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Author ORCID Identifier 0000-0003-4480-4556


Campus-Only Access for One (1) Year

Document Type


Degree Name

Doctor of Philosophy (PhD)

Degree Program

Environmental Conservation

Year Degree Awarded


Month Degree Awarded


First Advisor

Baoshan Xing

Subject Categories

Environmental Health | Food Chemistry


Food grade titanium dioxide particles (E171), as whitening agent, are commonly used in chewing gums, candies, sauces, salad dressings, and powdered milk. Recently, nanoplastics (NPs) (defined as < 1 µm), which are degraded from plastic debris undergoing environmental process, have received global attention. Because nanoplastics are ubiquitous in aquatic and terrestrial systems, and have been detected in marine animals, table salts, drinking water, and air. Thus, the presence of E171 as additives in the food, and the nanoplastics in food chains, both pose potential risks to human health through retarded processes in the gastrointestinal tract (GIT). However, the knowledge about the fate of E171 or nanoplastics and their impact on digestive enzymes activity or nutrient bioaccessiblity are currently limited. Therefore, it is necessary to investigate potential impacts of E171 or nanoplastics on digestion processes and nutrient bioaccessibility in the simulated human gastrointestinal tract, which includes mouth, stomach and intestinal phases, to mimic the digestion processes of food incubating with E171 or polystyrene (PS) nanoplastics. The objectives of my dissertation and major findings are presented below: 1) The impacts of E171 on lipid digestion and vitamin D3 (VD3) bioaccessibility encapsulated within oil-in-water emulsions in a simulated human gastrointestinal tract model were explored; 2) The impacts of E171 on the bioaccessibility of minerals (Ca, K, Mg, Fe, Mn, Zn, P and S) released from spinach leaves using a simulated human digestion tract were investigated; 3) The impacts of various concentrations or different functional group (-COOH, -NH2) of PS NPs on the starch hydrolysis in the simulated INFOGEST model were examined.