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Food Science

Food Structure

Microstructure

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Composition And Microstructure Of Commercial Full-Fat And Low-Fat Cheeses, V. V. Mistry, D. L. Anderson Jan 1993

Composition And Microstructure Of Commercial Full-Fat And Low-Fat Cheeses, V. V. Mistry, D. L. Anderson

Food Structure

The objective of this study was to analyze the composition of commercial full-fat and low-fat cheeses and to evaluate their microstructure. Commercial cheeses evaluated included full-fat and low-fat Cheddar, Mozzarella , processed, and Swiss cheeses. Cheddar cheeses ranged from 8.2% fat and 5 1.1% moisture in the 75% low-fat product to 33.2% fat and 35.9% moisture in the full-fat cheese . Mozzarella cheeses ranged in fat from a low of 2. I% to a high of 24% with corresponding moisture content of 56.6 to 45.5% respectively. Fatfree processed cheese had 0. 9% fat and 58.7 ...


Microstructural Studies In Fat Research, I. Heertje Jan 1993

Microstructural Studies In Fat Research, I. Heertje

Food Structure

Microstructural studies play an important role in establishing the relation between composition, processing and final properties of many food products. In order to arrive at a full description of microstructure many visualization- and preparation techniques are needed. A number of fatty products such as shortenings, margarine , butter, and low fat spreads are discussed from a microstructural point of view. Examples of the influence of process parameters on microstructure and rheological properties are given. In particular, attention is paid to the fat crystalline matrix and the emulsion structure.

Further, a new methodology is described making it possible to study interactions of ...


Whey Proteins As Microencapsulating Agents. Microencapsulation Of Anhydrous Milkfat - Structure Evaluation, M. Rosenberg, S. L. Young Jan 1993

Whey Proteins As Microencapsulating Agents. Microencapsulation Of Anhydrous Milkfat - Structure Evaluation, M. Rosenberg, S. L. Young

Food Structure

Microencapsulation of milkfat may open new fields of application for this milk constituent by transforming it into dry and stable powder. Research has been undertaken to study the microstructure of whey protein based, anhydrous milkfat-containing, spray-dried microcapsules. Whey protein concentrates of 50% and 75% protein and whey protein isolate were evaluated as microencapsulating agents (wall materials). The effects of wall composition, fat load , and drying conditions on the capsule's structure were studied by scanning electron microscopy (SEM). Spherical capsules with smooth , wrinkle-free surfaces were observed in all cases. Whey protein isolate-based microcapsules dried at a temperature higher than 105 ...


Microstructure Of Whey Protein/ Anhydrous Milkfat Emulsions, M. Rosenberg, S. L. Lee Jan 1993

Microstructure Of Whey Protein/ Anhydrous Milkfat Emulsions, M. Rosenberg, S. L. Lee

Food Structure

Research has been undertaken in order to determine the microstructure of emulsions consisting of whey proteins and anhydrous milk fat. The results revealed that whey protein films were formed at oil/water interfaces. Scanning electron microscopy (SEM) analysis of chemically fixed specimens1 and cryo-SEM analysis of partially etched, fro zen specimens revealed that the ad sorbed protein layer (coating the fat droplets) had a granular, aggregated appearance. Emulsions with a high fat load prepared under high homogenization pressure exhibited a bimodal particle-size distribution. Clu!;tering of the protein-coated droplets, and sharing phenomena at the oil / protein interfaces were evident in ...


Microstructure Of Mozzarella Cheese During Manufacture, Craig J. Oberg, William R. Mcmanus, Donald J. Mcmahon Jan 1993

Microstructure Of Mozzarella Cheese During Manufacture, Craig J. Oberg, William R. Mcmanus, Donald J. Mcmahon

Food Structure

Scanning electron microscopy was used to examine structural developments during the manufacture of low-moisture, part-skim Mozzarella cheese made by a stirred curd procedure. The micrographs showed changes in the protein matrix , dispersion of fat globules, and bacteria during processing. Most curd knitting occurred during the curd stirring step, particularly dry stirring. A thin (5 ,urn) curd skin was observed on curd particles at the end of dry stirring. Dry salting prior to stretching resulted in the rapid loss of whey from the curd particle. Protein fibers were aligned and longitudinal columns of whey and fat were formed when the cheese ...


