Life Sciences Commons^™

Soluble And Insoluble Dietary Fiber In Cooked Common Bean (Phaseolus Vulgaris) Seeds, Joe S. Hughes, Barry G. Swanson

Food Structure

The common bean (Phaseolus vulgaris) requires cooking for extended periods of time prior to consumption. In this investigation both quantitative and microstructural changes in common bean dietary fiber as a result of cooking were examined. Cooking resulted in a slight decrease in soluble dietary fiber and a marked increase in insoluble dietary fiber. The increase in insoluble dietary fiber was responsible for a 15 -30 percent increase in total dietary fiber.

Scanning electron microscopy was used to examine the microstructure of uncooked and cooked bean flours and the insoluble and soluble dietary fiber fractions of these two fl ours. In …

Heat-Set Gels Based On Oil/Water Emulsions: An Application Of Whey Protein Functionality, R. Jost, F. Dannenberg, J. Rosset

Food Structure

The microstructure of portein/lipid gels produced by heat treatment of whey protein stabilized oil-in-water(O/W) emulsions was studied. Scanning electron microscopy as well as transmission electron microscopy was performed on glutaraldehyde/osmium tetroxide fixed, and critical point-dried samples. Microstructure analysis showed that in the case of homogenized O/W emulsions, extensive coating of the fat globule surface with coagulated protein led to a "cauliflower - like" structure. In such gels, uncoated fat globules having smooth surfaces were not present. This specific microstructure was not obtained with protein/lipid gels in which whey protein was added in the continuous phase and mixed with a O/W …

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 …

Rheology And Microstructure Of Strained Yoghurt (Labneh) Made From Cow's Milk By Three Different Methods, A. Y. Tamime, M. Kalab, G. Davies

Food Structure

Labneh is the name for strained yoghurt, i.e., yoghurt made with an elevated solids content, which has originated in the Middle East. For this study , three types of Labneh were made from cow' s milk: (a) "Traditional Labneh" was produced by straining yoghurt in a cloth bag, (b) "UF Labneh" was made by ultrafiltration of warm yoghurt , and , (c) "UF Retentate Labneh" was obtained by culturing homogenised ultrafiltration (UF) milk retentate. A 11 products were passed through a lactic curd homogen is er to smoothen the Labneh curd . Total solids contents of t he products were …

Structural Characteristics Of Pennisetum Americanum (Pearl Millet) Using Scanning Electron And Fluorescence Microscopy, C. M. Mcdonough, L. W. Rooney

Food Structure

Fluorescence bright field and scanning electron microscopy were used to characterize the structure of selected mature pearl millet caryopses from the World Germplasm Collection. Kernel shape (globose, lanceolate, obovate and hexagonal). kernel endosperm color (while. yellow and grey) and external appearance (color) of the samples were documented for 96 varieties. Color of the pearl millet kernel was due to the combined effects of pigmentation in the pericarp. aleurone and endosperm. as well as the pericarp thickness. White kernels had few pigmented areas. yellow kernels had pigments primarily in the epicarp and endosperm. and brown kernels had pigments in the epicarp. …

Influence Of The Extrusion Process On Characteristics And Structure Of Pasta, M. Ambrogina Pagani, Plerpaolo Resmini, Gerardo Dalbon

Food Structure

The effects of the kneading and forming process or pasta quality have been investigated. Using the same blend of wheat flour and keeping mixing and drying conditions constant, three types of spaghetti were produced using the following three kneading and forming processes: A) kneading with a continuous press and forming by pressure-extrusion; B) kneading and forming by sheeting-rolls; C) kneading by hand and forming with sheeting-rolls. These three processes impart different mechanical work on the dough.

The three types of dried spaghetti exhibited differences in cooking requirements and in cooing quality. Spaghetti (A) absorbed water more slowly and showed poor …

Composition And Some Properties Of Spray-Dried Retentates Obtained By The Ultrafiltration Of Milk, Miloslav Kalab, Marijana Caric, Mansour Zaher, V. R. Harwalkar

Food Structure

Retentates containing 20, 27, and 34% total solids, obtained on commercial scale by the ultrafiltration of milk were spray-dried on laboratory scale using centrifugal atomization and single stage drying with the inlet air temperature of 220 C and the outlet air temperature of 90 C.

The protein content in the powders was 31% to 35% compared to 24.8% protein in the control whole-milk powder. Lactose contents were markedly lower in the retentate powders (-10.6%) than in the milk powder (40.4%). Storage of the powders at 37 C resulted in a marked increase in the 5-hydroxmethylfural contents with doubling of this …

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 …