Browsing by Author "Van Buiten, Charlene, committee member"
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Item Open Access Biologically active aromatic acids in phosphatidylcholine liposomes: benzoic and salicylic acids(Colorado State University. Libraries, 2022) Sanders, Sarah Ivy, author; Crans, Debbie, advisor; Van Orden, Alan, committee member; Van Buiten, Charlene, committee memberThe interactions of benzoic acid and salicylic acid with phosphatidylcholine liposomes were characterized to understand interfacial interactions of the two weak aromatic acids with the membrane. The liposomal system was comprised of soy l-ɑ-phosphatidylcholine (SPC) bilayers, which allowed the determination of interfacial interactions and position within the membrane using 1D 1H NMR. Benzoic acid was considered due to its effects as a food stabilizer, where salicylic acid was considered as a derivative due to its effects as an anti-acne agent. Both were found to penetrate the membrane interface deeper when in their protonated forms. The presence of the weak acids on the membrane surface allowed stabilization through hydrogen bonding with liposomal headgroups, which allowed deprotonation to occur. Broadening of aromatic peaks demonstrated a pH dependence for both benzoic acid and salicylic acid, showing a deeper penetration around the pKa values of the weak acids. This study offers justification for the antimicrobial activity of benzoic and salicylic acids in lower pH environments. Thus, this study provides the next piece in understanding the uptake of benzoic acid and salicylic acid in bacteria for microbial inhibition.Item Open Access Bridging the gap between biofortification and consumption: evaluating sorghum grain carotenoid degradation(Colorado State University. Libraries, 2023) Lepard, Ariel, author; Rhodes, Davina, advisor; Van Buiten, Charlene, committee member; Prenni, Jessica, committee member; Scanlin, Laurie, committee memberSorghum (Sorghum bicolor) is a major staple cereal crop consumed in sub-Saharan Africa and Southeast Asia, where some of the highest rates of vitamin A deficiency (VAD) are found. As with most cereals, sorghum has low concentrations of provitamin A carotenoids, which are converted to vitamin A in the body. Biofortification provides an opportunity to address VAD through the nutritional improvement of sorghum grain using a non-transgenic breeding approach to increase grain carotenoids. Though vitamin A biofortification in sorghum is possible, it is unknown if breeding for high carotenoids in the grain negatively affects carotenoid pathway functions in other tissues. Additionally, it is unknown if degradation during postharvest processing occurs to a significant degree in biofortified grain. To establish how breeding for high carotenoids in the grain affects the carotenoid pathway in other plant tissues, expression of ten genes in the carotenoid precursor, biosynthesis, or degradation pathways were evaluated in the grain, leaf, and root tissues. A correlation in the gene expression within the plant tissue, but not between the plant tissues, was found for most genes, which suggests that several of the carotenoid precursor, biosynthesis, and degradation genes are controlled by tissue-specific regulation. Correlation of carotenoid concentrations and gene expression was also found to be tissue specific, which further suggests tissue-specific regulation. The selection of genes with tissue-specific regulation for marker-assisted breeding reduces the chances of grain biofortification negatively affecting other tissues. Once carotenoids have been increased in the grain, it must be noted that vitamin A is not stable in most storage, processing, and cooking environments due to oxidative stress from light, heat, and oxygen. The degradation of the nutritional quality through post-harvest processing was evaluated by sampling carotenoid grain throughout harvest, drying, storage, processing, and cooking. Individual processing steps did not cause significant degradation but added up to significant degradation by the final cooking step, with ~39% of β-carotene loss. No significant difference between the loss in the different storage temperatures or cooking styles was seen. An increase in the target value from 4 μg β-carotene/g of sorghum to 5.6 μg/g will be needed to account for processing loss in order to provide 50% of the estimated average requirement (EAR) of vitamin A. Overall, both the information on tissue specific gene expression, and post-harvest degradation will further advance the development of carotenoid biofortified sorghum lines.Item Open Access Characterizing the impact of package type on different beer styles using advanced analytical tools(Colorado State University. Libraries, 2022) Fromuth, Kathryn Lenore, author; Prenni, Jessica, advisor; Sedin, Dana, committee member; Van