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Full-Text Articles in Life Sciences

From Milpas To The Market: A Study On The Use Of Metal Silos For Safer And Better Storage Of Guatemalan Maize, José Rodrigo Mendoza Jul 2016

From Milpas To The Market: A Study On The Use Of Metal Silos For Safer And Better Storage Of Guatemalan Maize, José Rodrigo Mendoza

Dissertations, Theses, & Student Research in Food Science and Technology

This project aimed to implement the use of metal silos to improve quality and safety of maize consumed by inhabitants of the highlands of Guatemala. This manuscript includes a literature review of the maize production chain in Guatemala, a survey about agricultural practices used in the region of study, as well as a characterization of the analyzed maize regarding its mycoflora, nutritional composition, and insect infestation. To better understand the current situation regarding agricultural practices and maize consumption, a survey was carried out. Sample consisted of 280 families representing 14 rural communities distributed in the townships of Todos Santos and ...


Simulation And Validation Of Radio Frequency Heating Of Shell Eggs, Soon Kiat Lau Jul 2015

Simulation And Validation Of Radio Frequency Heating Of Shell Eggs, Soon Kiat Lau

Dissertations, Theses, & Student Research in Food Science and Technology

Finite element models were developed with the purpose of finding an optimal radio frequency (RF) heating setup for pasteurizing shell eggs. Material properties of the yolk, albumen, and shell were measured and fitted into equations that were used as inputs for the model. When the egg was heated by itself, heating tend to be focused at the air cell to result in a “coagulation ring.” The focused heating near the air cell of the egg prevented satisfactory pasteurization of the egg, but deeper analysis of the simulation results offered a new perspective on how non-uniform RF heating could occur in ...


Characterization And Investigation Of Fungi Inhabiting The Gastrointestinal Tract Of Healthy And Diseased Humans, Mallory J. Suhr May 2015

Characterization And Investigation Of Fungi Inhabiting The Gastrointestinal Tract Of Healthy And Diseased Humans, Mallory J. Suhr

Dissertations, Theses, & Student Research in Food Science and Technology

Gastrointestinal microbiome studies have failed to include fungi in total community analyses. As a result, their diversity and function in the gut is poorly understood. Recent work has begun to uncover the role intestinal fungi play in diet, immune system development, interactions with other microorganisms in the gut, and pathogenesis of diseases. Advances in sequencing technologies allow for the ability to profile the fungal gut microbiome (“mycobiome”) in healthy and diseased states. This thesis explores the mycobiome in 1) healthy humans with a vegetarian diet and 2) pediatric small bowel transplant recipients that develop fungal bloodstream infections.

The gut mycobiome ...


Understanding The Factors Affecting Microbiological Quality Of Wheat Milled Products: From Wheat Fields To Milling Operations, Luis E. Sabillón Galeas Jul 2014

Understanding The Factors Affecting Microbiological Quality Of Wheat Milled Products: From Wheat Fields To Milling Operations, Luis E. Sabillón Galeas

Dissertations, Theses, & Student Research in Food Science and Technology

Although regarded as a low-risk commodity, wheat flour-based mixes have been implicated in several food safety incidents. The present thesis is a compilation of five scientific manuscripts on the effect of weather variation, milling steps and implementation of pre-milling interventions on the microbiological quality and safety of wheat and milled products. The first manuscript is a review of the microbiological quality and safety of wheat-based products. Despite the low water activity, wheat flour may harbor dormant but viable microorganisms, which could lead to safety concerns when flour is used to produce refrigerated dough products. The second manuscript illustrates the effect ...


