Doctor of Philosophy, The Ohio State University, 2009, Food Science and Nutrition

High pressure processing (HPP; 100-700 MPa at temperatures < 45°C) and pressure-assisted thermal processing (PATP) (500-700 MPa; 90-120°C) have been used to inactivate pathogenic and spoilage bacteria and produce high quality foods. The objectives of this dissertation were to evaluate the influence of various pressure-temperature combinations on quality, microbial lethality and thermophysical properties of selected foods. Experiments were conducted to investigate the influence of process temperature (95-121°C) at different pressures (0.1, 500-700 MPa) on carrot quality. Results indicated that under comparable process temperatures (up to 105°C), pressure-assisted thermal processing (PATP) retained the carrot quality attributes such as color and carotene content better than thermal processing (TP). However, process and preprocess thermal history greatly influenced carrot textural change. Pressure protective effects on product hardness at elevated temperatures (110-121°C) were less pronounced. Subsequently, experiments were conducted to evaluate the role of pressure during sequential (pressure pre-treatment at ambient temperature followed by TP) or simultaneous (PATP) treatment in preserving product quality attributes. To learn how different food matrices are influenced by various pressure-heat combinations, experiments were also carried out using carrot, jicama, red radish, zucchini, and apricot. Results showed that TP degraded product texture severely but HPP followed by TP improved texture retention. In comparison to TP alone, PATP better retained texture and color. The beneficial effects of PATP may come from the densification of the tissue due to pressurization or biochemical changes of the pectic substances. Texture retention was product dependent, with jicama being the least influenced among the foods tested. An instrumental based crunchiness index (CI) was developed and validated using sensory data. CI was able to describe textural transformation of various p (open full item for complete abstract)

Committee: V.M. Balasubramaniam PhD (Advisor); Sudhir Sastry PhD (Committee Member); Ahmed Yousef PhD (Committee Member); Luis Rodriguez-Saona PhD (Committee Member) Subjects: Food Science

Doctor of Philosophy, The Ohio State University, 2016, Food Science and Technology

High pressure with or without heat has been used to pasteurize or sterilize various foods. While numerous studies described the kinetics of microbial inactivation, very limited studies are available to describe kinetics of degradation of chemical constituents including nutrients and process induced toxic compounds during combined pressure-thermal treatment. The objective of this research was to estimate the kinetic model parameters for ascorbic acid degradation and furan formation in selected fruits and vegetable juices including that of pineapple at various pressure-thermal combinations. In addition, pressure-thermal kinetic and thermodynamic parameters were also estimated for inactivation of egg white avidin in buffer solution (pH 7.5). Experiments were carried out at various combination of pressures and temperatures in fruit and vegetable juices as well as in buffer solution. Samples were high pressure processed (HPP; up to 600 MPa at 30 °C), for holding times up to 45 min using laboratory and pilot scale high-pressure food processor. Thermal processing (TP) experiments (0.1 MPa, 65-120 °C) for holding times up to 60 min were carried out to study thermal only effects. In addition, combined pressure (600 MPa) and thermal (65 -105 °C) experiments were also conducted. Ascorbic acid, furan and avidin activity were determined (in raw and processed samples) by automated HPLC, headspace GC/MS, and fluorescence spectrometry, respectively. The experimental data were modeled with zero, first and second order kinetic equations coupled with Arrhenius and Eyring -Polanyi models. The models and its parameters were evaluated and selected based on coefficient of determination, root mean squared error and statistical significance (p < 0.05). HPP (600 MPa at 30 °C) preserved ascorbic acid without inducing furan in pineapple juice. It also preserved avidin activity and binding strength with biotin-4-fluorescein at all holding times. TP (0.1 MPa, 75-95 °C) degraded (open full item for complete abstract)

Committee: V.M. Balasubramaniam (Advisor); Dennis Heldman (Committee Member); Farnaz Maleky (Committee Member); Hannah Shafaat (Committee Member) Subjects: Agriculture; Chemistry; Engineering; Food Science; Technology

