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Full-Text Articles in Life Sciences

In Vitro Bioaccessibility Of Novel Low-Crystallinity Phytosterol Nanoparticles In Non-Fat And Regular-Fat Foods, Ali Ubeyitogullari, Ozan Ciftci Jan 2019

In Vitro Bioaccessibility Of Novel Low-Crystallinity Phytosterol Nanoparticles In Non-Fat And Regular-Fat Foods, Ali Ubeyitogullari, Ozan Ciftci

Faculty Publications in Food Science and Technology

Crystalline structure of phytosterols leads to poor bioavailability and makes their incorporation into foods challenging. Bioaccessibility of first-of-their-kind low-crystallinity phytosterol nanoparticles impregnated in nanoporous starch aerogels (PS-NSA) was evaluated in non-, low-, and regular-fat solid and aqueous food formulations, namely, granola bars and puddings for the first time. Bioaccessibility of the phytosterol nanoparticles was significantly higher than that of crude phytosterols in all food formulations (p < .05); it was 88.2 and 91.8% for low- or regular-fat granola bars, respectively, whereas bioaccessibility of crude phytosterols was ca. 30% in those formulations. However, decreasing the lipid content to zero resulted in lower phytosterols' bioaccessibilities from both PS-NSA (53%) and crude phytosterols (ca. 16%) in non-fat granola bars. Bioaccessibility of crude phytosterols (2%) was significantly enhanced with PS-NSA (19%) in the pudding formulation. PS-NSA allows preparation of low- and non-fat foods enriched with phytosterols while enhancing the health benefits of phytosterols with smaller doses.


Exogenous Lactobacilli Mitigate Microbial Changes Associated With Grain Fermentation (Corn, Oats, And Wheat) By Equine Fecal Microflora Ex Vivo, Brittany E. Harlow, Laurie M. Lawrence, Patricia A. Harris, Glen E. Aiken, Michael D. Flythe Mar 2017

Exogenous Lactobacilli Mitigate Microbial Changes Associated With Grain Fermentation (Corn, Oats, And Wheat) By Equine Fecal Microflora Ex Vivo, Brittany E. Harlow, Laurie M. Lawrence, Patricia A. Harris, Glen E. Aiken, Michael D. Flythe

Animal and Food Sciences Faculty Publications

Cereal grains are often included in equine diets. When starch intake exceeds foregut digestion starch will reach the hindgut, impacting microbial ecology. Probiotics (e.g., lactobacilli) are reported to mitigate GI dysbioses in other species. This study was conducted to determine the effect of exogenous lactobacilli on pH and the growth of amylolytic and lactate-utilizing bacteria. Feces were collected from 3 mature geldings fed grass hay with access to pasture. Fecal microbes were harvested by differential centrifugation, washed, and re-suspended in anaerobic media containing ground corn, wheat, or oats at 1.6% (w/v) starch and one of five treatments ...


Effect Of Dietary Starch Source And Concentration On Equine Fecal Microbiota, Brittany E. Harlow, Laurie M. Lawrence, Susan H. Hayes, Andrea Crum, Michael D. Flythe Apr 2016

Effect Of Dietary Starch Source And Concentration On Equine Fecal Microbiota, Brittany E. Harlow, Laurie M. Lawrence, Susan H. Hayes, Andrea Crum, Michael D. Flythe

Animal and Food Sciences Faculty Publications

Starch from corn is less susceptible to equine small intestinal digestion than starch from oats, and starch that reaches the hindgut can be utilized by the microbiota. The objective of the current study was to examine the effects of starch source on equine fecal microbiota. Thirty horses were assigned to treatments: control (hay only), HC (high corn), HO (high oats), LC (low corn), LO (low oats), and LW (low pelleted wheat middlings). Horses received an all-forage diet (2 wk; d -14 to d -1) before the treatment diets (2 wk; d 1 to 14). Starch was introduced gradually so that ...


