Food Science Commons^™

Thermal Processing Effects On Rice Characteristics, Shuh-Ming Chang, Hsiu-Chen Yang

Food Structure

Whole kernels of four cultivars of milled rice were treated under different conditions according to our traditional methods such as boiling, steaming, autoclaving or roasting with sand. During the vari ous processing conditions, the moisture contents of the kernel , heating temperatures, pressures and heating times were varied. In this paper, the physicochemical properties of those processed samples were investigated and compared.

Based on degree of gelatinization , water absorption index , water solubility index , swelling power, viscoamylograms and X-ray diffraction patterns, the propenies of waxy rice samples arc different from that of non -waxy rice samples. They are …

Summer Salad Recipes, Utah State University Extension

All Archived Publications

No abstract provided.

A Moving Optical Fibre Technique For Structure Analysis Of Heterogeneous Products: Application To Different Foodstuffs, J. C. Akkerman, C. G. J. Bisperink, A. D. Ronteltap

Food Structure

The macro structure of many soft heterogeneous products can be studied by a moving optical fibre technique . The method i s based upon an optical sensor that penetrates into the heterogeneous medium. The optical sensor discriminates between materials differing in refractive index or in scattering properties. Coupling of the signal of the optical sensor to its position reveals the spatial distribution of the materials in the product. Applications shown include bread, soft ice-cream, chocolate mousse and draining curd. The major advantages of the method are its speed and ease; moreover, the sample is hardly disturbed by the sensor. The …

Objective Measurement Of The Visual Aspect Of Dry Sausage Slices By Image Analysis, A-C. Roudot, F. Duprat, M.-G. Grotte, G. O'Lidha

Food Structure

The visual aspect of food is a problem very often neglected for different reasons; one being the difficulty of modelling vision. However, it has been shown that , on simple synthetic images, automatic sorting in the same manner as human vision is possible.

Distribution heterogeneity of spots within an image is one important parameter for its characterization. A new algorithm was tested over simple numerical pictures that gave good agreement with visual appreciation. Images of twenty dry sausage slices were analyzed and different factors corresponding to aspect structure were calculated. Principal component analyst:s based on these factors all owed discrimination …

Effects Of Processing On The Microstructure Of Oat (Avena Sativa) Bran Concentrate And The Physicochemical Properties Of Isolated B-Glucans, K. Autio, Y. Malkki, T. Virtanen

Food Structure

Fluorescence microscopy was used to study the microstructure of oat cell walls during concentration of oat bran and isolation of ,B-glucans. The bran concentrate separated from c.v. Nasta contained mainly the aleurone and subaleurone endosperm layers, whereas that separated from a commercial bran mixture contained more endosperm . In contrast to Nasta, the commercial bran mixture contained ,B-glucan degrading enzymes, which survived the ,B-glucan isolation procedure. In the presence of enzymes, the solubility and yield of ,B-glucans improved but the viscosity decreased when it was measured at the same ,B-glucan concentration. For inactivation of the enzymes, 80% ethanol at 78 …

Structure And Rheology Of String Cheese, S. Taneya, T. Izutsu, T. Kimura, T. Shioya

Food Structure

String cheese samples ranging in pH from 5.0 to 5.9 were prepared by kneading Mozzarella curd and stretching it 2 to 80 times. Rheological properties were examined by compression, stress relaxation , and flow property tests. Stringiness was tested by a device specifically designed for this purpose: a standardized string was pulled from the sample at a direction perpendicular to the orientation of the curd and the amount of fibres resulting from this process was quantitated using digital image analysis.

Force-deformation curves implied that the curd prepared by kneading may be considered to be an incompressible viscoelastic body similar to …

Computer Modeling: The Adjunct Micro Technique For Lipids, J. W. Hagemann, J. A. Rothfus

Food Structure

Chemistry by computer provides access to microsystem information not readily achieved by other means. Simple computational analysis of saturated triglyceride polymorphism by molecular mechanics within constraints provided by X-ray data show that polymethylene interactions determine hydrocarbon crystal properties when they account for more than 60 percent of the total molecular interaction energy. Modeling predicts multiple , nearly equivalent, a -form triglycerides and a -form character in liquid near-crystalline triglycerides. Symmetrical molecules pack better than asymmetric molecules in a-form configurations and transform readily to 13'forms if activated sufficiently to disrupt lateral chain interaction and allow dimensional displacements during transformation. The formation …

Microstructure And Texture Of Khoa, G. R. Patil, A. A. Patel, Paula Allan-Wojtas, Miloslav Kalab

Food Structure

Khoa, a partially dehydrated milk product indigenous to India, was prepared from buffalo milk by boiling it vigorously in an open pan and reducing its volume to approximately 25% within 30 min. The hot semi-solid product (Khoa pat) was held at 20•c for 3 h (fresh, cooled Khoa) or 48 h (swred Khoa); the products were either worked with a pestle in a mortar for 5 min or were left without working.

