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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Appetite for Innovation: The Mobilization of Change and Creativity at elBulli

Opazo, Maria Pilar January 2014 (has links)
This dissertation uses an organizational approach to examine how new ideas are mobilized in order to become radical innovations. I consider the case of elBulli, an avant-garde, three-Michelin star restaurant that has pioneered the "molecular" or "experimental" cuisine movement in the gastronomic field, to inductively study how innovation is made to work. Based on ethnographic data collected over a period of 16-months in Spain and in the United States, my research proposes that systematic and radical innovation is the result of concrete practices and collective efforts that enable new ideas and epistemic practices to be recognized, understood, and legitimated by the public. The research advances a new distinction in innovation studies between new final products and conceptual innovations and proposes that this distinction can contribute to clarify the dynamics behind the advancement of knowledge within a field. Also, I argue that this distinction can serve as a basis for the future development of a general framework of the different dimensions involved in the production of innovation. Throughout the research, I draw comparisons with different fields such as religion, politics, business, art and music to explore the potential applicability of the main insights obtained from my case study to illuminate innovation processes in general.
2

How about a vegan dessert? : men and women's attitudes towards vegan desserts, and how the appearance of vegan desserts affects the experience

Olsson, Tora January 2018 (has links)
Background: Women prefer to eat plant-based food more frequently than men. Previous studies show that there is a difference in what we eat depending on which gender we belong to. The experience of food can be influenced by various aspects such as colour, shape, serving, and food information. Objectives: The purpose of the study was to investigate if there were any differences between men and women's attitudes towards vegan desserts. Moreover, four vegan desserts were developed using creative design and molecular gastronomy, to investigate how the colour and shape of vegan desserts affects the experience of taste, flavour and texture. Material and methods: To answer the research question, two focus group interviews were conducted. Moreover, a creative design containing an online cross-sectional survey was performed to develop four vegan desserts using molecular gastronomy. The desserts had the same ingredients in equal quantities, but they differed in colour and shape.These desserts were subsequently tested in a sensory evaluation. Results: The results show that there is a difference between men and women regarding attitudes towards a vegan dessert. Women are more positive and curious, while men are more sceptical whether a vegan dessert tastesgood. There was sometimes a significant difference in taste, but never in flavour and texture. Conclusions: There are differences in men and women's attitudes towards vegan desserts, where women are more positive than men. Shape may affect the experience of taste, but not of flavour and texture in this study.
3

THE IMPACT OF DIETARY FIBER AND SUCROSE ALTERNATIVES ON TEXTURE PERCEPTION OF COOKIES

Sarah L Pitts (11565889) 22 November 2021 (has links)
<p>Low moisture baked goods (cookies, biscuits, etc.) are known for their high sugar content, low water content, and characteristic texture. The added sugar in baked goods has been a concern of health advocates due to the negative health implications of overconsumption of sugar. To minimize these health implications and support healthier food products, the replacement of sugar, sucrose, in low moisture baked goods with alternative sweeteners is of interest. The goal of this study was to improve understanding on how sweetener alternatives and dietary fiber interact with cookie ingredients and the subsequent cookie texture compared to sucrose containing cookies to aid in developing health-conscious low moisture baked goods.</p><p> The replacement of sucrose with sucrose replacers (SRs) encompassing a variety of structural and physicochemical properties (high fructose corn syrup (HFCS), amorphous sucrose, maltitol, allulose, isomalt, Benefiber, Miralax, fructooligosaccharides (FOS), and isomalto-oligosacchrides (IMO)) in wire-cut cookies was investigated in terms of starch thermal properties, model cookie formulations, and sensory descriptive analysis. Starch thermal properties were investigated using differential scanning calorimetry (DSC) while wire-cut cookie parameters were analyzed through a<sub>w</sub>, color (<i>a, b, L</i>), moisture loss, cookie dimensions (height, width, length), and cookie hardness (N) assays. Sensory descriptive analysis was used to ascertain texture perception of wire-cut cookies through five attributes (hardness, fracturability, pastiness, cohesiveness, and crumbliness).</p> The onset gelatinization temperature (T<sub>gel</sub>) was increased to a greater extent than sucrose by Miralax and FOS, and to the same extent by IMO, maltitol, and Benefiber at high concentrations (60%w/w). The SRs which performed similar to sucrose in wire-cut cookie baking (spread, moisture loss, hardness) and texture intensity ratings were amorphous sucrose, maltitol, and allulose. No significant differences in descriptive analysis intensity scores were found in crumbliness, cohesiveness, and pastiness between SRs and sucrose formulated wire-cut cookies. FOS, IMO, and Benefiber displayed significantly larger fracture intensity scores compared so sucrose and isomalt cookies were significantly less hard than sucrose cookies. Principal component analysis (PCA) related SRs effect on starch gelatinization, cookie baking properties, and descriptive analysis intensity scores, and indicated the mostly likely candidates for use in reduced sugar cookies are maltitol and allulose.
4