Microstructure And Fat Extractability In Microcapsules Based On Whey Proteins Or Mixtures Of Whey Proteins And Lactose, D. L. Moreau, M. Rosenberg Jan 1993

Microstructure And Fat Extractability In Microcapsules Based On Whey Proteins Or Mixtures Of Whey Proteins And Lactose, D. L. Moreau, M. Rosenberg

Food Structure

Research was undertaken to determine the microstructure of whey protein/lactose-based , anhydrous milk fat- containing , spray -dried microcapsules and to study the relationship between core extractability and the state of lactose in these microcapsules. Spherical microcapsules nearly free of surface dents were obtained in a ll cases The milkfat was found to be organized in the form of small droplets (0.2-0.8 um) embedded in the capsule wall. The surface topography of the capsul es ex hibited features that may be li nked to removal of mil kfat drop lets from th e outer surfaces at early stages of ...


Practical Aspects Of Electron Microscopy In Dairy Research, Miloslav Kalab Jan 1993

Practical Aspects Of Electron Microscopy In Dairy Research, Miloslav Kalab

Food Structure

Milk products are based mostly on casein micelles, fat globules, and whey proteins. The former two constituents are corpuscular and whey proteins become corpuscular when coagulated. Structural changes in these basic constituents during processing have been studied by electron microscopy. This review discusses the structures of yoghurt, curd, cheeses (hard cheeses, mould-ripened cheeses, cream cheeses, and process cheese), cream, milk powders, and nontraditional dairy products. Defects and deviations from traditional structures of these products are explained where the causes are known. Examples of such causes are foaming of milk, presence of unusual ingredients (bacterial polysaccharides, whey protein concentrates), and alterations ...


Relationship Between The Starch Granule Structure And The Textural Properties Of Heat-Induced Surimi Gels, V. Verrez-Bagnis, B. Bouchet, D. J. Gallant Jan 1993

Relationship Between The Starch Granule Structure And The Textural Properties Of Heat-Induced Surimi Gels, V. Verrez-Bagnis, B. Bouchet, D. J. Gallant

Food Structure

Starch, used as a textural additive in heat-induced surimi gel, influences the rigidity of the protein gel matrix and hence the gel strength according to its botanical characteristics. The present study focuses on the correlations existing between the textural properties of heatind uced surimi gels obtained by physical measurements and the characteristics of different commercial starches. The gelatinization temperature of starch was closely related to the expressible moisture, work to fracture, and elongation. Behaviour of starchy components during thermal processing and its relationship to fish protein gel matrix were studied by light and electron microscopy. These studies showed differences in ...


Changes In The Microstructure Of A Comminuted Meat System During Heating, Peter A. Koolmees, Gerrit Wijngaards, Monique H.G. Tersteeg, Jan G. Van Logtestijn Jan 1993

Changes In The Microstructure Of A Comminuted Meat System During Heating, Peter A. Koolmees, Gerrit Wijngaards, Monique H.G. Tersteeg, Jan G. Van Logtestijn

Food Structure

As part of a series of experiments on heating of a comminuted meat system , image analyses were conducted to quantify microstructural changes that could be visualized by light microscopy. Three different batches of comminuted meat were investigated. Two batches (A and B) were prepared without polyphosphate; one of these (B) was deliberately overchopped. One batch containing 0. I% polyphosphate was prepared (C). All batches were heated at I I different temperatures ranging from 40 to 115 °C. The microstructure of the three types of meat batte rs at the end of the com minu tion process differed. These types of ...


