Inhomogeneous plastic flow investigated by X-ray absorption microtomography of an aluminium alloy containing marker particles

By combining a synchrotron X‐ray source and the microtomography technique, the displacement gradient tensor components can be measured directly throughout the volume of a metal sample containing highly absorbing marker particles to detect material flow. The present article describes application of these techniques to compression of a rectangular Al–W specimen with a central hole. The results show that the externally imposed axial displacement gradient is accommodated mainly in two 45° shear bands passing through the hole. A simple deformation analysis provides insight into shear band formation.     

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…     

THE EFFECTS OF THERMAL AND NONTHERMAL PROCESSING METHODS ON APPLE CIDER QUALITY AND CONSUMER ACCEPTABILITY

Due to increased concern about the safety of fruit, vegetable and juice products, the FDA has mandated that these must undergo a 5‐log reduction in pathogens. The development of various processing methods for juice products has caused the need to determine the effects of these methods on said products. The effect of thermal pasteurization, UV irradiation and ozone treatment on apple cider quality and consumer acceptability was studied over 21 days. Thermally pasteurized samples were different in color and less preferred in all areas of consumer acceptability. UV‐irradiated samples were lower in soluble solids for the first 7 days and showed no significant difference in consumer acceptability. Ozone‐treated cider had greater sedimentation, lower sucrose content and a decrease in soluble solids by day 21. UV irradiation allows for a more cost‐effective method to produce safe apple cider with minimal quality and consumer acceptability differences.     

Influence of cephalosporins on the coagulation time of yogurt made from ewes’ milk

Ceftiofur and cephalexin were independently added to ewes’ milk at three different concentrations 50, 100 and 150 µg/kg. Spiked milk was used to produce yogurt and the acidification of the yogurt during incubation was then studied. Ceftiofur showed significant delays in the pH decrease rate at all concentrations assayed, but no significant delays occurred with cephalexin. When these antibiotics were administered intramuscularly to lactating ewes, from which the milk was used to make yogurt immediately after the corresponding withdrawal periods, absence of residues and pH delays were not observed during the yogurt fermentation in the presence of any antibiotic.     

Availability of Soybean Hull Iron Fed to Humans in a Mixed, Western Meal

Century soybeans were grown in a greenhouse and labeled by stem injection of iron-59. The intrinsically labled soybean hulls were incorporated into bread rolls and fed in mixed meals containing beef to six free-living female volunteers. Iron-59 retention, measured by whole body counting of these volunteers, was compared with retention from similar meals containing extrinsically labeled soybean hulls or bakery grade ferrous sulfate. Iron-59 retention averaged 23% from meals containing the intrinsically labeled soybean hulls, 18% from meals containing extrinsically labeled soybean hulls, and 22% from meals containing bakery grade ferrous sulfate. There were no statistically significant differences in retention among the various iron sources, indicating that soybean hulls were an excellent source of iron for bread enrichment.     

LIQUID HOLDING CAPACITY AND INSTRUMENTAL AND SENSORY TEXTURE PROPERTIES OF HERRING (CLUPEA HARENGUS L.) RELATED TO BIOLOGICAL AND CHEMICAL PARAMETERS

Instrumental texture measurements done on raw herring fillets only partly describe the sensory texture of marinated herring fillets. Sensory texture parameters of marinated fillets were related to instrumental texture measurements of raw fillets by three different data analysis approaches. Uniaxial compression measurements were used as a single parameter, as compression curves or fitted to polynomials. Data from all three methods were related to sensory firmness (r = 0.310–0.366, P < 0.05). Elasticity could be predicted from the maximum compression force (r = 0.181, P < 0.05). The compression curve contained information correlating with all the measured sensory texture parameters (r = 0.102–0.310, P < 0.05), while the fitted polynomials, in addition to firmness, could predict fatty mouthfeel (r = 0.201, P < 0.05). The most information about the sensory texture was obtained from the compression curves. This study shows that the texture properties of herring are highly intercorrelated and can be regarded as a multivariate complex of parameters. The liquid holding capacity (LHC), defined as the moisture held after a low centrifuge speed expressible moisture measurement, and the texture of herring are influenced by a variety of factors, e.g., spawning time of year, gonad maturity, body size, age and lipid content (P < 0.05). Increases in body weight, age and lipid content are intercorrelated and result in marinated fillets being more firm, elastic, juicy and fatty. Decreases in these factors will give marinated fillets that are perceived to be gritty and with low intensities of firmness, elasticity, juiciness and fatty mouthfeel.     

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.     

Changes of Selected Physical and Chemical Components in the Development of the Hard-to-Cook Bean Defect

The effects of storage temperature and humidity were monitored on several physical and chemical components of cowpeas and beans. Seeds stored at 29°C, 65% RH required prolonged cooking times; however, seeds stored in other conditions (5°C, 30% RH; 29°C 30% RH; and 5°C, 65% RH) maintained short, stable cooking times throughout storage. As cooking time increased, phytate, phytase activity, amylose solubility, high methoxyl pectin and protein solubility decreased. Solids leached during soaking and low methoxyl pectin increased as cooking time increased. These results were consistent with the proposed theory that the hard-to-cook defect involves interactions between phytate, minerals, and pectin. However, they did not eliminate possible roles of starch and protein solubility.     

COMPARISON OF INVERTASE AND PECTINESTERASE INACTIVATION IN PROCESSED TOMATO PULP1

The heat stability of pectinesterase (PE) and invertase in tomato pulp was investigated to examine the feasibility of using invertase inactivation to predict pectinesterase inactivation. Both invertase and PE were inactivated at 80C in macerated tomato pulp. Between temperatures of 65C to 75C invertase was less heat stable than PE. Results indicate that when temperatures above 80C are reached, almost instantaneously, it would be feasible to use invertase activity as measured by sucrose level to predict PE activity.