正己烷-乙醇-水三元体系的相平衡研究

研究正己烷-乙醇-水三元体系的相平衡及萃取中亚麻籽含水量与体系乙醇浓度的平衡关系。结果表明，乙醇-己烷-水构成的三元体系中，混溶程度随温度的升高和乙醇浓度的增大而增加。亚麻籽含水量与体系中乙醇浓度存在平衡关系，相应的平衡关系为：95％的乙醇浓度对应于7％～9％含水量的亚麻籽；90％的乙醇溶液对应于9％～11％含水量的亚麻籽；85％的乙醇溶液对应于10％～12％含水量的亚麻籽。     

[EMIM]+[BF4]-对乙醇-水体系相平衡的影响

[EMIM]^＋[BF4]^-是一种离子液体,本研究用改进的Othmer汽液平衡釜测定了101．3kPa下[EMIM]^＋[BF4]^-摩尔分率x3=0．1,0．2的乙醇-水-[EMIM]^＋[BF4]^-体系的汽液平衡数据,并用NRTL模型进行了关联,结果平均偏差为0．967％。实验表明：[EMIM]^＋[BF4]^-可以消除乙醇-水体系的共沸点,可以作为萃取精馏分离乙醇-水体系的溶剂。     

氯化钠-硫酸钠-水三元体系相平衡

采用等温法，在15℃和20℃下测定了氯化钠和硫酸钠在水中的相互溶解度数据，得到了平衡液相组成的密度和折光率。     

水-乙醇二元体系的低场核磁共振弛豫特性研究

应用低场核磁共振(1H LF-NMR)技术对不同浓度水-乙醇二元体系的弛豫特性进行了研究,并结合分子模拟计算获得的体系的氢键变化进行了分析。结果表明,不同浓度下水-乙醇体系的氢键缔合状态可引起低场核磁弛豫特性的变化。对0%≤XW≤10%的水-乙醇体系而言,水与乙醇可通过氢键形成H2O(Et OH)n团簇,表现为T21先增加,后减小并保持相对稳定,而单组分弛豫时间(T2w)逐渐减小。对10%≤XW≤100%的水-乙醇体系而言,单组分弛豫时间T2w呈先缓慢减小再逐渐增加的趋势;当10%≤XW30%时,乙醇分子间缔合为主,形成(H2O)m(Et OH)n团簇,T21先相对稳定再减小。当30%≤XW≤60%时,单体水分子与乙醇自缔合团簇的结合逐渐达到饱和,T21再次呈相对稳定的现象。当60%XW≤100%时,体系内以水分子间的氢键缔合为主,且(H2O)m(Et OH)n团簇解离,T21呈增大趋势。     

乙醇-水缔合体系光谱及其应用于白酒中乙醇含量测定方法的研究

利用乙醇-水缔合体系产生的吸收峰强度与乙醇含量成比例的关系，建立了测定乙醇的新方法。乙醇体积浓度在15％-85％范围内，相关系数0．9983，变异系数0．186％。回收范围在99．52％～104．87％。该方法操作简便、快速，将其应用于白酒中乙醇含量的测定，所得结果与比重法相近。     

氯化钠-过氧化氢-水三元体系的相平衡研究

利用等温法，在10℃、15℃和20℃下测定了氯化钠一过氧化氢-水三元体系相平衡，得到了平衡液相组成的密度和折光率。结果表明，氢化钠一过氧化氢-水是简单的三元体系，没有复盐的生成。     

酒类主要风味物质对乙醇- 水体系中氢键的影响

研究酒类主要风味物质对乙醇- 水体系中的氢键缔合影响。Plackett-Burman 试验可知,异丁醇、β - 苯乙醇、乙酸乙酯、KCl、NaCl、MgSO4、苹果酸、乳酸、丙酮酸对乙醇- 水体系中氢键缔合影响最大。根据相关性分析,酒精度与啤酒中氢键缔合强度的相关系数为0.629,是主要影响因素;原麦汁浓度、异丁醇、氯离子、钾离子、丙酮酸、乳酸与氢键缔合均有一定的正相关性。     

