比,聚(乳酸-乙烯基吡咯烷酮)材料的亲水性、拉伸强度和降解速度均有显著提升.水接触角由91°±2°下降至75°±4°,吸水率由0.43％提升至35％;拉伸强度和延伸率分别由28 MPa,3.82％提升至77 MPa,11.35％;24周内的降解速度由未发生降解提升至质量损失27.57％.该材料可作为3D打印基材,可用于定制要求和组织工程的材料领域.

选取小孔硬孔菌、硬毛栓孔菌、二年残孔菌、银杏多孔菌和血红密孔菌为菌种,发酵制得了5种多孔菌胞外多糖(EPSⅠ～Ⅴ)并进行了分离纯化.通过抑制自由基氧化DNA及捕获自由基反应探究了5种EPS的抗氧化性能和还原能力,对比确定了不同多孔菌EPS抗氧化活性差异.结果表明:5种多孔菌EPS均能够抑制自由基氧化DNA并捕获自由基,但抗氧化性能强弱存在规则性差异.在6个测试体系中,5种EPS的抗氧化性能排序基本一致,为EPSⅣ>EPSⅤ>EPSⅡ>EPSⅠ>EPSⅢ,其中,在抑制HO·、GS·和AAPH氧化DNA反应体系中,银杏多孔菌EPS(EPSⅣ)浓度为40 mg/L时,相对空白TBARS吸光度百分数分别可达44.9％、32.2％和64.4％;EPSⅣ对ABTS+·、DPPH·和galvinoxyl·三种自由基的清除率分别高达52.7％、63.2％和83.9％,表现出优异的抗氧化活性,多孔菌EPS的抗氧化性能与其构型高度相关.

选取不同参数(定量、透气度、麻浆质量分数、灰分质量分数、助燃剂质量分数、助燃剂中钾盐占比等)的卷烟纸制作细支卷烟样品,考察卷烟纸性状对细支卷烟燃烧锥落头倾向的影响,并对参数设置进行优化.结果表明:细支卷烟的燃烧锥落头倾向随卷烟纸定量的增大而迅速降低;卷烟纸的透气度、麻浆质量分数和灰分质量分数的增大均引起细支卷烟燃烧锥落头倾向的显著上升,其中卷烟纸的透气度与燃烧锥落头倾向正相关;助燃剂质量分数的变化对降低燃烧锥落头倾向无显著效果,但助燃剂中钾盐占比过高则会引起燃烧锥落头倾向的迅速增大;对细支卷烟燃烧锥落头倾向的影响大小依次为透气度>定量>助燃剂中钾盐占比>助燃剂质量分数,卷烟纸最优参数组合为透气度50 CU,定量34 g·m-2,助燃剂中钾盐占比50％,助燃剂质量分数1.5％,在该参数设置下,燃烧锥落头倾向由优化前的6.3％降至2.5％.

为区分不同浓香型烟叶风格特征的差异,对96种烟草重要香气成分的作用阈值进行了评价,以GC-MS法测定了其在许昌、郴州和潍坊烤烟烟气中的释放量,获得了香气活性值,将属于同一香韵的化合物的香气活性值加和得到10种香韵活性值并进行对比分析,揭示了不同浓香型烟叶的香韵特点.结果表明:①96种香气成分的作用阈值介于8.68×10-14和12.3μg/g之间.②郴州C3F、潍坊C3F和许昌C3F浓香型烟叶主流烟气中,乙酸的释放量最高,分别达475.103、551.326和455.425μg/g,其次为十六酸和油酸;坚果香、膏香、脂蜡香、甜香和烤甜香5种香韵香气成分总释放量存在差异.③香气活性值可用于判别3种浓香型烟叶的风格特征差异,其中,许昌C3F的烘焙香、膏香和烤甜香香韵相对突出,郴州C3F的甜香香韵最为突出,潍坊C3F脂蜡香香韵更为突出.

[目的]研究滤嘴参数(滤棒压降、滤嘴通风率)对细支烟香味成分释放的影响.[方法]按单因素设计制备60个卷烟样品,采用CH2Cl2浸提、GC/MS分析测定滤片捕集的代表性香味成分.在此基础上,建立并筛选了滤嘴参数对香味成分释放量的预测模型.[结果]①细支烟主流烟气中代表性碱性、中性、酸性和香味成分总释放量与滤棒压降和滤嘴通风率均呈显著负相关;②滤棒压降对细支烟主流烟气香味成分释放量的影响高于常规烟,而滤嘴通风则相反.③外部验证结果显示,4个预测模型的平均预测偏差在4.23％～5.95％之间,所建立的模型预测精度良好.

为提升再造烟叶品质,利用烟草中分离的类芽孢杆菌制备静息细胞,对再造烟叶原料浸提液进行发酵处理;采用连续流动分析、气质联用仪(GC-MS)、热裂解-气相色谱质谱(Py-GC/MS)等方法,测定了发酵过程中浸提液中蛋白质、还原糖、氨基酸含量变化;分析了其主要挥发性香味成分;并利用发酵浸提液浓缩涂布制备再造烟叶样品,进行热裂解产物分析和感官评价.结果表明:①发酵浸提液和对照组中的蛋白质、还原糖含量在5h内持续减少,而氨基酸含量先增高后降低,且发酵浸提液的蛋白质、还原糖含量低于对照,氨基酸含量高于对照;②发酵液中香味物质种类和总量较对照组均有所增加,其中糠醛、糠酮等致香组分增幅明显;③对比再造烟叶裂解产物,发现发酵浸提液浓缩后涂布样品裂解产生的γ-丁内酯、2,3-二氢-5-甲基呋喃、糠醛等典型烟气致香组分提高;④发酵液浓缩后涂布的再造烟叶样品感官品质较对照样品明显提升.利用类芽孢杆菌发酵烟草浸提液,对于提升再造烟叶的感官品质具有促进作用.

为了考察卷烟纸助燃剂对卷烟燃烧特性及主流烟气中CO释放量的影响,探讨了卷烟纸助燃剂的类型、用量、含钾比例与卷烟燃烧主流烟气中CO的释放量、卷烟燃烧特性之间的相关性.结果表明,卷烟纸助燃剂用量与卷烟的阴燃温度、烟碱量、焦油量具有相关性,提高助燃剂用量能提高卷烟燃烧时的阴燃温度、加快烟支的燃烧速度,且烟碱量和焦油量随之减少;保持卷烟纸助燃剂用量不变,助燃剂中的含钾比例与烟气常规成分和卷烟燃烧温度无明显相关性;卷烟纸助燃剂的类型、用量、含钾比例与CO释放量无明显相关性,CO释放量与卷烟燃烧时低温区域面积和高温区域面积的比值R具有强烈的正相关.

为降低再造烟叶中的果胶含量,采用单因素试验和正交试验对微紫青霉产果胶酶降解果胶的工艺条件进行优化,分析了酶解前后样品的热裂解产物,并将酶解后样品抄造制丝添加至卷烟中进行感官评价,结果表明:微紫青霉产果胶酶降解果胶的最佳反应条件为酶活力3000 U/mL,高浓混合浆干重与粗酶液体积的料液比1∶1,反应温度50℃,处理时间3h.在此条件下果胶降解率达到最大,为28.63％,相对分子量由341 kDa减小到55 kDa.酶解后样品裂解产物的组成和含量发生明显变化,除醇类物质外,其他香味物质酚类、醛酮类、酯类、杂环类减少.将酶解后的样品抄造制丝添加于卷烟中,香气质丰满细腻,透发性、甜润感增强,刺激性减小,余味纯净舒适,吸食品质得以改善,但劲头略有不足.