PHYSICOCHEMICAL AND SENSORY EVALUATION OF INVASIVE SILVER CARP (Hypophthalmichthys molitrix) FISH NUGGETS

Joseph L King (8788295) 01 May 2020 (has links)
<p>Silver carp (<i>Hypophthalmichthys molitrix</i>)<b> </b>are an underutilized, invasive fish threatening native species throughout major water systems in the United States. The goal of this research was to use silver carp meat to create a value-added product, to analyze the changes in physicochemical structure and consumer liking over time, and to evaluate the benefits of adding soy, pea, and a combination of soy and pea protein isolates to the formulations. Fish nuggets were prepared from minced meat in four treatments consisting of 3% soy protein isolate (SPI), 3% pea protein isolate (PPI), a combination of 1.5% SPI and 1.5% PPI, and a control without plant protein isolate. Nuggets from each treatment were stored frozen for 1.5, 8.5, and 13.5 weeks. Proximate composition, pH, cook loss, textural hardness, expressible moisture, color, microbial counts and lipid oxidation were evaluated. Sensory acceptability was also evaluated for each frozen storage time period and treatment. A descriptive (QDA<sup>™</sup>) trained sensory panel was also conducted on all treatments independent of the storage testing. Results showed that lipid oxidation and textural hardness significantly (P < 0.05) increased with frozen storage time. PPI had significantly lower expressible moisture compared to the control at week 1.5, but there were no statistically significant differences between treatments at weeks 8.5 and 13.5. Similarly, formulations with PPI improved (p<0.05) cook loss for week 1.5, but not week 8.5 or 13.5. Overall, sensory acceptability did not change (P > 0.05), with the exception of decreased degree of liking scores for SPI aroma (p=0.03) and flavor (p=0.03)) during the frozen storage period; all degree of liking scores remained above 6.5 throughout analysis, indicating that consumers’ acceptability of the sample treatments over time despite the changes in physicochemical structure. The descriptive panel created an attribute lexicon for the aroma, flavor, and mouthfeel of the fish nuggets and did not find significant differences in intensities for those attributes between the treatments. Although there were measurable changes in oxidation, texture, expressible moisture, and cook loss over 13.5 weeks, these changes did not impact sensory acceptance. The addition of protein isolates improved water holding capacity initially but did not maintain those benefits over extended shelf life and had little impact on consumer liking during any time period. Overall, this study demonstrated that value-added products such as silver carp nuggets can be created using an otherwise under-utilized fish. The fish nuggets had high sensory acceptability, and the addition of protein isolates did not significantly improve their sensory characteristics; therefore, silver carp nuggets can be formulated without the need of additional protein additives .</p>
5

Exploring the interaction between functional carbohydrate polymers and small-molecule active compounds

Jingfan Chen (6369032) 30 April 2021 (has links)
<p>Naturally occurring carbohydrates polymers and their functional derivatives play important roles in the research and technology development in the food, nutrition, and pharmaceutical areas. A major property of these polymeric materials is to associate, enable, enhance, and/or deliver small-molecule active compound such as phytochemicals, nutraceuticals, and active pharmaceutical ingredients (APIs). The goal of this project was to synthesize and characterize phytoglycogen-based materials and study their structure-function relationships in association with selected small-molecule active compounds, including resveratrol, a food-related poorly water-soluble phenolic compound, griseofulvin, an insoluble API, and CCVJ (9-(2-carboxy-2-cyanovinyl) julolidine) a molecular rotor used as a structural probe of polymeric materials. </p><p>In this study, phytoglycogen (PG) was derivatives to phytoglycogen octenyl succinate (PG-OS), hydroxypropyl phytoglycogen (HPP), and octenylsuccinate hydroxypropyl phytoglycogen (OHPP). PG, HPP, and OHPP were evaluated for their efficacy in improving the solubility and Caco-2 permeation of resveratrol and griseofulvin, and using CCVJ, PG-OS was evaluated on its performance at oil-water interface in comparison with OSA-starch, acacia gum, and sodium caseinate. The results showed that: 1) PG, HPP, and OHPP substantially improved the soluble amount and Caco-2 monolayer permeation of resveratrol and griseofulvin, and anti-fungal efficacy of griseofulvin in the aqueous system were significantly enhanced; suggesting that the active ingredients were effective solubilized and released to become bioavailable, 2) among all PG-based biopolymers, OHPP showed superior performance in solubilizing resveratrol and griseofulvin, and 3) in the oil-water two-layer model system, PG-OS, OSA-starch, acacia gum, and sodium caseinate all affected the transferring of CCVJ from oil to aqueous phase, and the effect was monitored and interpreted by the emission spectra of molecular rotor; in the emulsion system, the emission peak wavelength of CCVJ was correlated with the amount of biopolymer adsorbed at the interface of emulsion droplets, and the molecular rotor-based method can be used to characterize the interfacial adsorption of biopolymer at the interface in oil-in-water emulsion.</p><p>This study provides information on the interactions between phytoglycogen-based biopolymers and poorly water-soluble active ingredients, and may potentially supports the study of new functional ingredients interaction with phytoglycogen-based biopolymers in aqueous system. Furthermore, this work allowed us to advance the use of molecular rotor as new analytical tool to study the physicochemical properties of biopolymer.</p>
6

Investigating Phenolic-Mediated Protein Matrix Development for Potential Control of Cereal Starch Digestion

Leigh C R. Schmidt (6869153) 15 August 2019 (has links)
<div>Shifts in the human diet to more refined foods and ingredients have contributed to the rise in metabolic disease rates associated with long-term consumption of foods causing swift rises in blood glucose response. Foods which result in a more moderate blood glucose curve are considered healthier by increasing satiety and reducing oxidative stress. Sorghum products contain naturally slowly digested starch. The matrix of sorghum porridges contains kafirin protein bodies which cross link around gelatinizing starch molecules, while similar nascent matrices in other cereals aggregate and collapse. The 3-deoxyanthocyanidin pigments unique to sorghum may be accountable for the difference in matrix stability. The density of the starch entrapped in the matrices is thought to partially inhibit α-amylase access to the starch, reducing overall starch digestion and thereby mitigating glucose response. The purpose of this work was to increase our understanding of how phenolic compounds in sorghum interact with endosperm proteins to create a stable matrix, and to explore if the knowledge might be translated to other starchy cereal products. In the first study, phenolic extracts from flours (sorghum, corn masa, white rice) were characterized for phenolic content, antioxidant activity, phenolic components, and their ability to interact with a model protein system (ovalbumin) in order to examine protein polymerization. In the second study, specific phenolic compounds in sorghums (<i>p</i>-coumaric, sinapic, and gallic acids; (+)-catechin; and apigeninidin, a 3-deoxyanthocyanidin found in sorghums) were interacted in the model protein system at different concentrations to observe extent and type of protein polymerization, and promising compounds subjected to fluorescence quenching spectroscopy to examine the nature of the interactions. The final study explored the effects of apigeninidin addition to a yellow corn flour and naturally present anthocyanin (blue corn) on starch digestion and microstructure of porridges by utilizing an <i>in vitro</i> α-amylase assay and confocal microscopy. </div><div>The slow digestion of starch in cooked sorghum products can be attributed to the 3-deoxyanthocyanidin compounds present in the grain participating in sulfhydryl-disulfide interchanges which results in extensive kafirin cross-linking surrounding starch granules. While other phenolic and redox-active components may affect matrix formation and stability, 3-deoxyanthocyanidins appear to have the most direct influence, and their ability to modify food protein matrices appears to have a direct result on starch digestion <i>in vitro</i>.</div>
7

Physical Properties of Food Oils and Factors Affecting Bubble Dynamics During Frying

Shreya Narayan Sahasrabudhe (6533324) 10 June 2019 (has links)
The study is focused on study of surface and interfacial properties of oil at high temperatures, to understand the mechanisms of heat transfer and oil absorption during frying
8

FOOD MATERIALS SCIENCE: EFFECTS OF POLYPHENOLS ON SUCROSE CRYSTALLIZATION AND CHARACTERIZATION AND CREATION OF ALTERNATIVE SALTS OF THIAMINE

Collin J. Felten (5930618) 17 January 2019 (has links)
<div> <p>Proper understanding of materials science is critical in understanding the functionality of ingredients in food products, as well as their behavior in these products over time. Amorphous materials are metastable, eventually rearranging to the thermodynamically stable crystalline state. Amorphous materials have properties which are beneficial in some food products: they are softer in texture and dissolve more rapidly. The amorphous state of sucrose might provide an increase in quality in applications like powdered beverages where rapid dissolution is preferred. A number of classes of compounds have been shown to delay the crystallization of amorphous sucrose; however, polyphenols, particularly their glycosylated forms, have been little explored. Glycosylated polyphenols contain two distinct structural regions: a more hydrophilic sugar unit(s) and a more hydrophobic polyphenol backbone. While the sugar unit should be able to easily associate with sucrose molecules, the polyphenolic backbone may not and might provide hindrance to crystal nucleation and growth.</p> <p> </p> <p> Thiamine is an essential nutrient that is found naturally in foods such as whole grains and pork. The processing of grains removes nearly the entirety of the natural thiamine content; thus, foods are often enriched with synthetic thiamine. Two salts of thiamine are used commercially: thiamine mononitrate and thiamine chloride hydrochloride. The two forms have specific applications driven by their specific properties, specifically their aqueous solubility and hygroscopicity. While these two salts provide adequate functionality, it is possible new salts may have properties beneficial in certain food applications. A method making use of silver nitrate was developed to produce new salt forms. An intermediate in this reaction, TCl·H<sub>2</sub>O, was characterized including measurements of stability in aqueous solutions and solid state properties.</p> </div> <br>
9

Advanced Characterization of Glucan Particulates: Small-granule Starch, Retention of Small Molecules, and Local Architecture Defined by Molecular Rotor

Xingyun Peng (5930138) 04 January 2019 (has links)
<p>The discovery and utilization of novel starches with unique superb properties are highly demanded for modern industrial uses. Small-granule starch (SGS) is a category of unconventional starches with the granular size smaller than 10 μm. The potential use of SGS includes many conventional and novel high-value applications, such as texturizing, fat replacement, encapsulation, controlled delivery and nano-engineering. In the present work, we focused on three SGS isolated from amaranth (<i>Amaranth cruentus</i>), cow cockle (<i>Saponaria vaccaria</i>) and sweet corn (<i>sugary-1</i> maize mutant). The basic structural and unique physical properties of SGS were characterized and compared to common large-granule food starches. It was found that (1) the highly branched amylopectin contributed to low crystallinity and pasting viscosities of sweet corn starch, (2) cow cockle starch exhibited high shear-resistance and low retrogradation in prolonged storage, and (3) the amylopectin for amaranth starch was less branched with small clusters, which was associated with the high crystallinity, medium shear-resistance and low pasting viscosity of amaranth starch. Despite the small size of starch granules, SGS in both native and swelling states showed the capacity of retaining small molecules. Compared to large-granule starch, native SGS are more difficult for small molecules to reach an equilibrium permeation. This work provides insights to the fine structure and physicochemical behaviors of selected high-potent SGS, which is believed to support the industrial production and application of SGS in the future.</p> <p>The characteristics of local polymeric structure dominate many critical properties of glucan particles, such as starch retrogradation and the loading and stabilizing of active substance. Molecular rotor (MR), a fluorescent probe, was proposed to fulfill the simple, high-sensitive, and quantitative-based characterization of local glucan architecture (LGA). In the present work, two innovative studies relevant to this novel method were conducted: (1) MR was able to characterize glucans based on its unique fluorescent response to characteristic LGA, (2) MR was able to sensitively probe and visually demonstrate the transition of LGA induced by starch retrogradation. This novel MR-based approach is expected to advance carbohydrate-related researches in the future.</p>
10

