Effects of high hydrostatic pressure on structure and colour of red ginseng (Panax ginseng)

BACKGROUND: The conventional method of processing ginseng (Panax ginseng) roots into red ginseng involves mainly heating and drying processes. In the present study, this method was modified by using high hydrostatic pressure (HHP) to improve the physicochemical characteristics of red ginseng. RESULTS: The HHP process (600 MPa for 1 min) significantly improved the histological properties of red ginseng by increasing cellular disruption and release of cell contents. The total reducing sugar content was significantly (P < 0.05) higher (increased from 10.67 to 15.25 mg g^?1) in red ginseng processed at 600 MPa for 1 min. Similarly, the total free amino acid content also increased significantly (from 2.81 to 7.77 mg g^?1). The HHP process resulted in superior and more even colouration and gave an attractive visual appearance to red ginseng. The optical density at 420 nm and Hunter's colour a value (redness) of extracts prepared from red ginseng increased significantly (P < 0.05) with the application of HHP. CONCLUSION: HHP‐processed red ginseng has significantly higher reducing sugar and free amino acid contents together with a more compact cell structure and superior visual quality (brighter red colour). Hence the application of HHP in red ginseng processing can result in ginseng products of improved quality compared with those obtained by the conventional method. Copyright © 2012 Society of Chemical Industry     

滚筒式梗丝干燥加工参数的优化

为提高梗丝的加工质量特别是梗丝的丝状效果,增加梗丝与叶丝配伍性,采用正交实验方法,对滚筒式梗丝干燥加工参数(梗丝厚度、HT蒸汽压力和滚筒干燥温度组合参数)进行了分析优化,并对优化后的方案进行了验证。结果表明:1对干燥后梗丝的填充值、整丝率和丝状效果影响主次顺序均为HT蒸汽压力梗丝厚度滚筒干燥温度;2最优化加工参数为梗丝厚度0.10 mm,HT蒸汽压力0 MPa,滚筒干燥温度[筒壁温度(140±5)℃热风温度(120±2)℃],在此条件下可以提高梗丝填充值和整丝率,且对梗丝的丝状效果有明显改善;3在高档卷烟中掺配适当比例的丝状梗丝,与掺兑前相比,感官质量有所提高,焦油释放量降低约0.8mg/支。     

基于CFD数值模拟的纸浆压力筛筛鼓棒条形状改进分析

为了提高纸浆压力筛的产量,采用CFD(Computational Fluid Dynamics)对压力筛筛鼓棒条周围的流场进行数值模拟。通过比较压力筛筛鼓棒条形状变化时的流场压力、湍流动能和速度云图的变化,发现棒条形状变化时,涡流的位置和大小也发生变化。在其他工作状态及结构条件不变的情况下,棒条形状改变,还会引起出口流量的变化,即棒齿宽度AB值对筛浆口流场产生一定影响,该值存在一个最优值。     

超高压处理对干酪质构的影响

研究超高压(Ultra High Hydrostatic Pressure,HHP;200,600 MPa/10min)处理对5种市售干酪的硬度、黏着性、弹性、内聚性、咀嚼性和回复性6个功能特性的影响。结果显示,5种干酪在200 MPa处理时,其黏着性、弹性、内聚性、回复性差异不显著(P0.05),即较低压力处理对干酪的质构影响不大;超高压处理后,干酪的硬度和耐咀性分别降低31%,39%,且压力越大降低越显著(P0.05);高压处理后蓝纹、稀奶油干酪的内聚性分别增加了21%,15%;帕马森、切达干酪经超高压处理其各个性质基本无显著变化,而马索里拉、蓝纹、稀奶油干酪的各个功能性均有显著差异,说明超高压处理对干酪质构的影响与水分含量有关,即水分含量越高的干酪其质构受超高压处理变化越显著。     