Buiten, Charlene, committee memberIn 2020 there was over 9,000 breweries in the US, increasing the beer market competition and driving the importance of product stability under variable storage conditions. More breweries, specifically craft breweries, than ever before are choosing to package in cans due to ongoing effects of the current pandemic, the growing availability of smaller can line systems, and increased mobile canning options. Foundational beer stability research has focused on light lager styles packaged in bottles. Limited research has been conducted studying flavor stability in styles relevant to the American craft brewing industry, nor any comparisons of how package type (i.e., cans and bottles) affects flavor stability. Industry utilizes trained sensory panels to evaluate flavor stability; a resource that is both time consuming and expensive. Thus, this is a tool that is often inaccessible or inadequate for providing relevant and timely stability data. This research project, a collaboration between New Belgium Brewing and Colorado State University, aims to address the package-type knowledge gap and sensory panel restrictions by utilizing advanced analytical tools to characterize the changes in metabolite profiles over time between cans and bottles. A low-hopped amber ale (AA) and high-hopped India Pale Ale (IPA) were chosen for their distinct style and relevance to the American craft brewing industry. One batch of an IPA and AA was packaged into cans and bottles, then aged for a six-month period. The samples were stored under cold temperatures (4°C) for the first 30 days, and then at room temperature (20°C) for the subsequent time. Aliquots were collected biweekly for a total of 13 timepoints throughout the six-month aging period and stored at -80°C until chemical analysis. Chemical analysis was conducted by gas chromatography coupled to a mass spectrometer detector (GC-MS) and direct analysis in real time mass spectrometry (DART-MS) to address the research questions. Multivariate (MVA) and univariate (UVA) statistical analysis of the GC-MS data allowed for the characterization of the impacts of package container on the chemical profiles of AA and IPA over time. MVA of the DART-MS data explored the predictive power of the tool for streamlining beer flavor stability analysis. Partial least squares discriminant (PLS-DA) and Multiple Analysis of the Variance (MANOVA) statistical analyses were used to explore data produced by GC-MS and helped define a group of 17 detected metabolites important to explaining the data variation. PLS-DA models of AA samples demonstrated good model fit and package type predictability (R2 = 0.981, Q2 =0.964). This was not observed in IPA which indicates package effects are styles dependent. Differences in AA samples are due, in part, to can and bottle baseline differences in the detected amino acid and ester metabolites. Differences in the physical packaging process of cans, oxidations, and low hop polyphenol concentrations are proposed mechanisms for explaining the observed baseline differences. Analysis of variance (ANOVA) found ten metabolites in AA cans significantly (P ≥ 0.05) changing over time as compared to four metabolites in AA bottles. This indicates higher instability in cans for AA samples. Four detected hop volatiles (humulene, β-myrcene, α-calacorene, pinocarvone), identified by estimated marginal mean of linear models (95% confidence interval) had exhibited significant changes over time that were dependent on package type interactions, but to varying magnitudes and directions depending on the metabolite's polarity and susceptibility to packaging material interactions (e.g., scalping). PLS-DA models of data produced by DART-MS indicated a poor model fit and lack of beer storage time predictability in AA samples (R2 = 0.554, Q2 = -0.151) and IPA samples (R2 = 0.622, Q2 = -0.079). These results lack the evidence that DART-MS is a useful tool for streamlining beer stability analysis. However, results for package type predictability matched GC-MS analysis conclusions in that package type predictability is style dependent. The overall study results demonstrate there is much nuance in the effects of package type on beer flavor stability, and those effects depend on style, packaging material, and the individual metabolite. Targeted analysis is needed to fully understand the mechanisms driving the effects of package type on beer stability.Item Open Access High elevation food preparation: consumer assessment and toolkit development(Colorado State University. Libraries, 2021) Engelhardt, Heidi, author; Bunning, Marisa, advisor; Van Buiten, Charlene, committee member; Hyatt, Doreene, committee memberAt higher elevations, reduced air pressure and dry conditions impact food preparation in a multitude of ways. The boiling point of water decreases, the rate of