Life Sciences Commons^™

Whole Grain Processing And Effects On Carbohydrate Digestion And Fermentation, Sandrayee Brahma

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

Whole grains are a major source of dietary fibers in the human diet that provide specific nutrients to the gut microbiota and thereby plays a major role in modulating microbiota composition and increasing diversity of the gut ecosystem. A common approach of consuming whole grains is in the form of ready-to-eat extruded breakfast cereals. Studies reported herein established that extrusion conditions not only affected the physicochemical properties but also in vitro starch digestibility, β-glucan extractability and in vitro fermentation characteristics of whole grain oats. Moderate screw speed (300 rpm) led to higher slowly digestible starch (SDS) with an accompanying decrease …

Increasing Cis-Lycopene Content Of The Oleoresin From Tomato Processing Byproducts Using Supercritical Carbon Dioxide And Assessment Of Its Bioaccessibility, Lisbeth Vallecilla Yepez

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

In recent years, health- and wellness-promoting foods have been one of the major focus of consumers; therefore, the food industry is increasing its efforts in developing these food products. Tomatoes, tomato-food products and their byproducts have gained special attention in virtue of the carotenoids-rich source that they represent, especially lycopene (~90%). The role of lycopene in human diet has been highlighted as a result of its direct relationship with the decrease of chronic diseases. Nevertheless, lycopene is water-insoluble making its extraction simple with organic-toxic solvents; in addition, lycopene degrades easily with light, time, and storage. Lycopene exist in nature mostly …

Radiofrequency Processing For Inactivation Of Salmonella Spp. And Enterococcus Faecium Nrrl B-2354 In Whole Black Peppercorn And Ground Black Pepper, Xinyao Wei

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

Black pepper has been implicated in several foodborne illness outbreaks and food product recalls due to Salmonella contamination. Conventional decontamination methods for black pepper are challenged by harmful residues or quality deterioration. Radiofrequency (RF) heating reduces the come-up time which allows to design a high-temperature short-time processing to inactivate Salmonella with minimal deterioration in product quality. The objectives of this study were to investigate RF heating for inactivation of Salmonella in whole black peppercorn and ground black pepper samples, evaluate Enterococcus faecium NRRL B-2354 as a surrogate for Salmonella, and assess quality deterioration during RF heating of whole black peppercorn …

Validation Of Extrusion Processing For The Safety Of Low-Moisture Foods, Tushar Verma

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

Salmonella in low-moisture foods is an emerging challenge due to numerous food product recalls and foodborne illness outbreaks. The new Food Safety Modernization Act requires the food processors to validate their process controls that indeed kills the desired number of bacteria. This research had two major objectives: 1) Develop a response surface model for Salmonella inactivation during the extrusion of low-moisture food 2) Evaluate the use of Enterococcus faecium NRRL B-2354 as an adequate surrogate for Salmonella during the extrusion of low-moisture food. Oat flour was selected as a low-moisture food model. For inoculation, cocktail of five different strains of …

Modeling The Survival Of Salmonella In Soy Sauce-Based Products Stored At Two Different Temperatures, Ana Cristina Arciniega Castillo

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

Acidified foods are defined in the regulations as “low acid foods to which acid(s) has been added to bring finished pH to 4.6 or below”. As the market for these products expands, an increasing number of them are being processed with reduced heat treatment, relying on acid alone to ensure the destruction of pathogens. When considering the survival rate of microbial pathogens in these products, pH, water activity, temperature, salt content and holding time are integral and must be considered together.

Despite improvements in production, handling, and distribution of food products in recent years, protecting consumers from foodborne illness still …

Species And Trichothecene Genotypes Of Fusarium Head Blight Pathogens In Nebraska, Usa In 2015-2016, Esteban Valverde-Bogantes

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

Fusarium head blight (FHB) of wheat and other small grain cereals is a devastating and economically important disease caused by members of the Fusarium graminearum species complex (FGSC). FHB poses a threat to food security and food safety, due to yield and quality reduction, as well as mycotoxin contamination. To determine the diversity of species and trichothecene genotypes of the FGSC in Nebraska, 33 wheat samples were collected from FHB-affected fields during two consecutive years (2015 and 2016) and 50 Fusarium isolates were obtained from those wheat samples. Identification of F. graminearum was attempted by PCR using UBC85 and GO …

Development Of A Rapid Detection And Quantification Method For Yeasts And Molds In Dairy Products, Brandon Nguyen

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

A rapid quantitative PCR (qPCR) method was developed for the detection and quantification of fungi that are potentially present in dairy commodities. Genes of interest that were considered and used in the method development were the following: 18S rRNA, actin, beta-tubulin, and elongation factor 1-alpha. The following organisms were screened in this method development: Galactomyces candidus, Debaryomyces hansenii, Yarrowia lipolytica, Penicillium roqueforti, Penicillium verrocosum and Cladosporium cladosporioides. The developed method has a standard curve based on the organism, Galactomyces candidus, and the primers based on the elongation factor 1-alpha gene. Using this yeast and …