Authenticity green coffee bean species and geographical origin using near-infrared spectroscopy combined with chemometrics

To prevent the adulteration of agricultural resources and provide a solution to enhance the green coffee bean supply chain, authentication using the near-infrared spectroscopy (NIRS) technique was investigated. Partial least square with discrimination analysis (PLS-DA) models combined with various preprocessing methods were built from NIR spectra of 153 Vietnamese green coffee samples. The model combined with the standard normal variate and the first order of derivative yielded excellent performance in predicting coffee species with the error cross-validation of 0.0261. PLS-DA model of mean centre and first-order derivative spectra also yielded good performance in verifying geographical indication of green coffee with the error of 0.0656. By contrast, the predicting abilities of post-harvest methods were poor. The overall results showed a high potential of the NIRS in online authentication practices.     

全IP电视直播节目的即时回看技术

介绍了已运用于实践中的一种全IP电视直播节目即时回看技术,用户通过遥控器一键实现直播节目的即时回看,极大地提升了用户的观看体验。通过在临汾市智慧广电全IP融合业务网建设实践项目中的使用,技术的先进性和有效性得到实践验证。     

固相萃取结合气相色谱-三重四极杆质谱法测定方便面中16种多环芳烃

建立固相萃取-气相色谱-三重四极杆质谱测定方便面中16种多环芳烃的方法。方便面样品用正己烷和乙腈-丙酮提取,经Oasis HLB和Florisil柱两步净化,气相色谱-三重四极杆质谱检测。在试验浓度范围内,线性关系良好,各种多环芳烃的定量限在0.03μg/kg^0.54μg/kg之间。在不同的加标浓度下,加标回收率在75%~129%之间,相对标准偏差小于13.4%。该方法快速、准确、灵敏度高、重现性好,适用于大批量样品中多环芳烃的快速测定。     

咖啡渣活性炭的制备、表征及其对Cr(Ⅵ)的吸附机制研究

以碘吸附值为评价指标，活化时间、活化温度和浸渍比为影响因素，采用响应面法试验设计对磷酸活化法制备咖啡渣活性炭的工艺条件进行优化，并通过静态吸附试验研究了不同吸附时间、溶液pH值和吸附温度条件下，活性炭对水溶液中Cr（Ⅵ）吸附性能的影响，最后利用Langmuir、Freundlich吸附等温方程、准一级动力学方程、准二级动力学方程和颗粒内部扩散方程进行拟合。试验结果表明，制备咖啡渣活性炭的最佳工艺条件为活化时间1 h、活化温度498℃、浸渍比1.72；在此条件下活性炭得率为30.4%，碘吸附值为（799±16）mg/g，比表面积为1 006 m²/g，孔容为0.779 cm³/g、微孔孔容为0.051 cm³/g、平均孔径为3.088 nm。较低pH值和较高温度能够促进活性炭对Cr（Ⅵ）的吸附；Langmuir等温方程能够更好地描述活性炭对Cr（Ⅵ）的吸附效果；活性炭对Cr（Ⅵ）的吸附分3个阶段：快速吸附阶段、慢速吸附阶段和吸附平衡阶段，10 min内可完成吸附总量的79%，360 min内达到吸附平衡，该吸附过程符合准二级吸附动力学方程。分析表明咖啡渣活性炭对Cr（Ⅵ）的吸附主要为单分子层的化学吸附。     

Why do people purchase virtual goods? A uses and gratification (U&G) theory perspective

Few literature studies have investigated the relationships between different uses and gratifications (U&Gs) of mobile instant messaging (MIM) apps, continuation, and purchase intentions. To address this gap, the researchers aimed to examine the influence of the content, social, process, and technology U&Gs of MIM on continuation intentions toward MIMs, and purchase intentions toward virtual goods available on MIMs. A comprehensive research model was developed based on the U&G theory, which was tested using cross-sectional data from 309 Japanese MIM users. The study considered six different U&Gs of MIM as independent variables and purchase intentions towards stickers and continuation intentions towards MIM as dependent variables. The study results suggest that exposure U&G has a significant positive association with MIM sticker purchase intentions. The entertainment and affection U&G are positively associated with continuation intentions towards MIM use. The study contributes to the literature by investigating U&Gs that motivate MIM users to have both positive purchase intentions toward virtual goods, such as stickers, and continuation intentions toward MIMs. The study has significant theoretical and practical implications for both researchers and practitioners who are interested in virtual goods, the virtual economy, MIM apps, social media, new media, and the service economy.     

