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EFFECT OF HIGH PRESSURE PROCESSING ON MIGRATION CHARACTERISTICS IN POLYETHYLENE TEREPHTHALATE FILM
Title
EFFECT OF HIGH PRESSURE PROCESSING ON MIGRATION CHARACTERISTICS IN POLYETHYLENE TEREPHTHALATE FILM
Creator
Zhou, Yue
Date
2015, 2015-12
Description
High pressure processing (HPP) is gaining prominence worldwide as an alternative method of food preservation due to its benefits of improved...
Show moreHigh pressure processing (HPP) is gaining prominence worldwide as an alternative method of food preservation due to its benefits of improved quality, freshness and nutrient retention. The use of polymer-based flexible packaging materials has allowed application of HPP to prepackaged food products, without significant loss of physical and mechanical properties. However, there is limited data existing on migration properties in the materials before and/or after HPP. Therefore, it is necessary to evaluate potential migration issues in pre-packed foods during HPP (Song 2014). This research was conducted to determine the migration properties in polyethylene terephthalate (PET) films during and after HPP (121°C and 700MPa) and a comparable thermal processing (TP, 121°C and 0.1MPa), using gas chromatography (GC) coupled with mass spectrometer (MS) technique to quantify four model surrogates in FDA-suggested food simulants (Miglyol). This research will help the U.S Food and Drug Administration (FDA) and food industries to identify whether any safety issue related to chemical migration should be addressed concerning the use of HPP in production of pre-packaged foods.
M.S. in Food Safety and Technology, December 2015
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DYSFUNCTION OF BONE-MARROW-DERIVED MACROPHAGES IN GDX KNOCKOUT MICE
Title
DYSFUNCTION OF BONE-MARROW-DERIVED MACROPHAGES IN GDX KNOCKOUT MICE
Creator
Bonomo, Raiza Rafael
Date
2016, 2016-05
Description
Macrophages are cells of the immune system responsible for clearing up the organism, removing damaged and dead cells, pathogens and other...
Show moreMacrophages are cells of the immune system responsible for clearing up the organism, removing damaged and dead cells, pathogens and other foreign substances. They remove and destroy these compounds by a process called phagocytosis, in which the macrophages recognize what is to be destroyed, engulf it and digest it in the lysosome. The phagocytosis mechanism requires special cytoskeleton configurations formed by actin branches that allow the engulfment of substances into the cells. The cytoskeleton structures formed by actin branching are also known to be necessary during the macrophage migration towards its target. Our group has shown that the small cytosolic GdX protein has an important role in the actin filament branching. Therefore, the aim of this study is to analyze the migration ability and the phagocytosis potential of wild-type (WT) and GdX knockout macrophages (KO). Bone marrow cells from mice were isolated and cultured in presence of Macrophage Colony-Stimulating Factor (MCSF) to induce cell differentiation into macrophages. The bone marrow derived macrophages were then subjected to phagocytosis and migration assays. The results from the phagocytosis assay indicated no significant difference in the percentage of cells capable of internalizing the beads or in the amount of engulfed beads between WT and KO macrophages. However, the results from the migration assay suggested a decrease in the migration ability in GdX KO cells when compared to WT macrophages. Therefore,our results imply that the lack of GdX may cause macrophage dysfunction.
M.S. in Cellular and Molecular Biology, May 2016
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POTENTIAL EXPOSURE TO SUBSTANCES IN POLYMER COMPOSITES USED AS FOOD PACKAGING MATERIALS
Title
POTENTIAL EXPOSURE TO SUBSTANCES IN POLYMER COMPOSITES USED AS FOOD PACKAGING MATERIALS
Creator
Shah, Saloni S.
Date
2021
Description
In the food manufacturing, preservation, supply, and distribution chain, packaging plays a critical role. The fundamental goal of any...
Show moreIn the food manufacturing, preservation, supply, and distribution chain, packaging plays a critical role. The fundamental goal of any packaging method is to keep food contained and protected. There is an increasing demand for natural and "fresh-like" foods that are less processed and have a longer shelf life, necessitating a variety of packing strategies. With increasing demand, the biggest developments in the field of packaging technology have been innovative food packaging approaches, such as active packaging, intelligent packaging, and bioactive packaging, which include deliberate contact with the food or its surroundings and its effect on consumer health. Several research studies in the past few years have shown that nanocomposite materials have significant improvement in the strength, barrier characteristics, antimicrobial capabilities, and heat and cold stability of food packaging materials, but various studies have reported that these composites might be a source of engineered nanomaterials in the human diet or environment. It has also been reported in numerous studies that nanocomposites can migrate into the food during long-term storage. These studies use food simulants like acetic acid and water to mimic the food matrix. However, they raise issues regarding how ingredients in real foods could affect exposure. This research focuses on the migration of silver (Ag) ions into food matrix-like commercial beverages and demonstrating if the ingredients present in commercial food and beverages influence the migration process. For the study, polymer composites films and dogbones were made. Polymer composite films with 0.2%, 1%, and 5% of silver zeolite concentration in polylactic acid (PLA) were produced, and different media like water, Domino sugar, and Squirt were stored in packages manufactured from this material under accelerated room-temperature conditions. Polymer composite dogbones were made with low-density polyethylene (LDPE) and polypropylene (PP) with 1.25% and 2.51% of graphene and graphite. Further, these materials were characterized with the help of Thermogravimetric analysis (TGA), Fourier Transform Infrared Spectroscopy-Attenuated Total Reflection (FTIR-ATR), and inductively coupled plasma mass spectrometry (ICPMS). This hypothesis of this study was that, when polymer composites are employed in packaging applications, food and beverage components may impact dietary exposure to these particles, and the use of food simulants may underpredict the quantity of the migration in some cases
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Characterization and Migration of Silver Nanoparticles from Electron-Beam Irradiated Low-Density Polyethylene
Title
Characterization and Migration of Silver Nanoparticles from Electron-Beam Irradiated Low-Density Polyethylene
Creator
Donovan, Dylan
Date
2023
Description
Polymer nanocomposites (PNCs) and engineered nanomaterials (ENMs) may find use in a wide range of commercial applications, including food and...
Show morePolymer nanocomposites (PNCs) and engineered nanomaterials (ENMs) may find use in a wide range of commercial applications, including food and medical product packaging. Migration of nanofillers from polymer nanocomposites into food matrices could be a source of human dietary exposure to ENMs. Electron beam (e-beam) irradiation is a processing method used for microbial inactivation as well as for modifying properties of polymer films, such as stretch resistance and shrink tension. Process treatment of nanotechnology-based packaging materials either for sterilization or for strengthening of the polymer films may have a significant effect on the migration of ENMs into food matrices. The primary objective of this study is to investigate the effect of e-beam irradiation treatments of LDPE containing silver nanoparticles (AgNPs) and the subsequent migration of AgNPs into a food simulant under intended use conditions. The study observes a correlation between e-beam irradiation dose quantity and the release of AgNPs into a food simulant.
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