Food Science Commons^™

Physicochemical And Functional Property Modification Of Myofibrillar Protein By Phenolic Compounds Under Oxidative Stress, Anqi Guo

Theses and Dissertations--Animal and Food Sciences

Polyphenol-rich spices and extracts of phenolic compounds are widely utilized in meat processing to modify product flavors. Chemically, polyphenols are reactive with myofibrillar protein (MP), the most functional fraction of all muscle proteins responsible for texture development in comminuted meat products. Such protein–polyphenol interaction is prevalent under oxidative conditions that are common in meat processing. As a large group of phytochemicals with diverse structures, phenolic compounds are known to interact with MP with varying efficacies. Yet, the structure-function relationship of polyphenols in eliciting modification of MP is poorly understood. The overall objective of this dissertation research was to elucidate the …

Animal And Plant Protein Oxidation: Chemical And Functional Property Significance, Youling L. Xiong, Anqi Guo

Animal and Food Sciences Faculty Publications

Protein oxidation, a phenomenon that was not well recognized previously but now better understood, is a complex chemical process occurring ubiquitously in food systems and can be induced by processing treatments as well. While early research concentrated on muscle protein oxidation, later investigations included plant, milk, and egg proteins. The process of protein oxidation involves both radicals and nonradicals, and amino acid side chain groups are usually the site of initial oxidant attack which generates protein carbonyls, disulfide, dityrosine, and protein radicals. The ensuing alteration of protein conformational structures and formation of protein polymers and aggregates can result in significant …

Effect Of Haematococcus Pluvialis On Baking Quality Of Bread, Wang Bao-Bei, Dai Zi-Wei, Liu Lu-Lu, Chen Wen-Xuan

Food and Machinery

In this study, H. pluvialis was applied into bread to study its effect on baking quality. The results showed that the addition of H. pluvialis increased redness and yellowness of bread, and decreased the brightness. The specific volume of bread decreased slightly, but the moisture content did not change a lot with the addition of H. pluvialis. Within the content range studied, the hardness, stickiness and chewiness of bread increased gradually with increasing H. pluvialis, while the elasticity, resilience and cohesion did not change significantly. Similarly, during storage process, H. pluvialis had little effect on the changes of …

Effects Of Oats And Distiller’S Dried Grains Fibers On Fortification Of Asian Noodles – Evaluation Of Glycemic Response, Noodle Quality And Nutritional Composition, Kara Konst

Electronic Theses and Dissertations

The objective of this study was to develop Asian wheat noodle formulations enriched with oat flour and corn DDG at 10, 20 and 30 % wheat flour replacement levels and to evaluate the effects of this fiber and protein enrichment on the glycemic response of human subjects. We hypothesized that the addition of high-fiber oats and high-fiber, high-protein DDG will have synergistic effects in lowering the glycemic response in human subjects. In this study, steamed instant Asian noodles were prepared with DDG(D) and oats(OF) in combination with all-purpose wheat flour(W) in the following flour blends: (W:D) 90:10, (W:OF) 90:10, (W:D) …

Controlled Oxidative Modification With Glucose Oxidase To Enhance The Rheological And Gelling Properties Of Myofibrillar Proteins, Xu Wang

Theses and Dissertations--Animal and Food Sciences

This study investigated the feasibility of oxidative modification with glucose oxidase (GluOx) to enhance the rheological and gelling properties of myofibrillar protein. Differential oxidative modifications of myofibrillar protein (MP) by hydroxyl radicals generated in an enzymatic system with glucose oxidase (GluOx) in the presence of glucose/FeSO₄ compared to a Fenton system (H₂O₂/FeSO₄) were investigated. Firmer and more elastic MP gels were produced by the GluOx-oxidizing system than by the Fenton system at comparable H₂O₂ levels due to an altered radical reaction pathway.