288K时四元体系Na~＋,K~＋//Cl~-,B_4O_7~（2-）-H_2O相平衡研究

采用等温溶解平衡法研究了288 K时Na＋,K＋//Cl-,B4O72--H2O四元体系的相平衡关系,测定了平衡液相的溶解度和密度。依据实验测定的平衡溶解度数据及对应的平衡固相,绘制了该四元体系的平衡相图及其密度-组成图。研究结果表明：四元体系Na＋,K＋//Cl-,B4O27--H2O 288 K时的固液相平衡实验中,平衡相图中有2个共饱点,5条单变量曲线,4个结晶区,其平衡固相分别为：Na2B4O7.10H2O,K2B4O7.4H2O,NaCl和KCl;并对实验结果进行了简要讨论。     

白酒中乙醇-水缔合作用的研究进展

乙醇与水易形成氢键,氢键的存在对酒体口感起着重要的作用。综述了乙醇-水分子间氢键的研究进展及乙醇浓度、贮存时间和白酒中的微量成分对其中乙醇-水缔合作用的影响。     

脂肪酶催化拆分1-(4-甲氧基苯基)乙醇的研究

研究筛选了多种脂肪酶对1-(4-甲氧基苯基)乙醇对映体进行酶法催化拆分,表明来自洋葱假单胞茵脂肪酶(PS IM)在催化拆分中表现出了最高的活力和立体选择性,一种来自小麦胚芽的脂肪酶(WGL)在催化的过程中表现出了与其它脂肪酶相反的选择性.研究了有机溶剂体系中温度和水活度对PS IM催化拆分效果的影响,表明35C是最佳温度,水活度0.69为最佳水活度,在此条件下,转化率和对映体选择性分别达到很好的效果(C 50%,eep99%,ees99%).     

油酸-甘油-无水乙醇共混体系与超临界CO2的相平衡

旨在为生物柴油后处理阶段的超临界CO₂提纯工艺提供参考数据,以生物柴油生产过程中后处理阶段体系所含的油酸、无水乙醇及甘油为原料,通过在SYLG-01型超临界流体相平衡实验装置中,观察油酸-甘油-无水乙醇共混体系在温度为308 K下与CO₂达到相平衡状态的过程。结果表明,油酸-甘油-无水乙醇共混体系为液-液两相,与CO₂在相平衡实验装置内最开始是气-液-液态,随着压力的增加,当CO₂达到超临界状态时,不同相之间的流动性和传递性增强,共混体系变成了均一态。因此,改变超临界CO₂的压力,有望将体系中的游离脂肪酸和副产物甘油同时萃取分离。     

乙醇/水体系中改性蚕丝织物的活性染料染色动力学和热力学

为进一步提升蚕丝织物的染色深度,利用活性红3BS在乙醇/水体系中对经阳离子表面活性剂改性的蚕丝织物进行染色,分析了染色温度、pH值、染料用量和染色时间对改性蚕丝织物性能的影响,同时也探究了改性蚕丝织物在乙醇/水体系中的动力学和热力学机制。试验结果表明:染色温度是影响改性蚕丝织物K/S值、明暗值、红绿值、黄蓝值和总色差值最大的因素,且随着染色温度的升高,染色速率常数先增大后降低,饱和吸附量逐渐增大,而半染时间、染料分配系数和标准亲和力逐渐减小;改性蚕丝织物的染色焓为-28.693 kJ/mol,染色熵为-0.066 kJ/(℃·mol), 改性蚕丝织物在乙醇/水中的染色过程为放热反应;改性后的蚕丝织物染色深度有所提升,各项染色牢度基本未发生变化。     

Effect of water phase salt content and storage temperature on Listeria monocytogenes survival in chum salmon (Oncorhynchus keta) roe and caviar (ikura)