Master of Science, The Ohio State University, 2013, Food Science and Technology

Almond milk as a beverage has recently gained attention with increase in consumer awareness about health benefits of plant based beverages. The objective of this research was to investigate the influence of high pressure processing (HPP) on residual mmunoreactivity, protein solubility, and other selected quality attributes. Almond milk was prepared by disintegrating 10% almonds with water and were subjected to high pressure processing (HPP; 450 and 600 MPa at 30oC up to 600 s) and thermal processing (TP; 72, 85 and 99 oC, 0.1 MPa up to 600 s). After HPP (for all holding times), amandin, a key thermally resistant almond allergen, can no longer be detected by the anti-conformational epitopes MAb in ELISA while signal generated from the anti-linear epitopes MAb was reduced by half (P < 0.05). On the other hand, most TP samples did not show significant reductions in immunoreactivity (P > 0.05) unless processed at 85 and 99 °C for 300 s. Western blot (applicable for soluble proteins) and dot blot (applicable for soluble and insoluble proteins) also confirmed the loss of immunoreactivity by both antibodies for HPP almond milk. The reduced band intensity of the 61 and 63 kDa polypeptides and concomitant appearance of high molecular weight polypeptides in Western blot indicated that the observed decrease in immunoreactivity was partly due to the aggregation of amandin. Within the tested conditions of the study, HPP and TP treatments respectively caused a maximum of ~70% and ~75 % reduction in protein solubility in almond milk. Within the experimental ranges of the study, particle size analysis of pressure treated almond milk revealed the increase in volumetric diameter (D4,3), surface area diameter (D3,2) and volume median diameter (Dv0.5) with increase in pressure level and treatment time possibly due to protein aggregation. The apparent aggregation rate constant for 450 MPa and 600 MPa processed samples were k450MPa,30 oC = 0.0045 s-1and k600MPa, 30 oC = 0.00 (open full item for complete abstract)

Committee: V.M. Balasubramaniam (Advisor) Subjects: Food Science

Doctor of Philosophy, The Ohio State University, 2011, Food Science and Technology

Lycopene is a major carotenoid in tomatoes and epidemiological studies suggest that consumption of food rich in carotenoids lowers the risk of developing certain types of cancer and chronic diseases. However, very little is known about its fate in tomato products subjected to a range of combined pressure-temperature (P-T) treatments. Likewise, little is known about the pressure-temperature uniformity during combined P-T processing. This study was conducted to investigate the effect of pressure-thermal treatments (0.1, 500, 600 & 700 MPa; 30-100 deg. C, different time intervals) on post processing extractability, isomerization, bioaccessibility and storage stability of lycopene in tomato juice. Finally, a study was conducted to evaluate the feasibility of using a chemical M-2 (4-Hydroxy-5-methyl-3(2H)-furanone) as a potential marker for understanding combined P-T process non-uniformity. Combined pressure-thermal treatments (Pressure Assisted Thermal Processing (PATP), High Pressure Processing (HPP)) resulted in up to 12% increase in lycopene extractability over thermally processed (TP) and unprocessed control tomato juice. In addition, all-trans lycopene showed stability to isomerization in tomato juice samples subjected to HPP, PATP and TP. The post processing retention of β-carotene was a function of processing time, temperature, pressure, cultivar used and type of juice (raw vs. hot break). During storage, lycopene degradation varied as a function of cultivar, processing method, storage temperature, and time. Increase in storage temperatures also increased degradation. Among the stored juices, HPP processed juice showed the least lycopene degradation. Also, HPP and PATP juice samples better retained lycopene cis isomers and color during storage. β-carotene showed good stability in the processed samples during storage. A two-step first order equation was used to predict the changes in lycopene concentration over the course of storage. The processed juice sam (open full item for complete abstract)

Committee: V.M. Balasubramaniam (Advisor); S.J. Schwartz (Committee Member); S.K. Sastry (Committee Member); J.H. Litchfield (Committee Member) Subjects: Agricultural Engineering; Biochemistry; Chemical Engineering; Chemistry; Food Science

Master of Science, The Ohio State University, 2011, Food Science and Technology

The objective of this work was to determine the combined effects of pressure pre-treatment along with soluble zinc on selected quality attributes of thermally processed green beans. Green beans were vacuum packaged in flexible pouches with zinc chloride solution such that the zinc Concentration was 0, 100, 400, or 800 ppm. Pouches were then processed at 150 or 600 MPa for 5, 15, or 30 minutes at 45°C. Pouches held for 30 minutes at ambient pressure and 45°C served as controls. After pre-treatment, green beans were retorted in 1.5% NaCl solution at 122 ± 0.2°C. Maximum shear force, color, final zinc concentration, and chlorophyll derivative profile were determined. The texture of thermally sterilized green beans that were subjected to pressure pretreatment showed remarkable improvement. For example, pressure pretreatment at 600 MPa with 800 ppm zinc resulted in 51% increase in shear force values compared to control. In comparison to control, 600 MPa pressure treatment in combination with 400 and 800 ppm zinc concentration decreased the a* value by 1.65 and 3.38 respectively. High pressure pre-treatment (600 MPa, 45°C, 30 min) caused 38% more zinc to infuse into green beans compared to control. High pressure induced a significant effect upon chlorophyll derivatives. A 47% increase in zn-pyropheophytin and 46% decrease in pyropheophytin was observed when pressure was used for 30 minutes at 600 MPa and 45°C compared to control. Pressure pretreatment of green beans suspended in zinc solution prior to thermal sterilization appears to be an effective approach to improve the quality of processed green beans.

