Food Microbiology Commons^™

Chemical Effects Of Cold Atmospheric Plasma On Food Nutrients, Juan Manuel Pérez Andrés

Doctoral

A range of nonthermal techniques have demonstrated process efficacy in ensuring food product safety, extension of shelf-life and in general a retention of key quality attributes. However, various physical, chemical and biochemical effects of nonthermal techniques on both macro and micronutrients are evident, leading to both desirable and undesirable changes in food products. It is important to outline the effects of non-thermal techniques on food chemistry and the associated degradation mechanisms with the treatment of foods. Oxidation is one of the key mechanisms responsible for undesirable effects induced by non-thermal techniques. Degradation of key macromolecules largely depends on the processing …

Development Of Essential Oil Incorporated Active Film Based On Biodegradable Blends Of Poly (Lactide)/Poly (Butylene Adipate‑Co‑Terephthalate) For Food Packaging Application, Shubham Sharma, Sandra Barkauskaite, Swarna Jaiswal, Brendan Duffy, Amit Jaiswal

Articles

Active packaging improves food safety and quality with the incorporation of certain additives such as antimicrobial agents. The PLA/PBAT films were prepared with two essential oils—eucalyptus oil and cinnamon oil of various concentrations (1%, 5%, and 10% w/w) and characterized their optical and mechanical properties, surface hydrophobicity, chemical composition, and antimicrobial activity. Cinnamon oil composite films were observed as thicker films (88.88 µm) than the eucalyptus oil films (54.46 µm). The highest UV-blocking properties were observed in cinnamon oil films. However, transparency and tensile properties of the cinnamon oil films decreases as the concentration increases. The tensile strength of the …

Characterization And Antimicrobial Activity Of Biodegradable Active Packaging Enriched With Clove And Thyme Essential Oil For Food Packaging Application, Shubham Sharma, Sandra Barkauskaite, Brendan Duffy, Amit Jaiswal, Swarna Jaiswal

Articles

Bioactive packaging contains natural antimicrobial agents, which inhibit the growth of microorganisms and increase the food shelf life. Solvent casting method was used to prepare the Poly (lactide)-Poly (butylene adipate-co-terephthalate) (PLA-PBAT) film incorporated with the thyme oil and clove oil in various concentrations (1 wt%, 5 wt% and 10 wt%). The clove oil composite films depicted less green and more yellow as compared to thyme oil composite films. Clove oil composite film has shown an 80% increase in the UV blocking efficiency. The tensile strength (TS) of thyme oil and clove oil composite film decreases from 1.35 MPs (control film) …

Performance Of A Uv-A Led System For Degradation Of Aflatoxins B1 And M1 In Pure Water: Kinetics And Cytotoxicity Study, Judy Stanley, Ankit Patras, Brahmaiah Pendyala, Matthew J. Vergne, Rishipal R. Bansode

Agricultural and Environmental Sciences Faculty Research

The efficacy of a UV-A light emitting diode system (LED) to reduce the concentrations of aflatoxin B1, aflatoxin M1 (AFB1, AFM1) in pure water was studied. This work investigates and reveals the kinetics and main mechanism(s) responsible for the destruction of aflatoxins in pure water and assesses the cytotoxicity in liver hepatocellular cells. Irradiation experiments were conducted using an LED system operating at 365 nm (monochromatic wave-length). Known concentrations of aflatoxins were spiked in water and irradiated at UV-A doses ranging from 0 to 1,200 mJ/cm2. The concentration of AFB1 and AFM1 was determined by HPLC with fluorescence detection. LC–MS/MS …

Exploring The Connection Between Acid Exposure And Virulence In Listeria Monocytogenes, Minghao Li

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Listeria monocytogenes is a gram-positive food-borne pathogen that is widely dispersed in the environment and can cause listeriosis with high fatality rates when consumed in contaminated food products. They are capable of growing over a wide range condition. Listeria is also able to tolerate adverse conditions which allows the bacterium to survive in unfavorable environments. The ubiquitous nature of L. monocytogenes makes it difficult to eliminate from food systems. One major problem in the food industry is the survival of L. monocytogenes under sublethal low pH-environment since organic acids are widely used as food decontaminants. Prior research has suggested that …

Effect Of Long Pasteurization Run Times On Bacterial Numbers In Milk, Brynli Tattersall

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This project was funded by the Western Dairy Center to understand how long a milk pasteurizer can be operated before increases in bacterial numbers are observed in the pasteurized milk. While pasteurization kills pathogenic bacteria there are some non-pathogenic bacteria that can survive and have the ability to become attached to the surfaces in the cooling sections of the pasteurizer. Some bacteria can also produce spores that survive pasteurization even if the bacterial cells are killed. Temperatures in the cooling section remain in a range suitable for growth of these heat-tolerant bacteria and can allow germination of bacterial spores. While …

Improving Microbiological Safety Of Low Moisture Food Products Using Radio Frequency And Ethylene Oxide, Long Chen

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Recent foodborne illness outbreaks in US associated with consumption of low-moisture foods (LMF) have heightened concerns of their microbial safety. Salmonella is a pathogen of major concern in LMF due to its ability to persist in low water activity (a_w) environments. The disadvantages of existing decontamination technologies for LMF call for novel and efficient intervention technologies. Radio frequency (RF) and ethylene oxide (EtO) were evaluated in this dissertation for improving microbial food safety and quality of LMF. Cumin seeds and inshell hazelnuts were selected as model foods.

