Food Chemistry Commons^™

Plant Cell Wall Composition And In Vitro Fermentation Characteristics Of Cool-Season Forage Grasses From Two Growing Seasons In Central Kentucky, Sophia Danielle Newhuis

Theses and Dissertations--Animal and Food Sciences

Grass cell walls are rich in cellulose, hemicellulosic arabinoxylan (AX) polysaccharides, and lignin. AX structural differences such as degree and pattern of branching and the ester-linked phenolic acid content could affect plants’ digestibility when used as forage for livestock. However, there is little information about how these structural elements change over the growing season in the vegetative tissue of cool-season perennial grasses. Enhanced information about the cell wall composition and carbohydrate structure of forage material will provide a foundation for expanding our knowledge of how forage cell wall carbohydrate structures are utilized by ruminants. The objectives of this study were …

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 …

Arabinoxylan Structural Profiling Of Cool-Season Pasture Grasses Via High-Performance Anion-Exchange Chromatography With Pulsed Amperometric Detection (Hpaec-Pad) Analysis Of Endoxylanase Digests, Glenna Erin Joyce

Theses and Dissertations--Animal and Food Sciences

Arabinoxylan (AX) is a major structural polysaccharide found in the cell walls of monocots such as cereal grains and pasture grasses. The variety of AX structural components and substitution patterns contribute to AX structural diversity between different monocot species as well as plant tissues.

The rumen is the first digestion site of masticated food material in cattle and provides 70% of energy to host through fermentation of forage. There are many species of pasture grasses that act as a forage source. Differences in AX structure found in these pasture grasses may impact rumen microbial fermentation. Understanding the AX structure of …

Thermal, Interfacial, And Application Properties Of Pea Protein Modified With High Intensity Ultrasound, Aeneas Koosis

Theses and Dissertations--Animal and Food Sciences

The overall objective of the study was to investigate different food ingredient conditions and ultrasound treatment on pea protein in terms of surface morphology and thermal characteristics. The motivation of this work was based on previous studies focusing on non-chemical physical modifications of plant proteins and the increasing demand for functional alternative proteins.

Ultrasonication time and amplitude, pH, protein concentration, and salt concentration all influenced the thermal and interfacial properties of pea protein. Ultrasound treatment altered the quaternary and tertiary structure of the storage protein and disrupted non-covalent bonds. The structural altercations and a reduction in particle size led to …

Influence Of Dietary Ractopamine And Supranutritional Supplementation Of Vitamin E On Proteome Profile Of Postmortem Beef Longissimus Lumborum Muscle, Hyun Mok Kim

Theses and Dissertations--Animal and Food Sciences

The effects of dietary ingredients on the proteome profile of postmortem beef longissimus lumborum (LL) muscle were evaluated. In the first experiment, the influence of dietary ractopamine on the whole-muscle proteome of beef LL was examined. Five proteins were differentially abundant between ractopamine-fed (RAC) and non-ractopamine fed (CON) groups. The differentially abundant proteins were over-abundant in RAC and were related to muscle structure development (F-actin-capping protein subunit beta-2 and PDZ and LIM domain protein-3), chaperone (heat shock protein beta-1), oxygen transportation (myoglobin), and glycolysis (L-lactate dehydrogenase A chain). These findings indicated that ractopamine influences the abundance of proteins associated with …

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 …

Proteome Basis Of Muscle‐Specific Beef Color Stability, Mahesh Narayanan Nair

Theses and Dissertations--Animal and Food Sciences

Fresh beef color is critical to consumers’ purchase decisions, and beef color stability is muscle-specific. Sarcoplasmic proteome plays a critical role in beef color stability. This dissertation focuses on the proteome basis of inter- and intra-muscular variations in beef color.

The first experiment examined the sarcoplasmic proteome of three beef muscles with differential color stability, i.e., longissimus lumborum (LL), psoas major (PM), and semitendinosus (ST), during wet-aging. LL, PM, and ST (n = 8) were subjected to wet-aging for 0, 7, 14, and 21 days. On each aging day, steaks were fabricated, and color and other biochemical attributes were evaluated …

Relative Reactivity Of Protein And Lipid To Oxidants In Different Bi-Phasic Systems And Its Implication In Sausage Quality, Jiayi Yang

Theses and Dissertations--Animal and Food Sciences

This study investigated the progression of protein and lipid oxidation in different bi-phasic model systems: simple aqueous dispersions, liposome, and oil-in-water (O/W) emulsions. Varied concentrations of isolated pork myofibrillar protein (MFP) were mixed with free fatty acids (C18:1, C18:2, C18:3), lecithin, or vegetable oil to construct different lipid-protein dispersion systems, then subjected to hydroxyl radical stress at 4 °C. Comparison of the evolution of lipid oxidation with protein modification markers in all dispersion systems showed noteworthy attenuation of tryptophan fluorescence, protein carbonyl formation, and extensive polymerization of myosin in 2 h. This process preceded lipid oxidation which exhibited notable accumulations …

