Influence of high pressure treatment on rheological and other properties of egg white

Abstract

The paper deals with the influence of high pressure treatment of fresh egg white on its properties and protein composition (individual amino-acids predicted as a function of pressure and time levels). The rheological properties are changed by high pressure from Newtonian to non-Newtonian behaviour, with increasing apparent viscosity as the pressure and time increased. The pH, whipping ability, foam stability, gel strength of heat induced gels after treatment and the whole protein content, were also predicted.

The results showed that the foam stability is increased with increasing pressure and time of processing. The foam volume is also increased with pressure. The pH did not change with pressure or time of processing. Composition of proteins as indicated by individual amino-acids did not exhibit statistically important changes. Gel strength of heat induced gels prepared from previously pressured liquid whites showed no important change of values with pressure or time of treatment. The modulus of elasticity showed a decrease for samples pressured to 400 MPa for 5 up to 15 minutes.     

Resolution enhancement in hydrophobic interaction chromatography via electrostatic interactions

In this work, a new type of hydrophobic stationary phase that provide electrostatic interactions with analytes was developed by bonding β-phenylethylamine as a functional ligand to silica. This stationary phase can separate proteins with similar hydrophobicity that traditional hydrophobic resins cannot. Hen egg white was separated to examine the selectivity. The results show that the introduced electrostatic interactions are an important factor for the resolution enhancement and the new resin could have important applications in separation and purification of biological macromolecules.     

Symbiotic N2 Fixation and N Uptake of Yellow and White Lupines Influenced by Spontaneous Rhizobia Infection and Substrate

Abstract

By using soil as substrate, white and yellow lupines (Lupinus albus L., Lupinus luteus L.) assimilated higher N amounts than under quartz sand conditions. This was caused by spontaneous infection of lupines with wild Rhizobia strains and also by an additional N uptake from the soil. In yellow lupines without inoculation in non-sterile soil, only the additional N uptake played a role. Differences in P and K supply as the cause of different N acquisition from soil and quartz sand could be excluded. As compared with white lupines, yellow lupines inoculated with Rhizobia had a high N₂ fixation that exceeded the effect of spontaneous infections. This result as well as the positive effect of spontaneous infections with soil-borne Rhizobia on white lupines indicates insufficient effectiveness of the strains used for inoculation on this plant species.     

Screening of key odorants and anthocyanin compounds of cv. Okuzgozu (Vitis vinifera L.) red wines with a free run and pressed pomace using GC‐MS‐Olfactometry and LC‐MS‐MS

The principal purpose of the present work is to characterize the aroma, aroma‐active, and anthocyanin profiles of Okuzgozu wines and to observe the effect of the pomace pressing technique on these parameters. A total of 58 and 59 volatile compounds were identified and quantified in free‐run juice wine (FRW) and pressed pomace wine (PW). Alcohols were found as the most dominant group among aroma compounds followed by esters and acids. However, among all these compounds, only 11 and 13 of them could be considered as key odorants in aromatic extracts of FRW and PW, respectively. According to GC‐MS‐O analysis, ethyl octanoate (fruity), phenyl ethyl acetate (fruity), and 2‐phenyl ethanol (flowery) were found as the main contributors to the overall scent of both wines. Beyond the aroma profiles, anthocyanin contents of both types of wines were also investigated, and total 14 and 15 anthocyanins were identified and quantified in FRW and PW. Malvidin‐3‐glycoside and its acetyl and coumaroyl forms were identified as the dominant anthocyanins in both wines. It is worth noting the pressing application (2.0 atm) led to an increase of some unpleasant notes in the aroma providing chemical, pharmacy, and fermented aromas in wine. On the other hand, the wines produced with pressed pomace presented higher amounts of anthocyanins.     

繁昌窑址附近多种瓷土成分分析

繁昌窑青白瓷胎体配方工艺一直停留在理论推理阶段，尚未有确凿的测试数据和模拟实验加以证实。为深入探究繁昌窑的胎料配方工艺，选取了繁昌窑址附近的多种瓷土样品进行了测试分析，并采用了古代制瓷工艺进行了模拟烧制。主要运用了波长色散X射线荧光光谱法(WDXRF)、红外光谱（FTIR）和X射线衍射（XRD）等光谱分析方法对瓷土成分进行测试；借助同步热分析（TG-DSC）对样品烧造温度进行了探索；通过模拟烧制陶瓷样品，对繁昌窑青白瓷的烧制工艺进行了研究，并对烧制的陶瓷样品进行显微结构分析。研究表明，繁昌窑附近的几种瓷土无论是单独制胎还是添加高岭土混合制胎，其烧成温度皆接近古代繁昌窑青白瓷的烧制温度。繁昌窑附近的瓷土是可以作为制作古代青白瓷的原料之一，但由于其中的铝含量较低，不能单独用来制作青白瓷胎体的原料，繁昌窑青白瓷在制作过程中应添加了其他富铝类原料。该研究对探索古代繁昌青白瓷的生产工艺及其蕴含的科学价值，提升繁昌窑在中国陶瓷工艺技术发展史上的地位等具有重要的学术意义，并可为现代陶瓷产业技术改进提供有益启示。     

Multiresidue Method for the Determination of Organophosphorus Pesticides in Still Wine and Fortified Wine Using Solid-Phase Microextraction and Gas Chromatography – Tandem Mass Spectrometry

A SPME-GC-MS/MS method for the determination of eight organophosphorus pesticides (azinphos-methyl, chlorpyriphos, chlorpyriphos-methyl, diazinon, fenitrothion, fenthion, malathion, and methidathion) in still and fortified wine was developed. The extraction procedure is simple, solvent free, and without any sample pretreatment. Limits of detection (LOD) and quantitation (LOQ) values in the range 0.1–14.3 µg/L and 0.2–43.3 µg/L, respectively, were obtained. The LOQ values are below the maximum residue levels (MRLs) established by European Regulation for grapes, with the exception of methidathion. Coefficients of correlation (R²) higher than 0.99 were obtained for the majority of the pesticides, in all different wines analyzed.     

Eu2+掺杂MgY2Al3Si2O11N青光荧光粉的制备和发光性能

采用高温固相法合成了一系列Eu²⁺掺杂的MgY²Al³Si²O¹¹N(MYASON)青光荧光粉。详细探讨了不同制备方法对荧光粉的物相结构和发光强度的影响,利用X射线衍射精修和X射线光电子能谱实验证明Si⁴⁺-N^3-离子对成功掺入石榴石晶格中。通过荧光光谱、寿命衰减曲线和变温光谱研究了发光性能,研究结果表明,用365 nm紫外光激发MYASON∶Eu²⁺荧光粉时,在青光区域呈现不对称宽带发射,峰值为490 nm,可以为紫外芯片激发的白光发光二极管有效提供青光成分。