Doctor of Philosophy, The Ohio State University, 2022, Food Science and Technology

Around 40% of all food produced in the United States is wasted. This represents nearly $218 billion dollars' worth of food entering landfills every year, causing food waste to be one of the largest contributors to climate change. Consequently, the IPCC (Intergovernmental Panel on Climate Change) has stated food waste reduction as a climate change mitigation priority and cited streamlining date labels on food packages as one solution. Most of the food waste in the U.S. originates in consumer households due to the presence on confusing date labels intended to depict shelf-life. However, since date labels are static, they are unable to consider the effect of temperature fluctuations on food quality, and food manufacturers tend to be extremely conservative when setting the date horizons. This causes good quality food to be thrown out by consumers. To add to the confusion, no standardized date labeling system exists in the U.S. causing multiple phrases such as “sell by”, “use by”, “best if used by” etc. to be used on food packages. Recent recommendations have suggested a move to a standardized label phrase across all products - “best if used by”, but the effectiveness of this solution is unknown. The overall objective of this research was to investigate two food waste prevention solutions – date label standardization and real-time shelf-life monitoring, specifically for packaged milk - one of the highly wasted food products. The effect of date label standardization, consumer education and product age on consumer discard intentions were evaluated through an in-person consumer study with 437 participants. In most cases, changing label phrases to “best if used by” had no significant effect on discard intentions. The printed date had the strongest effect, increasing discard by 40 percentage points between 2-days pre-date and 7-days post-date milk. This led us to hypothesize the phrase may not be important to consumers when deciding to discard food. To test this hypothesis, (open full item for complete abstract)

Committee: Dennis Heldman Ph.D. (Advisor); Christopher Simons Ph.D. (Committee Member); Brian Roe Ph.D. (Committee Member); Rafael Jimenez-Flores Ph.D. (Committee Member) Subjects: Agricultural Economics; Behavioral Sciences; Chemistry; Climate Change; Food Science; Sustainability

Master of Science, The Ohio State University, 2018, Food Science and Technology

Food is often frozen to prolong shelf-life by maintaining safety and high quality. Since frozen food storage is energy intensive, careful evaluation of the influence of storage temperature on shelf-life is needed. Although the shelf-life of frozen meat at -18°C may be desirable, the influence of slightly higher storage temperatures on shelf-life have not been thoroughly investigated. Through the understanding of quality degradation reactions and their dependence on temperature, an argument may be made to encourage storage at a more sustainable temperature. The objective was to evaluate the effect of storage temperature on frozen chicken and ground beef quality attributes to identify improved energy efficiencies during storage. Whole muscle chicken breasts (pectoralis major) were frozen to -20°C [-4°F] then stored at -10°C [14°F], -15°C [5°F], or -20°C for one year. In a completely randomized design monthly quality testing was conducted on three replicates thawed overnight to 4°C. Quality analysis consisted of % drip loss measurements, water holding capacity (WHC), moisture content (WBMC), lipid oxidation by 2-thiobarbituric acid assay (TBARS), color, and cooked texture analysis by Blunt Meullenet-Owens Razor Shear (BMORS). Differences in temperature conditions across time were observed in % drip loss, WHC, L*a*b*, and BMORS (p<0.05). The creation of a shelf-life prediction model based on % drip loss results can be used to assess risk to processors considering increasing storage temperatures. This study has shown the potential energy savings may be accomplished without dramatic losses in quality by increasing storage temperatures modestly. In a completely randomized study 297 ground beef experimental units consisting of 90 patties were packaged in one of three ways then frozen to -22°C . Packaging included: plastic overwrap; a high oxygen permeability package, OTR <0.1 cc/100 in2/day; and a low oxygen permeability package, OTR <0.05cc/100in2/day. The units were (open full item for complete abstract)

Committee: Dennis Heldman PhD (Advisor); Wick Macdonald PhD (Advisor); Simons Christopher PhD (Committee Member) Subjects: Food Science

