Creatine and creatinine evolution during the processing of dry-cured ham

Dry-curing of ham involves many biochemical reactions that depend on the processing conditions. The aim of this study was to evaluate the effect of the dry-cured processing on the concentration of creatine, creatinine and the creatinine/creatine ratio. Dry-cured hams under study were salted using three different salt mixtures (100% NaCl; NaCl and KCl at 50% each; and 55% NaCl, 25% KCl, 15% CaCl₂ and 5% MgCl₂) in order to observe its influence on creatinine formation but no significant differences were found between them at any time of processing. However, significant differences between different post-salting times (20, 50 and 80 days) and the ripened hams (7, 9 and 11 months of ripening) were observed. Results showed that creatine and creatinine remain stable once the ripening period is reached. These results were confirmed when analysing dry-cured ham samples submitted to extreme conditions of temperature and time (20, 30, 40 and 70 °C during 0, 20, 40 and 60 min) as well as commercial dry-cured hams with more than 12 months of processing.     

Application of in-line monitoring for aiding interpretation and control of dextrose monohydrate crystallization

Two in-line monitoring probes were inserted into a 3.2 L batch cooling crystallizer to monitor the progression of a dextrose monohydrate crystallization and how it was influenced by process variables including impurities, seed size and initial dextrose concentration. The probes used were a K-patents refractometer and a Lasentec FBRM probe. These probes were applied to continuously monitor dextrose concentration in solution and crystal chord length distribution throughout the duration of the crystallization. The influence of process variables on crystallizer performance, as determined by final crystal yield and chord size, may not be intuitive and some unexpected results occurred. The continuous in-line measurement data proved very useful for interpreting how variations in the process variables influenced the crystallizer performance. Supersaturation is a key variable in the control of the crystallization process as it influences both nucleation and crystal growth. In-line monitoring of solution dextrose concentration can be applied to continuously evaluate supersaturation and this can then be applied to control supersaturation so as to achieve a desired crystallizer performance.     

N-羟基丁二酰亚胺的制备

本文介绍了制备N-羟基丁二酰亚胺的一般方法，研究了制备N-羟基丁二酰亚胺水合物的工艺方法，以及从一水合N-羟基丁二酰亚胺出发制备高纯度无水N-羟基丁二酰亚胺的方法。     

5-氨基四唑一水合物的制备及其分子结构

介绍了５ 氨基四唑（ＡＴＺ）一水合物的制备方法和分子结构。５ 氨基四唑（ＡＴＺ）一水合物晶体属单斜晶系,Ｐ２１／ｃ点群。测定结果表明,５ 氨基四唑分子具有很好的共面性,在其晶体内存在大量分子间氢键,致使整个分子形成了三维立体网格状结构     

混合颗粒系重叠图像分割与分类方法研究

针对传统图像处理算法对重叠颗粒的分割困难,引入Mask R-CNN深度学习算法并做针对性改进,通过调整残差网络ResNet-101加速训练,提出双FPN结构实现全局特征融合,使用Soft-NMS避免重叠颗粒漏检。设计了颗粒重叠图像实验系统,采集单一球形、球形与不规则混合多分散颗粒重叠图像用于分割研究。实验结果表明:该方法对混合颗粒分类准确率为91%,召回率为92%,均优于传统算法;其应用于含气泡的一水柠檬酸结晶过程中结晶的在线测量,所得结晶颗粒中位径误差为3.8%,数目误差为-1.3%。所提方法为混合颗粒的重叠图像分析提供了思路,后续有望解决图像法结晶过程后期在线监测乏力与气泡干扰的问题。     

一水合硫酸氢钠催化合成柠檬酸三丁酯

以一水合硫酸氢钠作为催化剂合成柠檬酸三丁酯，其优化工艺条件为：催化剂用量为总加料量的4.0％～4．5％，柠檬酸与正丁醇加料比为1：4．5～5．0，反应终点温度145～150℃。所得产品可达到国家优级品标准，酯化率达99％以上；催化剂价廉易得，可重复使用4次，再生容易，无腐蚀，环境污染小。     

