Food Microbiology Commons^™

Impacts Of Utilizing Reverse Osmosis Concentrate On Mashing, Fermentation, And Water Use In Bourbon Whiskey Production, Ryan C. Sarhan

Theses and Dissertations--Biosystems and Agricultural Engineering

This thesis addresses the feasibility of reusing reverse osmosis concentrate (ROC) in the bourbon whiskey fermentation processes. Initial work compared laboratory-scale mashing and fermentation methods, demonstrating that simultaneous saccharification and fermentation reliably reflects industrial-scale processes, with lower complexity and process time. Building upon this, laboratory and distillery-scale experiments demonstrated that reusing ROC in the mashing and fermentation steps does not negatively impact ethanol yields. ROC produced by systems with a water softener was found to significantly increase mash rheology, suggesting a need for potential process adjustments. Softened ROC also altered the production of flavor-influencing volatile congeners. Under worst case conditions, …

Utilization Of Probiotics To Compete With Clostridioides Difficile For Nutrient-Niches In A Variety Of In Vitro Contexts, April Elizabeth Johnson

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Clostridium difficile is a major threat to public health and primarily affects at risk groups such as elderly, immunocompromised individuals, and individuals on antibiotics. Many decades of research have been conducted to figure out ways to exclude or reduce C. difficile colonization and toxin production. Two major proposed mechanisms for colonization resistance are production of secondary bile salts and competition for nutrients.

In Chapter 2, we found that antibiotic treatment disrupted bile salt metabolism increasing the levels of the primary bile salt cholate and decreasing the levels of deoxycholate, a secondary bile salt. However, bile salts were not required …

Kluyveromyces Marxianus Prepared As A Ready To Use Supplemental Food (Rusf), Zachary Christman

Applied Science Program: Theses

Ready to Use Supplemental Food (RUSF) is a nutrient dense paste or compressed bar used to supplement a person’s nutritional needs because of malnutrition or due to food shortages. The purpose of this article is to demonstrate some methods of how the dairy organism Kluyveromyces marxianus can be used to enrich the protein value of bread or ferment a substrate such as wheat bran into a more digestible form.

Evaluating The Efficacy Of Germination And Fermentation In Producing Biologically Active Peptides From Pulses, Ashley Newton

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Recently, there has been a profound increase in demand of plant-based proteins, especially pulse proteins. However, pulses contain high concentrations of antinutritional factors that hinder the digestibility of proteins. Processing techniques such as enzymatic hydrolysis, microbial fermentation, and physical processing modulate nutritional quality and functionality of pulses. Processing also releases peptides from parent proteins that exhibit health-beneficial bioactivity against various disease risk factors. In this study, germination, gastrointestinal digestion, and microbial fermentation were evaluated to determine the nutritional quality and release of bioactive peptides during and after processing.

Germination of chickpeas (Cicer arietinum L.) modulated the protein profile, and …

Alternative Sweeteners For Cultivating Water Kefir Grains, Morgan Barnes

Honors Theses

Water kefir is traditionally fermented using dark brown sugar due to a fast growth rate, however the use of other sweeteners, such as honey, is relatively unexplored. This paper describes the investigation of using alternative mediums made with honey, agave nectar, Truvia/stevia, and monk fruit sweetener, each supplemented with dark brown sugar on the biomass growth of water kefir grains (WKGs). Growth in these alternative mediums was compared to WKG growth in the standard medium prepared using only dark brown sugar. Two trials were conducted, each with three replicates for each experimental medium as well as three replicates of dark …

16s Rrna Gene Sequence Analysis Of Acetic And Lactic Acid Bacteria Isolated From Philippine Sugarcane Wine (Basi) [Research Note], John Russel G. Sevilla, Michael Angelo S. Esteban, Honey Bhabes R. Iñigo, Audrey May V. Orillaza, Baby Richard R. Navarro

The Philippine Agricultural Scientist

Basi, a traditional sugarcane wine of the Philippines, was studied. Here, we used molecular- and cultural-based methods to isolate, identify and characterize acid-producing bacteria, specifically acetic and lactic acid bacteria, from basi. Acid producers were focused on owing to the rapid spoilage of basi via acidification with air exposure. Two strains each of acetic and lactic acid bacteria were isolated. DNA was extracted from these isolates. PCR-amplified DNA products were subjected to 16S rRNA gene sequencing. The sequences of the isolates were then aligned with BLAST database sequences and found to have high similarities to Acetobacter malorum (99%), …

Improving Nutritional Properties And Extractability Of Pea Proteins For Human Consumption Via Fungal Bioprocessing, Camille Massmann