Physico-Chemical, Rheological And Baking Properties Of Proso Millet, Manjot Singh Jan 2016

Physico-Chemical, Rheological And Baking Properties Of Proso Millet, Manjot Singh

Theses and Dissertations--Biosystems and Agricultural Engineering

Due to climate change, water scarcity, increasing population and rising food prices, agriculture and food security has been affected worldwide. Cereal grains being a major part of world food supply also act as important energy source in human diet. In order to counter food insecurity, alternative grains are being explored, and millet being drought-resistant has the potential to serve as an alternative grain due to its comparable nutritional composition with other major cereals and its gluten free proteins. The evidence that gluten sensitivity is one of the increasing food intolerances is driving an increasing demand for gluten-free foods. However, gluten ...


Effects Of Chemical And Enzymatic Modifications On The Starch-Inclusion Complex Formation, Emily Arijaje May 2015

Effects Of Chemical And Enzymatic Modifications On The Starch-Inclusion Complex Formation, Emily Arijaje

Theses and Dissertations

Starch-inclusion complexes have been proposed as delivery tools for bioactive molecules; however complexation yield is generally low with low solubility, which may limit the bioavailability of the included molecule. It was proposed that chemical (acetylation) and/or enzymatic (isoamylase and beta-amylase) modifications of starches prior to complex formation with fatty acids of different structures, including stearic, oleic and linoleic acid, may help increase complexation yield and solubility of the resulting starch complexes. Potato starch had a significantly higher complexation yield than common corn and high amylose (~70%) corn starches after debranching combined with a beta-amylase treatment. Debranched waxy maize starch ...


Studies On Mechanisms Of Resistant Starch Analytical Methods, Samuel Ahlias Moore Jan 2013

Studies On Mechanisms Of Resistant Starch Analytical Methods, Samuel Ahlias Moore

Graduate Theses and Dissertations

This study aimed to quantify resistant starch (RS) contents in native and modified starches from various botanical sources using standard methods for RS analysis (AOAC Methods 991.43, 2002.02, and the Englyst method) to better understand differences in RS contents of starchy foods analyzed using these methods. RS contents of octenyl succinic (OS) normal corn starch increased with increasing wt% substitution, whereas RS contents of OS-modified high-amylose maize starch decreased. Differences in RS contents of RS3 were within 10% regardless of the method used. The largest differences were observed in cross-linked wheat distarch phosphate and debranched high-amylose maize stearic-acid ...


Characterisation Of Starch Traits And Genes In Australian Rice Germplasm, Ardashir Kharabian Masouleh Jan 2013

Characterisation Of Starch Traits And Genes In Australian Rice Germplasm, Ardashir Kharabian Masouleh

Theses

The physio-chemical properties of starch influence the nutritional value and the functional properties of starch containing foods. In this thesis, a population of 233 breeding lines of rice was analysed for variation in 17 rice starch synthesis genes, encoding seven classes of enzymes such as AGPases, GBSSs, SSs, Bes, DBEs, SPHOL and GPT1. This approach employed next-generation sequencing technology followed by a comprehensive association study of 110 functional SNP. SNP loci were analysed for associations with rice pasting and cooking quality. In total, The GBSSI and SSIIa had major influence on starch properties and the other genes had minor associations.


Structures, Properties, And Digestibility Of Resistant Starch, Yongfeng Ai Jan 2013

Structures, Properties, And Digestibility Of Resistant Starch, Yongfeng Ai

Graduate Theses and Dissertations

This study aimed to understand effects of different treatments and modifications on the structures, properties, and digestibility of selected starches. Different lipids, including corn oil (CO), soy lecithin (SL), palmitic acid (PA), stearic acid (SA), oleic acid (OA) and linoleic acid (LA), were selected for the study, and their impacts on the properties and digestibility of normal corn (NCS), tapioca (TPS), waxy corn (WCS) and high-amylose corn (HA7) starch were investigated to elucidate mechanisms of starch-lipid interactions. After cooking with the lipids (10%, w/w, dsb), NCS, TPS and HA7 showed significant decreases in the percentage enzymatic hydrolysis, and their ...