High-Resolution Scanning Electron Microscopy Of Milk Products: A New Sample Preparation Procedure, William R. Mcmanus, Donald J. Mcmahon, Craig J. Oberg Jan 1993

High-Resolution Scanning Electron Microscopy Of Milk Products: A New Sample Preparation Procedure, William R. Mcmanus, Donald J. Mcmahon, Craig J. Oberg

Food Structure

A metal-impregnation technique (tannin-ferrocyanide- osmium tetroxide) and thin metal coating imparted excellent preservation , and electric and thermal properties to milk products for scanning electron microscopy, resulting in high- resolution images. Three nanometer resolution was obtained, with minimal edge effects, charging , thermal drift, and decoration. Samples were fixed in 2% gluta raldehyde, cryoprotected in 70% ethanol, and cryofractured, exposing internal structure. Fat was extracted with Freon 113 and the sample were metal -impregnated with 1.0% osmium tetroxide and 1.5% potassium ferrocyanide, reduced with 1% hydroquinone, dried using !he critical-point drying melhod , and ion beam sputter-coated with 2-5 nm of ...


Liquid Holding Capacity And Structural Changes During Heating Of Fish Muscle: Cod (Gadus Morhua L.) And Salmon (Salmo Salar), Ragni Ofstad, Siw Kidman, Reidar Myklebust, Anne-Marie Hermansson Jan 1993

Liquid Holding Capacity And Structural Changes During Heating Of Fish Muscle: Cod (Gadus Morhua L.) And Salmon (Salmo Salar), Ragni Ofstad, Siw Kidman, Reidar Myklebust, Anne-Marie Hermansson

Food Structure

The loss of water and fat in cod and salmon muscle was studied as a function of heating temperature from 5-70 C. The liquid-holding capacity was measured by a low speed centrifugation net test leading to the separation of released liquid. To obtain a better understanding of the liquid-holding properties, the microscopic changes of the samples were evaluated by light microscopy. Two different preparation techniques were used . Cod lost twice as much water as salmon upon beating. After an initial delay , the water loss increased at 20-35°C, attained a maximum at 45-50°C, and thereafter decreased in both fish ...


Effect Of Chemical Modifications On The Stability, Texture And Microstructure Of Cooked Meat Batters, Andre Gordon, Shai Barbut Jan 1992

Effect Of Chemical Modifications On The Stability, Texture And Microstructure Of Cooked Meat Batters, Andre Gordon, Shai Barbut

Food Structure

The effects of five chemical agents on the stability, texture and microstructure of cooked comminuted meat batters were studied. B-mercaptoethanol (/3-ME), hydrogen peroxide (H20~, ethylenediaminetetraacetic acid (EDT A), urea, and polyoxyetbylene sorbitan monooleate (fween 80) were used. The reduction of disulphide bonds by 8-ME or the oxidation of free sulphydryls by H20 2 prior to cooking did not affect liquid and fat losses during cooking as compared to the control (2.5% NaCI). However, texture profile analysis (fPA) showed that treatment with H20 2 resulted in a harder, more cohesive product than the control and ,8-ME treatments because a more ...


Structure Of Margarines Made With Low Erucic Acid Rapeseed Oil, J. Hojerova, S. Schmidt, J. Krempasky Jan 1992

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 ...


Effect Of Lactose And Protein On The Microstructure Of Dried Milk, V. V. Mistry, H. N. Hassan, D. J. Robison Jan 1992

Effect Of Lactose And Protein On The Microstructure Of Dried Milk, V. V. Mistry, H. N. Hassan, D. J. Robison

Food Structure

Skim milk of approximately 3% total protein was ultrafiltered to 16.2% protein and 4.1 % lactose, and then diafiltered to reduce lactose to 2.1% and 0.9%. Total protein con ten t was maintained at approximately 17%. A ponion of the skim milk was condensed in a rising film evaporator to 14.7% protein and 15.7% lactose . All concentrates were spray dried at 120 to 125 °C inlet air temperature and 75 to 80 C outlet temperature using a rotary atomizer in a pilot plant spray dryer . Moisture content of the powders were 4.7 to 6 ...