Committee: V.M. Balasubramanima PhD (Advisor); Steven Schwartz PhD (Committee Member); Sheryl Barringer PhD (Committee Member) Subjects: Chemistry; Food Science

Master of Science, The Ohio State University, 2009, Food Science and Nutrition

Pressure-assisted thermal processing (PATP) is an emerging alternative food processing technology that utilizes elevated pressure combined with heat to provide shelf-stable foods with superior quality attributes. This study examined the effect of PATP on texture, in vitro protein digestibility (IVPD), color, water imbibition and cooked volume of black beans (Phaseolus vulgaris L.). Beans were presoaked (15, 30, 60 and 120 min at 82°C, 24 hours at 23°C) and subjected to 600 MPa at 105°C for 1 second, 5, 10, 15 and 30 minutes. Pressure come-up time was 2 minutes and decompression time was 90 seconds. Thermally processed (TP; 105°C for 5 minutes) beans, using a still retort, were used as a control. PATP was found to significantly increase (p < 0.05) bean softening, IVPD and water absorption as compared to TP. Increasing pressure hold time during PATP generally increased bean softening. Changes in pressure holding time or soak time did not alter IVPD (≈79%) of PATP treated samples. Beans soaked for 15, 30 and 60 min showed lower volume increases after 5 min PATP as compared to thermally processed beans. Neither soak time nor processing time were found to have any influence on bean color. Within the range of process conditions of the study, PATP may be a viable alternative for preserving black beans.

Committee: V.M. Balasubramaniam (Advisor); Sheryl Barringer (Committee Member); Lynn Knipe (Committee Member) Subjects: Food Science

Doctor of Philosophy, The Ohio State University, 2009, Food Science and Nutrition

Selected approaches for enhancing pressure-assisted thermal processing (PATP) lethality on bacterial spore inactivation were investigated using high pressure microbial kinetic testing equipment. Bacillus amyloliquefaciens TMW 2.479 spores were used as the test organisms. Efficacy of pressurization rate and double-pulse treatment in enhancing PATP lethality was examined. Pressurization rate influenced the PATP lethality as a function of pressure-holding time. During short pressure holding times (≤2 min), PATP treatment with the slow pressurization rate (3.75 MPA/s) provided enhanced spore reduction over that of fast pressurization rate (18.06 MPa/s). Regardless of the pressurization rate, after 5-min treatment at 105°C-600 MPa, 6 log reduction of B. amyloliquefaciens spores were observed. Double-pulse treatment enhanced PATP lethality by approximately 2.4 to 4 log CFU/ml, in comparison to single pulse for a given pressure holding time. The efficacy of combining organic acids (acetic, citric, and lactic; 100 mM, pH 5.0) with PATP treatment in enhancing B. amyloliquefaciens inactivation was studied. In combination with 2-min PATP treatment at 700 MPa-105°C, acetic and citric acids were found to provide synergistic effect on inactivating B. amyloliquefaciens spores than the spores suspended in lactic acid or deionized water. Organic acids in combination with PATP treatment also induced spore germination (33% to 80%) as a function of pressure holding time and type of organic acid used. Combining organic acids with PATP also inhibited the growth and recovery of the remaining survivor population during 28-day storage at 32°C in a low-acid food model system (carrot puree, pH 5.0). Biochemical changes in B. amyloliquefaciens spores grown in two different sporulation media (TSAYE and NAYE) as influenced by PATP, high pressure processing (HPP), and thermal processing (TP) were investigated using Fourier-transform infrared spectroscopy (FT-IR). FT-IR spectra of the bacterial (open full item for complete abstract)

Committee: V.M. Balasubramaniam PhD (Advisor); Ahmed Yousef PhD (Committee Member); Alvarez Valente PhD (Committee Member); Luis Rodriguez-Saona PhD (Committee Member) Subjects: Food Science

Master of Science, The Ohio State University, 2005, Graduate School

Committee: Not Provided (Other) Subjects:

Doctor of Philosophy, Case Western Reserve University, 2024, Macromolecular Science and Engineering

