Food Science Commons^™

Changes In The Ultrastructure Of Beef Muscle As Influenced By Acidic Conditions Below The Ultimate Ph, M. V. Rao, N. F. S. Gault, S. Kennedy

Food Structure

Ultrastructural changes in meat incubated with different concentrations of acetic acid were investigated by transmission electron microscopy. Discs of bovine M. longissimus dorsi (48 h postmortem) were incubated at 46 C for 48 h in various acetlc acid solutions, giving discs with pH values ranging from 5.1 to 3.9 . Below pH 4. 5 , the volume of the discs increased markedly due to water absorption.

Discs incubated in 0.01M acetic acid had a pH of 5.1, lower swelling ratios and shorter sarcomeres than control samples at pH 5. 5. Structural studies of the samples at pH 5.1 revealed that …

The Size Distribution Of Casein Micelles In Camel Milk, Z. Farah, M. W. Ruegg

Food Structure

The size distribution of casein micelles in camel milk has been determined by electron microscopy. Individual and pooled samples were cryo-fixed by rapid freezing and freeze-fractured. Electron micrographs of the freeze-fracture replica revealed a relatively broad size distribution, with an average micelle dimeter around 280 nm in the volume distribution curve. The distribution was significantly broader than that of the particles of cow's or human milk and showed a greater number of large particles. The submicelles were also somewhat larger than those observed in cow's and human milk (approx. 15, 10 and 7 nm, respectively). The average values for the …

Cereal Structure And Its Relationship To Nutritional Quality, S. H. Yiu

Food Structure

Factors that determine the digestibility of carbohydrates and minerals in cereals are examined . Most carbohydrates and minerals in cereals are structurally bound, either surrounded by or associated with cell wall components not easily digested by non-ruminant animals and humans. Treatments such as mechanical grinding and heat improve the digestibility of nutrient s . Further processing and cooking result in structural and physeochemical changes of cereal starch, phytate, and dietary fiber. Such changes greatly Influence the physiological and metabolic effects in animals and humans. The digestive breakdown of most nutrient components is also dependent on the activities of enzymes 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 …

Effects Of Protein Concentration In Ultrafiltration Milk Retentates And The Type Of Protease Used For Coagulation On The Microstructure Of Resulting Gels, Dragoljub D.J. Gavaric, Marijana Caric, Miloslav Kalab

Food Structure

Milk retentates (35~ total solids, 13~ protein) obtained by ultrafiltration were diluted with the permeate to 3 . 2, 5.0, 6.5, 10.0, and 13.0% protein and coagulated using conrnerc1al proteases. Rennet or one of microbial proteases isolated from Bacillus potymlxa , Endothla parasfttca, Mucor mtehel, or Mucor pusfllus were used . Coagulation times were decreased with the Mucor proteases as the protein concentrations in the retentates were increased but the coagulation times were increased with B. potymlxa and f. parasltlca proteases under similar conditions . Firmness was higher in gels made from homogenized retentates than from nonhomogenized retentates of the …

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 …

Use Of Image Analysis To Predict Milling Extraction Rates Of Wheats, A. D. Evers, R. P. Withey

Food Structure

Image analysis of grain morphological characteristics was examined as a possible means of predicting extraction rates of a wide variety of wheat types.

Two elevations of grain were examined and measured for the top view whole grains were used, while for the lateral view grains were sagittally bisected in the plane of the crease. Extraction rate was assessed on laboratory mills and expressed as flour yield.

Milling extraction rate correlated with one shape factor with a coefficient of 0.78. Inclusion of a second factor in a stepwise regression increased the correlation coefficient to 0.925.

No satisfactory predictor of extraction rate …

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 …

Safe Kitchen Rules, Georgia C. Lauritzen Ph. D.

Archived Food and Health Publications

Publication gives tips and instructions on how to be safe in the kitchen.

Elderberries, Georgia C. Lauritzen Phd, Carl M. Johnson

Archived Food and Health Publications

Publication gives identification characteristics of elderberries and how to make syrup, jelly, and pie using elderberries.

Rice, Unknown Unknown

Archived Food and Health Publications

Publication gives information on the different types and uses of rice.

Changes With Time In The Availability Of Soil Applied Zinc To Navy Beans And In The Chemical Extraction Of Zinc From Soils, J. D. Armour, G. S.P. Ritchie, A. D. Robson

Food Science and Nutrition

The effect of the incubation of zinc (Zn) applied to the soil on Zn uptake and the Zn concentrations in chemical extractants was studied. In a glasshouse experiment using a Zn-deficient gravelly sandy loam, the effect of recently applied Zn was compared with that of Zn incubated with the soil for 15 days at 40°C on growth and Zn uptake by navy beans (Phaseolus vulgaris cv. Gallaroy). At the second harvest (33 days after sowing), the dry weight of shoots of recently applied Zn was consistently higher than that of incubated Zn, except at the highest rate of 1 …

Cost Of Home Canning, Marilyn B. Noyes

All Archived Publications

No abstract provided.