Interactional Effects Of Β-Glucan, Starch, And Protein In Heated Oat Slurries On Viscosity And In Vitro Bile Acid Binding, Hyun Jung Kim, Pamela J. White Jun 2012

Interactional Effects Of Β-Glucan, Starch, And Protein In Heated Oat Slurries On Viscosity And In Vitro Bile Acid Binding, Hyun Jung Kim, Pamela J. White

Food Science and Human Nutrition Publications

Three major oat components, β-glucan, starch, and protein, and their interactions were evaluated for the impact on viscosity of heated oat slurries and in vitro bile acid binding. Oat flour from the experimental oat line “N979” (7.45% β-glucan) was mixed with water and heated to make oat slurry. Heated oat slurries were treated with α-amylase, lichenase, and/or proteinase to remove starch, β-glucan, and/or protein. Oat slurries treated with lichenase or lichenase combined with α-amylase and/or proteinase reduced the molecular weight of β-glucan. Heat and enzymatic treatment of oat slurries reduced the peak and final viscosities compared ...


Dsc Enthalpic Transitions During Starch Gelatinization In Excess Water, Dilute Sodium Chloride, And Dilute Sucrose Solutions, Wajira S. Ratnayake, Chika Otani, David S. Jackson May 2012

Dsc Enthalpic Transitions During Starch Gelatinization In Excess Water, Dilute Sodium Chloride, And Dilute Sucrose Solutions, Wajira S. Ratnayake, Chika Otani, David S. Jackson

Faculty Publications in Food Science and Technology

Background: Starch phase transition characteristics were studied by pre-treating starch samples in excess water, dilute sodium chloride and dilute sucrose solutions and subjecting them to differential scanning calorimetry (DSC). Unmodified maize, wheat and potato starches were held at specific temperatures between 30 and 90 °C for 30 min and promptly cooled to 25 °C. Treated samples were then analyzed in situ by DSC. Results: It was found that the progression of the phase transition behavior differed among the three starches and was dependent on the solvent. It was also revealed that phase transition-related enthalpic changes started to occur at low ...


Effect Of Enzymatic Treatments On The Physiochemical Properties Of Different Corn Starches, Curtis Robert Luckett May 2012

Effect Of Enzymatic Treatments On The Physiochemical Properties Of Different Corn Starches, Curtis Robert Luckett

Theses and Dissertations

Amylose readily reassociates to form films and crystalline structures that are resistant to digestion by amylolytic enzymes and known as resistant starch type III (RS3). This study investigated the RS3 formation and cereal coating properties from enzyme-modified corn starches with varying amylose contents, including Hylon VII (70% amylose), Hylon V (50% amylose), and common corn (25% amylose). For RS3 formation, corn starches were first gelatinized and then hydrolyzed using β-amylase to varying degrees. The resultant hydrolyzed starch was debranched with isoamylase and then exposed to 3 times of temperature cycling at 135/133/133°C for 30 min and 95 ...


Characterization Of Normal And Waxy Corn Starch For Bioethanol Production, Hanyu Yangcheng Jan 2012

Characterization Of Normal And Waxy Corn Starch For Bioethanol Production, Hanyu Yangcheng

Graduate Theses and Dissertations

The uncertainty of future oil supply and growing concerns of the energy security of the United States have boosted the investment in alternative energy carriers, including biofuels. Bioethanol, made from bio-renewable resources, has gained the mainstream usage in the USA. Ethanol is almost exclusively made from corn in the USA. The objectives of the study were: 1) To compare the differences of ethanol production between the normal and waxy corn using a cold-fermentation process; 2) To understand the effects of starch structure and properties on the ethanol production. Ethanol yields of the waxy corn ranged from 33.1% (33.1g ...


