Doctor of Philosophy, The Ohio State University, 2024, Environmental Science

Historical and current anthropogenic activity combined with land turnovers and rampant vacancies have increased human exposure risk to contaminants. This exposure risk disproportionately affects lower income communities and can have detrimental impacts on human health, particularly children. A management solution is needed to address this widespread contamination of vacant lots. Additionally, federal and state regulators continue to lower residential soil Pb standards which will likely require new risk-based approaches to address urban soil Pb contamination. This dissertation examines three different amendment types (P amendments, Fe oxide containing amendments, and potassium permanganate (KMnO4)) for their ability to address urban Pb soil contamination and reduce human health exposure risk. Remediation strategies that can address both organic and inorganic pollutants are also needed. This is addressed in Chapter 3. This dissertation is written as a series of manuscripts to be submitted to the appropriate journals; this will be reflected by slight differences in formatting. In Chapter 1, readily available P sources (biosolids incinerator ash, poultry litter, biosolids compost, and triple super phosphate) of varying solubility were assessed as soil amendments to reduce Pb bioaccessibility and serve as an inexpensive remediation strategy for urban soil. Contaminated soil from Cleveland, OH was treated with the P soil amendments at a 1:5 Pb:P molar ratio and incubated for 3 months. A slurry analysis was also conducted to assess reduction in bioaccessible Pb independent of time. Pb bioaccessibility was evaluated using US EPA Method 1340 at pH 1.5 and the Physiologically Based Extraction Test (PBET). Treatments were largely found ineffective regardless of IVBA extraction method, incubation duration, slurry analyses, or P source. Method 1340 had one significant treatment (combined poultry litter and BIA) but only resulted in a 8% IVBA Pb reduction. The same treatmen (open full item for complete abstract)

Committee: Nicholas Basta (Advisor); Brian Lower (Committee Member); Steven Lower (Committee Member); Darryl Hood (Committee Member) Subjects: Environmental Science; Soil Sciences

Master of Science, The Ohio State University, 2020, Food Science and Technology

Curcumin, the bioactive compound found in turmeric, exhibits a wide range of health-promoting properties. However, its application in food and medicine is limited by its poor bioaccessibility. The purpose of this study was to investigate the potential for corn oil oleogels structured with three different concentrations of rice bran wax (RBW) (2%, 6%, and 10% w/w) to serve as a delivery system for curcumin to increase its bioaccessibility compared to an ungelled (0% RBW) control. The physical properties of oleogels were characterized with and without curcumin to assess the impact of curcumin on oleogel physical properties. Various measures, including texture profile analysis (TPA), solid fat content (SFC), polarized light microscopy (PLM), differential scanning calorimetry (DSC), and x-ray diffraction (XRD), were used to characterize the oleogels. Additionally, an in vitro simulated digestion study was used to assess the bioaccessibility of curcumin in oil and oleogel systems. Data analysis revealed no significant differences in polymorphic or thermal properties between oleogels with and without curcumin; however, differences in microstructural properties were documented for oleogels with curcumin. Curcumin did not appear to have any significant impact on SFC of oil or oleogel samples at a given RBW concentration. Oleogel hardness also differed between control and curcumin-containing oleogels at 10% RBW. After in vitro simulated digestion, oleogels prepared with 2%, 6% and 10% RBW all significantly increased the concentration of curcumin in the micellar fraction relative to the ungelled (0% RBW) control. This finding demonstrates that oleogels structured by RBW effectively increased curcumin bioaccessibility in a simulated digestion model. Results from this study provide insight into the potential utilization of RBW oleogels for delivering curcumin and other poorly water-soluble compounds in food, dietary supplement, pharmaceutical, and cosmetic industries.