Master of Science, The Ohio State University, 2018, Food Science and Technology

About 40% of the food intended for human consumption in the United States goes eaten and 43% of this food loss or waste occurs in consumer households mainly due to confusion over date labels (“sell by”, “use by”, “best if used by” etc.) conveying shelf-life of food. Time-Temperature Indicators (TTIs) are dynamic labels that indicate shelf-life after taking product temperature variations into consideration. The objectives of this study were to 1) demonstrate that TTIs can respond to fluctuating temperatures and to study their applicability for predicting milk shelf-life based on microbiological considerations 2) develop a prediction model for milk shelf-life based on microbial growth inside a milk container 3) evaluate consumer perception of date labels and TTIs used to convey shelf-life of milk. The kinetics of TTI colour response was determined by placing them at four constant temperatures and under a varying temperature environment. Colour intensity values were obtained by taking images periodically and processing them. Using a non-isothermal modelling procedure, the TTI response under dynamic temperatures was modelled. Published growth data for Pseudomonas was obtained and its growth inside a milk container was simulated using a MATLAB program and a non-isothermal modelling procedure. The applicability of the TTIs for predicting microbial milk shelf-life was tested. To study consumer perception of date labels and TTIs, eighty-eight regular milk consumers were presented with milk samples in two flights that were identical except that one flight had “sell by” dates while the other flight had no labels. In another set of two flights, the consumers were presented with temperature abused milk samples that either featured a date label or a TTI; the difference between flights was that the temperature abuse was not announced in the first flight. Headspace volatile analysis of the milk samples was also done using Dynamic Headspace Gas Chromatography-Mass Spectroscopy. T (open full item for complete abstract)

Committee: Dennis Heldman PhD (Advisor); Christopher Simons PhD (Committee Member); Rafael Jimenez-Flores PhD (Committee Member) Subjects: Food Science; Sustainability

Master of Science, The Ohio State University, 2015, Food Science and Technology

This study explored the potential of selected food additives to extend the shelf life of seed butter made with sesame, sunflower and pumpkin seeds. The results showed that grape seed extract is potent as an antimicrobial agent against Salmonella enterica and Listeria innocua in the seed butter. Cinnamaldehyde was also able to reduce S. enterica but L. innocua in the seed butter. To maintain the texture and to prevent oil separation in the seed butter, hydrogenated rapeseed oil (HRO) was found to prevent excessive hardness and effectively control the oil separation of the seed butter during the storage time in this study. On the other hand, palm kernel oil (PKO) was weak in preventing excessive hardness, and it did not prevent oil separation in the seed butter. This showed that HRO was a more efficient stabilizer than PKO in the seed butter. This study also reported the antioxidant effect of a-tocopherol in the seed butter. The results showed that by adding a-tocopherol to the seed butter oil above the level of its natural background concentration did not effectively inhibit or delay lipid oxidation.

Committee: Melvin Pascall (Advisor); Hua Wang (Committee Member); Farnaz Maleky (Committee Member) Subjects: Food Science

Doctor of Philosophy, University of Toledo, 2010, College of Engineering

Poly(ethylene Terephthalate) (PET) is a prominent packaging material which is widely used in the plastic packaging industry. When compared with traditional packaging materials, such as steel and glass, the oxygen barrier property of PET is moderate at ambient temperature. The moderate oxygen barrier property of PET limits the application of PET for packaging some oxygen sensitive products, such as beer. Several approaches have been made to enhance “shelf life” of PET packaging material, especially for oxygen sensitive foods. The active barrier packaging technique, which absorbs oxygen during its permeation route into packaged article, was studied in this research. Unsaturated hydrocarbons were used to modify PET to develop an oxygen scavenging system which can react with oxygen as an oxygen scavenger. In this research the unsaturated hydrocarbon is low molecular weight hydroxyl terminated polybutadiene. After the modification, the modified PET should maintain the favorable properties of PET and have an oxygen scavenging capability. The reason for blending hydroxyl terminated polybutadiene (HTPB) and PET was that the hydroxyl end group of HTPB was expected to react with end groups of PET to form a copolyester. The PET/HTPB copolyester will have different optical, thermal and mechanical properties than those of a unreacted PET/PBD physical blend. In this research, the oxidation mechanisms and kinetics of pure polybutadiene was studied first. Factors such as the molecular weight and composition of polybutadiene, which can affect oxidation mechanisms and kinetics, were analyzed. Activation energies of unsaturated olefin groups in the oxidation reactions were obtained. In the second portion of this research, low levels of hydroxyl terminated polybutadiene were reactively extruded with PET to form a polybutadiene modified PET. The oxidation kinetics and mechanism of this polybutadiene modified PET were also studied. Factors that can affect oxidation kinetics, such as th (open full item for complete abstract)