Effect Of Starch Sources And Protein Content On Extruded Aquaculture Feed Containing Ddgs, Sankaranandh Kannadhason, Kasiviswanathan Muthukumarappan, Kurt A. Rosentrater Feb 2011

Effect Of Starch Sources And Protein Content On Extruded Aquaculture Feed Containing Ddgs, Sankaranandh Kannadhason, Kasiviswanathan Muthukumarappan, Kurt A. Rosentrater

Kurt A. Rosentrater

A 3 × 3 × 3 completely randomized design was used to investigate extrusion cooking behavior and product characteristics of distillers dried grains with solubles (DDGS), protein levels, and various starch sources in a laboratory scale single screw extruder. Cassava, corn, and potato starches with varying levels of DDGS (20%, 30%, and 40% wet basis (wb)) were extruded with three different proportions of protein levels (28%, 30%, and 32% wb). The extrusion cooking was performed at a constant feed moisture content of 20% wb, barrel temperature of 120 °C, and a preset screw speed of 130 rpm (13.6 rad/s). Extrudate ...


Individual And Interactional Effects Of Β-Glucan, Starch, And Protein On Pasting Properties Of Oat Flours, Yanjun Liu, Theodore B. Bailey, Pamela J. White Aug 2010

Individual And Interactional Effects Of Β-Glucan, Starch, And Protein On Pasting Properties Of Oat Flours, Yanjun Liu, Theodore B. Bailey, Pamela J. White

Food Science and Human Nutrition Publications

Seven experimental oat lines with high (6.2−7.2%), medium (5.5−5.9%), and low (4.4−5.3%) β-glucan concentrations were evaluated for contributions of β-glucan, starch, protein, and their interactions, to pasting properties of oat flours by using a Rapid Visco Analyser (RVA, Newport Scientific, Warriewood, NSW, Australia). Significant correlations (P < 0.05) between β-glucan concentration and pasting parameters of oat slurries were obtained under autolysis without 1 h of incubation, inhibition, and amylolysis. The relative decrease of viscosity after enzymatic hydrolysis of β-glucan correlated with β-glucan concentration (P < 0.05). These data demonstrated the important contribution of β-glucan to pasting. The relative decrease of viscosity after either amylolysis or enzymatic removal of protein correlated with β-glucan concentration (P < 0.1), which might be explained by the considerable contribution of the interaction of β-glucan with starch and protein, to pasting. The viscosity decrease by hydrolysis of protein was much greater than the actual viscosity remaining after hydrolysis of both β-glucan and starch, reconfirming the importance of interactions between protein and other oat components to pasting. Optimal multiple linear regression (MLR) models were generated to predict key pasting parameters in both buffer without 1 h of incubation and silver nitrate solution by using a stepwise procedure. The β-glucan concentration alone or together with the concentration of starch, rather than protein, was selected as the predictor under certain conditions. These results illustrated the major unit contribution of β-glucan, secondary unit contribution of starch, and minimal unit contribution of protein to pasting.


Functionality Of Native Tetraploid Wheat Starches: Effects Of Waxy Loci Alleles And Amylose Concentration In Blends, L. E. Hansen, David S. Jackson, R. L. Wehling, J. D. Wilson, Robert A. Graybosch Jan 2010

Functionality Of Native Tetraploid Wheat Starches: Effects Of Waxy Loci Alleles And Amylose Concentration In Blends, L. E. Hansen, David S. Jackson, R. L. Wehling, J. D. Wilson, Robert A. Graybosch

Faculty Publications in Food Science and Technology

Partial waxy (reduced amylose) and fully waxy (amylose-free) tetraploid durum wheats (Triticum turgidum L. var. durum) were used to investigate the relationships between both intra- and inter-granular variation in amylose concentration and starch functionality. Starches isolated from each genotype (intra-granular amylose variants) were compared to those of commercially available hexaploid wild-type and waxy starches, and functionalities compared to blends (inter-granular variants) of durum waxy and wild- type starches of 0, 6, 12, 18, 24, & 30% amylose content. Starch particle size distributions were not significantly different amongst partial waxy and wild-type genotypes; waxy samples had significantly smaller mean starch granule size. Few significant differences for crystallite melting and related intrinsic heat as determined by differential scanning calorimetry (DSC ...