Committee: Farnaz Maleky PhD (Advisor); Christopher Simons PhD (Committee Member); Martha Belury PhD (Committee Member) Subjects: Food Science; Nutrition

Master of Science, The Ohio State University, 2012, Food Science and Technology

We evaluated the effects of soluble fiber, including oligosaccharides, and resistant starch on the micellarization of lutein, α-carotene, and β-carotene from a raw spinach and carrot “salad” using a simulated in vitro digestion. Fiber variables were either combined with raw salad alone or with raw salad and nonfat yogurt to simulate a more complex meal. Raw and ripe bananas were used to examine the potential impact of the natural, inherent resistant starch fiber in the banana on the micellarization of lutein, α-carotene (AC), and β-carotene (βC). It was expected that the soluble fibers, fructooligosaccharide (FOS), galactooligosaccharide (GOS), and pectin, as well as fibers displaying characteristics of soluble fiber, such as resistant starch (RS) would decrease xanthophyll and carotene micellarization as previous soluble fiber studies had shown in vitro and in vivo. The efficiency with which lutein, 13-cis-β-carotene, α-carotene, β-carotene, and 9-cis-β-carotene from the raw salad partitioned in the aqueous fraction were 54.1 ± 1.3%, 18.5 ± 0.6%, 22.0 ± 1.4%, 19.6 ± 1.0%, and 52.7 ± 2.2%, respectively. High viscosity citrus pectin significantly inhibited micellarization of lutein (α< 0.0001), 13-cis-β-carotene (α< 0.0001), α-carotene (α< 0.0001), β-carotene (α< 0.0001), and 9-cis-β-carotene (α< 0.0001) relative to the fiber free control at 4% (wt: wt). Unexpectedly, oligosaccharide and resistant starch samples (FOS, GOS, RS2, and RS3) significantly increased micellarization of lutein, AC, and βC. Micellarization of lutein in the spinach and carrot salad was significantly increased by 12%, 12%, and 14% with the addition of 2% FOS (α= 0.0377), 4% FOS (0.0306), and 2% RS3 (α= 0.0054), respectively. Alpha- and beta-carotene showed very similar results. Micellarization of beta-carotene was significantly increased by 41%, 60% and 49% with the addition of 2% (wt: wt) FOS (α= 0.0136), RS2 (α< 0.0001), and RS3 (α= 0.0014), respectively. Micellarization of beta-carotene cis (open full item for complete abstract)

Committee: Steven Schwartz (Advisor); Mark Failla (Advisor); Yael Vodovotz (Committee Member) Subjects: Agriculture; Analytical Chemistry; Anatomy and Physiology; Biology; Chemistry; Food Science; Health

Master of Science, The Ohio State University, 2007, Human Nutrition and Food Management

A carotenoid-rich salad meal with varying amounts and types of triglycerides (TG) was digested using simulated gastric and small intestinal conditions. Xanthophylls (lutein and zeaxanthin) and carotenes (alpha-carotene, beta-carotene and lycopene) in chyme and micelle fraction were quantified to determine digestive stability and the efficiency of micellarization (bioaccessibility). Micellarization of lutein (+zeaxanthin) significantly exceeded alpha- and beta-carotenes which significantly exceeded that of lycopene for all test conditions. Micellarization of carotenes, but not lutein (+zeaxanthin), was enhanced (P< 0.05) by addition of TG (2.5% v/w) to meal and dependent on fatty acyl length of chains in structured TG (c18:1 > c8:0 > c4:0). The degree of unsaturation of c18 fatty acyl chains in TG added to the salad puree did not significantly alter the efficiency of micellarization of carotenoids. Relatively low amounts of triolein and canola oil (0.5-1%) were required for maximum micellarization of carotenes, but more oil (~2.5%) was required when TG with medium chain length saturated fatty acyl groups (e.g., trioctanoin and coconut oil) was added to salad. Uptake of lutein and beta-carotene by Caco-2 cells also was examined by exposing cells to micelles generated during simulated digestion of salad puree with either triolein or trioctanoin. Cell accumulation of beta-carotene was independent of fatty acyl composition of micelles, whereas lutein uptake was slightly, but significantly, increased from samples with digested triolein compared to trioctanoin. The results show that in vitro transfer of alpha-carotene, beta-carotene and lycopene from chyme to mixed micelles during digestion requires minimal (0.5-1%) lipid content in the meal and is affected by length of fatty acyl chains, but not degree of unsaturation, in TG. In contrast, fatty acyl chain length has limited, if any, impact on carotenoid uptake by small intestinal epithelial cells. These data suggest that (open full item for complete abstract)

Committee: Mark Failla (Advisor) Subjects: