Food Science Commons^™

Characteristics Of Yogurt And Culture Bacteria As Affected By Ingredients That Help Treat Leaky Gut, Ricardo Jose Santos Aleman

LSU Doctoral Dissertations

At least 100 million people have leaky gut syndrome. This syndrome is associated with multiple health problems such as diabetes, celiac disease, asthma, multiple sclerosis, and inflammatory bowel disease, costing more than $3 billion per year to treat. L-Glutamine, quercetin, slippery elm bark, marshmallow root, N-acetyl-d-glucosamine (NAG), licorice root, maitake mushrooms, and zinc orotate have been reported to help treat leaky gut.

The objectives were to explore the characteristics of yogurt and culture bacteria as affected by ingredients that help treat leaky gut. In yogurt, the pH, titratable acidity, syneresis, viscosity, color, Streptococcus thermophilus, Lactobacillus bulgaricus, yeast and mold and …

Influence Of Hesperidin On The Physico-Chemical, Microbiological, And Sensory Characteristics Of Frozen Yogurt, Roberto Antonio Cedillos Hernández

LSU Master's Theses

Frozen yogurts contain yogurt culture bacteria which might impart health benefits to its consumers. Global frozen yogurt market sales are expected to grow 4.8% by 2028 which represents an important opportunity for the industry, consumers, and researchers. Polyphenols are metabolites found in plants which have antioxidant and anti-inflammatory properties and might prevent chronical diseases such as cancer, diabetes, and cardiovascular diseases. The objective of this study was to elucidate the effect of the polyphenol hesperidin on the physico-chemical, microbiological, and sensory characteristics of frozen yogurts. Hesperidin was incorporated in frozen yogurt at three concentrations (500, 250 and 125 mg/90g of …

Effect Of Contact Time And Attachment Level Of Bacterial Pathogens On Efficacy Of Chlorine Treatment In Fresh Produce, Jyoti Aryal

LSU Master's Theses

Bacterial attachment or biofilm formation on produce surfaces may result in limited penetration ability of sanitizers. This study examined the wet and dry contact time (WCT or DCT) of produce during washing with sanitizer and evaluated the effect of attachment level of Listeria monocytogenes during storage on the efficacy of chlorine treatment. Spinach and bell peppers were inoculated with Listeria monocytogenes and Salmonella enterica. The produce was then washed by dipping into a 100 ppm of chlorine solution for 1 min and an additional 1, 3, or 5 minutes (WCT) or removed from the chlorine solution and held for 1, …

Effect Of Storage Temperature On The Survival Or Growth Of Listeria Monocytogenes On Whole And Fresh-Cut Produce, Juan F. Moreira Calix

LSU Master's Theses

Whole and fresh-cut produce are minimally processed and, therefore susceptible to microbial contamination. This study examined the survival or growth of Listeria monocytogenes on whole, and fresh-cut produce at different storage temperatures. Fresh fruits (cantaloupes, pears, pineapples, papayas, and watermelon) and vegetables (broccoli, cauliflower, lettuce, kale, and green bell peppers) were cut into 25 g pieces and were spot inoculated with 0.5 mL (8 Log CFU/mL) of Listeria monocytogenes. Inoculated fresh-cut samples were stored at 4°C or 13°C for 6 days. To represent the outer surface of the produce, cantaloupes and green bell pepper disks (20 cm2) were cut with …

Prevalence And Control Of Salmonella Spp. And Sanitary Indicator Microorganisms In Wild Caught And Farm Raised Catfish (Ictalurus Punctatus), Bilan Costley Jessie

LSU Doctoral Dissertations

Catfish inspections have transitioned from the U.S. Food and Drug Administration (FDA) to the United States Department of Agriculture (USDA). The USDA Food Safety and Inspection Service (FSIS) and Food Emergency Response Network (FERN) consider it important to assess the food safety risk associated with consuming catfish in the United States. Surveillance of farm-raised and wild-caught catfish for pathogens is relevant as a public safety protocol. The purpose of this study was to detect the prevalence of Salmonella spp., identify and examine isolates for antibiotic resistance to clinical treatments, evaluate the effectiveness of antimicrobial chemical treatments against Salmonella enterica, and …

Occurrence Of Aflatoxin And Zearalenone In Concentrate Feeds And Milk Contamination With Aflatoxin M1 And Bacterial Pathogens In Malawi, Chunala Alexico Njombwa

LSU Doctoral Dissertations

Multiple studies were conducted in Malawi to: 1) evaluate knowledge and perception of dairy farmers towards molds, mycotoxins and associated adverse effects; 2) evaluate dairy farmers’ knowledge and perception on milk contamination, proper milk handling practices and adverse health effects associated with raw milk consumption; 3) determine levels of aflatoxins and zearalenone (ZEN) in concentrate feedstuffs; 4) assess prevalence and levels of aflatoxin M₁(AFM₁) in raw milk, dietary exposure and estimate HCC risks to children and adults; 5) assess Salmonella and E. colicontamination in raw and processed milk from selected small scale farms and major …

Comparison Of The Kinetic Parameters Of Escherichia Coli 0157:H7, Listeria Monocytogenes And Salmonella Typhimurium Derived From The Baranyi And Huang Models In A Chemically Defined Minimal Medium, Jose Isidro Fuentes

LSU Master's Theses

Microbial growth can be characterized by parameters such as lag time, growth rate, and maximum population density at any specific point of time. Mathematical models that predict microbial growth of foodborne pathogens are increasingly used in the food industry as a viable alternative to traditional methods of microbial enumeration. The Baranyi model has been widely used as the primary model of choice by many authors because of its performance and accuracy. The most recently developed Huang model has been less implemented and few comparisons between the Baranyi and Huang models have been made when modeling pathogenic growth. For this research, …