Electronic Theses and Dissertations

Yellow peas are a rich source of protein and phytochemicals. Peas are compatible with many diets restricted by sensitivities, allergies, or personal choice. As a result, peas are gaining popularity in food markets, despite the challenges they present. The biggest challenges for pea proteins in food markets are high content of fiber, starch, and saponins. These components cause processing challenges and create undesirable textures and bitter flavors. Pea proteins are typically extracted with alkaline extraction or air classification methods which result in 80% and 50% protein products respectively. With low protein purity, these products are not competitive with other, more …

Investigation Of Fermentation Efficiency In Saccharomyces Cerevisiae Through Telomere Integrity And Maltase Expression, Dana Bennett

All Graduate Theses, Dissertations, and Other Capstone Projects

Many microbreweries practice serial fermentation, or serial repitching. Serial repitching is the process by which one yeast culture is reused for multiple batches of beer. Each batch of subsequent beer is called a “pitch.” This technique helps breweries limit production costs. However, fermentation is difficult to predict throughout serial fermentation. This leads to beer quality issues such as fluctuation in alcohol production, buildup of unwanted flavor compounds, and decreased carbon dioxide production, which results in reduced profit. To combat this issue, many breweries will attempt to predict fermentation efficiency through viable cell counting in order to ensure a consistent number …

Phylogenetic Diversity Of Arkansas Vineyard And Wine Microbiota, Natacha Cureau

Graduate Theses and Dissertations

Microorganisms inhabiting the soil, leaves, and grapes in vineyards influence the terroir, a set of environmental factors that impact wine characteristics. Previously, the main method to identify microorganisms was to culture on different media, but a large portion (> 99%) could not be cultured and were consequently unidentified. However, the emergence of new molecular tools has enabled further study and identification of microorganisms such as indigenous vineyard microbiota. The objective of this research was to investigate the phylogenetic diversity of Arkansas vineyard and wine microbiota using high-throughput sequencing. In terms of the Arkansas vineyards, the fungal and bacterial diversity of …

The Exploration Of Nanotoxicological Copper And Interspecific Saccharomyces Hybrids, Matthew Joseph Winans Phd

Graduate Theses, Dissertations, and Problem Reports (ETD)

Nanotechnology takes advantage of cellular biology’s natural nanoscale operations by interacting with biomolecules differently than soluble or bulk materials, often altering normal cellular processes such as metabolism or growth. To gain a better understanding of how copper nanoparticles hybridized on cellulose fibers called carboxymethyl cellulose (CMC) affected growth of Saccharomyces cerevisiae, the mechanisms of toxicity were explored. Multiple methodologies covering genetics, proteomics, metallomics, and metabolomics were used during this investigation. The work that lead to this dissertation discovered that these cellulosic copper nanoparticles had a unique toxicity compared to copper. Further investigation suggested a possible ionic or molecular mimicry …

Effect Of Processing On Microbiota Accessible Carbohydrates In Whole Grains, Caroline Smith

Department of Food Science and Technology: Dissertations, Theses, and Student Research

There is potential to increase microbiota accessible carbohydrates (MAC) in whole grains through food processing. Therefore, different processing conditions for boiling and extrusion of whole wheat flour were studied for their effect on MAC. Processing conditions had a minimal effect on fermentation response using 2 fecal samples of disparate composition. However, the processing method had an impact on the fermentation of non-digestible carbohydrates and subsequent short chain fatty acids production, but only for a microbiome with high diversity and a predominance of microbes associated with dietary fiber intake. Subsequently, five processing methods: boiling, extrusion, unleavened bread, yeast bread, and sourdough …

A Comparative Analysis Of The Fermentation Capabilities Of Various Bifidobacterium Strains, Ella Oney

Honors Program: Senior Projects (Public)

Bifidobacterium is a genus of anaerobic bacteria that are commonly found to inhabit the gastrointestinal tract of many members of the animal kingdom. These microorganisms are adapted to obtain their carbon from the breakdown of complex carbohydrates. Marmosets, a mammal whose gut microbiome is inhabited by high levels of Bifidobacteria, consume gum Arabic as a major part of their diet. The purpose of this experiment is to determine whether Bifidobacterium strains isolated from the guts of marmosets are able to degrade and ferment this complex carbohydrate or one of its main constituents, arabinose. This was accomplished by inoculating isolates of …

The Evaluation Of Pathogen Survival In Dry Cured Charcuterie Style Sausages, Jennifer Michelle Mcneil

Theses and Dissertations--Animal and Food Sciences

The objective of this study was to evaluate the survival of non-O157:H7 STEC, Salmonella spp., and S. aureus in dry fermented sausages. Chorizo and Landjager sausages were inoculated with individual bacterial cocktails and stuffed into natural casings. Temperature, relative humidity, pH, and water activity were monitored through fermentation, drying, and storage. Bacterial counts were determined by serial dilution and plated in triplicates on selective media. Plates were incubated at 37°C for 24 hours and colony forming units per gram (CFU/g) were observed.

