Food Microbiology Commons^™

The Use Of Inorganic And Organic Acids As Short Duration Antimicrobial Dips On Mitigating Pathogens Present On Commercial Chicken During Peri-Harvest, Dana Kristen Dittoe

Graduate Theses and Dissertations

With poultry being the most consumed meat in the United States, poultry processors must provide consumers with safe, wholesome products. As a consequence, poultry processors are faced with the challenge of reducing the presence of foodborne pathogens such as Salmonella spp. and Campylobacter jejuni among raw poultry products. Though multi-hurdle approaches using antimicrobials are placed throughout processing to reduce these pathogens, Salmonella and C. jejuni still persist among raw poultry. Thus, it was the objective of the current dissertation to investigate various antimicrobials, organic and inorganic acids, as short duration dips and sprays as means to reduce common pathogens (Salmonella, …

An Impedimetric Aptasensing System For The Rapid Detection Of Salmonella Typhimurium, America Sotero

Graduate Theses and Dissertations

Salmonella Typhimurium is a foodborne pathogen associated with raw and undercooked eggs, poultry, beef, fruits, and vegetables. In the United States, Salmonella is responsible for approximately 1.2 million illnesses, 23,000 hospitalizations, and 450 deaths annually. For many years, conventional detection methods such as culture-dependent and PCR-based methods have been the “golden standards” for the detection of this pathogen due to their high sensitivity and reliability. However, they still have some disadvantages such as long enrichment steps and high costs that need to be overcome. The development of a rapid and reliable method for the detection of S. Typhimurium is needed …

Development Of Novel Pectinase And Xylanase Juice Clarification Enzymes Via A Combined Biorefinery And Immobilization Approach, Shady Hassan

Doctoral

Hydrolytic enzymes, such as pectinase and xylanase, maybe harnessed for numerous industrial applications in food industry. Therefore, economic factors such as achievement of optimum yieldsandoverall production costs, in addition to biocatalyst instability,are the main obstacles tothe industrial production and exploitation of a enzymes. For example, microbially-derived enzymes are typically produced in fermenters using expensive growth media, which may account for 30 to 40% of the production cost, and such expense may be compounded further by downstream processing operations.To counter such disadvantages, the major trend in industrial utilization of enzymes in cost-sensitive processes has been to immobilize such biocatalysts on a …

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) …

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 …

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 …

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 …

Detection Of Fish Fillet Substitution And Mislabeling 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

Substitution of high-priced fish species with inexpensive alternatives and mislabeling frozen-thawed fish fillets as fresh are two important fraudulent practices of concern in the seafood industry. This study aimed to develop multimode hyperspectral imaging techniques to detect substitution and mislabeling of fish fillets. Line-scan hyperspectral images were acquired from fish fillets in four modes, including reflectance in visible and near-infrared (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 …

Microplate Immunocapture Coupled With The 3m Molecular Detection System And Selective Plating For The Rapid Detection Of Salmonella Infantis In Dry Dog Food And Treats, Danielle K. Rosen, Miguel Gallardo, Mcclain Vail, Rosalee S. Hellberg

Food Science Faculty Articles and Research

The objective of this study was to use microplate immunocapture (IC) to reduce the enrichment time required for detection of Salmonella in pet food with the 3 M Molecular Detection System (MDS) or selective plating on XLD. Dog food and pig ear treats were inoculated with Salmonella Infantis at concentrations of 10⁰–10⁴ CFU/25 g, followed by a 3-h enrichment, then microplate IC and 3 M MDS or microplate IC and selective plating on XLD. Another set of samples underwent a traditional 24-h enrichment followed by 3 M MDS or selective plating. Based on the results of three …

Ferulic Acid Incorporated Active Films Based On Poly(Lactide) /Poly(Butylene Adipate-Co-Terephthalate) Blend For Food Packaging, Shubham Sharma, Amit Jaiswal, Brendan Duffy, Swarna Jaiswal

Articles

Active natural antibacterial blend of poly(lactide) - poly(butylene adipate-co-terephthalate) (PLA-PBAT) incorporated with ferulic acid was formed by solvent casting method. The influences of FA on the structural, colour, optical, thermostability and antibacterial efficiency of PLA-PBAT blend films were studied. On the incorporation of the FA, the thickness of the film was increased by 1.5–10 %. The tensile strength (TS) of the FA incorporated blend film increased to a value of 10.78 MPa at 10 wt% as compared to the control film which has 5.42 MPa. The temperature of degradation of the film increases as the FA content increases in the …

Growing Torula Yeast (Candida Utilis) For Food Grade Fatty Acids, Zachary Christman

