Protein-Protein Interactions Between Soybean Beta-conglycinin (B1-B6) and Myosin

Protein-protein interactions between soybean beta-conglycinin (B₁- B₆) and myosin were studied by turbidity, solubility and SDS-poly- acrylamide gel electrophoresis (SDS-PAGE) analysis. Turbidity and solubility studies showed that, under the experimental conditions used, these proteins interacted at temperatures between 60° and 100°C, while SDS-PAGE analysis indicated that the interaction also occurred at 50°C. The interasction was such that no detectable complexing between these two proteins was observed. The presence of beta-conglycinin resulted in diminished aggregations of myosin heavy chains between 50° and 100°C.     

Forming Process of Strong Anisotropic Material Based on the Hydrodynamic Deep Drawing with Radial Pressure

1.IntroductionA sketch of the conventional hydrodynamic deepdrawing(HDD)process is shown in Fig.1(a)[1~5].Ini-tially,the flange of the blank is in contact with the drawdie.When the punch is moved down,the liquid pres-sure in the die cavity increases and when the pressurereaches a certain magnitude,the flange is lifted from thedraw die and the liquid starts to flow out through thegap between the draw die and the flange[6~9].In FEMsimulation of the conventional HDD,it is very difficult todet…     

Influence of Atmospheric Oxygen Content on Growth and Fumitremorgin Production by a Heat-resistant Mold, Neosartorya fischeri

Growth and fumitremorgin production by a heat-resistant mold, Neosartorya fischeri, in atmospheres containing 0.0095-20.9% O₂ were studied over a 38-day period. The mold was cultured on Czapek Yeast Autolysate agar adjusted to pH 3.5 and 7.0 and incubated at 25°C in darkness. Colonies were examined and extracts were analyzed for fumitremorgin content using high performance liquid chromatography. Growth occurred at O₂ levels as low as 0.10% but not at 0.0095%. Growth was always associated with production of verruculogen and fumitremorgins A and C. Production of these fumitremorgins was essentially the same in atmospheres containing 3.0 and 20.9% O₂, but was greatly reduced in an atmosphere containing 1.0 and 0.10% O₂. Fumitremorgin production was not significantly different at pH 3.5 and 7.0     

Relationships between microstructure,fracture–surface morphology,and mechanical properties in ethylene and propylene polymers and copolymers

The fracturing of four different polyolefin materials (a polypropylene homopolymer, a propylene–ethylene copolymer, a polyethylene homopolymer, and an ethylene–hexene copolymer) was studied with the objective of developing a better understanding of the relationships between the morphology of semicrystalline polymers, the morphology and growth kinetics of their fracture surfaces, and their mechanical properties. A scanning electron microscope and an optical microscope were used to obtain images of the fracture surfaces. The samples were injection‐molded or hot‐pressed to generate different microstructures. Fracture experiments were performed at 23, 0, and −20°C to generate fracture surfaces with different morphologies from the same supermolecular structure. It appears that the fracture propagates through the spherulites in a brittle manner. The macroscopic aspect of the fracture surfaces is temperature‐independent and changes are visible only at the microscopic scale. Over the range of temperatures studied, the rms roughness [root mean square roughness decreased by only about 20%, while the fracture energy of all but one of the materials (a high‐density ethylene–hexene copolymer) decreased by about 60% as the temperature was reduced. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2370–2382, 2000     

Effect of Lenient Steam Injection (LSI) heat treatment of bovine milk on the activities of some enzymes,the milk fat globule and pH

This study investigated the effects of Lenient Steam Injection (LSI) treatment at temperatures 70–150 °C on the enzymatic activities of the indigenous milk enzymes alkaline phosphatase, lactoperoxidase (LPO), xanthine oxidase (XO), lipoprotein lipase (LPL) and plasmin in comparison with two reference heat treatments of 63 °C for 30 s and of 72 °C for 15 s by indirect heating. Milk fat globule (MFG) size distributions and pH were also monitored. Alkaline phosphatase, LPO, XO and LPL activities decreased with increasing LSI temperature. Plasmin activity was increased at temperatures <80 °C and decreased at temperatures above 90 °C. Milk fat globule homogenisation was observed at temperatures above 110–130 °C.     

Elimination of impurities from the surface of silicon using hydrochloric and nitric acid

Acid leaching of silicon is insufficient in order to achieve solar grade silicon. Leaching of silicon previously purified by the copper gathering method can significantly reduce amount of impurities congregated in the Cu–Si intermetallic phase during solidification process. Two samples of 50 wt% Cu–50 wt% Si alloy were solidified at 0.5 and 1.0 °C/min cooling rate. They were treated with 10 vol% HNO₃ and 5 vol% HCl and 7 vol% HNO₃. The inductively Coupled Plasma Mass Spectrometry technique was employed to measure traces of impurities before and after the treatment. It was determined that the overall impurity level in purified silicon was reduced from 5277 ppm_wt to 225.5 ppm_wt. The samples cooled at 0.5 °C/min achieved lower impurities levels in all instances while the sample leached with 10% HNO₃ produced the greatest reduction in impurity level. Scanning electron microscopy and Energy Dispersive X-Ray Spectroscopy analysis showed that the traces of Cu–Si intermetallic together with gathered impurities can be found only in the large silicon particles after the acid leaching treatment. In all instances, the surface of the silicon particles was free of impurities while Si yield was preserved at above 97%.     

Low Frequency Ultrasonics for Texture Measurements in Cooked Carrots (Daucus carota L.)

The use of low frequency ultrasound for texture evaluation of carrots cooked at 100°C for 0 to 15 min was examined. Uniaxial compression, microscopy and analyses of density and dry matter were used to provide comparative results for evaluating relationships between texture and ultrasonic parameters. During the first minutes of cooking the sound velocity (v) decreased and a positive correlation was found between compressive Young's modulus (E_cy) and sound velocity (v). During extended heating, sound velocity (v) increased and attenuation (α) decreased as a result of changes in mechanical properties and air and water content of the tissue.     

Reversibility of the Hard-to-Cook Defect in Dry Beans (Phaseolus vulgaris) and Cowpeas (Vigna unguiculata)

The hard-to-cook defect, assumed to be a permanent condition in legume seeds, can be reversed. Dry beans (Phaseolus vulgaris) and cowpeas (Vigna unguiculata) which had developed the hard-to-cook defect when stored at 29°C, 65% RH had progressively shorter cooking times after additional storage at 6.5°C, 71% RH. This would suggest that the mechanism(s) leading to development of the defect should be easily reversed. The ability to reverse the hard-to-cook defect in legume seeds would provide several economic and nutritional benefits.