evaporation is higher, and the functionality of leavening agents can be altered. Cooks, bakers, and food scientists alike face challenges in adjusting processing methods and ingredients to ensure desirable results of recipes at various elevations. Current information on food preparation at high elevations lacks consistency and accessibility and often requires using multiple sources that may not be reliable. This leaves the home cook vulnerable to failed recipes and in some cases, foodborne illness. An assessment of consumer cooking, baking, and food preserving practices was needed to identify and prioritize information that could contribute to successful and safe food preparation at higher elevations. To assess these needs, a survey was developed, conducted, and results were analyzed to guide resource development for a high elevation food preparation toolkit. The purpose of the project was to construct useful materials as part of a set of tools to empower home cooks to apply research-based knowledge in Colorado and other high elevation locations in the United States. Developed resources included eight ingredient information sheets, a troubleshooting guide with suggestions for nine food products or methods. A set of presentation slides and two activities with pre- and post-evaluations to measure behavior change are included for county extension agents to use while engaging with their communities. Expanding awareness related to the impacts that higher elevations have on food preparation connects home cooks with food science as well as food safety. In addition to nutritional needs, food related pastimes often serve a greater purpose providing comfort and a rewarding way to cope with stress, promoting general well-being. Success in a high elevation kitchen would include recipes that do not fail as often, have desired taste and texture, and appropriately address food safety. This toolkit can be utilized in many different ways with the goal of helping consumers become more knowledgeable and successful when safely preparing foods at high elevation. We expect these materials to have national usefulness and aid in the development of skills that can be routinely incorporated in food preparation at higher elevations.Item Open Access Metabolite fingerprinting of hops (Humulus lupulus) to track chemical variations(Colorado State University. Libraries, 2022) Nasiatka, Katie, author; Prenni, Jessica, advisor; Rhodes, Davina, committee member; Van Buiten, Charlene, committee memberIn the brewing industry, identification of quality crops that provide unique organoleptic properties to beer flavor (aroma, taste) are of critical importance. Hops represent a key ingredient in beer and are utilized to impart specific flavors. India Pale Ales (IPAs) are a popular style of "hoppy beers" in the U.S. and customer expectations for consistency, quality, and unique organoleptic properties of hops are growing. While the contribution of chemical compounds in hops (Humulus lupulus) such as alpha-acids (e.g. humulone) is well-understood, the influence of the hop metabolome (e.g. composition of hop chemical compounds) is still in the early stages of discovery. There is a gap in the knowledge regarding our understanding of chemistry variations in hops among cultivars and growing locations that impact the sensory quality. Traditional sensory evaluation relies on the ability to organize a group of unbiased and trained panelists, who are also subject to sensory fatigue, which can add to the challenge of this method. An alternative approach, ambient mass spectrometry (AMS) is an objective, intuitive, analytical tool capable of rapid chemical fingerprinting. The overall goal of this research is to develop a robust, high-throughput assay using AMS technology to evaluate hop quality that is reflective of both cultivar and environmental variations impacting sensory. To address this goal, twelve hop samples were sourced from three different suppliers across four different farms located in Washington and Oregon over two growing seasons. The samples included three commercial cultivars, Cascade, Centennial, and Strata. The hop samples were extracted using an 80% ethanol solution and fingerprints were acquired by Direct Analysis in Real Time Mass Spectrometry (DART-MS). The resulting data were used to train predictive models and validation was performed to evaluate classification accuracy. Additionally, authentic standards of important hop compounds (hop alpha-acids, terpenes) were used to putatively annotate DART-MS signals reflective of sensory attributes. This study demonstrates the potential of this approach for rapid evaluation of hops quality and lays groundwork for further method optimization. Ultimately, implementation of this tool could have applications for quality assurance programs and for phenotyping of hops for producers and craft brewers.