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Food Chemistry Commons

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Full-Text Articles in Food Chemistry

The Impact Of A Non-Ionic Adjuvant To The Persistence Of Pesticides On Produce Surfaces, Daniel Barnes Mar 2024

The Impact Of A Non-Ionic Adjuvant To The Persistence Of Pesticides On Produce Surfaces, Daniel Barnes

Masters Theses

Adjuvants can enhance the performance of the pesticide active ingredients in many ways including decreasing surface tension and reducing evaporation. Understanding how adjuvants effect pesticide behavior (e.g., surface persistence) is crucial for developing effective pesticide formulations, as well as facilitating the development of effective approaches to reduce pesticide residues from the surface of fresh produce post-harvest. The objective of this study is to investigate the effect of a non-ionic surfactant, Surf-Ac 910, on the persistence of two model pesticides, thiabendazole and phosmet on apple surfaces. The result shows that the addition of Surf-Ac 910 increased both the maximum wetted area …


Detection Of Mycotoxins Using Surface-Enhanced Raman Spectroscopy, Lourdes B. Martinez Rojas Mar 2022

Detection Of Mycotoxins Using Surface-Enhanced Raman Spectroscopy, Lourdes B. Martinez Rojas

Doctoral Dissertations

Mycotoxins are toxic metabolites produced by fungus that can be parasites or saprophytes of crops or livestock forage. Consumer demand for plant-based foods and interest in animal-based foods originating from animals fed plant-based feed has been on the rise. Therefore, monitoring mycotoxins occurring in the food supply is more critical than ever. The goal of this project is to improve surface-enhanced Raman spectroscopy’s (SERS) ability to identify and detect mycotoxins using label-free SERS substrates. Two simple approaches were designed to enhance the detection of mycotoxins produced by the Aspergillus and Penicillium genera, ochratoxin A and aflatoxin B1. Ochratoxin A was …


Analysis Of Plant And Animal Proteins Using Raman Spectroscopy, Noopur Bapardekar Mar 2022

Analysis Of Plant And Animal Proteins Using Raman Spectroscopy, Noopur Bapardekar

Masters Theses

There has been a notable rise in the alternative protein market in the recent years which promotes an interest in the research of both animal and plant proteins to establish better structure-function relationships. Over the years many analytical tools have been used to study proteins and compare them, however Raman Spectroscopy and Surface Enhanced Raman Spectroscopy (SERS) have not been as much used for this application. SERS consolidates Raman Spectroscopy that primarily measures molecular vibrations and nanostructures that enhance the weak Raman signals. The objective of this study is to explore the capability of the Raman instrumentation in combination with …


Silver Mirror Substrate And Rolling Method For Improved Surface-Enhanced Raman Spesctroscopic Analysis In Food, Yanqi Qu Oct 2019

Silver Mirror Substrate And Rolling Method For Improved Surface-Enhanced Raman Spesctroscopic Analysis In Food, Yanqi Qu

Doctoral Dissertations

Surface-enhanced Raman spectroscopy, short for SERS, is an emerging technology with great potential in food analysis due to rapid detection, high sensitivity, portable instrumentation, and simple sample preparation. However, it is always a bottleneck to obtain reproducible SERS measurements in real analytical cases due to the complicity of food systems and inhomogeneous aggregation of colloidal nanoparticles. To improve its performance for practical applications in food analysis, efforts have been made in improving the reproducibility, enhancing the selectivity and reducing the matrix interference to the analyte. Herein, a self-assembly silver nanoparticles mirror substrate was fabricated to improve the and the quantitative …


In Situ And Real-Time Monitoring And Characterization Of Pesticide Residues On And In Fresh Produce Using Sers, Tianxi Yang Jul 2018

In Situ And Real-Time Monitoring And Characterization Of Pesticide Residues On And In Fresh Produce Using Sers, Tianxi Yang

Doctoral Dissertations

Understanding of the behavior and fate of pesticides in fresh produce is of great significance for effectively applying pesticides and minimizing pesticide residues in food. There is lack, however, of an effective method that can monitor and characterize pesticide behaviors including penetration, persistence and translocation. Herein, we developed a novel method for real-time and in situ monitoring of pesticide behaviors in fresh produce based on surface-enhanced Raman scattering (SERS) mapping method. Taking advantage of penetrative gold nanoparticles as probes to enhance the internalized pesticide signals, the internal signals from pesticides were successfully obtained in situ. We found that systemic pesticides …


Label-Free And Aptamer-Based Surface Enhanced Raman Spectroscopy For Detection Of Food Contaminants, Shintaro Pang Nov 2016

Label-Free And Aptamer-Based Surface Enhanced Raman Spectroscopy For Detection Of Food Contaminants, Shintaro Pang

Doctoral Dissertations

The development of analytical methods to detect food contaminants is a critical step for improving food safety. Surface enhanced Raman spectroscopy (SERS) is an emerging detection technology that has the potential to rapidly, accurately and sensitively detect a wide variety of food contaminants. However, SERS detection becomes a challenge in real complex matrix, such as food, since non-specific matrix signals have the potential to drown out target associated Raman peaks. In this dissertation, we focused on the development and application of label-free, aptamer-based SERS in order to improve the accuracy and specificity of target contaminant detection in food. To accomplish …


Investigate The Interactions Between Silver Nanoparticles And Spinach Leaf By Surface Enhanced Raman Spectroscopic Mapping, Zhiyun Zhang Nov 2016

Investigate The Interactions Between Silver Nanoparticles And Spinach Leaf By Surface Enhanced Raman Spectroscopic Mapping, Zhiyun Zhang

Masters Theses

Owing to their increasing application and potential toxicity, engineered nanoparticles (ENPs) have been considered as a potential agricultural contaminant that may pose unknown risk to human beings. However, many techniques require invasive and complicated sample preparation procedures to detect and characterize engineered nanomaterials in complex matrices. In the first part of this thesis, we present a non-destructive and label-free approach based on surface enhanced Raman spectroscopic (SERS) mapping technique to qualitatively detect and characterize gold nanoparticles (AuNPs), on and in spinach leaves in situ. We were able to detect the clearly enhanced signals from AuNPs at 15 to 125 nm …