Functional Properties And Microstructure Of Chicken Breast Salt Soluble Protein Gels As Influenced By Ph And Temperature, S. F. Wang, D. M. Smith Jan 1992

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 ...


Scanning Electron Microscopy Studies Of A Typical Spanish Confectionery Product: "Xixona Turron", M. A. Lluch, M. J. Galotto, A. Chiralt Jan 1992

Scanning Electron Microscopy Studies Of A Typical Spanish Confectionery Product: "Xixona Turron", M. A. Lluch, M. J. Galotto, A. Chiralt

Food Structure

The microstructure of "Xixona turron" , a typical Spanish confectionery product, made with toasted almonds, sugar and honey, was elucidated, in order to confirm the nature of those physical changes occurring in its manufacturing process, which has not been previously studied. The effect of the major components of "Xixona turron" (oil, proteins and sugar) on its structural c!Jange was established. The initial oil suspension of sugar syrup drops and proteins undergoes a phase inversion , becoming an oil /water emulsion when hot, and a solid-like structure, when the aqueous sugar continuous phase solidifies at room temperature. In order to determine the ...


Relationship Between Microstructure And In Vitro Digestibility Of Starch In Precooked Leguminous Seed Flours, Juscelino Tovar, Alicia De Francisco, Inger Bjorck, Nils-Georg Asp Jan 1991

Relationship Between Microstructure And In Vitro Digestibility Of Starch In Precooked Leguminous Seed Flours, Juscelino Tovar, Alicia De Francisco, Inger Bjorck, Nils-Georg Asp

Food Structure

Precooked flours (PCFs) were prepared by milling boiled and freeze-dried red kidney beans, white beans and lentils. As demonstrated by scanning electron microscopy, PCFs were rich in relatively large particles which contained cell structures filled with starch. In contrast, flours from raw seeds contained a large number of free starch granules. The in vitro a-amylolysis rate ofPCFs was remarkably low, but increased after physical and chemical treatments of the flours. Homogenization resulted in the largest increase of hydrolysis rate. The susceptibility to enzymatic hydrolysis was also enhanced when PCFs were preincubated with pepsin or submitted to additional boiling. These treatments ...


Comparison Of The Effects Of Three Different Grinding Procedures On The Microstructure Of "Old-Fashioned" Non-Stabilized Peanut Butter, Clyde T. Young, William E. Schadel Jan 1991

Comparison Of The Effects Of Three Different Grinding Procedures On The Microstructure Of "Old-Fashioned" Non-Stabilized Peanut Butter, Clyde T. Young, William E. Schadel

Food Structure

Three different grinding procedures were utilized to prepare "old-fashioned" non-stabilized peanut butters. A leading commercial brand of stabilized peanut butter was used for comparison. The microstructure of each non-stabilized peanut butter was then evaluated with light microscopy and compared to the microstructure of the commercial brand of stabilized peanut butter. Major findings include: (1) dense spatial relationships of protein bodies, starch grains, and cell and tissue fragments that exist in "old-fashioned " non-stabilized peanut butter as compared to the well-dispersed spatial relationships which exist in commercially prepared stabilized peanut butter; and (2) degree of homogenization in the nonstabilized peanut butters was ...


Distribution Of Amylose And Amylopectin In Potato Starch Pastes: Effects Of Heating And Shearing, K. Svegmark, A. M. Hermansson Jan 1991

Distribution Of Amylose And Amylopectin In Potato Starch Pastes: Effects Of Heating And Shearing, K. Svegmark, A. M. Hermansson

Food Structure

The microstructure of potato starch pastes and gels in the concentration range 5-10% (w/w) was studied as a function of shear and heat treatment usi.ng light microscopy. Heating induced extensive swelling of potato starch granules, and the swollen granules filled the whole volume of the starch pastes that were subjected to a minimum of shear. The volume of the aqueous phase outside and in the center of the swollen granules is practically negligible compared to the volume occupied by the walls of the swollen granules. The granules with the lowest gelatinization temperatures swelled quickly without restrictions, so that ...