The study further explored the effect of GluOx-mediated …

Effect Of Pulse Flours On The Physiochemical Characteristics And Sensory Acceptance Of Baked Crackers., Kim Millar, Catherine Barry-Ryan, Róisín Burke, Sinead Mccarthy, Eimear Gallagher

Conference papers

Pulse flours offer nutritional alternatives to wheat flour in the production of baked snacks due to their high protein and fibre levels and low glycaemic index. In this study, broad-bean (Vicia faba), yellow-pea and green-pea (Pisum sativum) flours were each blended with wheat flour at 40% in the formulation of chemically-leavened crackers. The effects of flour type and baking time on the physiochemical properties, sensory acceptability, nutritional composition and antioxidant activity of the crackers were observed in comparison to 100% wheat crackers. Broad-bean crackers had the highest protein content and antioxidant activity (13g/100g DM and 38.8 …

Valorization Of Fish By-Products: Rheological, Textural And Microstructural Properties Of Mackerel Skin Gelatins, Zied Khiari, Daniel Rico, Ana Belen Martin-Diana, Catherine Barry-Ryan

Articles

The fish processing industry generates significant amounts of waste which is usually discarded. The present study investigated the recovery of gelatins from Atlantic mackerel (Scomber scombrus) skins after pre-treatment with different environmentally-friendly organic acids (acetic, citric, lactic, tartaric or malic acid). The chemical composition, the rheological and the textural properties as well as the microstructural characteristics of the extracted gelatins were analysed and compared to commercial bovine hide gelatin. Although the organic acid used in the pre-treatment step did not affect the extraction yield and the chemical composition of the prepared gelatins, differences were observed in terms of rheology and …

Effects Of Chelating Agents On Texture Of Lowfat Cheddar Cheese, Mariela Fernanda Poveda

Master's Theses

Effects of two types of chelating agents on proteolysis and texture properties of low fat Cheddar cheese (LFC) were analyzed and compared to full fat Cheddar (FFC) control during ripening for 120 days at 8°C. We hypothesized that chelating agents would bind calcium ions from cheese matrix to give a softer curd due to a decrease of protein-protein interactions and simultaneously increasing moisture content. Cheese milk containing (0.59% fat) was divided into three lots (A, B & C). Sodium citrate (3Na) and disodium EDTA (EDTA) were added to A & B at the rate of (0.02% and 0.2% respectively. C …

Effect Of Post Manufacture Thermal Dip Treatment On Proteolysis Of Commercial String Cheese During Storage, Melissa Karen Hsu

Master's Theses

String cheese, a Mozzarella cheese, has the unique ability to string in fibrous strands when pulled apart. Graders judge string cheese by its stringy texture; samples with copious amounts of string are awarded high ratings. But just as the texture of natural cheeses softens with time, the stringy texture of string cheese can diminish with age too.

Age related softening in cheese is due primarily to an important biochemical event known as proteolysis, which is attributed to inherent milk proteinases, residual coagulant activity, and enzymes from the lysis of starter culture microorganisms. It is hypothesized that a post manufacture heat …

Degradation Kinetic Modelling Of Colour, Texture, Polyphenols And Antioxidant Capacity Of York Cabbage After Microwave Processing, Amit Jaiswal, Nissreen Abu-Ghannam

Articles

Vegetables as an essential component of the human diet usually undergo some type of processing before being consumed. In the present study, impact of microwave (MW) processing on various physiochemical properties of York cabbage was studied. York cabbage was processed at 400, 560 and 800W for 0 to 14 min with an increment of 2 min followed by a kinetic study for the degradation of polyphenols, flavonoids, antioxidant capacity, colour and texture were carried out. Results showed that MW processing leads to significant reductions in the texture, colour, polyphenols and antioxidant capacity. For all the MW processing power studied total …

1% Calcium Chloride Treatment In Combination With Gamma Irradiation Improves Microbial And Physicochemical Properties Of Diced Tomatoes, Anuradha Prakash, Pei-Chen Chen, Richard L. Pilling, Nicole Johnson, Denise Foley

Food Science Faculty Articles and Research

The purpose of this study was to determine the effect of a combination of a 1% calcium chloride dip with low dose irradiation on microbial populations, and biochemical and physical properties, of fresh diced tomatoes during a two-week storage period. Vine tomatoes at the light-red stage (trial 1) and Celebrity tomatoes at the table ripe stage (trial 2) were diced, dipped in 1% CaCl2, and irradiated at 1 kGy from a Co-60 source. Tomatoes were also contaminated with cocktail of nalidixic-acid resistant Salmonella strains (S. Poona, S. Hartford, S. Gaminara, S. Michigan, and S. Montevideo) and subjected to gamma irradiation. …