IMPROVEMENT OF FUNCTIONAL AND BIOACTIVE PROPERTIES OF CHIA SEED (SALVIA HISPANICA) PROTEIN HYDROLYSATES AND DEVELOPMENT OF BIODEGRADABLE FILMS USING CHIA SEED MUCILAGE

Uriel C Urbizo Reyes (7909295) 14 January 2021 (has links)
<div> <p>Chia seed (<i>Salvia hispanica</i>) has shown potential as an alternative source of nutrients with a high content of fiber (36 %), protein (25%), and fat (25%). Unfortunately, the presence of a viscous biopolymer (mucilage), surrounding the chia seed (CS), limits the accessibility of the protein and other nutrients. Nevertheless, this biopolymer’s chemical composition makes it suitable for the development of biodegradable films. Regarding CS protein, disulfide bonding, and nonprotein-protein interactions often frequent in plant protein, have limited its technological application in food matrices. Therefore, scientists have pointed at processing methods involving enzymatic proteolysis to improve the functionality of plant protein ingredients. The objective of this study was to establish processing techniques to exploit the functionality, extraction, and health benefits of chia seed components. First, ultrasonication followed by vacuum-filtration was used to separate mucilage from CS prior to fat extraction by oil press. Mucilage-free and defatted CS were treated using conventional (enzymatic hydrolysis with alcalase) or sequential (enzymatic hydrolysis with alcalase+flavourzyme), and under water bath or microwave-assisted hydrolysis. Chia seed protein hydrolysates (CSPH) derived from the sequential hydrolysis with microwave treatment showed superior (p<0.05) in vitro antioxidant activity. The highest (p<0.05) cellular antioxidant activity was achieved by the sequential (94.76%) and conventional (93.13%) hydrolysis with microwave. Dipeptidyl peptidase-V inhibition was higher (p<0.05) for sequential hydrolysis with water bath, while Angiotensin-Converting Enzyme (ACE) inhibition activity increased (p<0.05) with hydrolysis for all treatments compared to the control. Regarding functionality, sequential hydrolysis with microwave showed higher (p<0.05) solubility at lower pH (3 and 5), while conventional hydrolysis with microwave was better at pH 7 and 9. Emulsification properties and foaming capacity were also higher in conventional hydrolysis with microwave, but conventional hydrolysis with water bath was more stable for foaming properties only. In terms of mucilage applicability, biodegradable films were developed by casting technique where CS mucilage was plasticized with different polyol mixtures (sorbitol and glycerol). CS mucilage films with higher sorbitol content showed superior tensile strength (3.23 N/mm<sup>2</sup>), and lower water vapor permeability (1.3*109 g/ m*s*Pa) but had poor flexibility compared to other treatments. Conversely, films with high glycerol content showed high elongation at break (67.55%) and solubility (22.75%), but reduced water vapor permeability and tensile strength. The hydrophobicity, measured as water contact angle, was higher (p<0.05) for mixtures containing equal amounts of polyols. Lastly, Raman Spectroscopy analysis showed shifts from 854 to 872 cm<sup>-1</sup> and 1061 to 1076 cm<sup>-1</sup>, which corresponded to β(CCO) modes. These shifts represent an increase in hydrogen bonding, responsible for the high tensile strength and decreased water vapor permeability. This study demonstrated that ultrasonication followed by vacuum filtration can successfully separate mucilage from chia seeds; microwave-assisted and enzymatic hydrolysis generated protein hydrolysates with improved bioactivity and functionality. Finally, chia seed mucilage was able to form films with potential to be used in drug delivery and edible food coating applications.</p> </div> <br>

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