ABSTRACT:  Salmon caviar, or ikura, is a ready-to-eat food prepared by curing the salmon roe in a brine solution. Other seasonings or flavorants may be added, depending upon the characteristics of the product desired. Listeria monocytogenes growth is a potential risk, since it can grow at high salt concentrations ( > 10%) and in some products at temperatures as low as 3 °C. Ikura was prepared from chum salmon ( Oncorhynchus keta ) roe by adding food-grade NaCl to yield water phase salt contents (WPS) of 0.22% (no added salt), 2.39%± 0.18%, 3.50%± 0.19%, and 4.36%± 0.36%. A cocktail containing L. monocytogenes (ATCC 19114, 7644, 19113) was incorporated into the ikura at 2 inoculum levels (log 2.4 and 4.2 CFU/g), and stored at 3 or 7 °C for up to 30 d. L. monocytogenes was recovered by plating onto modified Oxford media. Aerobic microflora were analyzed on plate count agar. Samples were tested at 0, 5, 10, 20, and 30 d. L. monocytogenes did not grow in chum salmon ikura held at 3 °C during 30 d at any salt level tested; however, the addition of salt at these levels did little to inhibit Listeria growth at 7 °C and counts reached 5 to 6 logs CFU/g. Components in the salmon egg intracellular fluid appear to inhibit the growth of L. monocytogenes. Total aerobic microflora levels were slightly lower in products with higher salt contents. These results indicate that temperature control is critical for ikura and similar products, but that products with lower salt contents can be safe, as long as good refrigeration is maintained.     

A new makeup remover prepared with a system comprising dual continuous channels (bicontinuous phase) of silicone oil and water

Removing makeup is considered to be the first step in the skincare process. Makeup that has served its purpose is a kind of impurity that should ideally be removed completely to maximize the effects of skincare products applied afterwards. However, the use of silicone resins has significantly improved the long‐lasting property of makeup with the result that makeup can hardly be removed efficiently either with surfactant‐type cleansers like soaps or with oil‐based cleansers like liquid crystalline cleansers. Furthermore, oil‐based makeup removers do not leave the skin feeling fresh but oily, and often have been used in combination with surfactant‐type cleansers. In other words, complete makeup removal and a fresh skin feel are considered to be incompatible in conventional formulation technologies. To obtain compatible systems, we investigated the applicability of a system known as the bicontinuous phase and eventually succeeded in developing a novel system for a makeup remover. This phase can be prepared with a specific composition with a complete hydrophilic‐lipophilic balance in an oil/surfactant/water system by using cyclo‐siloxane, which dissolves silicone resin well. The bicontinuous phase has an oil‐ and water‐continuous microstructure, showing affinity for both aqueous and oily substances. This bicontinuous phase was applied to the development of a novel makeup remover. Determination of remover cap‐ability and fresh skin feel revealed that the makeup could be completely removed and that the amount of oil remaining on skin surface after wash‐off was much less than with previous oil‐based removers. The results of the sensory test also supported the finding that the remover was far superior to conventional products. This makeup remover is the first example of the application of the bicontinuous phase technology to a cosmetic product and clearly seems to provide the best conditions for subsequent skin care, meaning that it is suitable for the first step in the skincare process.     

CIP在巴氏杀菌奶生产中的重要性

主要介绍了CIP的原理及在巴氏杀菌奶生产中的重要性,具有较高的使用价值。     

固相微萃取技术分析番茄香气成分的方法建立

除了酸甜苦咸四种基本味觉外,消费者选择食品时,食品所释放出来的香气也是一个考虑因素。通过固相微萃取结合气相色谱技术,可以很好地分离和鉴定番茄中的香气成分,最佳测定条件是:固相微萃取萃取头选用CW/DVB,吸附时间是25min,吸附温度为40℃,解析时间为4min,采样瓶中样品量为6g;气谱条件是:不分流进样,色谱柱为极性柱,采用程序升温进行分离鉴定。     

聚天冬氨酸为结合相的薄膜梯度扩散技术富集测量自来水中痕量铬(Ⅲ)

建立了以0.05mol/L聚天冬氨酸(PASP)溶液为结合相的薄膜梯度扩散(DGT)装置(PASP DGT)富集测量自来水中痕量CrIII的分析方法。DGT法测得配制水中CrIII的回收率为94.4%~105.6%,相对标准偏差(RSD)为2.78%~5.03%;测得自来水中CrIII的浓度为2.99~3.47μg/L,加标回收率为93.2%~107.7%;DGT方法对水中CrIII的检出限为0.081μg/L(采样48h),可应用于自来水中痕量CrIII的定量检测与早期预警。      

