Food Science Commons^™

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 …

Microstructure Of Nunas: Andean Popping Beans (Phaseolus Vulgaris L.), Stephen C. Spaeth, Daniel G. Debouck, Joseph Tohme, Janny Van Beem

Food Structure

Nunas, popping beans (Phaseous vulgaris L.), burst and expand when heated rapidly. Differences in seed microstructure between popping and conventional (non-popping) bean genotypes conceivably contribute to popping in nunas However, the microstructural characteristics which contribute to the popping attribute and sites of expansion have not been identified. Seeds and excised cotyledons of unpopped and popped nunas were examined using scanning electron microscopy (SEM). Protoplasts of unpopped nunas were similar to protoplasts of conventional beans. Intercellular spaces of unpopped nunas were occluded by schizogenous cell walls. The occluded form of intercellular spaces differed distinctively from the open form in popped nunas …

The Effect Of Chloride Salts On The Texture, Microstructure And Stability Of Meat Batters, A. Gordon, S. Barbut

Food Structure

The stability, texture and microstructure of six mechanically deboned chicken meat bat.ters prepared with NaCL (1.25 and 2.5%) and replacement of the 2. 5 NaCl with HgC12 , CaC12 , KCl and LiCl based on isoionic strength were examined . The uncooked HgCL2 batter showed the poorest fat binding, The monovalent chloride salts produced stable cooked batters, whereas both divalent salts did not, CaC12 produced a more unstable batter than MgC1 2 High correlation was found between water and fat loss and total cookout losses from cooked batters. Texture was significantly affected by the type of chloride salt used. The …

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 …

Apples, Georgia C. Lauritzen Ph. D.

Archived Food and Health Publications

Publication gives information on apples, including seasons, storing, canning, freezing, and whitening.

Utah Tart Cherries, Georgia C. Lauritzen Ph. D.

Archived Food and Health Publications

Publication gives information and instruction on how to select, handle, serve, freeze, and can Utah Tart Cherries.

Utah Peaches, Georgia C. Lauritzen Ph. D.

Archived Food and Health Publications

Publication gives information on selecting, freezing, canning, drying, and consuming peaches.

The Fibers, Georgia C. Lauritzen Ph. D.

Archived Food and Health Publications

Publication gives information on the different types of fiber and how the body uses each of them. It also lists common foods that provide fiber for the body.

Evaluation Of Frogurt: A New Product Prepared By Fermentation Of Ice Cream Mix, Morteza Mashayekh

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ice cream mix was fermented with yogurt cultures of Streptococcus thermophilus and Lactobacillus bulgaricus to four different pH's then frozen in a batch ice cream freezer. A consumer panel of 120 people tasted samples of strawberry flavored product with pH's of 4.4, 4.7, 5.1, and 5.4 and commercial frozen yogurt as a standard. Results from the panel were used to predict a preferred pH of 4.9. Another panel of 181 people compared product at pH 4.9 with 10, 15 and 20% strawberry flavoring. There was not a statistically significant difference among levels of flavoring.

Starter culture populations and lactase activity …

Measurement Of Proteins In Milk And Dairy Products, Marie K. Walsh

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to develop a short, easy procedure to measure five major proteins in milk and to detect concentrations of added protein to dairy products. Combinations of casein or whey protein with nonfat-dry milk were made with concentration ratios from 0:10 to 10:0. Similar mixtures of defatted goat milk with defatted cow milk were prepared. Samples were hydrolyzed in 6 N HCl at 145°C for 4 h and analyzed for amino acid composition. Multiple regression equations were derived to estimate the relative content of whey protein or casein added to nonfat-dry milk and goat milk added …

The Bioavailability Of Iron From Meat, Spinach, Soy Protein Isolate, Meat:Spinach And Meat:Spi Mixtures Fed To Anemic And Healthy Rats, Dejia Zhang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Two Experiments were conducted to investigate the effect of iron status and iron source on iron bioavailability using the rat model. Beef was proportionally mixed with spinach (Experiment I) or soy protein isolate (Experiment II) to test if meat enhances the absorption of iron from spinach or SPI. Five diets with the iron from meat:spinach (or SPI) ratios of 100:0, 75:25, 50:50, 25:75 and 0:100 were prepared and fed to rats. FeS04 was used as a reference. Two trials of rats were used in Experiment I. In trial I, half of the rats were made severely iron deficient (Hb 6.3 …

Eat A Healthful Diet- An Absolute Cure, Georgia C. Lauritzen Ph.D

Archived Food and Health Publications

Publication gives tips and suggestions for eating a healthful diet.

The Retention Of Contractility Of Rabbit Myofibrils During Storage At 25 C, Makoto Nakamura, Michio Muguruma, Toshiyuki Fukazawa, Mamoru Yamaguchi

Food Structure

During postmortem storage of muscle at 25 degrees C, myofibrils retained the ability to contract for more than 400 hours under experimental conditions used to prevent bacterial contamination of the meat surface. During t his time, rapid breakdown of troponin T was observed. Storage beyond 500 hours resulted in rapid loss of contractility correlating with proteolysis of the heavy chain of myosin, an din this stage some granules were observed along the whole A-band within the sarcomere.

Microstructure Of Shortenings, Margarine And Butter - A Review, A. C. Juriaanse, I. Heertje

Food Structure

Fat spreads are composed of liquid oil, fat crystals and water. The fat crystals in these products give the product the required consistency and stabilize the water droplets. Shortenings are waterfree products , the rheology of which depends on the solid fat content and interactions between fat crystals. Size and interaction between crystals is influenced by both composition and processing. Crystals form a three - dimensional network. Recrystallization phenomena, especially formation of large beta- crystals , can create product defects like sandiness. Margarines and halvarines are water- in - oil emulsions and have a relatively simple product structure. Because of …

Proceedings From The 25th Annual Italian Cheese Seminar, Various Authors

Cheese Industry Conference

No abstract provided.