Antimicrobial Properties Of Different Chitosans Against Gram-Negative And Gram-Positive Foodborne Pathogens In Food Products, Nancy Katherine Rubio Zapata

LSU Doctoral Dissertations

Chitosan is a polymer derived of the deacetylation of chitin that is one of the most abundant material in nature. Chitosan solutions applied as edible coatings, and dipping solutions have shown positive results in the extension of shelf life on seafood and meat products. The purpose of this study was to evaluate the antimicrobial activities of a newly invented high molecular weight water-soluble (HMWWS) chitosan against selected Gram-negative (Salmonella Typhimurium, Vibrio parahaemolyticus, Vibrio vulnificus, and Vibrio cholerae) and Gram-positive (Listeria monocytogenes, Staphylococcus aureus, and Bacillus cereus) foodborne pathogens (initial inoculation of 6.5 Log). Chitosans with …

Improving The Food Safety Of Louisiana Strawberry Industry, Jose L. Brandao Delgado

LSU Doctoral Dissertations

Escherichia coli O157:H7, Salmonella sp., and Listeria monocytogenes have been linked to foodborne outbreaks in produce. The most recent outbreaks in produce have been associated with irrigation water due to infiltration of well water or water run-off from contaminated sources. The Food Safety Modernization Act (FSMA) requires all irrigation water to be safe for use on produce, as a strategy to reduce foodborne illnesses. A surfactant modified zeolite (SMZ) filtration system could provide produce farmers with a sustainable low-cost system for high-quality and safe irrigation water. The objective of this study was to evaluate the effectiveness of hexadecyltrimethylammonium …

Efficacy Of Aqueous And Gaseous Chlorine Dioxide In Reducing Salmonella, E. Coli O157:H7, And Listeria Monocytogenes On Sweet Potatoes, Strawberries, And Blueberries, Phillip Luu

LSU Master's Theses

Chlorine dioxide, a stronger oxidizing agent, is effective against a broad spectrum of microorganisms. This study evaluated the efficacy of chlorine dioxide on reducing Salmonella, E. coli O157:H7, and Listeria monocytogenes on sweet potato (aqueous ClO₂), strawberries and blueberries (gaseous ClO₂). Sweet potatoes inoculated with multi-strain cocktails of each bacterial pathogen (10⁷ CFU/cm²) were treated with 5 ppm aqueous ClO₂ or water for 10, 20, and 30 minutes. Strawberries and blueberries spot inoculated with multi-strain cocktails of each bacterial pathogen (10⁷ CFU/g) were treated with gaseous ClO₂ sachets (63 mg/l for strawberry and 30 mg/l for blueberry) …

Effect Of Environmental Factors And Residual Sanitizers On Survival And Attachment Of Indicator Organism And Human Pathogens On Fresh Produce, Vijay Singh Chhetri

LSU Doctoral Dissertations

A comprehensive understanding of the behavior of microbial contaminants on produce surfaces in agricultural farms and during post-harvest activities is essential for the development of produce safety risk management strategies. Our studies investigated the survival and the attachment of E. coli on watermelon surfaces in agricultural settings with different levels of vegetation, and the effect of residual sanitizers on the survival and the attachment of E. coli O157: H7 and L. monocytogenes on spinach leaves. The attachment strength (S_R) of the E. coli cells on watermelon surfaces significantly increased (P<0.05) from 0.04 to 0.99 in the first 24 h, which was primarily due to the decrease in loosely attached population, given that the population of strongly attached cells was constant. The daily die-off rate of E. coli ranged from -0.12 …

Effect Of Hot Water Conditioning On Microbial Safety And Quality Of In-Shell Pecans, Karuna Kharel

LSU Master's Theses

Hot water conditioning of in-shell pecans is one common practice followed by industries to facilitate shelling. It also acts as a preventive control for potential microbiological contamination that might occur during pre- and post-harvest processes. However, heat treatment may have an effect on the eating quality of nuts. The main objectives of the study were to develop a post-harvest hot water treatment intervention as a kill step to destroy foodborne pathogens on in-shell pecans and evaluate the effect of treatments on physicochemical properties, consumer acceptance and purchase intent of dehulled and roasted pecans. The time (1-5 min) and temperature (70, …

Heat, Acid And Osmotic Stress Tolerance Of Leuconostoc Mesenteroides As Influenced By Prior Exposure To Various Mild Stress Conditions, Ingrid C. Osorio Rodriguez

LSU Master's Theses

The importance of Leuconostoc mesenteroides is recognized for its contribution to taste in cultured dairy products. It has been cited for its potential role as a probiotic. Consumer demand exists for new dairy products with health benefits. In the manufacture of probiotic-products survival of Leuconostoc mesenteroides would depend on its ability to tolerate challenging processing and storage conditions. Improved viability by prior exposure to mild stresses can increase stress tolerance toward a more severe stress. Furthermore, it can result in cross-protection due to connection of several proteins in response to stresses. Objective was to evaluate the effect of prior …

Interaction Of Cocoa Powder With Intestinal Microbiota, Martha M. Escoto Sabillon

LSU Master's Theses

Cocoa is the fully fermented and dried seed of the cacao tree (Theobroma cacao L.) which has prebiotic properties, due to their high concentration of polyphenols. Therefore, the ingestion of cocoa could cause changes in the proportions of the intestinal microbiota that can influence the intestinal immune response. The objective of this study was to determine the effect of alkalization process of the cocoa bean in the diversity of the gut microbiota. The samples were “lavado” unprocessed cocoa powder, “natural” unprocessed cocoa powder, “D-11-S” as alkalized cocoa powder, “D-11-B” heavily alkalized cocoa powder, and raw cocoa “shells” and a control …