预处理方法对再造烟叶中烟梗品质的影响

研究高压预处理、常规预处理两种工艺对烟梗理化特性、短梗萃取率及磨浆后浆料性质的影响。研究结果表明:高压预处理后烟梗的热水可溶物和乙醇可溶物含量均有一定程度的升高,提取效率提高,生产线效率得到提升;高压预处理及磨浆后烟梗产生的细小纤维量较少,有利于产品得率的提升;高压预处理后烟梗浆料动态滤水性能优于常规预处理烟梗,有利于浆料的抄造。     

HPLC-APCI-MS法快速测定面包中联二脲的含量

为快速检测面包中的联二脲(HDC)含量,建立高效液相色谱串联大气压化学电离源质谱(HPLC-APCI-MS)法快速测定面包中联二脲含量的方法。采用80℃水作为提取剂,正己烷萃取除去样品杂质,净化后的样品采用Xbridge BEH Prep OBD Amide色谱柱进行分离,以体积比3:7的水—乙腈溶液为流动相,流速0.6 mL/min,进行梯度洗脱,大气压化学电离源(APCI)正离子模式电离,多反应监测模式检测,外标法定量,采用添加回收法进行测定。结果表明,该测定方法适用线性范围为0.2~10.0 mg/L,相关系数为99.5%~99.9%。室内平均回收率为82%~110%,实验室内精密度10.3%,能够满足一般分析方法的要求。该方法操作简便、快速、灵敏度高,适合面包中联二脲含量的测定。     

Real-time quality authentication of honey using atmospheric pressure chemical ionisation mass spectrometry (APCI-MS)

The aim of this study was to use gas chromatography-mass spectrometry (GC-MS) and APCI-MS techniques to detect adulteration in honey. The key volatile compounds in the headspace of the adulterated honey were marked by GC-MS and their representative fragment ions were utilised in scanning honey samples using the real-time APCI-MS system. The PLS models validated using independent data sets resulted in coefficient of the determination () of 0.97 and 0.96 and root mean square error in prediction (RMSEP) of 2.62 and 2.45 for the GC-MS and APCI-MS data sets respectively. The most efficient volatiles from GC-MS analysis and their corresponding fragment ions m/z from APCI-MS data analysis were then identified and used to develop new PLS models to predict the level of adulteration. The best PLS model gave of 0.95 and RMEP of 2.60% in the independent validation set indicating that the model was very accurate in predicting the level of adulteration.     

Characteristics of the Arc Voltage of a High‐Current Air Arc in a Sealed Chamber

The effect of the arc voltage on various factors of design and control was investigated for high currents in order to develop design guidelines for circuit breakers. In this study, the dependence on such factors, namely, the current, arc length, electrode surface area, and internal pressure of the arc voltage, was evaluated quantitatively. As a result of the evaluations, it was estimated that the arc voltage near the electrode surface rises linearly with the arc current and the power ?0.8 of the surface area, and that the voltage in the arc column rises as the 0.3 power of the pressure increase. We confirmed the validity of the estimated voltage characteristics by comparison with the generated voltage in an actual arc‐extinction chamber. The characteristics of the estimated voltage can provide effective guidelines for the design of arc extinguishing chambers. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 186(1): 34–42, 2014; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.22487     

Decomposition Characteristics of an Artificial Biogas in a Low‐Pressure DC Glow Discharge

The decomposition characteristics of an artificial biogas, which is a mixture of CH ₄, CO ₂, and H ₂ S, using a low‐pressure DC glow discharge have been investigated. It is found that H ₂, CO, C ₂ H ₂, H ₂ O, CS ₂, and COS are produced from the artificial biogas in the glow discharge. About 65% of the hydrogen atoms in CH ₄ are converted into H ₂ at an input energy of 800 J, at which CH ₄ is completely decomposed, and the decomposition characteristics of the artificial biogas are minimally dependent on the H ₂ S additive. Further, H ₂ S has a tendency to be decomposed earlier than the other components of the artificial biogas. When the glow discharge is generated in the artificial biogas with H ₂ S, some of the carbon atoms are found to deposit on the electrodes and the wall of the discharge chamber. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 186(1): 26–33, 2014; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.22304