Functionality Of Chemically Modified Wild-Type, Partial Waxy And Waxy Starches From Tetraploid Wheats, L. E. Hansen, David S. Jackson, R. L. Wehling, Robert A. Graybosch Jan 2010

Functionality Of Chemically Modified Wild-Type, Partial Waxy And Waxy Starches From Tetraploid Wheats, L. E. Hansen, David S. Jackson, R. L. Wehling, Robert A. Graybosch

Faculty Publications in Food Science and Technology

Partial waxy (reduced-amylose) and fully waxy (amylose-free) tetraploid durum wheats (Triticum turgidum L. var durum) were developed by introgression of null alleles at the Wx-A1 and Wx-B1 loci from common hexaploid wheat (Triticum aestivum L.). Purified starches were obtained from each genotype, and chemically modified by: 1) cross-linking with phosphorus oxychloride, 2) substitution with propylene oxide, and 3) sequential cross-linking with phosphorus oxychloride followed by substitution with propylene oxide. Functional properties were compared to blends of waxy and wild-type durum starches of known amylose contents. Significant differences in functionality were observed amongst the genotypes and blends after each ...


Characterization Of Corn Grains For Dry-Grind Ethanol Production, Sathaporn Srichuwong, Jelena Gutesa, Michael Blanco, Susan A. Duvick, Jay-Lin Jane, C. A. Gardner Dec 2009

Characterization Of Corn Grains For Dry-Grind Ethanol Production, Sathaporn Srichuwong, Jelena Gutesa, Michael Blanco, Susan A. Duvick, Jay-Lin Jane, C. A. Gardner

Food Science and Human Nutrition Publications

The objectives of this study were to understand how the composition of corn kernels and starch structure affected the enzyme hydrolysis of starch in dry-grind corn and the ethanol yield from yeast fermentation. Four selected corn inbred lines were used in this study. Starch in uncooked dry-grind corn samples showed greater enzyme digestibility than did the uncooked starch isolated from the same source by wet-milling process. The greater digestibility of starch in uncooked dry-grind corn correlated with a physical damage of starch granules. In contrast, starch in cooked dry-grind corn samples displayed less enzyme digestibility than did the cooked isolated ...


Effects Of Starch Addition On Low Fat Rennet Curd Properties And Their Partitioning Between Curd And Whey, Kelly Marie Larsen Dec 2009

Effects Of Starch Addition On Low Fat Rennet Curd Properties And Their Partitioning Between Curd And Whey, Kelly Marie Larsen

All Graduate Theses and Dissertations

This study determined the impact of starches on the properties of low fat rennet curd as measured by microstructural and instrumental analysis. In experiment 1, 17 starches were initially screened for swelling power, impact of curd yield at 5 g/L and 10 g/L in milk, and settling in rennet-induced partially acidified low fat curd. Starches examined were narrowed down to five in experiment 2; they included: modified waxy corn starch, waxy rice starch, instant tapioca starch, dextrin, and a modified tapioca starch. These starches were added to skim milk to make rennet-induced partially acidified milk gels. Gels were ...


Structure And Function Of Starch And Resistant Starch From Corn With Different Doses Of Mutant Amylose-Extender And Floury-1 Alleles, Ni Yao, Alix V. Paez, Pamela J. White Mar 2009

Structure And Function Of Starch And Resistant Starch From Corn With Different Doses Of Mutant Amylose-Extender And Floury-1 Alleles, Ni Yao, Alix V. Paez, Pamela J. White

Food Science and Human Nutrition Publications

Four corn types with different doses of mutant amylose-extender (ae) and floury-1 (fl1) alleles, in the endosperm, including no. 1, aeaeae; no. 2, fl1fl1fl1; no. 3, aeaefl1; and no. 4,fl1fl1ae, were developed for use in making Hispanic food products with high resistant starch (RS) content. The RS percentages in the native starch (NS) of 1−4 were 55.2, 1.1, 5.7, and 1.1%, respectively. All NS were evaluated for pasting properties with a rapid viscoanalyzer (RVA) and for thermal properties with a differential scanning calorimeter (DSC). NS 1 had a low peak viscosity (PV) caused by ...


