Life Sciences Commons^™

A Method For Light And Scanning Microscopy Of Drought-Induced Damage Of Resting Peanut Seed Tissue, Clyde T. Young, William E. Schadel

Food Structure

Tissue damage creates numerous problems for the microscopic examination of resting peanut (Arachis hypogaea L. cv . Florunner) seed physical structure. This paper presents a method to deal with specific problems encountered in light microscopy (LM) and scanning electron microscopy (SEM) of drought - induced damage of peanut tissue . Major findings include: (1) improved SEM imaging through reduction of charging by increasing coating thickness from 25 nm to 30 nm; (2) improved stain affinity for LM tissue preparations by decreasing osmium tetroxide fixation time from 2 hours to 1 hour; and (3) im proved tissue fixation for LM and …

Fluorescence Microscopy Studies On (1,3) - B-D-Glucan In Barley Endosperm, A. W. Macgregor, G. M. Ballance, L. Dushnicky

Food Structure

Development of (1,3;1,4)-B-D-glucan and (1,3)-B-D-glucan in kernels of Himalaya and Bonanza barley has been followed by fluorescence microscopy using calcofluor and aniline blue fluorochromes. Specific enzymes were used to confirm the identity of these two polysaccharides in sections of endosperm tissue. All barley lines tested contained both types of B-glucan but (1,3;1,4)-B-glucan was synthesized at an earlier stage of development than was (1,3)-BGlucan. Small bead-like deposits of (1,3)-B-glucan were detected in all cultivars examined. These deposits were present throughout the endosperm and appeared to be associated with the inner walls of endosperm cells. After treatment of sections with (1,3)-B-glucanase, these …

Microstructural Changes In Wheat Starch Dispersions During Heating And Cooling, M. Langton, A. M. Hermansson

Food Structure

Microstructural changes in 8-11% wheat starch dispersions during heating, cooling and cold storage have been evaluated by light microscopy and scanning electron microscopy.

Heat treatment of wheat starch dispersions gives rise to two stages of swelling and solubilization. During the first phase of swelling, solubilized amylose was observed ln the centre of the granules and, to some extent, outside the granules. Further swelling deformed the granules and more amylose was released. When the temperature treatment took place under shear, the outer layer of the swo llen granules fra ctured at 94°C and above, and amylopectin fragments were dispersed into the …

The Structural Basis Of The Water-Holding, Appearance And Toughness Of Meat And Meat Products, Gerald Offer, Peter Knight, Robin Jeacocke, Richard Almond, Tony Cousins, John Elsey, Nick Parsons, Alan Sharp, Roger Starr, Peter Purslow

Food Structure

A structural approach greatly clarifies which components of meat are responsible for its tenderness, water-holding and appearance, and the events occurring during processing.

In living muscle, water is held in the spaces between the thick and thin filaments. Changes in the content and distribution of water within meat originate from changes in this spacing. Myofibrils shrink laterally post mortem . The fluid expelled accumulates between fibre bundles and between fibres and is drain ed by gravity forming drip. In pale, soft and exudative meat, shrinkage of the myosin heads on denaturation increases myofibrillar shrinkage. In salt solutions used in meat …