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

The focus of this article is the cultivation of a food grade yeast for the production of fatty acids without the restrictions of climate or growing season. Torula yeast (Candida utilis) was selected since it can grow on a wide variety of culture media and has over 60 years of use in the food industry. The fatty acid composition of C. utilis grown on two different media are presented in this article; the first example using completely synthetic media and another using distiller’s vinasse. Also, the effect of different culturing conditions on the percentage of various fatty …

Moisture Sorption Behavior And Shelf Life Prediction Of Teff Seed And Flour, Baba Abdissa, Rudrayya Math, Kodandaramreddy Desham, Srinivasulu Korra

Journal of Applied Packaging Research

Moisture sorption isotherms of Teff seed and its flour were determined over the range of relative humidity (11–92%) using a gravimetric technique at constant temperature (27°C). The results obtained showed that the moisture sorption isotherm of both is almost similar and sigmoid with increasing equilibrium water content at the constant temperature. The curves start raising high above 64% RH indicating the products deteriorates faster above 64% RH. Hence the moisture content equilibrating to 64% RH was taken as critical for both Teff seed and flour variants. The sorption isotherm fits the GAB equation as per GAB generalized equation for sorption …

Labeling Compliance And Species Authentication Of Fish Fillets Sold At Grocery Stores In Southern California, Priscila Liou, Angela Banda, Rachel B. Isaacs, Rosalee S. Hellberg

Food Science Faculty Articles and Research

Seafood mislabeling has numerous consequences, including economic deception and food safety risks. The focus of this study was to investigate fish species labeling, use of acceptable market names, and Country of Origin Labeling (COOL) compliance for fresh fish fillets sold at grocery store seafood counters in Southern California. A total of 120 fillets representing 16 different categories of fish were collected from 30 Perishable Agricultural Commodities Act (PACA)-listed grocery stores. Each sample underwent DNA barcoding to identify the species. Acceptable market names were confirmed using the FDA Seafood List. Samples were determined to be compliant with COOL if both …

An Evaluation Of Sonication Pretreatment For Enhancing Saccharification Of Brewers’ Spent Grain, Shady Hassan, Rajeev Ravindran, Swarna Jaiswal, Brijesh K. Tiwari, Gwilym A. Williams

Articles

This paper deals with the investigation of ultrasound (US) pretreatment of brewer’s spent grain (BSG) as ameans of releasing fermentable sugars, and the subsequent production of ethanol from this lignocellu-losic biomass. Using response surface methodology (RSM), the influence of US power, time, temperatureand biomass loading on fermentable sugar yield from BSG was studied. The optimal conditions werefound to be 20% US power, 60 min, 26.3°C, and 17.3% w/v of biomass in water. Under these conditions,an approximate 2.1-fold increase in reducing sugar yield (325 ± 6 mg/g of biomass) was achieved, relativeto untreated BSG (151.1 ± 10 mg/g of biomass). In …

Characterization And Use Of Pathogen Specific Bacteriophages To Reduce The Viability Of Escherichia Coli O157:H7 Contamination On Fresh Produce, Badrinath Vengarai Jagannathan

Theses and Dissertations--Animal and Food Sciences

Fresh produce is one of the most common sources of food-borne outbreaks, involving various pathogenic microorganisms such as Escherichia coli. Recent outbreaks have clearly shown that post-harvest washing has limited effectiveness on decontaminating produce and may contribute to cross-contamination of produce due to various limitations. Excessive use of sanitizers and antibiotics has also led to the development of many antibiotic-resistant strains of bacteria that have made the food industry more vulnerable.

Bacteriophages are a bacterial viruses that can selectively infect and replicate within bacteria leading to cell lyse and death. Bacteriophages have become widely recognized due to their ability …

A Review Of Technologies For Malt Flour And Sourdough From Brewery Spent Grain, Zachary Christman

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

The utilization of brewer's spent grain for the production of malt flour is the focus of this article. The reader is presented with superheated steam and extrusion as technologies to reduce mycotoxin contamination and improve shelf life. Another option is the fermentation of brewer's spent grain with a cereal grade lactic acid bacteria for the production of sourdough bread. Milling of the brewer's spent grain for the production of bread is also covered.