Porosity, Specific Gravity And Fat Dispersion In Blue Cheeses, K. M. K. Kebary, H. A. Morris

Food Structure

Porosity was measured in Blue cheeses made from (i) homogenized butter oil - reconstituted nonfat dry milk (4% fat). (ii) homogenized butter oil reconstituted nonfat dry milk (14% fat) standardized to 4% fat with reconstituted nonfat dry milk , (iii} homogenized raw c ream (14% fat) standardized to 4% fat with raw skim milk , and (iv) homogenized pasteurized cream (14% fat) standardized to 4% fat with pasteurized skim milk. Cheeses made from (i) were the most porous and were significantly different from the other cheeses . In cheeses made from (i) and (ii) , about 40% of the holes …

Development Of Microstructure In Raw, Fried, And Fried And Cooked Paneer Made From Buffalo, Cow, And Mixed Milks, Miloslav Kalab, S. K. Gupta, H. K. Desai, G. R. Patil

Food Structure

Paneer was made from cow, buffalo, and mixed cow and buffalo milk by coagulation with citric acid at pH 5.5. All milk samples were heated to 90°C. Cow milk was coagulated at this temperature but buffalo and mixed milks were cooled to 70°C before coagulation. Differences in the composition and the treatments of the cow and buffalo milks were reflected in the composition and structure of the paneers. Electron microscopy revealed that raw paneer samples had a granular structure consisting of protein particles having a core-and-lining ultrastructure. Deep-frying in vegetable oil at 175'C for 4-5 min led to the compaction …

Functional And Microstructural Effects Of Fillers In Comminuted Meat Products, Frederick W. Comer, Paula Allan-Wojtas

Food Structure

Fillers are used in comminuted meat products such as wieners to increase yield, improve stability, and modify textural properties. Light microscopy, scanning electron microscopy and transmission electron microscopy show that comminutred meat products are mechanical mixtures in which the microstructural features of starch and insoluble protein ingredients are largely retained. The water absorption and gelation properties of these ingredients contribute to the stability and textural firmness. Soluble proteins may improve stability through emulsion formation but the role of emulsion formation i s clearly secondary to that of gelation. The characteristic springy gel structure of wieners is determined by the gelation …

The Use Of Transmission Electron Microscopy To Study The Composition Of Pseudomonas Fragi Attachment Material, Paula J. Herald, Edmund A. Zottola

Food Structure

Electron microscopy techniques were used to study the attachment matrix of Pseudomonas fragi used to demonstrate the presence of attachment fibrils of P. fragi adhered to stainless steel. Transmission electron microscopy (TEM) was used to examine thin sectioned cells strained with ruthenium red or alcian blue. Extracellular substances surrounding cells stained with ruthenium red or alcian blue had a mat- or spike-like morphology. This indicated that these substances were acidic mucopolysaccharides that may be involved in the attachment of P. fragi to food contact surfaces.

Changes In The Ultrastructure Of Emulsions As A Result Of Electron Microscopy Preparation Procedures, M. Liboff, H. D. Goff, Z. Haque, W. K. Jordan, J. E. Kinsella

Food Structure

Various methods of preparing emulsions for electron microscopy were examined with peanut oil/protein and ice cream mix emulsions. For transmission electron microscopy {TEM) , fresh peanut oil/bovine serum albumin emulsions were mixed with 2% agar , fixed in phosphate-buffered (pH 7 . 0) 4% glutaraldehyde solution and postfixed in phosphate-buffered (pH ? . 0) 1% osmium tetroxide alternatively , the glutaraldehyde- fixed samples were briefly rinsed in acetone prior to postfixation . Both preparations yielded satisfactory fat globule preservation. Similar emulsions were prepared on loops and suspended over vapors of 25% gJ nt.RrBl r'lehyr'le Rnc'l 1% oRmi urn tetroxide . …

Ultrastructural And Textural Properties Of Restructured Beef Treated With A Bacterial Culture And Splenic Pulp, E. A. Elkhalifa, N. G. Marriot, R. L. Grayson, P. P. Graham, S. K. Perkins

Food Structure

Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Instron measurements were used to evaluate the effects of an Achromobacter iophagus culture {BC) and splenic pulp (SP) treatments one structural and textural properties of flaked and restructured beef steaks. Both treatments improved the textural character is tics of the product when conditioned at 35°C . Electron microscopy studies revealed that the bacterial culture treatment caused a greater effect than SP on the connective tissue elements, with a degradation of the endomysial sheath and sarcolemma. Treatment with splenic pulp produced an overall excessive disruption a t the Z-lines with little definition …

Scanning Electron Microscopy Of Cellular Structure Of Granny Smith And Red Delicious Apples, Gassinee Trakoontivakorn, Max E. Patterson, Barry G. Swanson

Food Structure

Immature and mature Granny Smith and Red Delicious apples (Malus domestica Borkh . ) were studied with scanning electron microscopy (SEM). Parenchyma cells were observed to form a net-like pattern in sections transverse to the stem-calyx of the apple. Bundles of about six intact cells were connected, creating large intercellular spaces. The intercellular spaces were different in shape from different perspectives to the cut surfaces ; round in stem-calyx transverse sections and elliptical in stem-calyx cross sections. Cell areas, cell lengths and intercellular space areas were determined with image analysis. The patterns of mature apple cell structure of both cultivars …