Traditionally, extrinsic approaches (e.g. blending and using additives) have been used to enhance the mechanical properties (e.g. toughness) of commercially available semicrystalline thermoplastics. In a continual search for economically scalable, scrapless, simple, and versatile manufacturing approaches, novel solid-state processes have a unique advantage over melt-processing methods alone. Cold-roll milling, or plastically deforming a workpiece by passing it through two counter-rotating rollers below its primary softening temperature, is well-established in the production of ductile metals. Roll-milling not only reduces thickness, but also cold-works the material improving its strength through microstructural refinement. In polymers, a crystalline network structure develops. The focus of this work is on biaxial cold-rolling (cross-rolling) which involves cross-passes alternately 90 ° apart, resulting in a sheet with planar isotropy. In the first part of this dissertation (chapter 2), the deformation of HDPE by cross-rolling is studied. Enhanced barrier properties (measured by oxygen permeability analyzer), increased visible light transmission (measured by spectrophotometer), and increased tensile fracture strength were observed after cross-rolling. A connection to discontinuous change in crystalline structure with thickness reduction (i.e. lamellar fragmentation) detected by density measurement, thermal analysis, and small-angle x-ray scattering (SAXS) is discussed. The second portion (chapters 3-5) focuses on the cross-roll pre-deformation of semicrystalline polymers below both the Tm and Tg at room temperature, and subsequently annealing at temperatures both below and above the Tg. In chapter 3, the Izod impact toughness of poly(p-phenylene sulfide), a notoriously low toughness high-temperature engineering thermoplastic, is found to increase by a factor of 10 after cross-rolling. The elongation to failure is enhanced by a factor of nearly 6 by cross- (open full item for complete abstract)

Committee: Gary Wnek (Committee Chair); Lei Zhu (Committee Member); Ica Manas (Committee Member); John Lewandowski (Committee Member) Subjects: Materials Science; Mechanical Engineering; Mechanics; Plastics

Doctor of Philosophy, The Ohio State University, 2023, Food Science and Technology

Consumer demands for ethically sourced and environmentally friendly food products have led to development efforts to replace animal-based proteins with plant-based alternatives. However, plant-based protein ingredients can be limited by their functional and sensory properties, and thus processing techniques to improve these properties must be explored. Enzymatic hydrolysis has been suggested to improve key functional properties, such as solubility, but the research methodology in this area is questionable and hydrolysis does not fully address sensory deficits in plant-protein ingredients, notably bitterness. In this dissertation, commercial extruded snack products containing soy protein hydrolysates were used as a model to quantify bitterness and test the viability of reformulation with flavor maskers or alternatively processed proteins to improve off-flavor. This study revealed that commercial flavor maskers are not effective at reducing bitterness in products containing soy hydrolysate, but soy protein hydrolysates made by different manufacturers with different processing methods proved a viable replacement with improved off-flavor. In search for conclusive evidence that enzymatic hydrolysis results in improved functionality, a review of literature was conducted. This review concluded that enzymatic hydrolysis process may result in the formation of insoluble aggregates, which in most studies are removed by centrifugation or filtration during processing, thus artificially increasing the reported solubility values for plant-protein hydrolysates. The phenomenon of hydrolysis induced aggregation was confirmed for protein isolates from soy and as well as a pulse protein alternative to soy, chickpea, which were hydrolyzed by Flavourzyme and Alcalase. Analysis of physical and structural properties of the hydrolyzed proteins revealed that hydrolysis led to protein destabilization, causing hydrogen-bond mediated aggregation during thermal enzyme inactivation. The knowledge (open full item for complete abstract)

Committee: Farnaz Maleky (Advisor); Osvaldo Campanella (Committee Member); Emmanuel Hatzakis (Committee Member); John Litchfield (Committee Member); Lynn Knipe (Committee Member) Subjects: Biochemistry; Food Science

Doctor of Philosophy, Case Western Reserve University, 2021, Macromolecular Science and Engineering