Starch Structures And Physicochemical Properties Of A Novel Β-Glucan Enriched Oat Hydrocolloid Product With And Without Supercritical Carbon Dioxide Extraction, David G. Stevenson, Fred J. Eller, Jay-Lin Jane, George E. Inglett Jan 2007

Starch Structures And Physicochemical Properties Of A Novel Β-Glucan Enriched Oat Hydrocolloid Product With And Without Supercritical Carbon Dioxide Extraction, David G. Stevenson, Fred J. Eller, Jay-Lin Jane, George E. Inglett

Food Science and Human Nutrition Publications

Starch structures and physicochemical properties of C-trim30, a β-glucan-enriched oat product (32% β-glucan), with or without supercritical carbon dioxide extraction (SCD) were studied to evaluate suitability for commercial applications and potential to degrade starch to increase β-glucan concentration. Scanning electron micrographs showed C-trim30 was composed of 200-300 μm long, porous particles. HPSEC equipped with MALLS and RI detectors showed C-trim30 had three peaks, corresponding to amylopectin with weight-average molecular weight (Mw) of 1.0x108, breakdown amylopectin product (Mw 1.1x107) and amylose (Mw 1.7x106). β-glucans were not observed due to HPSEC column ...


Gelatinization And Solubility Of Corn Starch During Heating In Excess Water: New Insights, Wajira S. Ratnayake, David S. Jackson Jan 2006

Gelatinization And Solubility Of Corn Starch During Heating In Excess Water: New Insights, Wajira S. Ratnayake, David S. Jackson

Faculty Publications in Food Science and Technology

Starch gelatinization is associated with the disruption of granular structure causing starch molecules to disperse in water. This study was designed to examine starch granules as they were heated in water, and their resulting morphological, structural, and solubility traits. The results indicate that starch gelatinization is a more complex process than the previously suggested order-to-disorder transition. The energy absorbed by the granules facilitates the rearrangement or formation of new bonds among molecules prior to the temperatures normally associated with the melting of amylopectin crystallites during gelatinization. It is also evident that amylose plays an important role during the initial stages ...


Carbon Isotope Ratios Of Amylose, Amylopectin And Mutant Starches, M. Paul Scott, Jay-Lin Jane, Madhavan Soundararajan Oct 1999

Carbon Isotope Ratios Of Amylose, Amylopectin And Mutant Starches, M. Paul Scott, Jay-Lin Jane, Madhavan Soundararajan

Agronomy Publications

Carbon isotope ratios (expressed as δ13C values) were determined for various sources of starch and the starch fractions amylose and amylopectin. The δ13C values of amylose were consistently less negative, 0.4–2.3 ‰, than those of amylopectin in kernal starch from maize (Zea mays) and barley (Hordeum vulgare) and in tuber starch from potato (Solanum tuberosum). Kernel starch isolated from the maize mutants wx1 and ae1, with known genetic lesions in the starch biosynthetic pathway, also showed significant differences in δ13C values. Collectively, these results suggest that variation in carbon isotope ratios in the amylose and ...


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 ...


Physico-Chemical Changes Occurring In Gamma Irradiated Flours Studied By Small-Angle X-Ray Scattering, K. Ciesla, T. Zoltowski, R. Diduszko Jan 1993

Physico-Chemical Changes Occurring In Gamma Irradiated Flours Studied By Small-Angle X-Ray Scattering, K. Ciesla, T. Zoltowski, R. Diduszko

Food Structure

Commercial samples of wheat, rye and potato flour and flaked oats, as well as ground flaked oats and fresh potatoes were gamma-irradiated (20 or 30 kGy dose). The products and appropriate control samples were inves tigated by small-angle X-ray scattering (SAXS) in the range of 28 from 0.357 to 6.46 degree (CuKa radiation). The results were compared with those obta ined for pure potato starch. Effects of grinding and heating at 100° Con SAXS results were also examined.

