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Postmortem Biochemical And Textural Changes In The Patinopecten Yessoensis Adductor Muscle (Pyam) During Iced Storage, Xin Xiong, Baoyu He, Di Jiang, Xiufang Dong, Aeneas Koosis, Chenxu Yu, Hang Qi Jun 2019

Postmortem Biochemical And Textural Changes In The Patinopecten Yessoensis Adductor Muscle (Pyam) During Iced Storage, Xin Xiong, Baoyu He, Di Jiang, Xiufang Dong, Aeneas Koosis, Chenxu Yu, Hang Qi

Agricultural and Biosystems Engineering Publications

Postmortem characteristics of Patinopecten yessoensis adductor muscle (PYAM) were evaluated by biochemical, chemical and textural changes during iced storage for 14 days. Triphosphate (ATP) and its breakdown products, K-value, total volatile basic nitrogen (TVB-N), pH, water-holding capacity (WHC), color, texture, protein degradation and cathepsin activities were monitored. K-value increased linearly from 5.9 ± 0.9% at day 0 to 28.1 ± 2.4% at day 2 and 70.2 ± 1.8% at day 12. Spoilage indicator TVB-N (mg/100 g) increased from 10.0 ± 0.6 to 34.6 ± 3.1 at day 12. Textural parameters (e.g., hardness, chewiness ...


Development Of Gluten-Free Egg Pasta Based On Amaranth, Maize And Sorghum, Laura Paux, Kurt A. Rosentrater Jan 2018

Development Of Gluten-Free Egg Pasta Based On Amaranth, Maize And Sorghum, Laura Paux, Kurt A. Rosentrater

Agricultural and Biosystems Engineering Publications

Due to increase of the population affected by Coeliac disease and awareness of consumers about the relationship between food and health, the production of cereal products from raw materials other than wheat is of interest. The aim of the work was to produce good quality gluten-free spaghettis, based on sorghum, amaranth and maize flour. Response surface methodology was applied to determine optimal formulation for the production of pasta. The resulting products of the experimental design were characterized regarding humidity, color, density, water activity, texture (firmness and elasticity), optimal cooking time, cooking weight, and cooking loss. The main trials were compared ...


Controlled Oxidative Modification With Glucose Oxidase To Enhance The Rheological And Gelling Properties Of Myofibrillar Proteins, Xu Wang Jan 2017

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 ...


Textural And Biochemical Changes Of Scallop Patinopecten Yessoensis Adductor Muscle During Low-Temperature Long-Time (Ltlt) Processing, Xiufang Dong, Hui Fu, Sijia Chang, Xiaoyu Zhang, Hao Sun, Baoyu He, Di Jiang, Chenxu Yu, Hang Qi Jan 2017

Textural And Biochemical Changes Of Scallop Patinopecten Yessoensis Adductor Muscle During Low-Temperature Long-Time (Ltlt) Processing, Xiufang Dong, Hui Fu, Sijia Chang, Xiaoyu Zhang, Hao Sun, Baoyu He, Di Jiang, Chenxu Yu, Hang Qi

Agricultural and Biosystems Engineering Publications

In this study, the effects of low-temperature long-time (LTLT) processing on the quality of Patinopecten yessoensis adductor muscle (PYAM) were investigated at 55°C. The texture of processed PYAM was characterized by textural profile analysis (TPA), and significant increases of cook loss, hardness, and shear force with time during LTLT processing were observed. The degradation of structural proteins was analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and fragments with molecular weights of 208 kDa (myosin heavy chain, MHC), 97 kDa (paramyosin) and 35–40 kDa, respectively, were among the main products. Chemical characterization revealed elevated levels of activity ...


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 Aug 2016

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 mgAAE/100g ...


Modified Milk Protein Concentrates In High-Protein Nutrition Bars, Justin Charles Banach Jan 2016

Modified Milk Protein Concentrates In High-Protein Nutrition Bars, Justin Charles Banach

Graduate Theses and Dissertations

This dissertation research focuses on studying time-dependent texture changes in high-protein nutrition (HPN) bars and their underlying mechanisms to possibly prevent or reduce change when formulated with high-protein (≥ 80% protein w/w) milk protein concentrate (MPC). HPN bars (20-50% protein w/w) are a target application for these nutritious and flavorless powder ingredients. However, high-protein MPCs produce HPN bars with undesirable texture that harden and lose cohesion during storage. The overall goal of this work is to improve the performance of MPCs for use in HPN bars by modifying their physicochemical properties to impart softness, cohesion, and textural stability. Twin-screw ...