The step polymerization reaction between diisocyanates and diols results in a tremendously functional material with wide-ranging applications including medical devices and sealants, known as thermoplastic polyurethane (TPU). The microphase separation of urethane-rich hard segments (HS) and hydrocarbon soft segments (SS) provide TPU with the unique morphology responsible for its elastomeric properties. The structure-property relationships of TPU have been understood in terms of either a rubber-like material where HS-rich regions act as crosslink points or a nanocomposite where hard regions are the reinforcing agent. In both views, attempts to model the mechanical behavior based on morphology are hampered by the difficulty in determining parameters that describe the morphology from the chemical composition. The distribution of HS block length and the attractive hydrogen bonding forces make predicting the morphology using block co-polymer theory imprecise, especially for low HS content (HSC) TPUs. Furthermore, TPU has typically been viewed as a binary system with a hard phase dictated by the HSC and a soft phase whose properties are only dependent on the diol type and molecular weight. The first part of this thesis challenges the binary view of TPU through an experimental and modeling investigation. An analytical micromechanical model, the Eshelby double inclusion model, was used to evaluate the observed mechanical behavior of a series of polyester TPUs with increasing HSC, a series of polyether TPUs softened by triols in the SS, and a series of polyester TPUs softened by triol chain extenders. The model was used to probe the mechanical reinforcement contribution from morphological parameters. The TPU morphology was modeled as a composite of HS-rich “hard particles” and a SS-rich “soft matrix”, with the necessity of a third, intermediary phase, the “interphase” evaluated based on experimental results. The second part of the thesis goes beyond neat TPU by prepa (open full item for complete abstract)

Committee: Ica Manas-Zloczower (Advisor); Donald Feke (Committee Member); Michael Hore (Committee Member); Gary Wnek (Committee Member) Subjects: Polymers

MS, University of Cincinnati, 2018, Engineering and Applied Science: Computer Science

A major public health problem which affects people from all walks of life is muscle injury. Muscle fatigue can be defined as a reversible decrease in the contractile strength of the muscle(s) that occurs after long lasting or repetitive muscular activity. Whenever a certain muscle or muscle groups are subjected to repetitive movements and pushed beyond their limits, it leads to muscle fatigue, which results in sub-optimal performance. Muscle fatigue, when not diagnosed and treated in the early stages, leads to muscle injuries which tend to have long-lasting effects. The current technologies which are used to detect and treat muscle fatigue are highly invasive and often require the personnel to visit specialized clinics. The invasiveness and inaccessibility of muscle fatigue detection techniques have contributed to delayed diagnosis which leads to undesirable effects like permanent muscle damage. A non-invasive, cost-efficient method for detecting muscle fatigue is crucial. Whenever a muscle(s) is put to use, the corresponding muscle temperature increases. The human body maintains thermal homeostasis and it is achieved with the help of two processes called vasodilation and vasoconstriction. Vasodilation occurs when the temperature of a certain muscle group increases. The blood flow to this particular region is increased and the heat is absorbed by the blood capillaries and dissipated through the skin. Infrared thermography is a non-radiating and contact-free technology which measures the surface temperature of objects. As skin surface temperature has been proven to be a good indicator of localized muscle fatigue, Infrared thermography can be an effective non-invasive associative technology which can be used to detect muscle fatigue. In our study, we have conducted experiments which involve test subjects performing repetitive exercises involving the upper body muscle groups. The thermal images of the test subjects were taken before and after the exercise routine (open full item for complete abstract)

Committee: Dharma Agrawal D.Sc. (Committee Chair); Yizong Cheng Ph.D. (Committee Member); Wen-Ben Jone Ph.D. (Committee Member) Subjects: Computer Science

Master of Science, The Ohio State University, 2018, Food Science and Technology

Processors of American pickles utilize fermentation or direct acidification in conjunction with thermal processing as a part of their preservation step. Health conscious consumers are demanding for clean-labeled products that are minimally processed with reduced salt/sugar and free from synthetic preservatives. This has prompted the pickle manufactures to investigate clean food processing methods such as high pressure processing (HPP) and other minimally processed methods with reduced thermal impact. Our hypothesis is that by reducing thermal exposure, combined pressure-thermal treatment can help to better retain quality attributes of selected acidified vegetable pickles over 30 days storage at 25oC. The objective of this research were to evaluate the heat of compression of pickling liquid with various solute concentration as well as vegetables subjected to two different acidification pretreatment approaches (2) assess the quality changes of acidified vegetables treated by various pressure (600 MPa)-thermal (45-65oC) combinations with and without thermal blanching. First set of experiments investigated the heat of compression values of pickling solution with varying solute concentration as well as pickling vegetables subjected to two different pre-treatments. Subsequently samples were pressure treated in a pilot scale high-pressure processor at 600 MPa, 45° or 65°C for 5 min and stored at ambient temperature for 30 days. Quality analyses included texture, enzyme activity, color, pH and °Brix. Solute concentration, initial temperatures and vegetable pretreatments significantly influenced heat of compression values of pickling liquid and vegetables. At 25oC, heat of iii compression values of the pickling liquid varied as a function of varying solute concentration (p<0.05). On the other hand, thermal effect dominated over solute concentration at 60oC. Both methods of acidification (thermal blanching and overnight soaking) of vegetables influenced heat of compressio (open full item for complete abstract)