Effect Of Calcium Lactate And Heat-Shock On Texture In Fresh-Cut Lettuce During Storage, Ana Belen Martin-Diana, Daniel Rico, Jesus Maria Frias, Gary Henehan, Jemina Mulcahy, J. Barat, Catherine Barry-Ryan

Articles

Textural and microstructural changes in fresh-cut lettuce were analysed over 12 days storage. The vegetable was treated with 120 ppm chlorine and with 15 g/L calcium lactate at room temperature (18–20 °C) and at 50 °C (heat-shock). Texturometer analysis showed that samples washed with calcium lactate had significantly (p > 0.05) higher crispness values than samples washed with chlorine. However the use of 50 °C treatment (heat-shock) gave better textural properties at the end of storage and significantly retarded the softening process, being in agreement with the sensorial results. Cryo-SEM micrographs showed a loss of turgor (shrinkage) of the tissue cells …

Effect Of Calcium Lactate On Quality, Safety And Nutritional Senescence Parameters Of Minimally Processed Vegetables, Ana Belen Martin-Diana, Daniel Rico, Jesus Maria Frias, Jemina Mulcahy, Gary Henehan, Catherine Barry-Ryan

Articles

Calcium lactate maintained quality senescence indicators, as well as chlorine in Iceberg lettuce, and enhanced nutritional values during storage in sliced carrots better than chlorine. Colour and texture objective measurements did not show differences between treatments for Iceberg lettuce; however there were differences in colour in sliced carrots, showing greater change in colour values in samples treated with chlorine. Calcium lactate washing treatments prevented the bleaching effect on saladcut lettuce and sliced carrots and also diminished the appearance of white surfaces over storage. The ascorbic acid decreased during storage independently of the type of treatment used for both vegetables, however …

Effect Of Ph, Fat Level, And Various Browning Agents On Composition, Color, Texture, And Sensory Characteristics Of Dark-Cutting Beef Patties, Igor V. Moiseev

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Extra lean (3.3% fat) and lean (20.0% fat) hamburgers in three pH groups (≤ 6.0; 6.01-6.49; 6.50-6.92) were evaluated for cooking-temperature profile, total process lethality, and physical properties after cooking to 71°C by double-side frying on an electric grill. Neither cooking-temperature profile nor cooking time was affected by hamburger fat content or pH. Double-side frying to 71.1°C internal temperature was adequate for more than 6-log destruction of viable E. coli O157:H7 and Salmonella at the geometrical center of extra lean and lean hamburgers. The coldest spot was on the circumferential surface, as indicated by the presence of a red ring …

Effects Of Nonfat Dry Milk, Whey Protein Concentrate, And Calcium Caseinate On Color And Texture Of Turkey Rolls, Brent Neeley Dobson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Two studies were conducted to evaluate the effects of milk solids on restructured and emulsified turkey rolls. the milk solids used were nonfat dry milk (NFDM), whey protein concentrate (WPC), and calcium caseinate (CC). Turkey rolls consisted of 100% breast meat or 90:10 or 70:30 breast-to-thigh, salt (1%), water (10%), internal or cluster fat (10%), and 3% of various milk solids (WPC, NFDM, CC).

The objectives of these studies were to 1) determine which ratio between light and dark meat is preferred; 2) determine which of milk solids evaluated will permit the highest level of dark meat incorporation into evaluated …

Effects Of Whey Protein Concentrate, Phosphate, And Sodium Hydroxide On Texture And Acceptability Of Turkey And Beef Rolls, Igor V. Moiseev

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Processed turkey rolls were prepared with 1 or 3% whey protein concentrates WPC-50 (pH=5.80), WPC-60 (pH=4.53) and WPC-75 (pH=6.85} containing 50, 60 and 75% protein along with controls (phosphate and no phosphate). Control rolls made with 0.5% phosphate had the highest bind strength, and sensory evaluation scores. Only WPC-75 (1%) was acceptable as a binding agent and flavor enhancer. WPC-60 reduced pink discoloration of rolls, but flavor, bind and cohesiveness scores were unacceptably low. WPC-50 was not an effective binding agent. In general, rolls made with 3% WPC had lower scores for intensity of turkey flavor.