高效液相色谱法同时测定咖啡中6种绿原酸

目的建立咖啡中同时测定5-咖啡酰奎宁酸、3-咖啡酰奎宁酸、4-咖啡酰奎宁酸、3,4-二咖啡酰奎宁酸、4,5-二咖啡酰奎宁酸、3,5-二咖啡酰奎宁酸6种绿原酸的高效液相色谱(high performance liquid chromatography,HPLC)检测方法,以及测定产自云南普洱的铁皮卡品种咖啡在不同烘焙风味下的绿原酸含量规律。方法样品经纯水超声提取2次,过滤后供HPLC测定,采用甲醇(A)和0.1%磷酸(B)作为流动相进行梯度洗脱采用C18柱进行分离,光电二极管阵列(photo-diode array,PDA)检测器最终检测。结果本方法在1 h内完成了6种绿原酸的分离分析。6种绿原酸在0.10～100.0 mg/L范围内具有良好的线性,相关系数(r)≥0.999,检出限为0.05～0.10 mg/kg,定量限为0.18～0.29 mg/kg。在2000、5000、10000 mg/kg添加水平的加标回收率为96.3%～104.8%,相对标准偏差(relative standard deviation,RSD)为0.58%～2.10%之间(n=6)。在生咖啡豆中总绿原酸含量最高,意式烘焙(23 min,250℃)最低,5-咖啡酰奎宁酸、4-咖啡酰奎宁酸和4,5-二咖啡酰奎宁酸这3种绿原酸在生咖啡豆到极轻度烘焙(12 min,230℃)这个阶段,含量逐渐上升并达到含量最高,由极轻度烘焙(12 min,230℃)到意式烘焙(23min,250℃)含量逐渐降低,而3-咖啡酰奎宁酸、3,4-二咖啡酰奎宁酸和3,5-二咖啡酰奎宁酸3种绿原酸从生咖啡豆至意式烘焙(23 min,250℃)都呈下降趋势。结论该方法快速、准确、灵敏,适合测定绿原酸含量。     

An outlook on the role of decaffeinated coffee in neurodegenerative diseases

Abstract

Coffee is reported to be among the most widely consumed beverages in the world and coffee consumption has been associated with reductions in the risk of several chronic diseases. Among its constituents, caffeine represents the most investigated component. The main impact of caffeine on health is associated with the central nervous system, the cardiovascular system, the inflammatory mechanisms, the metabolism of carbohydrates, and the cancer. Current research is devoted to the role of this compound and its analogs or derivatives on neuroinflammation and neurodegenerative disorders, mainly Alzheimer’s Disease and Parkinson’s Disease. However, coffee is also rich in polyphenols, mainly phenolic acids (chlorogenic acids, caffeic acid, ferulic acid), quinic acid, and quercetin. Many aspects still require greater clarification, including the effect of coffee compounds different from caffeine, on several pathologies. This review aimed to provide a comprehensive overview of the potential benefits of decaffeinated coffee constituents, focusing the attention on neurological processes and pathologies, such as mainly memories disorders, Parkinson’s Disease, neurophatic pain disorders, and cerebral ischemia.     

脉冲喷动床微波冻干方便面品质与能耗研究

以湿面条为实验原料,进行脉冲喷动床微波冻干(PSBMFD)面饼品质与能耗研究,并与传统电加热冻干(CFD)方式进行对比分析。研究表明:PSBMFD面饼的复水时间、复水比及复水前后硬度值分别为150 s、3.07、4 692.36 g、520.45 g,水分、色差及收缩率的均匀度分别为94.51%、94.31%、92.23%,感观评价总分为8.2,干燥时间为3.5 h,干燥产品总耗能为8.05 kWh/kg。PSBMFD技术不仅提高冻干面饼的干燥均匀度,改善冻干面饼的品质,而且与CFD相比,能够明显地缩短冻干时间(58.83%),降低冻干能耗(66.63%)。     

The influence of brewing method on bioactive compounds residues in spent coffee grounds of different roasting degree and geographical origin

The content of bioactive compounds in spent coffee grounds (SGC) was studied. SGC were obtained from Coffea arabica beans of different roasting degrees (light and dark) and different geographical origins (Nicaragua, Columbia and Mexico) processed using four brewing methods (mocha, filtered, drip and infusion). The highest caffeine and chlorogenic acid contents were determined in filtered spent coffee extracts. All extracts of light roasted spent coffee grounds showed lower browning index levels in comparison to that from dark roasted spent coffee grounds. Generally, the highest content of total polyphenolic compounds and highest antioxidant capacity were determined in extracts prepared in drip. In conclusion, the results obtained in this study indicate that the spent coffee grounds produced of domestic levels, especially those obtained from filter coffeemaker, could be considered as a good source of natural antioxidants.     

加工工艺对空心面型非油炸荞麦方便面品质的影响

以传统空心面生产工艺为基础,挤压预糊化荞麦粉和高筋粉混合原料,加工冲泡即食非油炸荞麦方便面。考察一次长时间发酵、多次短时间发酵以及压片对面粉粉质特性、面条质构特性和冲泡时复水性以及感官品质等的影响。结果表明,发酵可显著改善冲泡性,压片对面条品质没有影响。通过发酵和预糊化荞麦粉的应用,可以得到冲泡性和口感均较好的非油炸荞麦方便面。