Abstract

Ensuring food safety and quality is crucial for consumer health, satisfaction, and regulatory compliance. This study aims to develop rapid, reliable methods for detecting food constituents (i.e. lactose), pathogens (i.e. Listeria monocytogenes), and contaminants (i.e. micro- and nano-plastics) using Raman spectroscopy. With advantages like high specificity, minimal sample preparation, and fast analysis, Raman spectroscopy offers a promising alternative to traditional methods. This research explores its application in assessing chemical, biological, and physical properties of food to enhance safety and quality monitoring. Lactose-free products are increasingly popular due to the global prevalence of lactose intolerance, creating a need for effective verification methods. This study explored the development of rapid, cost-effective techniques to detect and quantify lactose in dairy products, including milk, yogurt, cheese, and ice cream, using Raman spectroscopy. Chemometric tools enabled differentiation of target sugars (lactose, glucose, galactose, sucrose), with detection limits of 0.5% (milk), 0.1% (yogurt), and 1% (cheese, ice cream). Partial least squares (PLS) modeling demonstrated strong quantification accuracy, with correlation coefficients of 0.8682 (milk), 0.8977 (yogurt), 0.9918 (cheese), and 0.9985 (ice cream). Results were validated using high-performance liquid chromatography, confirming the potential of Raman spectroscopy for lactose analysis. However, given the high limit of detection obtained, its practical application may still be limited for lactose-free product testing. Foodborne pathogens are a major food safety concern and a leading cause of recalls in the U.S. Rapid detection methods are needed to reduce health risks and economic losses. This study explored surface-enhanced Raman spectroscopy (SERS) for detecting Listeria monocytogenes (LM) using label-free and capturer-based approaches. Label-free SERS, utilizing silver dendritic nanostructures and silver nanoparticles, distinguished LM with varying spectral clarity, with nanoparticles providing stronger Raman peaks. The capturer-based method used a 3-mercaptophenylboronic acid (3-MPBA) SERS sandwich assay, yielding distinct peaks at 997 and 1073 cm⁻¹ in the presence of LM. While results showed potential for LM detection at high levels (i.e. 109 CFU/mL), further analysis at lower concentrations were inconclusive. Future direction may include focusing on sensitivity enhancement of the method. Plastic contamination in food is a growing concern, with micro- and nano-plastics detected in various food sources and linked to potential health risks. Polystyrene samples of varying sizes and colors were analyzed under optimized spectral parameters, producing data consistent with previously published literature. These findings provide a foundation for future research on detecting plastic contamination in food products, using Raman spectroscopy.

Degree

MS

College and Department

Life Sciences; Nutrition, Dietetics, and Food Science

Rights

https://lib.byu.edu/about/copyright/

Date Submitted

2025-04-21

Document Type

Thesis

Keywords

Raman spectroscopy, lactose detection, Listeria monocytogenes, microplastics, food safety, food quality, analytical techniques

Language

english

Download

Included in

Life Sciences Commons

Share

COinS