Effect Of Extruder Die Temperature On Texture And Microstructure Of Restructured Mechanically Deboned Chicken And Corn Starch, V. B. Alvarez, D. M. Smith, S. Flegler Jan 1991

Effect Of Extruder Die Temperature On Texture And Microstructure Of Restructured Mechanically Deboned Chicken And Corn Starch, V. B. Alvarez, D. M. Smith, S. Flegler

Food Structure

Proximate composition, textural properties and microstructural changes of mechanically deboned chicken/15% corn starch extrudates were evaluated when restructured at die temperatures of 25, 71, 82, 93 , 104 and ll5°C in a twin-screw extruder. Total sol ids and fat content decreased, whereas protein content increased die temperatures were increased. When die temperature was increased from 71°C to 104°C, apparent stress at failure of extrudates increased by 44 kPa , but decreased at a die temperature of 115°C. Changes in the protein matrix, fat globules and starch granules due to changes i n extruder die temperature were observed ...


Textural And Microstructural Properties Of Frozen Fish Mince As Affected By The Addition Of Nonfish Proteins And Sorbitol, K. S. Yoon, C. M. Lee, L. A. Hufnagel Jan 1991

Textural And Microstructural Properties Of Frozen Fish Mince As Affected By The Addition Of Nonfish Proteins And Sorbitol, K. S. Yoon, C. M. Lee, L. A. Hufnagel

Food Structure

Changes in textural and microstructural properties of washed and unwashed frozen fish mince were studied as affected by the addition of non fish proteins (soy protein isolate, milk protein isolate, egg white, and wheat gluten at 2 , 4 or 6%) and 6% crystalline sorbitol. Soy and milk proteins and sorbitol reduced the hardness of frozen fish mince, while egg white and wheat gluten made the texture firmer without rubberiness developing after frozen storage. All nonfish proteins and sorbitol stabilized the myofibrillar organization by reducing freeze-induced contraction of myofibrils.

The mechanisms of reducing texture hardening appear to be different between sorbitol ...


The Microstructure Of Raw Meat Batters Prepared With Monovalent And Divalent Chloride Salts, Andre Gordon, Shai Barbut May 1990

The Microstructure Of Raw Meat Batters Prepared With Monovalent And Divalent Chloride Salts, Andre Gordon, Shai Barbut

Food Structure

Cold stage scanning electron microscopy (cryo-SEM), transmission electron microscopy (TEM) and light microscopy (LM) were used to examine the effect of NaCl (2.5%), MgC12 , CaC12 , KCl, LiCl (calculated ionic strength, IS = 0.43) and 1.5% NaCl (IS = 0.26) on the microstructure of comminuted raw meat batters (fat added) and comminuted meat mixes (no fat added). Cryo-SEM revealed that comminuting the lean meat with different chloride salts resulted in the formation of different types of gel structures. Differences were mainly in gel strand thickness, the degree of interlinking between strands and the size of pores within ...


Light And Scanning Electron Microscopy Of The Peanut (Arachis Hypogaea L. Cv. Florunner) Cotyledon After Roasting, Clyde T. Young, William E. Schadel Jan 1990

Light And Scanning Electron Microscopy Of The Peanut (Arachis Hypogaea L. Cv. Florunner) Cotyledon After Roasting, Clyde T. Young, William E. Schadel

Food Structure

Changes in the microstructure of peanut (Arachls ~ L. cv Florunner) cotyledons after roasting at a temperature of 160°C (16 min) were investigated with light and scanning electron microscopy. Major changes included: (1) pitting and pock -marking of the epidermis of the cotyledons caused by the escape of steam and on released during roasting; (2) loss of cellular organization of the cytoplasmic network surrounding the Jipid bodies, protein bodies, and starch grains ; (3) alteration of the structures of cytoplasmic network. lipid bodies, and protein bodies; and (4) heat destruction of some middle lamellae of cell - t o-cell junctions.


