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Structural Matrix (structural + matrix)
Selected AbstractsSpecial decompositions for eigenproblems in structural mechanicsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING, Issue 9 2006A. Kaveh Abstract The main objective of this paper is to study those matrices which can be written as the sum of two Kronecker products. Special decompositions are proposed. Applications are extended to the eigensolution of problems from structural mechanics. It is also shown how the analysis of structures can be performed without finding the inverse of the structural matrices. Copyright © 2006 John Wiley & Sons, Ltd. [source] Moisture adsorption by milk whey protein filmsINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 3 2002C. M. P. Yoshida Edible films, using whey protein as the structural matrix, were tested for water vapour diffusion properties. Whey protein films were prepared by dispersing 6.5% whey protein concentrate (WPC) in distilled water with pH kept at 7.0. Glycerol was the plasticizer agent. Film slabs (13.5 × 3.5 cm) were put in a chamber at 25 °C and 75% relative humidity, being held in vertical planes for different periods of time. The mass gain was determined throughout the experiment. We show that moisture adsorption by milk whey protein films is well described by a linear diffusion equation model. After an adsorption experiment was performed the solution of the diffusion equation was fitted to the data to determine the diffusion coefficient of the material. [source] Transglutaminase Catalysis of Modified Whey Protein DispersionsJOURNAL OF FOOD SCIENCE, Issue 4 2010Debra A. Clare ABSTRACT:, Transglutaminase (TGase) cross-linking reactions were accomplished using a heat-modified whey protein concentrate (mWPC) substrate after pH adjustment to 8. Based on earlier reports, the degree of lactosylation with respect to ,-lactoglobulin was lower in mWPC dispersions than measured in commercial whey concentrate (cWPC) protein solutions. In this study, a higher concentration of free sulfhydryl groups was detected in soluble supernatant fractions. Both factors potentially impact the availability of reactive lysine/glutaminyl residues required for TGase reactivity. The addition of 10 mM dithiothreitol (DTT) to the substrate mix, CBZ-glutaminyl glycine and hydroxylamine, revealed a 3.6-fold increase in TGase activity, likely due in part to maintenance of the catalytic cysteine residue in a reduced state. Furthermore, inclusion of DTT to mWPC dispersions significantly raised the apparent viscosity, independently of enzyme modification, while the rate of polymerization increased 2-fold based on OPA assay measurements. Limited cross-linking slightly increased the apparent viscosity, whereas extensive coupling lowered these values compared to equivalent nonenzyme-treated mWPC samples. Carbohydrate-staining revealed formation of glyco-polymers due to covalent linkages between glucosamine and mWPC proteins after TGase processing. Again, the apparent viscosity decreased after extensive enzymatic modification. Larger particles, sized 11.28 ,m, were observed in the structural matrix of TGase-mWPC-fixed samples compared to 8 ,m particles in control mWPC samples as viewed in scanning electron micrographs. Ultimately, the functional characteristics of TGase-mWPC ingredients may be custom-designed to deliver alternative functional attributes by adjusting the experimental reaction conditions under which catalysis is achieved. Practical Application: Taken together, these results suggest that unique TGase-mWPC and/or TGase-mWPC-glucosamine ingredients may be designed to provide novel, value-added, polymeric/glyco-polymeric protein products that afford added benefit for the milk industry. [source] The linkage between cell wall metabolism and fruit softening: looking to the futureJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 8 2007Ariel R Vicente Abstract The softening that accompanies ripening of commercially important fruits exacerbates damage incurred during shipping and handling and increases pathogen susceptibility. Thus, postharvest biologists have studied fruit softening to identify ways to manage ripening and optimise fruit quality. Studies, generally based on the premise that cell wall polysaccharide breakdown causes ripening-associated softening, have not provided the insights needed to genetically engineer, or selectively breed for, fruits whose softening can be adequately controlled. Herein it is argued that a more holistic view of fruit softening is required. Polysaccharide metabolism is undoubtedly important, but understanding this requires a full appreciation of wall structure and how wall components interact to provide strength. Consideration must be given to wall assembly as well as to wall disassembly. Furthermore, the apoplast must be considered as a developmentally and biochemically distinct, dynamic ,compartment', not just the location of the cell wall structural matrix. New analytical approaches for enhancing the ability to understand wall structure and metabolism are discussed. Fruit cells regulate their turgor pressure as well as cell wall integrity as they ripen, and it is proposed that future studies of fruit softening should include attempts to understand the bases of cell- and tissue-level turgor regulation if the goal of optimising softening control is to be reached. Finally, recent studies show that cell wall breakdown provides sugar substrates that fuel other important cellular pathways and processes. These connections must be explored so that optimisation of softening does not lead to decreases in other aspects of fruit quality. Copyright © 2007 Society of Chemical Industry [source] | ||||||||||