It took < 2 min of stationary RF heating to achieve > 5 log reductions of Salmonella in cumin seeds without …

Authentication Of Red Snapper (Lutjanus Campechanus) Fillets Using A Combination Of Real-Time Pcr And Dna Barcoding, Rachel B. Isaacs, Rosalee S. Hellberg

Food Science Faculty Articles and Research

Red snapper (Lutjanus campechanus) is a historically overfished and highly valued species that is commonly substituted with other fish, such as tilapia, rockfish, and other snapper species. The objective of this study was to assess the ability of real-time PCR to be used as a screening tool to rapidly test commercial fillets for the presence of red snapper, followed by species identification of negative samples with DNA barcoding. A total of 24 frozen, fresh, or thawed (previously frozen) fillets labeled as “red snapper” were tested with real-time PCR, along with 54 fillets from fish that are common substitutes …

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 …

Investigating The Potential Of Sodium Butyrate To Control Salmonella Enteritidis In Poultry, Anamika Gupta

Graduate Theses and Dissertations

Salmonella Enteritidis (SE) is a major poultry associated food borne pathogen that causes enteric illnesses in humans. Despite using various pre-harvest and post-harvest intervention strategies to reduce Salmonellosis, SE infection is still an extensive problem in the poultry industry with increased incidences since SE has developed multiple strategies to adapt in the chicken intestinal tract particularly in the ceca. Therefore, reducing SE in the intestine of chickens would reduce contamination of poultry derived foods and minimize the risk of human infection. Short chain fatty acids such as butyrate are microbial metabolites known to modulate inflammatory response. In this dissertation, the …

Impact Of Selected Infrared Wavelengths Treatment On Inactivation Of Microbes On Rough Rice, Rebecca Bowie

Food Science Undergraduate Honors Theses

Formation of harmful microbes and their associated mycotoxins on rough rice during storage present negative socioeconomic impacts to producers and consumers. The objective for this study was to investigate the impact of treating rough rice with selected infrared (IR) wavelengths at different IR intensities and heating durations, followed by a tempering step for further inactivation of microbes (mold and bacteria) on the grain. Freshly-harvested long-grain, hybrid, rough rice (XL 745) with initial moisture content (IMC) of 18.4% wet basis (w.b.) was used. Two-hundred grams (200 g) of the samples were treated at different IR wavelengths (λ) which were 3.2, 4.5, …

Elucidating Basis Of Rice Discoloration And Developing Prevention Strategies, Zeinab Mohammadi Shad

Graduate Theses and Dissertations

Economically, discolored rice kernels have less market value, which can seriously impact farm net profit. The reasons for rice discoloration during storage have not been studied extensively and many questions remain. Therefore, the primary goal of this study was to improve understanding of the role and contributions of storage practices on rice quality degradation and discoloration. In this study, three rice cultivars including XL753 (hybrid), Roy J (pureline), and Titan were assessed for changes in quality and microbial kinetics. The rice samples at a high moisture content (MC) of 21% w.b. and a low MC of 16% were stored at …

Microbiota Characterization Of Poultry Processing Systems And Associated Microbiological Sampling Materials Collected At Commercial Processing Facilities, Jennifer A. Wages

Graduate Theses and Dissertations

The poultry industry and associated regulatory bodies use whole bird carcass (WBC) rinsates to evaluate different stages of broiler processing systems for the prevalence of food-borne pathogens, including Salmonella spp. and Campylobacter spp. Within industry and research groups, the same sample collections are enumerated to determine E. coli, Enterobacteriaceae (EB), and Aerobic Plate Count (APC) microorganisms. Analysis of these indicator microorganisms provides numerical data that can be used to demonstrate the effects of specific process control steps where low occurrences of target pathogens hinder the exclusive use of prevalence data. With the utilization of next generation sequencing (NGS), including analysis …

Food Safety Risk In An Indoor Microgreen Cultivation System, Gina Marie Misra

Graduate Theses and Dissertations

Microgreens are immature sprouts of edible plants, sharing some similarities with sprouted seeds and petite leafy greens. Since they are most often grown in containers in buildings or greenhouses, they present a new area for food safety research at the intersection of the built environment and produce farming. Contamination by human pathogens has been extensively studied in other types of produce typically eaten raw, including sprouted seeds, which have been implicated in numerous outbreaks of salmonellosis over the last several decades. There is a paucity of knowledge about the microgreen sector of the fresh-cut industry; thus, it was determined that …