Food Preservation--Plan Ahead, Marilyn B. Noyes, Jean Alder

All Archived Publications

No abstract provided.

Aluminum, Georgia C. Lauritzen

Archived Food and Health Publications

This publication discusses aluminum and its different uses. It also discusses the health effects of aluminum.

Vegetable Freezing Methods, Georgia C. Lauritzen Ph. D., Charlotte P. Brennand

Archived Food and Health Publications

Publication gives instructions for properly freezing vegetables, including beets, broccoli, carrots, corn, peas, peppers, and more.

Cauliflower Fact Sheet, Alvin R. Hamson

Archived Food and Health Publications

Publication gives information on cauliflower, including how to grow it, how to store it, and how to cook it.

Food Preservation- Plan Ahead, Marilyn B. Noyes Ph. D., Jean Alder M.S.

Archived Food and Health Publications

Publication gives instructions on how to prepare for preserving your own food, including equipment needed, preparation instructions, and hints for a successful preservation process.

Food Safety And The Microwave, Georgia C. Lauritzen Ph. D.

Archived Food and Health Publications

Publication gives information on how to properly cook using a microwave as well as the benefits and risks to this type of cooking.

Asparagus, Alvin R. Hamson

Archived Food and Health Publications

Publication discusses varieties of asparagus and how to best grow it.

Electron Microscopic Localization Of Cholesterol In Bovine Milk Fat Globules, Robert W. Martin Jr.

Food Structure

An electron microscopic method designed for the detection of cholesterol in milk fat was evaluated for reliability. This method is based on the incubation of cream from raw milk with fillipin (a polyene antibiotic) which has a specific affinity for cholesterol followed by freeze fracturing and electron microscopic examination of fat globules. Cholesterol was localized within the membrane and the triglyceride core of milk fat globules. Cholesterol was highly organized within membrane portions and less organized within triglyceride portions of milk fat globules. The configuration of localized cholesterol was similar to configurations reported for plasma membranes.

The Effect Of Irradiation On Starch Content In Golden Delicious Apples, E. Kovacs, A. Keresztes

Food Structure

Starch content in apple (Golden Delicious) skin and flesh was studied as a function of radiation dose (0, 0.5, 1, 2 and a 5kGy) after 8 weeks shelf life (16 C, 80-90% RH).

Starch was generally not found in the flesh with the exception of the 5 kGy sample. Starch grains were observed, however, in plastids of the epidermis and especially in the hypodermis in correlation with the radiation dose. 1 kGy dose caused a significant effect (p>99, 98%) on retardation of starch breakdown measured by electron microscopic morphometry and chemical analysis.

Analysis showed that increasing radiation dose increased …

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 …

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. …

Grittiness In A Pasteurized Cheese Spread: A Microscopic Study, H. W. Modler, S. H. Yiu, U. K. Bollinger, M. Kalab

Food Structure

Coagulation of pasteurized (63 C for 30 min) milk and blending of the resulting curd with high-fat cream followed by heat treatment (44 to 80 C for 10 min) of the blend in preparation of a hot-pack cheese spread led to the formation of a gritty product. Microscopic examination of hard particles causing the grittiness indicated that they consisted of compacted protein. Staining for calcium failed to detect any elevated concentration of this element in the particles. They were amorphous and contained no crystalline structures.

Encapsulation of the gritty curd in agar gel tubes made it possible to freeze-fracture the …

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 …

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 …

Microstructure Of Extruded Mixtures Of Cereals And Oil Seed Processing Residues, A. Salgo, Sz. Torok, Sz. Sandor

Food Structure

The utilization of valuable by-products of seed processing residues as coextrusion materials was investigated. By mixing sunflower, pumpkin, corn or rice germ presscake with cereals (wheat, corn, rice), the good protein quality of the former group might improve the biological value of the resulting coextrudates. The microstructure of such coextruded products was analysed with reference to their chemical compositions, nutritional characteristics and functional properties. As seed processing residue was increased, the microstructure of the products became more compact and uniform and the air/solids ratio decreased considerable. The results showed that the highest acceptable concentration of the additive was not more …

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 …

Observation Of Seeding Effects On Fat Bloom Of Dark Chocolate, I. Hachiya, T. Koyano, K. Sato

Food Structure

Surface microstructures and polymorphism of seeded dark chocolate were observed with cryo-SEM, to clarify the effects of seeding on fat bloom stability of dark chocolate. Two thermal tests, cycling between 32 adn 20C (32/20) and 38 and 20 C (38/20), were applied to examine the fat bloom stability of the chocolate. We used three crystalline powders: Form VI of cocoa butter; the most stable B1 form of SOS (1,3-distearoyl-2-oleoylglycerol); and the second stable B2 form of BOB (1,3,-dibehenoyl-2-oleoylglycerol) as seed materials. Seeding with cocoa butter (Form VI) and SOS (B1) at concentrations of 0.5 ~ 1 wt. % showed good …