一水盐酸环丙沙星初级成核机理的研究

A general expression for the ralationship between induction period and supersaturation was developed based on polynuclear approach.Different mechanism of primary nucleation in solution can be illustrated by the expression.The results of induction period determined by laser scatering method shows that the crystallization of ciprofloxacin hydrochloride monohydrate in water/ethanol or aqueous solution is by the mechanism of primary nucleation followed by one-dimensional diffusion growth,and then one-dimensional continuous or “birth and spread” growth on crystal face. The growth mechanism on the crystal face is affected by temperature and solvent.     

NaHSO_4·H_2O催化蓖麻油酯交换制备生物柴油动力学

采用过量浓度法对一水硫酸氢钠催化蓖麻油与甲醇酯交换反应宏观动力学进行了研究。考察了不同温度下蓖麻油转化率和时间的关系以及甲醇转化率和时间的关系。用高效液相色谱仪测定了不同反应时刻系统的甲酯含量。用线性回归方法处理实验数据得出：蓖麻油分级数为1.5,甲醇分级数为0.5;当反应温度为303、313、323、333K,催化剂加入量为油质量的5%,搅拌速率为600r/min时,表观速率常数分别为：0.003934、0.005271、0.006656、0.008237dm3/（mol.min）,表观活化能为20.627kJ/mol,表观频率因子为14.2806dm3/（mol.min）。动力学方程的预测结果和实验结果吻合较好。     

Analysis of the milling rate of pharmaceutical powders using the Distinct Element Method (DEM)

The milling behaviour of microcrystalline cellulose (MCC) and α-lactose monohydrate (αLM) in an oscillatory single ball mill has been analysed by using the Distinct Element Method (DEM). The experimental results suggest that the milling behaviour of αLM is more strongly influenced by the milling frequency as compared to MCC. A similar conclusion is also drawn from the DEM results. The milling behaviour of MCC and αLM is described by a first order rate process, and its rate constant, K_p, is found to correlate very well with the milling power, P_n, determined by the DEM simulation, except for the milling behaviour of αLM at 18 Hz. For the latter, there appears to be an incubation time after which the milling rate increases substantially. The results presented here provide a basis for predicting the milling behaviour of a material systematically based on the fundamental material properties and the machine dynamics without the need for extensive experiment and use of large quantities of materials.     

Crystal engineering of lactose using electrospray technology: carrier for pulmonary drug delivery

Context: Dry powder inhalers (DPIs) consisting of a powder mixture containing coarse carrier particles (generally lactose) and micronized drug particles are used for lung drug delivery. The effective drug delivery to the lungs depends on size and shape of carrier particles. Thus, various methods have been proposed for engineering lactose particles to enhance drug delivery to lungs.

Objective: The objective of current work was to assess suitability of electrospray technology toward crystal engineering of lactose. Further, utility of the prepared lactose particles as a carrier in DPI was evaluated.

Materials and methods: Saturated lactose solutions were electrosprayed to obtain electrosprayed lactose (EL) particles. The polymorphic form of EL was determined using Fourier transform infrared spectroscopy, powder X-ray diffractometry, and differential scanning calorimetry. In addition, morphological, surface textural, and flow properties of EL were determined using scanning electron microscopy and Carr’s index, respectively. The aerosolization properties of EL were determined using twin-stage impinger and compared with commercial lactose particles [Respitose^® (SV003, Goch, Germany)] used in DPI formulations.

Results and discussion: EL was found to contain both isomers (α and β) of lactose having flow properties comparable to Respitose^® (SV003). In addition, the aerosolization properties of EL were found to be significantly improved when compared to Respitose^® (SV003) which could be attributed to morphological (high elongation ratio) and surface characteristic (smooth surface) alterations induced by electrospray technology.

Conclusion: Electrospray technology can serve as an alternative technique for continuous manufacturing of engineered lactose particles which can be used as a carrier in DPI formulations.