Structural features of Khoa were studied by light microscopy and electron microscopy. Freshly prepared coo led Khoa had a granular structure consisting of protein granules several hundred micrometers …

Importance Of Enzymes To Value-Added Quality Of Foods, J. R. Whitaker

Food Structure

New uses of enzymes are of major importance for value-added quality of foods. At the production and postharvest handling levels, enzymes associated with maturation , color , texture, flavor and nutritional changes are important. Recent examples are discussed which include longer storage prior to initiation of ripening , deletion or control of genes that result in softening1 browning and other quality defects and the enhancement of genes that improve the nutritional quality of foods. At the processing level, new uses of enzymes are described to change the properties of proteins and lipids , to eliminate off-flavor in beers and sterilized …

Light Microscopy Measurements Of Ice Recrystallization In Frozen Corn Starch Pastes Using Isothermal Freeze Fixation, C. Ferrero, M. N. Martino, N. E. Zaritzky

Food Structure

Isothermal freeze fixation was used to analyze ice recrystallization by light microscopy in a 10 % (W/W) frozen corn starch paste during storage at temperatures in the range of -5 to -20 °C.

Different formulations were tested in order to obtain a suitable fixative for this method of indirect observation of the ice crystals. A solution of formaldehyde, ethanol and water (10:45:45 V:V) was selected because it minimized substitution-induced distortion and contraction of the matrix. The diffusion coefficients of the selected fixative in the frozen system were measured at different temperatures in conditions of unidirectional mass transfer in a semi …

Scanning Electron Microscopy And Ultraviolet Absorption Microspectrophotometry Of Plant Cell Types Of Different Biodegradabilities, D. E. Akin, L. L. Rigsby

Food Structure

Phenolic components within cell walls are the greatest limitation to biodegradation of plants, but the location and types of compounds within specific walls are poorly understood . Leaf blades of warm-season (Coastal and Coastcross-1 bermuda grasses and sudangrass) and cool-season grasses (orchardgrass and tall fescue) and leaflets of legumes (alfalfa and lespedeza) were evaluated before and after incubation with rumen microorganisms for 7 days to determine cell types and wall structures most resistant to biodegradation. UV absorption microspectrophotometry was used to characterize aromatics within selected undegraded cell types, which had been shown in digestion studies to vary in biodegradability, from …

Heat-Induced Structural Changes In Acid-Modified Barley Starch Dispersions, K. Autio, K. Poutanen, T. Suortti, E. Pessa

Food Structure

The effect of heat treatment on the gel formation and microstructure of barley starch dispersions , hydrolyzed with I M HCI for 0.5, 1.0 and 4.0 hours , was studied by dynamic viscoelastic methods and by light microscopy . The effects of acid hydrolysis on the molecular weight of amylopectin and amylose were studied by high -performance liquid chromatography (HPLC) with post-column iodine staining.

Microstructural studies of 8% hydrolyzed barley starch dispersions heated to 90 0 C showed that even a short acid treatment induced considerable changes in the granule structure. The molecular weight of amylopectin decreased substantially. As the …

Effect Of Ionizing Y-Radiation On Thermoluminescence And Electron Spin Rosonance Intensities In Milk Protein Concentrate Powders, J. Kispeter, L. I. Horvath, L. I. Kiss

Food Structure

Milk protein concentrate powder has found a wide application as a food ingredient. We investigated the effects of ionizing ')'-radiation at doses ranging from 2 to 20 kGy on electron spin resonance and thermoluminescence intensities in samples of milk protein concentrate powder with varying protein contents (36-73 %wt), containing addltional Fe++ ions (12-910 ppm) and stored under different conditions.

Electron spin resonance and thermoluminescence intensities increased unambiguously with absorbed -ydose. Added Fe++ ions showed a quenching effect as measured by both methods. Storage conditions affected strongly the decay of electron spin resonance signal intensity . Lineshape analysis of thermoluminescence curves …

Structure Of Margarines Made With Low Erucic Acid Rapeseed Oil, J. Hojerova, S. Schmidt, J. Krempasky

Food Structure

Margarine based on hydrogenated low erucic acid rapeseed oil shows a strong tendency to produce an unacceptable grainy structure. This is caused by rapid transition of the B-form into the B-form of fat crystals. Sorbitan esters, monoacylglycerols, and a blend of acylglycerols were investigated as possible B-stabilizers. Polymorphic transitions were evaluated by visual assessment, examination by polarized light microscopy, and x-ray diffraction analysis in margarines prepared on a laboratory scale and containing varying amounts of stabilizers. The evaluation was extended over a 7-week period of storage at 10 C. Sorbitan esters of fatty acids were found to be the most …

Microstructural Differences Among Adzuki Bean (Vigna Angularis) Cultivars, Anup Engquist, Barry G. Swanson