Committee: V.M. Balasubramaniam (Advisor); Rafael Jimenez-Flores (Committee Member); Lynn Knipe (Committee Member) Subjects: Engineering; Food Science

Doctor of Philosophy, The Ohio State University, 2018, Food Science and Technology

Pressure-Assisted Thermal Processing (PATP) is an emerging food preservation technology for sterilizing low-acid foods by inactivating bacterial spores using the combination of pressure and heat. PATP technology has the potential to produce high-quality, nutritious, microbially safe, shelf stable low-acid foods without adding chemical preservatives. Limited studies have evaluated the influence of product properties (salt, sugar, and water activity) and packaging parameters on spore inactivation during PATP. The objectives of this research are (a) to investigate the influence of packaging systems on Bacillus spore inactivation, (b) to evaluate the effect of salt and sugar on the Bacillus amyloliquefaciens spore inactivation, and (c) to generate a model to describe spore inactivation as a function of water activity and temperature. Experiments were conducted using laboratory and pilot scale custom fabricated high-pressure equipment. Thermal processing (TP) experiments were conducted using aluminum discs suspended in a temperature-controlled oil bath. Experiments utilized Bacillus amyloliquefaciens TMW 2.479 Fad 82 and Bacillus cereus as the model test microorganisms. To investigate the influence of packaging systems on spore inactivation, Bacillus amyloliquefaciens spore and Bacillus cereus spore samples (~2 x 106 spores/mL), suspended in N-2-hydroxyethylpiperazine-N-2'-ethanesulfonic acid (HEPES) buffer pH7, were packaged into polyethylene pouches, polyethylene tubes, and semi-rigid polypropylene cryogenic vials. The calculated D-values for B. amyloliquefaciens spore inactivation packaged in pouches, tubes, and vials at 105 °C were 2.1, 2.1, and 1.9 minutes, respectively. Meanwhile, D-values of B. cereus treated in pouches, tubes, and vials at 85 °C were 2.2, 2.0, and 2.0 minutes. The D-values were not significantly different (p>0.05). The difference in spore inactivation could be attributed to the influence of different packaging materials, thermal properties (open full item for complete abstract)

Committee: V.M. Balasubramaniam (Advisor); Ahmed Yousef (Committee Member); Sudhir Sastry (Committee Member); Lynn Knipe (Committee Member) Subjects: Food Science

Doctor of Philosophy, The Ohio State University, 2011, Food Science and Technology

Flavones are abundant in parsley and celery and possess unique anti-inflammatory properties in vitro and in animal models. However, their bioavailability and bioactivity depend in part on the conjugation of sugars and other functional groups to the flavone core. Two studies were conducted to determine the effects of processing on stability and profiles of flavones in celery and parsley, and a third explored the effects of deglycosylation on the anti-inflammatory activity of flavones in vitro and their absorption in vivo. In the first processing study, celery leaves were combined with beta-glucosidase-rich food ingredients (almond, flax seed, or chickpea flour) to determine test for enzymatic hydrolysis of flavone apiosylglucosides. Although all of the enzyme-rich ingredients could convert apigenin glucoside to aglycone, none had an effect on apigenin apiosylglucoside. Thermal stability of flavones from celery was also tested by isolating them and heating at 100 °C for up to 5 hours in pH 3, 5, or 7 buffer. Apigenin glucoside was most stable of the flavones tested, with minimal degradation regardless of pH or heating time. Apigenin, luteolin, and chrysoeriol were stable at pH 3, but degraded steadily at pH 5 or 7. Apigenin apiosylglucoside was least stable at pH 3, but its primary degradation product was apigenin glucoside. Further experiments with thermal processing and enzyme treatments showed that apigenin apiosylglucoside could be converted stepwise to apigenin glucoside and then to aglycone, resulting in over 95% conversion of total apigenin derivatives. The second processing study explored the effects of juice extraction, acidification, thermal processing, and endogenous enzymes on flavone profiles and concentrations in parsley and celery. Parsley yielded 72% juice with 64% of the total flavones extracted, while celery yielded 79% juice with 56% of flavones extracted. Fresh parsley juice averaged 281 mg flavones/100 g, and fresh celery juice 28.5 mg/100 g. Fla (open full item for complete abstract)