A Method For The Examination Of The Microstructure Of Stabilized Peanut Butter, Clyde T. Young, William E. Schadel Jan 1990

A Method For The Examination Of The Microstructure Of Stabilized Peanut Butter, Clyde T. Young, William E. Schadel

Food Structure

A method for light and scanning electron microscopy of damaged resting peanut seed tissue was adapted as a research tool for evaluating the microstructural features of commercially available stabilized peanut butter. This method was used in the present study to evaluate the degree of homogenization of stabilized peanut butter by examining the spatial relationship which exists among the microstructural features. Light and scanning electron microscopy of three commercially available stabilized peanut butters revealed varying degrees of homogenization of broken cell and tissue fragments, protein bodies, and starch grains within a matrix of stabilized oil.


The Role Of The Interfacial Protein Film In Meat Batter Stabilization, A. Gordon, S. Barbut Jan 1990

The Role Of The Interfacial Protein Film In Meat Batter Stabilization, A. Gordon, S. Barbut

Food Structure

The microstructure of meat batters made with equal ionic strengths of NaCl, MgC1 2 , CaCl2 and KCl (IS- 0.43) and a reduced-NaCl batter (IS- 0.43) were examined by scanning and transmission electron microscopy. Micrographs revealed that fat globules with smooth and rough protein coats were present in all treatments. The roughly-coated globules were prevalent in the unstable batters. Pores were observed in the interfacial protein film (IPF) surrounding the globul es and were more prevalent in the globules with rough protein coats. Fat was seen to exude from the pores in both types of globules, Fat globules were ...


Microstructure And Firmness Of Processed Cheese Manufactured From Cheddar Cheese And Skim Milk Powder Cheese Base, A. Y. Tamime, M. Kalab, G. Davies, M. F. Younis Jan 1990

Microstructure And Firmness Of Processed Cheese Manufactured From Cheddar Cheese And Skim Milk Powder Cheese Base, A. Y. Tamime, M. Kalab, G. Davies, M. F. Younis

Food Structure

Processed cheese (10 different types) was made from Cheddar cheese and a cheese base produced from reconstituted skim milk powder by blending and melting with commercial emulsifying salts at 9Q<>C. In one experiment, the cheese base was subjected 10 accelerated cheese ripening by added enzyme. The finished products had 50.1- 53.5% total solids, 18.2-19.3% protein, 47.4-49.7% fat in dry matter, and 2.7-3.0% salt in water; pH was 5.3-5.4 after three months of storage at 10 C and 30 C.

The experimental cheeses were markedly firmer than the control cheeses ...


Structural Characteristics Of Pennisetum Americanum (Pearl Millet) Using Scanning Electron And Fluorescence Microscopy, C. M. Mcdonough, L. W. Rooney Jan 1989

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 ...


Microstructure Of Extruded Mixtures Of Cereals And Oil Seed Processing Residues, A. Salgo, Sz. Torok, Sz. Sandor Jan 1989

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 ...


Microstructure And Texture Of Meat Emulsions Supplemented With Plant Proteins, Allan T. Paulson, Marvin A. Tung Jan 1989

Microstructure And Texture Of Meat Emulsions Supplemented With Plant Proteins, Allan T. Paulson, Marvin A. Tung

Food Structure

A model meat emulsion system was used to evaluate the effects of cooking time and temperature on texture, microstructure and cook stability of meat emulsions containing soy or canola protein isolate. The plant proteins were incorporated either dry or rehydrated at replacement levels of 33.3% and 66.7% of the meat protein, and the emulsions were cooked at 70 or 95 C tor 25 or 50 min. Texture of the cooked emulsions was assessed by an instrumental texture profile analysis (TPA) using an lnstron tester . Analysis of TPA and stability data revealed several complex Interactions between experimental variables; however ...


Heat-Set Gels Based On Oil/Water Emulsions: An Application Of Whey Protein Functionality, R. Jost, F. Dannenberg, J. Rosset Jan 1989

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 ...