Food Structure

Scanning electron microscopy (SEM) was used to study microstructural differences among five adzuki bean cultivars: Erimo, Express, Hatsune, Takara and VBSC. Seed coat surfaces showed different patterns of cracks, pits and deposits . Cross-sections of the seed coats revealed well organized layers of elongated palisade cells followed by many layers of amorphous parenchyma cells. Typical sub-epidermal layers of organized columnar, hour-glass cells were characteristica11y absent in the five cultivars of adzuki beans. The cross-sections of the cotyledons revealed intercellular materials between storage cells. Storage cells in Hatsune cultivar were loosely packed with many intercellular spaces as compared to the other …

Scanning Electron Microscopy Structure And Firmness Of Papain Treated Apple Slices, Yaguang Luo, Max E. Patterson, Barry G. Swanson

Food Structure

'Mcintosh' apple (Malus domesrica Borkh.) slices were treated with papain. Textural changes were recorded with an Instron Universal Testing Machine. Structural changes and distribution of microorganisms in apple tissues after treatment were observed with a scanning electron microscope (SEM). Apple slices submerg ed in a 1% papain solution were significantly firmer than apple slices submerged in the distilled water control for a 24 hour period (P < 0.05). Three and four days after slicing , a significantly smaller decay index was observed on the apple slices submerged in papain solution than on the control slices. Under SEM, less severe cell wall breakdown was observed on the apple tissues treated with papain than on apple tissues without treatment. Less spores were also observed on the papain treated apple slices than apple slices without treatment. Apple tissues treated with papain solution and distilled water also demonstrated noticeable st ru ctural differences. The apple tissues treated with papain solution for 18 hours retained the original cell structure while the cells in the apple tissues treated with distilled water collapsed.

A Moving Optical Fibre Technique For Structure Analysis Of Heterogenous Products: Application To The Determination Of The Bubble-Size Distribution In Liquid Foams, C. G. J. Bisperink, J. C. Akkerman, A. Prins, A. D. Ronteltap

Food Structure

The bubble-size distribution in liquid foams measured as a function of time can be used to distinguish between the physical processes that determine the breakdown of foams. A new method based on an optical fibre technique was developed to measure various foam characteristics e.g. the rate of drainage, the rate of foam collapse, the change in gas fraction, interbubble gas diffusion (disproportionation) and the evolution of the bubble - size distribution during the ageing of the foam. The method consists of an optical sensor that can distinguish between phases with distinct refractive indexes as are found in liquid foams.

Ingredient Substitution, Georgia C. Lauritzen

All Archived Publications

No abstract provided.

Whole Kernel And Bulgur Wheat Preparation And Usage, Georgia C. Lauritzen, Charlotte P. Brennand, Deloy G. Hendricks

All Archived Publications

No abstract provided.

Storage Of Dry Milk, Charlotte P. Brennand

All Archived Publications

No abstract provided.

What Is Protein, Georgia C. Lauritzen

All Archived Publications

No abstract provided.

Reduced Sugar And Sugar-Free Food Preservation, Georgia C. Lauritzen

All Archived Publications

No abstract provided.

Asparagus, Alvin R. Hamson

All Archived Publications

No abstract provided.

Cauliflower, Alvin R. Hamson

All Archived Publications

No abstract provided.

Broccoli, Alvin R. Hamson

All Archived Publications

No abstract provided.

Elderberries, Georgia C. Lauritzen, Carl M. Johnson

All Archived Publications

No abstract provided.

How To Turn Your Kitchen Into A Lab, Charlotte P. Brennand

All Archived Publications

No abstract provided.

Can Antibiotic Test Kits Be Useful?, Bart Weimer

All Archived Publications

No abstract provided.

A Low-Temperature Scanning Electron Microscopy Study Of Ice Cream. I Techniques And General Microstructure, K. B. Caldwell, H. D. Goff, D. W. Stanley

Food Structure

The objective of this study was to investigate techniques suitable for viewing the microstructure of ice cream in the frozen and fully hydrated state using low temperature scanning electron microscopy (L T-SEM), and to examine the microstructure of the frozen product. lee cream bad four distinct structural phases: ice crystals, air bubbles, fat globules and serum. Air bubbles, 10 to 60 ~-tm in diameter, were lined with fat globules, 0.5 to 2.5 J.tnl in diameter. Ice cry stals with a mean di ameter of 40 J.Lffi showed a characteri stic reticulat e structure after sublimation. The appearance of the ice …

Functional Properties And Microstructure Of Chicken Breast Salt Soluble Protein Gels As Influenced By Ph And Temperature, S. F. Wang, D. M. Smith

Food Structure

The effects of different pH's (4 .5 , 5.5, 6.5 and 7.5) and temperatures (30-80 •c) on the functional properties and microstructure of chicken breast salt soluble protein (SSP) in 0.6 M NaCI were investigated. Protein solubility decreased from 98% at pH 6.5 to less than I% at pH 4.3 and below. Salt soluble protein at pH 4.5 produced a discontinuous gel which could not be measured by back extrusion and had an expressible moisture above 80% at all heating temperatures . Aggregated globular microstructures were observed at pH 4.5 by scanning electron microscopy (SEM). Thin-sectioned images as seen by …