Committee: Steven Schwartz (Advisor); Sheryl A. Barringer (Committee Member); Erich Grotewold (Committee Member); Andrea Doseff (Committee Member) Subjects: Analytical Chemistry; Biochemistry; Cellular Biology; Food Science; Nutrition

Doctor of Philosophy, The Ohio State University, 2011, Materials Science and Engineering

Porous inorganic membranes made from sintered ceramic oxides are considered for water purification applications. In particular, inorganic membranes are attracting attention because of their chemical, thermal and mechanical stability. These characteristics imply that ceramic membranes can be subject to large pressure differences, high temperatures and rigorous cleaning procedures, and have operational lifetimes on the order of decades. Inorganic membranes are considered for wastewater treatment, desalination, and recycling of produced water. In this work, synthesis and properties of mesoporous γ-alumina, titania, tin oxide and gadolinium-doped cerium oxide (CGO) nano-filtration membranes are presented. “Mesoporous” refers to pore sizes of 2…50 nm and “nano-filtration” refers to removal of 1 to 2 nm species. The membranes were synthesized by dip-coating nanoparticle sols onto smooth, macro-porous α-alumina supports followed by thermal consolidation. Synthesis conditions were optimized for increased ion rejection. Single layer γ-alumina membranes with 800 nm thickness and a typical pore diameter, Øp, of 4 nm were made and studied for aqueous NaCl, CaCl2, AlCl3, NaCl+1%AlCl3, and CaCl2+1%AlCl3 nano-filtration. It was found that a small amount of AlCl3 in the solution can suppress dissolution of the γ-alumina membrane. This leads to a major improvement in the reproducibility of mechanical permeance measurement so that, for the first time, osmotic effects could be unmistakably demonstrated. The nearly 100% rejection values for CaCl2, CaCl2+AlCl3 and AlCl3 solutions indicate that virtually no connected pore defects with Ø > 10 nm are present in the supported membranes. Mesoporous titania membranes were studied because of their excellent aqueous stability. Thin double-layer membranes of 250 nm thickness were made, and their transport properties were studied with solutions of NaCl, CaCl2, MgCl2, Na2SO4 and CaSO4. It was found that for solutions containing Cl- ions, the ma (open full item for complete abstract)

Committee: Henk Verweij PhD (Advisor); Gerald Frankel PhD (Committee Member); W.S. Winston Ho PhD (Committee Member); John Lenhart PhD (Other) Subjects: Materials Science

Master of Science, The Ohio State University, 2010, Food Science and Nutrition

Poly (hydroxybutyrate) (PHB) is biodegradable aliphatic polyester that is produced by a wide range of microorganisms. Basic PHB has relatively high glass transition and melting temperatures. To improve flexibility for potential food packaging applications, syntheses of PHB with various co-polymers such as Poly-(3-hydroxyvalerate) (HV) decreases the glass and melting temperatures as well as broadens the processing window since there is improved melt stability at lower processing temperatures. In this study, PHB was synthesized with different valerate contents (5, 12, and 20%) and molecular weights ranging from 150 to 600 kDa. This study focused on characterizing the thermal, mechanical, rheological, and barrier properties of PHB synthesized with different valerate contents, and second to compare these properties in PHBV with similar hydroxyvalerate content but different molecular weight. All PHBV materials displayed a glass transition between -10 to 20°C. The two melting transitions found for Aldrich 5%, 12%, and Tianan 20%, resulted from crystals formed during cooling of the samples. The melt rheology suggested thermal instability of samples as the complex viscosity decreased with increasing temperature due to a decrease in molecular weights of the materials. These results suggest that processing the copolymer below 160°C would be beneficial with low screw speed. The mechanical results indicate all PHBV materials had high elastic modulus and flexural strength with low tensile strength and elongation at break. The WVTR results indicated the polymer to be very hydrophilic resulting in higher transmission rates. Individually PHBV and PLA polymers have serious disadvantages when compared to thermoplastics that are currently used. To address high costs and thermal instability, blends of PHBV with PLA were explored as an alternative way of acquiring novel materials with desired properties. At the start of this work, three grades of PLAs were commercially available for pu (open full item for complete abstract)

Committee: Yael Vodovotz Phd (Advisor); Kurt Koelling PhD (Committee Member); Sudhir Sastry PhD (Committee Member) Subjects: Polymers

Doctor of Philosophy, The Ohio State University, 2007, Food Science and Nutrition