Associations Between The Home Environment, Feeding Practices And Children’S Intakes Of Fruit, Vegetables And Confectionary/Sugar-Sweetened Beverages, Carolina Bassu, Clare Corish, John Kearney

Articles

Within the home environment, parents influence their children’s dietary intakes through their parenting and dietary practices, and the foods they make available/accessible. The aim of this cross-sectional study was to examine the associations between home environmental characteristics and children’s dietary intakes. Three hundred and thirty-two children aged three–five years and their parents participated in the study. Home environmental characteristics, including parental control feeding practices, were explored using validated and standardized questionnaires such as the Child Feeding Questionnaire (CFQ), the Physical and Nutritional Home Environment Inventory (PNHEI) and the Healthy Home Survey (HHS). Parent and child food consumption was also measured. …

Computational Modelling Approach For The Optimization Of Apple Juice Clarification Using Immobilized Pectinase And Xylanase Enzymes, Shady Hassan, Gwilym Williams, Amit Jaiswal

Articles

Apple juice is typically marketed as a clear juice, and hence enzymatic treatments are common practices in juice industry. However, enzymatic treatments have been shown to face some challenges when process efficiency, and cost effectiveness are concerned. Therefore, it is necessary to optimize the enzymatic treatment process to maximize efficiency, and reuse enzymes to minimize the overall cost via immobilization. In this context, the present work features the immobilization of pectinase and xylanase from M. hiemalis on genipin-activated alginate beads, with subsequent evaluation of its efficacy in apple juice clarification. A central composite rotatable design (CCRD), coupled with artificial neural …

Salcaprozate Sodium (Snac) Enhances Permeability Of Octreotide Across Isolated Rat And Human Intestinal Epithelial Mucosae In Ussing Chambers, Sarinj Fattah, Mohamed Ismaiel, Brenda Murphy, Aleksandra Rulikowska, Jesus Maria Frias, Desmond C. Winter, David J. Brayden

Articles

Octreotide is approved as a one-month injectable for treatment of acromegaly and neuroendocrine tumours. Oral delivery of the octapeptide is a challenge due mainly to low intestinal epithelial permeability. The intestinal permeation enhancer (PE) salcaprozate sodium (SNAC) has Generally Regarded As Safe (GRAS) status and is a component of an approved oral peptide formulation. The purpose of the study was to examine the capacity of salcaprozate sodium (SNAC), to increase its permeability across isolated rat intestinal mucosae from five regions and across human colonic mucosae mounted in Ussing chambers. Apical-side buffers were Kreb's-Henseleit (KH), fasted simulated intestinal fluid (FaSSIF-V2), rat …

Temperature Stability And Effectiveness Of Plasma-Activated Liquids Over An 18 Months Period, Evanthia Tsoukou, Paula Bourke, Daniela Boehm

Articles

Non-buffered plasma-activated liquids such as water and saline have shown bactericidal effects. In the present study, we investigated the anti-bacterial efficacy and stability of plasma-activated water (PAW) and plasma-activated saline (PAS), generated using a high voltage dielectric barrier discharge system. This study compares the potential of non-buffered plasma-activated liquids (PAL) for the inactivation of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) after storage of the solutions at five different temperatures for a storage time up to 18 months after their generation. The temperatures used were room temperature, 4 °C, −16 °C, −80 °C, −150 °C. Both PAW and …

Effect Of Atmospheric Cold Plasma On The Functional Properties Of Whole Wheat (Triticum Aestivum L.) Grain And Wheat Flour, Sonal Chaple, Chaitanya Sarangapani, John B. Jones, Ed Carey, Lucie Causeret, Annaik Genson, Brendan Duffy, Paula Bourke

Articles

Atmospheric cold plasma (ACP) has emerged as a novel processing technology, with demonstrated efficiencies in microbial inactivation. However, studies on the effects of ACP and potential to modify the functional properties of foods are sparse. The objective of this study is to determine the effect of ACP on physico-chemical and functional properties of wheat flour. In this study, both whole wheat grains and wheat flour were subjected to a dielectric barrier discharge (DBD) contained plasma reactor for a range of treatment times (5–30 min) at 80 kV. Plasma treatment increased the flour hydration properties of wheat flour. Rapid visco-analyser results …

Assessing The Biological Safety Of Atmospheric Cold Plasmatreated Wheat Using Cell And Insect Models, Agata Los, Dana Ziuzina, Daniela Boehn, Paula Bourke

Articles

Atmospheric cold plasma (ACP) is under investigation for an extensive range of biocontrol applications in food biosystems. However, the development of a novel intervention technology requires a thorough evaluation of the potential for negative effects and the implications for the human and animal food chains’ safety. The evaluations were performed using a contained, high-voltage, dielectric barrier discharge plasma system. The cytotoxicity of two types of food models—a liquid model (wheat model medium (WMM)) vs. a solid model (wheat grain extract (WGE)) was compared in vitro using the mammalian cell line CHO-K1. The residual toxicity of ACP treatment of grains for …