Structural Design Approaches For Creation Of Reduced Fat Products, Bicheng Wu Nov 2015

Structural Design Approaches For Creation Of Reduced Fat Products, Bicheng Wu

Doctoral Dissertations

In awake of the health issues related with high-calorie diet, there was a strong focus in the development of reduced-fat products in the food industry. However, fat plays an important role in determining the quality attributes of food products such as texture, appearance, flavor and stability, therefore there has been limited success for reduced-fat products. This thesis project thus targeted liquid and semi-solid products such as dressings, sauces, and aimed to address problems associated with low-fat by utilizing structural designed approach.

The first part of this project focused on using controlled aggregation of protein-stabilized lipid droplets to regulate the microstructure ...


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 May 2015

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 ...


Influence Of Aba On Calcium Binding In Tomato Fruit And Its Impact On Fruit Texture, Kendall Cressman May 2014

Influence Of Aba On Calcium Binding In Tomato Fruit And Its Impact On Fruit Texture, Kendall Cressman

Chancellor’s Honors Program Projects

No abstract provided.


Effects Of Chelating Agents On Texture Of Lowfat Cheddar Cheese, Mariela Fernanda Poveda Jun 2013

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

Master's Theses and Project Reports

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 ...


Effect Of Post Manufacture Thermal Dip Treatment On Proteolysis Of Commercial String Cheese During Storage, Melissa Karen Hsu Mar 2013

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

Master's Theses and Project Reports

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 Jan 2013

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 ...


Development Of Carrot Pomace And Wheat Flour Based Cookies, Navneet Kumar Dr. Jul 2011

Development Of Carrot Pomace And Wheat Flour Based Cookies, Navneet Kumar Dr.

Navneet Kumar

Carrot is the excellent source of beta carotene and other vitamins. The carrot is utilized as raw, cooked vegetable, sweet meats or as juice and beverages. Carrot pomace is the by-product of carrot juice extraction process. The carrot pomace was dried in hot air oven at 65°C and then grinded to pass through 2 mm sieve. Dried carrot pomace was added in different proportions (0 –9%) to fine wheat flour, shortening, sugar and water. The formulation was baked at 175 °C for 12 min. in the gas oven with air circulation. The moisture content of cookies was measured using ...


Relationship Between Rheological, Textural And Melting Properties Of Dark Chocolate As Infuenced By Particle Size Distribution And Composition, Emmanuel Ohene Afoakwa, Alistair Paterson, Mark Fowler, Joselio Vieira Feb 2008

Relationship Between Rheological, Textural And Melting Properties Of Dark Chocolate As Infuenced By Particle Size Distribution And Composition, Emmanuel Ohene Afoakwa, Alistair Paterson, Mark Fowler, Joselio Vieira

Professor Emmanuel Ohene Afoakwa

In dark chocolate, rheological properties during processing are influenced by particle size distribution (PSD), fat and lecithin contents with consequential effects on finished texture and melting characteristics. Multivariate regression, correlation and principal component analyses (PCA) were used to explore their interrelationships. A 4 x 3 x 2 factorial experiment was conducted with varying PSD [D90 (90% finer than this size) of 18ìm, 25ìm, 35ìm and 50ìm), fat (25%, 30% and 35%) and lecithin (0.3% and 0.5%). Rheological properties (yield stress and apparent viscosity), textural properties (firmness, index of viscosity and hardness) and melting index (duration) were respectively measured ...