Bind strength and sensory …

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 …

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.

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 …

The Cellular Structure Of Selected Apple Varieties, K. G. Lapsley, F. E. Escher, E. Hoehn

Food Structure

Apple cultivars (Sauergrauech, Klarapfel, James Grieve, Granny Smith, Mcintosh, Robinette) which had different textures based on sensory and instrumental analysis (particularly in firmness and mealiness) were examined by conventional scanning electron microscopy (SEM), cold-stage SEM (cryoSEM) and confocal scanning laser microscopy (CSLM) using various preparative procedures. Advantages, lim itations and artifacts of each technique are discussed.

SEM with glutaraldehyde-fixation and criticalpoint- drying produced minimal tissue distortion and the fracture pattern and appearance of mealy versus non mealy tissue was different. Freeze-drying unfixed tissue caused cell collapse and firm versus soft varieties could not be differentiated. Freeze-fracturing and cryoSEM of apple …

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 fine-stranded, …

Cryo-Scanning Electron Microscopy Investigation Of The Texture Of Cooked Potatoes, J. T. Van Marle, A. C.M. Clerkx, A. Boekestein

Food Structure

The texture of steam-cooked potatoes was investigated by examining the fracture planes of four different cultivars, using cryo-scanning electron microscopy (cryo-SEM), which yielded a good preservation of the hydrated structures in potato tissue . For all cultivars , fracturing after steam -cooking took place between cells preferentially alongside the cell walls. However, textural difference appeared from the degree of intercellular contact, the cell shape and the appearance of cell surfaces. Cells in the fracture planes of firm potatoes had large intercellular contacts. In this case, most of the cells were flat and cell surfaces showed folds and cracks . For …

Structure And Rheology Of Dairy Products: A Compilation Of References With Subject And Author Indexes, David N. Holcomb

Food Structure

No abstract provided.

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 by scanning electron …

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, level …

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 …

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 …

Textural Properties And Structure Of Starch-Reinforced Surimi Gels As Affected By Heat-Setting, J. M. Kim, C. M. Lee, L. A. Hufnagel

Food Structure

The gel forming behavior of red hake (Urophycis chuss) surimi with and without starch and its relationship to the structure of the gel matrix were studied. For surimi gels without starch, a combination of preheat- setting at 40 C and cooking at 90 C resulted in significantly greater gel strength than cooking alone. However, preheat - setting of gels containing wheat or potato starch had no significant effect on gel strength demonstrating an opposite trend in gel strength due to the differences in swelling power, water holding ability and gelatinization temperature between potato and wheat starches. This difference in gel …

Texture And Microstructure Of Soybean Curd (Tofu) As Affected By Different Coagulants, J. M. Deman, L. Deman, S. Gupta

Food Structure

The coagulating properties of five coagulants and the nature of the curd obtained from soymilk was investigated . Viscosity changes during coagulation were studied using a Namctrc Vibrating Sphere Viscometer and texture measurements were made by compression and computer assisted analysis. pH and amount of solids in the whey were determined. The microstructure of the tofu was examined by sca nning electron microscopy. It was observed that CaCI2.2H20 and MgCI2.6H20 coagulaled the milk in stantl y while CaS04 .1/2H20. glucono delta l a~tonc (GOL) and MgS04 .7H20 acted comparatively slowly. The t exture of the curd was greatly influenced by …

A Review Of The Muscle Cell Cytoskeleton And Its Possible Relation To Meat Texture And Sarcolemma Emptying, D. W. Stanley

Food Structure

A review of the muscle cytoskeleton is presented. Current evidence leads to the concept of a muscle cell cytoskeleton consisting of at least two elements - gap filaments which are located parallel to the fiber ax~s and provide intracellular elasticity and tensile strength and intermediate filameots found in the zdisc area that function to connect adjacent Z- discs and promote lateral registration. The former constituent consists of the high molecular weight protein connectin (titinl while the latter is composed of the smaller protein desmin (skeletinl. Both proteins exist in filamentous form, are susceptible to proteolysis and are insoluble in physiological …