安吉白茶、桑叶复合功能性饮料的研制及其抗氧化性研究

以安吉白茶、桑叶为主要原料,经过筛选配方和优化工艺,研制成了具有抗氧化保健功效的复合茶饮料;并采用化学模拟体系测定了该饮料清除DPPH·和ABTS·+的能力,采用全血总抗氧化能力评价了其生物抗氧化效应。结果表明,主辅料用量均对该饮料的质量有较大影响,最佳配方为200ml饮料中含安吉白茶提取液3ml、桑叶提取液0.8ml、白砂糖4.4g、50%柠檬酸0.16ml,苯甲酸钠0.03g。该功能性饮料对自由基的清除能力很强,其清除DPPH·和ABTS·+的IC50分别为2.95mg/L和2.55mg/L(以总酚计);在全血体系中也具有良好的抗氧化效应。     

Purification of serine protease from mango (Mangifera Indica Cv. Chokanan) peel using an alcohol/salt aqueous two phase system

An alcohol/salt-based aqueous two-phase (ATPS) system, as a novel method of purification, was employed to purify serine proteases from mango (Mangifera Indica Cv. Chokanan) peel. The effectiveness of different parameters, such as type and concentration of alcohol (1-propanol, 2-propanol, and ethanol), type of salt (sodium citrate, potassium phosphate, and ammonium sulphate), pH, and NaCl, on the purification and selective separation of serine protease was investigated. Desirable conditions of partition coefficient (K), selectivity (S), purification factor (P), and yield (Y%) of serine protease, using ATPS, were determined. The highest partition coefficient (64.5) and selectivity (343.2) for serine protease purification value were achieved in an ATPS of 16% (w/w) 2-propanaol, 19% (w/w) potassium phosphate, and 5% (w/v) NaCl at pH 7.5. It was demonstrated that serine protease could be recovered with a yield of 96.7% and a purification factor of 11.6.     

The Pathogen-annotated Tracking Resource Network (PATRN) system: A web-based resource to aid food safety,regulatory science,and investigations of foodborne pathogens and disease

Investigation of foodborne diseases requires the capture and analysis of time-sensitive information on microbial pathogens that is derived from multiple analytical methods and sources. The web-based Pathogen-annotated Tracking Resource Network (PATRN) system (www.patrn.net) was developed to address the data aggregation, analysis, and communication needs important to the global food safety community for the investigation of foodborne disease. PATRN incorporates a standard vocabulary for describing isolate metadata and provides a representational schema for a prototypic data exchange standard using a novel data loading wizard for aggregation of assay and attribution information. PATRN currently houses expert-curated, high-quality “foundational datasets” consisting of published experimental results from conventional assays and next generation analysis platforms for isolates of Escherichia coli, Listeria monocytogenes, and Salmonella, Shigella, Vibrio and Cronobacter species. A suite of computational tools for data mining, clustering, and graphical representation is available. Within PATRN, the public curated data repository is complemented by a secure private workspace for user-driven analyses, and for sharing data among collaborators. To demonstrate the data curation, loading wizard features, and analytical capabilities of PATRN, three use-case scenarios are presented. Use-case scenario one is a comparison of the distribution and prevalence of plasmid-encoded virulence factor genes among 249 Cronobacter strains with similar attributes to that of nine Cronobacter isolates from recent cases obtained between March and October, 2010–2011. To highlight PATRN's data management and trend finding tools, analysis of datasets, stored in PATRN as part of an ongoing surveillance project to identify the predominant molecular serogroups among Cronobacter sakazakii isolates observed in the USA is shown. Use-case scenario two demonstrates the secure workspace available for private users to upload and analyze sensitive data, and for collating cross-platform datasets to identify and validate congruent datapoints. SNP datasets from WGS assemblies and pan-genome microarrays are analyzed in a combinatorial fashion to determine relatedness of 33 Salmonella enterica strains to six strains collected as part of an outbreak investigation. Use-case scenario three utilizes published surveillance results that describe the incidence and sources of O157:H7 E. coli isolates associated with a produce pre-harvest surveillance study that occurred during 2002–2006. In summary, PATRN is a web-based integrated platform containing tools for the management, analysis and visualization of data about foodborne pathogens.