Different scattering curves were obtained for various unirradiated products. Refl ect ions derived from starch were de tected for some ...


Microstructural Approach To Legume Seeds For Food Uses, Kyoko Saio, Michiko Monma Jan 1993

Microstructural Approach To Legume Seeds For Food Uses, Kyoko Saio, Michiko Monma

Food Structure

This review summarizes the microstructures of several seed legumes based on previous work and some new findings. Fifteen species of tropically grown legumes , adzuki bean and soybeans (a leading variety and two local va rietie s) were examined by light and transmission electron microscopy in relation to food uses. Processing of adzuki beans to form Q!l bean paste is dis cussed to illustrate the effects of processing on microstructure of starch g rains. Differences in contents, shape and size of starch grains are emphasized in a comparison of soybeans wi th other legumes.


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 ...


Properties Of Irradiated Starches, A. S. Sokhey, M. A. Hanna Jan 1993

Properties Of Irradiated Starches, A. S. Sokhey, M. A. Hanna

Food Structure

Properties of irradiated starches have been outlined in this review . ')' -radiation generates free radicals on starch molecules which cause changes in starch properties . The intensity of free radicals is dependent upon starch moisture content , and temperature and duration of storage. Increasing dosages of -y-irradiation creates in creasing intensities of free radicals on carbohydrates. These free radicals are responsible for bringing about molecular changes and fragmentation of starch molec ules. Increasing ')' -irradiation dosages cause an in crease in acidity , and decreases in viscosity and water solubility of starches. The granule structure remains visually undamaged at low dosages of irradiation, but may ...


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 ...


Ultrastructural Changes In Cherimoya Fruit Injured By Chilling, Margarita Gutierrez, Maria Del Mar Sola, Luis Pascual, Maria Isabel Rodriguez-Garcia, Alberto M. Vargas Jan 1992

Ultrastructural Changes In Cherimoya Fruit Injured By Chilling, Margarita Gutierrez, Maria Del Mar Sola, Luis Pascual, Maria Isabel Rodriguez-Garcia, Alberto M. Vargas

Food Structure

Cherimoya (Annona cherimola Mill.) is an important fruit crop that is grown in the South of Spain. Ultrastructural modifications of cherimoya fruit were studied after low-temperature storage. When cherimoya was stored at 4 oc for 6 days, the starch grains did not suffer degradation and the cell walls remained intact. The membrane systems were severely damaged , result ing in a loss of cell compartmentalization. Cherimoya rewarmed to 22 0 C after 9 days of low temperature storage is not able to recover , showing the irreversibility of the ultra structural changes. In addition, disorgani zation of the internal lamella of chloroplasts ...


Heat-Induced Structural Changes In Acid-Modified Barley Starch Dispersions, K. Autio, K. Poutanen, T. Suortti, E. Pessa Jan 1992

Heat-Induced Structural Changes In Acid-Modified Barley Starch Dispersions, K. Autio, K. Poutanen, T. Suortti, E. Pessa

Food Structure

The effect of heat treatment on the gel formation and microstructure of barley starch dispersions , hydrolyzed with I M HCI for 0.5, 1.0 and 4.0 hours , was studied by dynamic viscoelastic methods and by light microscopy . The effects of acid hydrolysis on the molecular weight of amylopectin and amylose were studied by high -performance liquid chromatography (HPLC) with post-column iodine staining.

Microstructural studies of 8% hydrolyzed barley starch dispersions heated to 90 0 C showed that even a short acid treatment induced considerable changes in the granule structure. The molecular weight of amylopectin decreased substantially. As the ...