Committee: Saleh A. Jabarin PhD (Committee Chair); G. Gleen Lipscomb PhD (Committee Member); Maria R. Coleman PhD (Committee Member); Isabel C. Escobar PhD (Committee Member); Yong Wah Kim PhD (Committee Member) Subjects: Chemical Engineering; Materials Science; Polymers

Master of Science, The Ohio State University, 2011, Food Science and Technology

A study of the microbial growth and chemical changes occurring during the shelf life of chocolate and regular milks is presented. In order to study the milks' microbiological growth, Standard Plate Counts (SPC), Psychrotrophic Plate Counts (PPC), and Psychrotrophic Sporeformer Counts (PSF) were performed on 1% fat chocolate and regular milks of three different commercial brands on Day 0 and Day 14, with an additional plating of PSF being performed on Day 7. Fourier Transform Infrared Spectroscopy (FTIR) was used to chemically analyze chloroform extracts of the milks on Day 0, Day 4, Day 7, Day 11, and Day 14. Statistical analysis showed for the PPC and PSF that by Day 14 chocolate milk had significantly more CFU/mL than regular milk for the milks from all three brands. However, the value of this microbiological study was limited by the fact that the numbers of colonies in both regular and chocolate milk exceeded 10^6 by 14 days. There is a need to follow the change in the microbial populations over time more closely. Chemically the two milks showed distinct changes between Day 0 and Day 7 with the chocolate milk having the greatest changes in wavenumbers in the 1624.1-1658.8 cm-1 range and the regular milk experiencing the greatest changes in the 1735-1755 cm-1 range. A follow-up study was performed focusing on the first half of the expected shelf-life of milk. SPC, counts on Pseudomonas Isolation Agar (PIA), and PSF were carried out on Day 0, Day 4 and Day 7 on a true replicate of 1% fat chocolate and regular milks from one commercial brand. On these same days, chloroform extracts of the milks were chemically analyzed by the FTIR. Statistical analysis was completed on the data obtained to determine the microbiological and chemical differences occurring in the two milks. The SPC and PIA analyses showed that chocolate milk had significantly more CFU/mL than regular milk on Days 4 and 7. When analyzed, all three plate-count methods suggested the regular milk was expe (open full item for complete abstract)

Committee: W. James Harper PhD (Advisor); Sheryl Barringer PhD (Committee Member); Luis E. Rodriguez-Saona PhD (Committee Member) Subjects: Food Science

Doctor of Philosophy, The Ohio State University, 2003, Food Science and Nutrition

Effects of commercial scale pulsed electric field (PEF) processing on the qualities of tomato juice and orange juice were studied and compared with those of thermal processing. The inactivation of tomato juice lipoxygenase (LOX) by PEF was studied using kinetic models. Tomato juice was prepared by hot break at 88 C for 2min or cold break at 68C for 2min and then thermally processed at 92C for 90s or PEF processed at 40kV/cm for 57micros. Freshly squeezed orange juice was thermally processed at 90C for 90s or processed by PEF at 40kV/cm for 97micros. Tomato juice was treated by a laboratory scale PEF system with the combinations of electric field strength (0, 10, 15, 20, 30, 35kV/cm), PEF treatment time (20, 30, 50, 60, 70micros), and PEF treatment temperature (10, 20, 30, 40, 50C) to study inactivation kinetics of tomato juice LOX by PEF. Both thermally and PEF processed tomato juices maintained microbial shelf life at 4C for 112d. PEF processed tomato juice retained more flavor compounds than thermally processed or unprocessed control juice (p<0.05). The lipoxygenase activities of thermally and PEF processed tomato juices were 0 and 47%, respectively. PEF processed tomato juice retained more ascorbic acid than thermally processed juice at 4C for 42d (p<0.05). PEF processed tomato juice had significantly lower nonenzymatic browning than thermally processed or control juice (p<0.05). Sensory evaluations indicated that PEF processed tomato juice had more preferred flavor and higher overall acceptability than thermally processed juice (p<0.01). Thermally and PEF processed orange juices maintained microbial shelf life at 4C for 196d. PEF processed orange juice retained more ascorbic acid, flavor, and color than thermally processed juice (p<0.05). Sensory evaluation of texture, flavor, and overall acceptability were ranked highest for control orange juice, followed by PEF processed juice and then by thermally processed juice (p<0.01). Laboratory scale PEF treatment at 30 (open full item for complete abstract)

Committee: Qinghua Zhang (Advisor) Subjects: