PURIFICATION OF CELLULASE FROM FUSARIUM MONILIFORME AND ITS APPLICATION TO THE PRODUCTION OF RED BEAN STARCH PRECIPITATE

To investigate the effect of cellulase on increase of recovery of red bean starch precipitate, cellulases from Fusarium moniliforme were purified and applied to the production of red bean starch precipitate. Oneã-glucosidase, two filter paper degradation enzymes (FPase), one endo-ã-glucanase (endo-Cx) and one exo-ã-glucanase (exo-Cx) were purified by ammonium sulfate fractionation, gel filtration and ion-exchange chromatography. Optimum temperature and time of submersion of red beans for reduction of hardness was 50°C and 2 h. Maximum sedimentation rate of starch was obtained when the red bean was incubated in a mixture of 0.004 units/mL of FPase and 0.3 units/mL of CMCase, and maximum recovery of red bean starch precipitate was obtained with 0.004 units/mL of FPase and 0.2 units/mL of CMCase. Enzyme treatment reduced suspended solids about 40% in waste water compared with control. A little hydrolysis in cell wall, intercellular space and interstarch granular space was observed.     

Differential Scanning Calorimetry of Fish Muscle: The Effect of Processing and Species Variation

Differential Scanning Calorimetry (DSC) has been used to study the thermal properties of fish muscle proteins and to measure the extent of their denaturation under various processing conditions. Fish myosin was susceptible to denaturation by frozen storage and dehydration. Denaturation of certain fish proteins was partially reversible. Although fish myosin was very unstable, its thermal stability was found to increase in species adapted, to higher environmental temperatures.     

CAPILLARY EXTRUSION VISCOMETER FOR THE VISCOSITY MEASUREMENT OF FISH PROTEIN PASTE

To overcome various limitations of conventional viscometers in measuring salted or unsalted surimi paste, a capillary extrusion viscometer was developed. The viscosity of surimi paste was measured as a function of moisture content (MC) (75–80%), salt content (2–4%) and liquid egg white (LEW) content (2–4%). As moisture, salt and LEW contents increased, viscosity gradually decreased. The viscosity values, as affected by MCs, showed a highly negative relationship with fracture properties of surimi gel, especially shear stress from the torsion test, indicating that MC is linearly correlated to the strength of gels at fracture. This easy and quick viscosity measurement can effectively facilitate the production control of comminuted muscle foods, including surimi paste.

PRACTICAL APPLICATIONS

There had been a difficulty to measure the exact viscosity of comminuted muscle food pastes when conventional viscometers were used. This was due to the non-linearity between dilution rates and viscosity of muscle paste, or limited range of shear rate during viscosity measurement. New developed small capillary extrusion viscometer can measure a wide range of comminuted muscle paste viscosity. When using this capillary viscometer, flow behavior of non-Newtonian surimi paste and other comminuted muscle paste can be well defined.     

ANTIOXIDANT ACTIVITIES OF ENZYMATIC EXTRACTS FROM AN EDIBLE SEAWEED SARGASSUM HORNERI USING ESR SPECTROMETRY

The antioxidant activity of water-soluble natural extracts from an edible seaweed , Sargassum horneri, was evaluated by examining the radical scavenging activities of the extracts of hydrolyzates from S. horneri on 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl and alkyl radicals. A spin-trapping electron spin resonance (ESR) spectrophotometer was employed and the results were compared for their ESR signal intensity. The brown seaweed S. horneri was enzymatically hydrolyzed to prepare water-soluble extracts by five carbohydrases (AMG, Celluclast, Termamyl, Ultraflo and Viscozyme) and five proteases (Alcalase, Flavourzyme, Kojizyme, Neutrase, Protamex). The extracts so prepared exhibited strong scavenging activity on DPPH, hydroxyl and alkyl radicals. The scavenging activity of the radicals increased with increased concentration of the extracts. The scavenging results were higher or similar for hydroxyl and alkyl radicals, and lower for DPPH radical compared with vitamin C as a reference. Viscozyme and Alcalase extracts were superior and scavenged radicals examined better than the extracts prepared by other carbohydrases and proteases.     

环氧树脂/碳化硅复合材料的热性能及韧性

采用碳化硅作为增强剂制备了环氧树脂/碳化硅复合材料,考察了复合材料的热学及力学性能。实验结果表明,碳化硅的添加使环氧树脂的玻璃化温度提高。当碳化硅添加质量分数为3%时,复合材料的韧性与纯环氧树脂相比提高了35%。     

亚临界和超临界状态下甲苯-多环芳香烃体系的气液相平衡

The phase behaviors of toluene/polycyclic aromatic hydrocarbon mixture systems were investigated with a continuous-flow type apparatus at 573.2,598.2.623.2 and 648.2K,while the pressure changed from 1 tp 5 MPa,The pseudo-binary phase behaviors were predicted with the Peng-Robinson equation of state with interaction parameters between toluene and pseudo-components considered.The phase diagrams of the system have been classified following the category of phase boundary diagram models.The extraction selectivity and efficiency of toluene as a solvent was discussed by comparing with that of hexane .The prediction model for selectivity was also suggested.     

MAGNETOTHERMAL CONVECTION OF POLYATOMIC GASES IN HOMOGENEOUS MAGNETIC FIELDS Part I: Theory

The theory of magnetothermal convection of gases in homogeneous magnetic fields is developed from magnetogas-dynamic theory. Application is made to nonionized paramagnetic and diamagnetic gases between parallel vertical plates. An additive contribution to the natural thermal convection heat transfer results from the temperature dependence of the magnetic permeability of the gas. The result may be expressed parametrically in a dimensionless magnctoconvection number, which characterizes the magnetothermal contribution to the total heat transfer just as the Grashof number characterizes the natural thermal contribution. For oxygen gas at low pressure the magnetothermal contribution is shown to be proportional to p ³ H ²(ΔT)² /ηT ⁵ where p is the gas pressure, H is the magnetic field strength, ΔT is the temperature difference between plates, η is the viscosity coefficient and T is the absolute temperature.     

A NEW TOOL FOR NUCLEATE BOILING RESEARCH

A new tool for the study of nucleate boiling heat transfer has been developed. Photographic etching was shown to be effective in the manufacture of copper lest surfaces containing precise arrays of artificial pits, with densities as high as 2742 pits/cm².

The pits were shallow segments of spheres, with depth: diameter ratios on the order of 0.1. Pit diameters were on the order of 0.003 cm. Data showed that the pits significantly affected the characteristic boiling curves and critical fluxes for the surfaces studied while boiling Freon 113 at one atmosphere pressure.

Photoetching can be used in the future to produce a wide variety of test surface textures or site arrays. Careful control of such surface conditions may well lead to a better understanding of the nucleate boiling phenomena.     

旋转浓缩-蓄热氧化法处理涂装废气的中试研究

用旋转浓缩-蓄热氧化(RC-RTO)系统对某车轮厂涂装废气进行了中试处理研究,以废气处理前后总挥发性有机物(T-VOCs)浓度及苯、甲苯、乙苯、对二甲苯、邻二甲苯浓度的变化为指标,考察了RC转速对吸附性能、RTO氧化效果的影响.结果表明,RC转速对吸附效果及进入RTO单元浓缩气体中VOCs浓度有较大的影响,RC转速过高或过低均不利于系统稳定高效的运行.系统在RC转速为3r/h的条件下连续运行1个月,期间系统不需外加能源即可维持热量平衡,且RC单元及RTO单元排气中5种VOC物质浓度均远低于国家规定的排放标准(GB16297-1996).