Impact Of Algae Supplemented Diets Combined With Antioxidants On The Nutritional Profile, Quality Attributes, And Storage Stability Of Chicken Breast Meat, Rebecca G. Norcross

Theses and Dissertations--Animal and Food Sciences

Consumers’ demands for ω-3 polyunsaturated fatty acids (PUFAs) are at all-time high. Algae, a common source of PUFAs, and antioxidants are both used as supplements in livestock feeds, are known to affect the overall quality of meat. To implement PUFA deposits into broiler meat, this study evaluated combining antioxidants and algae in broiler feed to enhance the breast meat quality. Broilers were fed diets supplemented with 50 IU Vitamin E or 200 g/ton EconomasE (EcoE, an antioxidant pack) plus 10 IU Vitamin E, with or without 0.5% algae extract (SP-1). The feed oil was partially oxidized soybean oil (POV: 86 …

Rheological, Foam, And Physical Properties Of Low Sucrose Meringue And Angel Food Cake Formulated With Non-Nutritive Sweeteners And Polydextrose, Kevin J. O'Niones

Theses and Dissertations--Animal and Food Sciences

The object of this research was to determine if an acceptable angel food cake alternative could be produced that had reduced calories and sucrose content. This was accomplished through replacing sucrose in meringue, angel food cake batter, and baked angel food cakes with polydextrose and either sucralose, acesulfame-K, or Rebaudioside A at different replacement levels (25, 50, 75, 100%). Meringue and cake batter properties were measured using rheological techniques. Baked angel food cakes were analyzed based on height, weight loss, moisture content, color, and TPA analysis. With meringue batter, 100% sucrose replacement was unacceptable since undissolved polydextrose made analyzing and …

Analysis Of Antiviral And Chemoprotective Effects Of Strawberry Anthocyanins, Jennifer A. Willig

Theses and Dissertations--Animal and Food Sciences

This study investigated the antiviral, chemoprotective and proliferative effects of strawberry anthocyanins on herpes simplex virus type-1, cancerous cell lines HT-29 and AGS, and normal cell lines Hs 738.St/Int and CCD-18Co. Antiviral properties were measured by infecting vero cells from adult grivet (Cercopithecus aethiops) with herpes simplex virus type-1 (HSV-1) and treating with a concentration of 1.25-20 µg/mL of strawberry anthocyanins. Infectivity and replication were quantified for herpes simplex virus type-1 using the direct plaque assay and reporting PFU/mL. Strawberry anthocyanins (>20 µg/mL) inhibited the herpes simplex virus infectivity in vero cells by 100% (p<0.05). Strawberry anthocyanins at concentrations of 5, 10 and 20 μg/mL were reduced to 75.36, 57.98, and 31.46 percent of the control (100%) (p<0.05).

Chemoprotective and …

Effect Of Amylose And Protein Oxidation On The Thermal, Rheological, Structural, And Digestive Properties Of Waxy And Common Rice Flours And Starches, Jing Liu

Theses and Dissertations--Animal and Food Sciences

The effects of oxidation by sodium hypochlorite (0, 0.8, 2, and 5%, NaOCl), the presence of endogenous proteins, and amylose content on waxy and common rice flours (WF, CF) and starches (WS, CS) were investigated in terms of in vitro starch digestibility, morphology and surface properties, and thermal and rheological characteristics.

The concentration of NaOCl had an effect on all the samples including WF, CF, WS, and CS. The carbonyl and carboxyl group contents increased up to 25 and 10 folds (P < 0.05) of oxidized starches (WS, CS), respectively. Only mild oxidation (P < 0.05) occurred in flours (WF, WS). In addition, endogenous proteins were oxidized according to amino acid analysis and SDS–PAGE results. Glu+Gln, Gly, His, Arg, Tyr, and Lys were more sensitive to NaOCl oxidation. Disulfide bonds, hydrophobic force, and hydrogen bonds were involved in protein polymerization after NaOCl oxidative modification. In granular state, the in vitro starch digestibility of WF, WS, and CS decreased by 5% NaOCl oxidation. After gelatinization, …

Dietary Antioxidant Supplementation (Economase–Bioplex) To Alleviate Adverse Impacts Of Oxidized Oil On Broiler Meat Quality: A Chemical, Textural, Enzymatic, And Proteomic Study, Rebecca Delles

Theses and Dissertations--Animal and Food Sciences

This study investigated the influence of dietary antioxidants and quality of oil on the oxidative and enzymatic properties of chicken broiler meat stored in an oxygen-enriched package (HiOx: 80% O₂/20% CO₂) in comparison with air-permeable polyvinylchloride (PVC) or skin (SK) packaging systems during retail display 2–4 °C for up to 14, 7, and 21 d, respectively. Broilers were fed a diet either with a low-oxidized oil (peroxide vale POV 23 meq O₂/kg) or with a high-oxidized oil (POV 121 meq O₂/kg), supplemented with an antioxidant pack (200 ppm EconomasE and organic minerals …