Effects Of Traditional Processing Techniques On The Nutritional And Microbiological Quality Of Four Edible Insect Species Used For Food And Feed In East Africa, Dorothy N. Nyangena, Christopher Mutungi, Samuel Imathiu, John Kinyuru, Hippolyte Affognon, Sunday Ekesi, Dorothy Nakimbugwe, Komi K.M. Fiaboe

All Peer-Reviewed Publications

Edible insects are increasingly being considered as food and feed ingredients because of their rich nutrient content. Already, edible insect farming has taken-off in Africa, but quality and safety concerns call for simple, actionable hazard control mechanisms. We examined the effects of traditional processing techniques—boiling, toasting, solar-drying, oven-drying, boiling + oven-drying, boiling + solar-drying, toasting + oven-drying, toasting + solar-drying—on the proximate composition and microbiological quality of adult Acheta domesticus and Ruspolia differens, the prepupae of Hermetia illucens and 5th instar larvae of Spodoptera littoralis. Boiling, toasting, and drying decreased the dry matter crude fat by 0.8–51% in the order: …

Producer Willingness To Pay For Enhanced Packaging To Prevent Postharvest Decay Of Strawberries, Brian Coffey, Valentina Trinetta, Londa Nwadike, Umut Yucel

Journal of Applied Farm Economics

We surveyed specialty crop producers in Kansas and Missouri to determine producer willingness to pay for new active packaging technology that prevents postharvest loss and increases shelf life. The survey also asked demographic questions to determine the producer and operation traits for this growing segment of production agriculture. More than half of those surveyed were female, and 60% were under 50 years of age. Smaller operations tend to utilize direct marketing and social media activity more than larger operations. Parametric willingness to pay estimates are approximately $0.39 per cardboard flat to purchase the antifungal film that increases shelf life of …

Do Lactic Acid Bacteria In Fermented Foods Persist In The Gastrointestinal Tract: An In Vitro Investigation, Chloe M. Christensen, Car Reen Kok, Robert W. Hutkins

UCARE: Research Products

It is now well established that the composition of the gastrointestinal (GI) microbiota has a profound influence on intestinal and overall health. Many contemporary diseases such as type two diabetes, IBS and obesity are associated with a dysbiotic microbiota. Therefore, researchers are interested in how diet and specific dietary components can modulate the gastrointestinal microbiota and possibly repair a dysbiotic state. One approach to improve gastrointestinal health is by consuming probiotics and prebiotics or a diet rich in fermented foods containing live microbes. Fermented foods are popular because of their enhanced preservation, safety, organoleptic, functionality, and nutritional properties. These fermented …

Research Tools And Their Uses For Determining The Thermal Inactivation Kinetics Of Salmonella In Low-Moisture Foods, Soon Kiat Lau

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

The reputation of low-moisture foods as safe foods has been crumbling over the past decade due to repeated involvement in foodborne illness outbreaks. Although various pasteurization technologies exist, a majority are thermal processes and have not been well-characterized for pasteurizing low-moisture foods. In addition, the nature of a low-moisture food matrix introduces various experimental complications that are not encountered in high-moisture foods. In this dissertation, the development, building instructions, and characterization of various open source tools for studying the inactivation kinetics of microorganisms in low-moisture foods are described. The first tool is the TDT Sandwich, a dry heating device for …

Inspecting Species And Freshness Of Fish Fillets Using Multimode Hyperspectral Imaging Techniques, Jianwei Qin, Fartash Vasefi, Rosalee S. Hellberg, Alireza Akhbardeh, Rachel B. Isaacs, Ayse Gamze Yilmaz, Chansong Hwang, Insuck Baek, Walter F. Schmidt, Moon S. Kim

Food Science Faculty Articles and Research

This study developed multimode hyperspectral imaging techniques to detect substitution and mislabeling of fish fillets. Line-scan hyperspectral images were collected from fish fillets in four modes, including reflectance in visible and nearinfrared (VNIR) region, fluorescence by 365 nm UV excitation, reflectance in short-wave infrared (SWIR) region, and Raman by 785 nm laser excitation. Fish fillets of six species (i.e., red snapper, vermilion snapper, Malabar snapper, summer flounder, white bass, and tilapia) were used for species differentiation and frozen-thawed red snapper fillets were used for freshness evaluation. A total of 24 machine learning classifiers were used for fish species and freshness …

Edible Films Made Of Corn Zein Protein And Cellulose Derivatives, Gloria Dukuzeyesu, Changmou Xu, Zhang Yue

UCARE: Research Products

A composite edible film made of corn zein protein (Z) and cellulose derivatives (C) was successfully fabricated. Edible films are coatings used to wrap food products to protect them against microbial deterioration, loss of moisture, and to extend the shelf life of the product. These edible films are consumed together with the product . The mechanical properties, water vapor permeability, application on fruits, and shelf life of the composite film were studied. Zein demonstrated excellent packing characteristics; due to its high no polar contents and hydrophobic nature, zein film served as a moisture barrier. Hydroproxy methylcellulose (HPM) is tasteless, odorless …