Results of the first study validate that contaminated raw materials contribute to pathogen survival and background bacteria outcompeted …

Growing Yeast For Livestock, Zachary Christman

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Over 500,000 tons of organic materials such as food scraps are disposed of each year in Wisconsin. A large percentage of this material could be composted or turned into useful products. The purpose of this article is to educate farmers and organizations on how to turn food waste into a high value food source for livestock. Yeast can be grown at any time of the year without the large inputs of agricultural chemicals and machinery that is common with other feed production methods. A yeast growing facility can be scalable to any size the producer wants such as a small …

The Use Of Lactobacillus Salivarius L28 As A Bioprotective Culture In Dry Fermented Sausages, Kathy Flynt Collins

Theses and Dissertations--Animal and Food Sciences

A challenge study to validate a 5 log₁₀ CFU/g reduction of non-O157 Shiga-toxin producing Escherichia coli (STEC) in dry fermented sausage (DFS) was performed. A 4.49 ± 0.474 log₁₀ CFU/g was achieved over two trials. The results indicated that the process was not effective in reducing the pathogen to the level required of most pathogens by the USDA.

Lactobacillus salivarius L28 (L28) was screened in vitro for the ability to inhibit STEC utilizing the paper disk diffusion method. This strain is a known bacteriocin producer. The results revealed that L28 would be a good candidate for use as …

Effects Of Fermentation By Yeast And Amylolytic Lactic Acid Bacteria On Grain Sorghum Protein Content And Digestibility, Christina Day

Graduate Theses and Dissertations

Grain sorghum is an underutilized crop despite many advantages to its cultivation. A drought-tolerant plant with many pest-resistant cultivars, its applications are limited by problems with nutrient availability, particularly protein digestibility. Digestibility of grain sorghum protein is reduced by antinutritional compounds in the grain like tannins and phytates, and by moist-heat cooking. Some of these concerns can be mitigated by how the grain is processed. Fermentation is one processing method that can improve digestibility. Fermentation can also concentrate protein in a substrate. In this experiment, grain sorghum was subjected to different treatments and used as a substrate for yeast fermentation. …

Direct Fermentation Of Sweet Potato Starch Into Lactic Acid By Lactobacillus Amylovorus: The Prospect Of An Adaptation Process, Winifred Akoetey

Graduate Theses and Dissertations

Several studies have verified that lactic acid bacteria are capable of directly producing lactic acid from starch. One of these bacteria, L. amylovorus, has been studied using corn, potato, and cassava starches. However, the use of sweet potato starch, a widely available starch, has not been considered. Furthermore, there exists the possibility that the efficiency of lactic acid production can benefit from the systematic exposure of bacteria to increasing concentrations of a particular starch. In this work, fermentation studies were conducted to understand the adaptation of L. amylovorus to rising concentrations of sweet potato starch. L. amylovorus was cultured in …

Optimization Of Fermentation Conditions For The Utilization Of Brewing Waste To Develop A Nutraceutical Rich Liquid Product, Shilpi Gupta, Amit Jaiswal, Nissreen Abu-Ghannam

Articles

Utilization of brewers’ spent grain (BSG), for the development of a fermented liquid product rich in value-added phenolic compounds was investigated. Changes in and liberation of phenolic compounds and antioxidant activity during fermentation of BSG was studied. The effect of various particle size (PS), solid liquid (SL) ratio, fermentation time and rotation speed was optimized using response surface methodology (RSM) for the purpose of improving bacterial growth and the enhancement in the release of polyphenolic compounds. Contour maps generated using the response surface equation showed that the experimental variables significantly affected the response. A production of 10.4 log cfu/ml, 2.95 …

Lactic Acid Production Using Sweet Potato Processing Waste, Irene Pagana

Graduate Theses and Dissertations

Organic waste generated from industrial sweet potato canning is estimated to be 30% of incoming raw material. This waste contains carbohydrates (sugars and starch) that could be used as substrates for the production of useful compounds via fermentation (e.g. lactic acid), resulting in the production of value-added products. The goal of this research project is to produce a substrate from the sweet potato processing waste material that supports the growth of lactic acid bacteria, which results in the production of lactic acid. The sweet potato waste product was characterized, and found to contain 16.5% solids. The solids components were 18.5% …