Knowledge about temperature and pressure history is important for evaluating process uniformity during high pressure processing (HPP). Process uniformity is further influenced by the food's thermal properties. This study was conducted to estimate thermal conductivity and heat of compression of selected materials under pressure to evaluate thermal behavior of foods under pressure. Thermal conductivity (k) of selected foods was determined using a line heat source probe. The probe was calibrated using distilled water. Probe specific calibration factors were developed by comparing experimental data against National Institute of Standards and Technology (NIST) data for water. Thermal conductivity of selected liquid (apple juice, canola oil, clarified butter, honey and high fructose corn syrup) and solid foods (carrot, cheddar cheese, guacamole, chicken breast and chicken fat) were determined at pressures between 0.1 and 700 MPa. The process temperatures used were 25° for liquids and 25, 50 and 75° for solid foods. Thermal conductivity increased linearly for all foods with increasing pressures. Among the liquids tested, water and apple juice had the highest k (0.82 W/m°C), while fatty foods had the lowest (0.4 W/m°) at 700 MPa. In solid foods, k increased with increasing moisture content and process temperature and decreased with increasing fat content. Carrot had the highest k (0.90 W/m°), while chicken fat had the lowest k (0.43 W/m°C) at 700 MPa and 75° The combined uncertainty in the measured k values ranged from 0.6% (canola oil) to 4.2% (chicken fat). Effect of polarity and molecular structure on heat of compression (δ) was analyzed in a separate study. While polar liquids showed a linear trend with the δ, non-polar liquids exhibited a nonlinear relationship. Heat of compression decreased with increasing polarity index (8.8° per100 MPa for chloroform to 3° per100 MPa for water). Change in carbon chain length (C2 to C4) and degree of saturation (C18:1 to C18:3) of s (open full item for complete abstract)

Committee: V.M. Balasubramaniam (Advisor) Subjects:

Master of Science (MS), Ohio University, 2009, Mechanical Engineering (Engineering and Technology)

The thermal design of a nanocomposite mold for the blow molding process has been studied. For low production cycles, there is a significant interest in using lower cost composite molds to replace the expensive traditional metal molds used in the blow molding process. A critical issue in using a polymer matrix composite as an alternative to a metal for mold material is the large difference in the thermal transport properties. The composite mold design must integrate enhanced cooling so that the product can cool sufficiently within a short cycle time. Nanocomposites that use carbon nanofiber offer improvements in thermal and mechanical properties; therefore they are potential candidates for making molds for polymer products. This project describes the design of a nanocomposite blow mold using numerical simulations of the thermal transport in the mold and the stress analysis of the final blow molded product.

Committee: Khairul Alam PhD (Advisor); Hajrudin Pasic PhD (Committee Member); Peter Klein PhD (Committee Member); Xiaoping Shen PhD (Committee Member) Subjects: Mechanical Engineering; Plastics; Polymers

Master of Science in Engineering (MSEgr), Wright State University, 2013, Biomedical Engineering

Real-time, stand-off sensing of humans to detect emotional state would be valuable in many defense, security and medical scenarios. Using a multimodal sensor platform that incorporates high-resolution visible-wavelength and mid-wave infrared cameras and a millimeter-wave (mmW) radar system, the detection of physiological indicators of psychological stress is tested through laboratory experiments. Our approach focuses on thermal imaging to measure temperature patterns in distinct facial regions representative of underlying hemodynamic patterns. Experiments were designed to: 1) determine the ability of thermal imaging to detect high levels of psychological stress and assess responses to physical versus psychological stressors; 2) evaluate the fidelity of vital signs extracted from thermal imagery and radar signatures; and 3) investigate the stability of thermal imaging under various confounding factors and real-world limitations. To achieve the first objective, registered image and sensor data were collected as subjects (n=32) performed mental and physical tasks. In each image, the face was segmented into 29 non-overlapping segments based on fiducial points automatically output by our facial feature tracker. Image features were defined that facilitated discrimination between psychological and physical stress states. Four classifiers (artificial neural network, naive Bayes, linear discriminant analysis, and support vector machine) were trained and tested, using a down-selected set of salient features, to evaluate efficacy under several classification paradigms. The method proved very successful. Based on estimated physiological ground truth, we were 100% accurate in classifying subjects with high mental stress, and nearly 99% accurate in the classification of mental versus physical stress. The performance of two non-contact techniques to detect respiration and heart rate were evaluated: chest displacement extracted from the mmW radar signal and temperature fluct (open full item for complete abstract)

Committee: Julie Skipper Ph.D. (Advisor); Ping He Ph.D. (Advisor); Doug Petkie Ph.D. (Committee Member) Subjects: Biomedical Engineering