Characterization Of The Gut Microbiota And Colitogenic Bacterial Species In Core 1 O-Glycans Deficient Mice, Maria E. Perez-Munoz Jul 2013

Characterization Of The Gut Microbiota And Colitogenic Bacterial Species In Core 1 O-Glycans Deficient Mice, Maria E. Perez-Munoz

Dissertations, Theses, & Student Research in Food Science and Technology

Mucus is one important component of the intestinal mucosal barrier, and loss of its functionality is associated with colitis in humans and mice. Mice deficient in core 1 O-glycans (TM-IEC C1galt1-/-) display a thinner mucus layer upon mutation of the glycosyltransferase enzyme (C1GALT1) responsible for core 1 O-glycans attachment, thus constituting an experimental model for human Ulcerative Colitis (UC). Under conventional conditions, these mice experience spontaneous inflammation of the colon. However, the exact role of the microbiota in colitis development in these mice has not been systematically investigated.

Aimed to gain insights into the role of the microbiota ...


Validation Of Microwave Heating Instructions For The Destruction Of Salmonella Spp. In Microwaveable Foods, Carol J. Valenzuela Apr 2013

Validation Of Microwave Heating Instructions For The Destruction Of Salmonella Spp. In Microwaveable Foods, Carol J. Valenzuela

Dissertations, Theses, & Student Research in Food Science and Technology

Microwave heating instructions for three products (chicken nuggets, turkey pot-pies and mashed potato) were developed and validated based on end point temperatures using two microwave ovens (2,459 MHz; 700 W and 1,350 W). Heating instructions for chicken nuggets were validated using different configuration of product placement (edge or center of the carousel) and number of units (4, 6 and 8). Salmonella spp. reductions of 6.56 log CFU/g (700 W) were observed in chicken nuggets heated in groups of 4 and placed at the center of the carousel with 1 min 26 s of heating time with ...


The Evolution Of Host Specificity In The Vertebrate Gut Symbiont Lactobacillus Reuteri, Steven Frese Nov 2012

The Evolution Of Host Specificity In The Vertebrate Gut Symbiont Lactobacillus Reuteri, Steven Frese

Dissertations, Theses, & Student Research in Food Science and Technology

The vertebrate gut is home to one of the densest populations of life on Earth. This microbial community has a profound effect on host health, nutrition, development, behavior, and evolution. However, very little is known about how these microbes have evolved with their vertebrate hosts, how and whether they select hosts or how they remain associated with their hosts. Recent work identified Lactobacillus reuteri as an organism that is composed of host-specific sub-populations, each population associated with a different host animal. Representatives from each host-associated population were tested for their ability to colonize gnotobiotic mice, which only rodent strains could ...


Analysis Of Microbial Diversity By Amplicon Pyrosequencing, Ryan Legge Aug 2012

Analysis Of Microbial Diversity By Amplicon Pyrosequencing, Ryan Legge

Dissertations, Theses, & Student Research in Food Science and Technology

Microorganisms numerically dominate terrestrial biodiversity, and play important biochemical and geochemical roles in the environments they inhabit. To understand structure and function of complex ecosystems, it is essential to identify primary drivers of microbial diversity and community structure. Historically, the study of microbial ecology was reductive, limited to microbes able to be cultured and enumerated. Microbes meeting this criterion were thought to comprise the dominating members of the environments they were isolated from, however, estimates suggesting up to 99% of the endogenous species are uncultivable with existing methodologies; a concept that reflects experimental failure, rather than a verifiable conclusion. Therefore ...


Host-Microbe-Diet Interplay: Dietary Modulation Of The Gut Microbiota In Relation To Health, Inés Martínez Aug 2012

Host-Microbe-Diet Interplay: Dietary Modulation Of The Gut Microbiota In Relation To Health, Inés Martínez

Dissertations, Theses, & Student Research in Food Science and Technology

Vertebrates are associated with trillions of bacteria, with the densest populations residing in the large intestine. The symbiosis between vertebrates and their gut microbiota has resulted in important implications of the gut microbiome on host health. Diet is an important factor that shapes gut microbiota composition, and because of the interplay between host-microbiome-diet, dietary strategies that modulate gut microbiome structure are deemed a relevant tool to improve host health. However, gaps in knowledge exist with respect to these interactions, and it is essential to obtain a mechanistic understanding of how these relations take place to develop successful therapeutic strategies that ...