Particle Size Distribution And Compositional Effects On Textural Properties And Appearance Of Dark Chocolates, Emmanuel Ohene Afoakwa, Alistair Paterson, Mark Fowler, Joselio Vieira Feb 2008

Particle Size Distribution And Compositional Effects On Textural Properties And Appearance Of Dark Chocolates, Emmanuel Ohene Afoakwa, Alistair Paterson, Mark Fowler, Joselio Vieira

Professor Emmanuel Ohene Afoakwa

Particle size distribution (PSD) and composition in dark chocolate were varied and their effects on textural properties of molten and tempered chocolates determined using a TA.HD Plus Texture Analyzer. Surface colour was evaluated in terms of CIELAB parameters L*, C* and h° using a HunterLab Miniscan Colorimeter. Compositional parameters for particle size distribution were [D90 (>90% finer) of 18 ìm, 25 ìm, 35 ìm and 50 ìm], fat (25%, 30% and 35%) and lecithin (0.3% and 0.5%) contents. Results showed that PSD, fat and lecithin content significantly (p<0.05) influenced the textural parameters with significant interactions among factors. Particle size was inversely correlated with firmness (1235 - 173 g), consistency (50410 - 7029 g.s), cohesiveness (1594 - 262 g), index of viscosity (5737 - 1099 g.s) and hardness (7062 - 5546 g) with chocolates containing 25% fat and 0.3% lecithin. With higher fat and lecithin contents, PSD influence was reduced. PSD and fat concentration inversely influenced all colour measurements (L*, C* and h°) of samples. High correlations (r = 0.71 – 1.00, P<0.001) were observed between texture parameters and colour. It was concluded that PSD, fat and lecithin contents and their interactions were central to changes in textural properties and appearance during processing of dark chocolates.


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 Jan 2007

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 Sugar, Pectin And Acid Balance On The Quality Characteristics Of Pineapple (Ananas Comosus) Jam., Emmanuel Ohene Afoakwa, Dorinda Nartey, Joseph Ashong, George Annor Sep 2006

Effect Of Sugar, Pectin And Acid Balance On The Quality Characteristics Of Pineapple (Ananas Comosus) Jam., Emmanuel Ohene Afoakwa, Dorinda Nartey, Joseph Ashong, George Annor

Joseph Okai Ashong

Investigations were conducted on the effects of sugar concentration (0%, 50%, and 100%), pH balance (3.0, 3.2, and 3.5) and high methoxy pectin concentration (0%, 0.5%, and 1.0%) on the chemical, physico-chemical characteristic of pineapple jams using standard analytical methods. Inclusion of 50% sugar was observed to improve the colour of the jam as well as the texture, gel set and solid content. The low calorie jams had unacceptable texture, colour, gel set and total soluble solids content. The jams of this formulation were too soft, and could not hold their form. Addition of 100 ...


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 Jan 2006

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 ...


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 Jan 2005

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 May 1997

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

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 ...


Potato Cultivar Differences Associated With Mealiness, Diane R. Mccomber, Harry T. Horner, Mark A. Chamberlin, David F. Cox Nov 1994

Potato Cultivar Differences Associated With Mealiness, Diane R. Mccomber, Harry T. Horner, Mark A. Chamberlin, David F. Cox

Botany Publication and Papers

Russet Burbank, Norchip, Pontiac, and LaSoda potato cultivars were examined for the parameters mealy and waxy. Russet Burbank was judged dry, hard and particulate, typifying mealiness. Using phase contrast microscopy and scanning electron microscopy, raw mealy cells were determined to be larger and more irregularly shaped than cells from waxy cultivars. Mealy cooked cells were engorged with gelatinized starch, cell walls were more polarized, and cell shapes were better retained after mashing, when compared to waxy cells. NMR-T2 bound water readings from Russet Burbank and Pontiac samples did not differ from each other. Starch granule sizes and shapes varied by ...


Effects Of Whey Protein Concentrate, Phosphate, And Sodium Hydroxide On Texture And Acceptability Of Turkey And Beef Rolls, Igor V. Moiseev May 1994

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

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 ...


Effects Of Nonfat Dry Milk, Whey Protein Concentrate And Calcium Caseinate On Color And Texture Of Turkey Rolls, Brent Neeley Dobson May 1994

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

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 ...


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 ...


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 ...


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 ...


Cryo-Scanning Electron Microscopy Investigation Of The Texture Of Cooked Potatoes, J. T. Van Marle, A. C.M. Clerkx, A. Boekestein Jan 1992

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 mealy potatoes , it ...


Scanning Electron Microscopy Structure And Firmness Of Papain Treated Apple Slices, Yaguang Luo, Max E. Patterson, Barry G. Swanson Jan 1992

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.


The Cellular Structure Of Selected Apple Varieties, K. G. Lapsley, F. E. Escher, E. Hoehn Jan 1992

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 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 ...