铁路冷藏运输主要技术条件的研究

铁路冷藏运输作为我围食品冷藏链的重要环节,对食品安余供应和流通质量起着重要作用。铁路现有冷藏运输条件标准较低,不能满足当今市场供应要求,有必要依食品贮运要求进行更新提高,以有效提高铁路冷藏运输水平,提高食品质量及安全性。在充分研究借鉴国内外相关食乩标准的基础卜,结合我围国情、路情和易腐产品市场发展需求等情况,全面系统地对铁路冷藏运输技术条件进行了更新修订,补充完善了关键质量指标,严格了各项运输指标。文章介绍了其中的关键技术指标的确定过秤。     

In vivo and in vitro testing for selenium and selenium compounds bioavailability assessment in foodstuff

The assessment of selenium and selenium species bioavailability in foodstuff is of special concern on the context of human nutrition. In vivo (human and animal), and in vitro tests are important approaches for estimating the bioavailability of toxic and essential compounds to humans. An overview on in vivo and in vitro bioavailability assays for releasing selenium and selenium species in foodstuffs is summarized. Se and Se species content in a foodstuff critically influence Se bioavailability and bioactivity to humans and animals. Se bioavailability is affected by foodstuff-matrix major composition and minor components. Foodstuffs processing and/or treatments could enhancement or decrease Se bioavailability. Experimental conditions such as the selection of healthy status of examined people (in in vivo humans approaches), the selection of animal model (in vivo animals approaches), or the selection of GI conditions (in in vitro tests) could determines the results. Thus, international standardized protocol for in vivo and in vitro approaches assessment is mandatory.     

Product Design and Process Engineering using the Example of Flavors

Recently, formulation processes have become increasingly important in the product design of flavors. Traditionally, the focus of flavorists and the chemists that support them has mostly been on the chemical composition of the flavors, which are generally in liquid form, although product characteristics that can be influenced by process engineering, e.g., shelf life and controlled release, are currently been seen to be just as important. An exact knowledge of the physico‐chemical properties of the flavor and carrier materials is important if process engineering measures are to be used to influence product properties. This review article discusses recent progress in microencapsulation of flavors and presents a detailed discussion of the topic using the processes of spray drying, spray granulation, extrusion and multi‐material nozzles as examples.     

Foodstuff authentication from spectral data: Toward a species-independent discrimination between fresh and frozen–thawed fish samples

The substitution of fresh fish with frozen–thawed fish is a typical fraud that can damage consumers for several reasons. In fact, not only the quality of thawed meat can be negatively affected during freezing, but also safety issues can arise, as thawed meat is more susceptible to microbial growth. Though several strategies have been proposed for fresh fish authentication, their classification ability is strongly affected by the fish species being considered.     

Effect of High Pressure Processing on the Extraction of Lycopene in Tomato Paste Waste

The effect of high pressure processing on the extraction of lycopene in tomato paste waste was studied. The experimental results show that high pressure processing did not destroy the molecular structure of lycopene. The extraction yield of lycopene obtained by high pressure processing for 1 min was higher than that obtained with solvent extraction for 30 min. These excellent results for the extraction by high pressure processing are promising for the future extraction of lycopene from tomato paste waste.     

Comminution of Organic Material

The comminution of materials of bioorganic origin such as organic solids, biological agglomerates or micro‐organisms is described in this work. The intent of this disintegration process is to release products, to improve the product quality or to enhance biological degradation processes. Special analytical techniques based on biochemical parameters are required in order to characterize the result of the comminution of organic materials. These techniques supplement techniques that are known from the comminution of brittle inorganic materials. The defined stressing of single particles can be used to characterize the comminution properties of solid bioorganic materials. The disintegration of micro‐organisms has been investigated in the fields of biotechnological product release and biodegradability of wastewater sludges. It is possible to optimize the operational parameters of stirred ball mills based on stress intensity and stress number in order to reduce the energy input and to improve product release.     

A comparison of models and methods for simulating the microwave heating of moist foodstuffs

We study the problem of heating a one-dimensional approximation to a slab-sided moist foodstuff in a microwave oven, allowing for a phase change and drying. We initially investigate the accuracy of the Lambert law of exponential decay of the applied electric field into the foodstuff and derive an approximation for the field comprising the exponential decay term and an oscillatory component. We then show that the temperature of the foodstuff is given, to a good approximation, by only considering the heating effects of the exponentially decaying field. We then study the effects of drying. This process changes the dielectric properties of the material, which leads to changes in the field. However, these lead to smaller changes in the moisture content. A fast and accurate numerical method is derived which relies on smoothing the phase transition.     

Dual mode diffusion and sorption of sodium chloride in pre-cooked egg white

The concentration profiles of NaCl by the one-dimensional diffusion in pre-cooked EW (egg white) were obtained at 5-80 °C. D's (Fick's diffusion coefficients) estimated at respective concentrations of NaCl in EW showed peaks at a certain NaCl concentration in the substrate. The peak became prominently high with the increase in temperature. These variations were interpreted in terms of the dual mode sorption and diffusion theory, which was successfully applied to the diffusion behavior of NaCl in Japanese radish. In EW, the water swollen protein phase coexists with the dispersed liquid water phase. It is in the former phase where the diffusion rate in EW is determined via the dual mode mechanism. By applying the theory, thermodynamic diffusion coefficients, D_T(p), of the partitioned species at respective temperatures were found to be smaller than those, D_T(L), of the Langmuir sorption species. The variations of D with peaks were interpreted with these two D_T's and equilibrium parameters of the two species. The sorption isotherms of NaCl by EW were found to be slightly convex upward at low NaCl concentrations, which were successfully interpreted by considering the two phases mentioned above and the equilibrium parameters for the partitioned and Langmuir species.     

基于蓝牙技术的粮情测控方案

随着无线通讯技术的高速发展，对通讯系统的经济性、可靠性提出了越来越高的要求。就此方面考虑，基于蓝牙的基本技术特点和拓扑结构，针对蓝牙技术灵活、快速、抗干扰能力强等特点，将蓝牙技术具体应用于粮情测控。介绍了AT76C55X蓝牙模块，并给出了系统现场测控单元硬件实现框图、主机和蓝牙模块的HCI接口方式及蓝牙模块间采用文件传输剖面进行数据交换的软件实现流程图，最后指出了蓝牙技术应用的特点和优势。     

高压静电场在食品保鲜中的应用研究

从食品的保鲜期，酶活性，杀菌和结解等四个试验探讨了高压民场在食品中保鲜中的作用。