Food Chemistry Commons^™

Analysis Of The Cannabinoid Compositions, Byproducts And Heavy Metals In Unregulated Cannabinoid Products By Hplc-Ms/Icp-Ms, Simone K. Melle

All NMU Master's Theses

The rapid expansion of unregulated hemp-derived products has created a need for analytical methods that characterize both cannabinoid composition and contaminant occurrence. This thesis used liquid chromatography-tandem mass spectrometry (LC-MS/MS) to quantify cannabidiol (CBD), Δ8-tetrahydrocannabinol (Δ8-THC), and Δ9-tetrahydrocannabinol (Δ9-THC), and inductively coupled plasma mass spectrometry (ICP-MS) to measure Al, As, Cd, Cr, Cu, Fe, Mg, Ni, Pb, and Zn in commercial hemp-derived products, laboratory-prepared hemp oils, cultivated hemp tissues, extracted material, and post-harvest soil. Commercial products showed wide cannabinoid variability, with several samples containing more than one target cannabinoid, while laboratory-prepared plant oils showed a more consistent profile dominated by …

Comparison Of Methods For Defatted Human Milk And Nutrient Composition: An Experimental Study, Kristin Cheng, Gina O'Toole, Stephanie Chang, Richard Chang, John Miklavcic

Food Science Faculty Articles and Research

Background

Human milk is considered the gold standard for infant nutrition; however, it is often discontinued in chylothorax and severe very long-chain acyl-CoA dehydrogenase (VLCAD) deficiency. As an alternative to complete human milk restriction, defatted human milk may be fed, though it may not fully support optimal infant growth and development. This study aimed to assess the micronutrient profile of defatted human milk.

Methods

Human milk was obtained from UCSD Human Milk Research Biorepository (San Diego, CA). Thirty samples representing 10 independent expressions in the morning, afternoon, and evening were pooled for analysis. Fat removal was performed by centrifugation at …

Evaluating Variety- And Market-Class-Specific Effects Of Dietary Pulses On Human Health, Jiayu Tang

Department of Food Science and Technology: Dissertations, Theses, and Student Research

While pulses are globally recognized for their high levels of dietary fibers, protein, and polyphenols, research often focuses on characterizing the physiological effects of a single variety. This approach overlooks the substantial genetic and compositional diversity that exists across pulse varieties and individual market classes, which can differ extensively in nutrient content and structure. These compositional differences have the potential to produce distinct physiological and microbial responses in humans, yet variety- and market-class-specific effects remain poorly characterized.

This thesis uses two complementary research methodologies to investigate the health-relevant effects of different pulse varieties and market classes, providing foundational knowledge to …

Evaluating The Impact Of Region, Vintage, And Carbon Dioxide-Based Winemaking Techniques On Wine Quality Of Mediterranean Varietals, Coleman R. Imrisek

Master's Theses

Changing Vitis vinifera ripening patterns as a result of increasing climate variability has provided challenges against the production of wines with a balanced sensory profile, with adequate acidity, color, aroma, and texture. This thesis aimed to evaluate the ripening patterns and wine profiles of potentially climate-adaptive Mediterranean varietals in two different California Central Coast climates. Additionally, different carbon-dioxide based winemaking techniques were also assessed. Viognier and Grenache Noir grapes were sourced from the warmer, diurnal Paso Robles AVA and the cooler, marine Santa Maria AVA during the 2024 and 2025 growing seasons, with Syrah and Grenache Blanc grapes being only …

Allosteric And Uncompetitive Inhibition Of Yeast Alcohol Dehydrogenase Identified By Enzyme Kinetics, Dylan Jeremy Harrison, Jenny A. Cappuccio

IdeaFest: Interdisciplinary Journal of Creative Works and Research from Cal Poly Humboldt

Enzyme kinetics is a powerful technique used to quantify the rate at which an enzyme converts a substrate into a product and to identify potential inhibitors. In this study, kinetic analysis was employed to assess the activity of yeast alcohol dehydrogenase (YADH) in the presence and absence of sweeteners commonly found in alcoholic beverages. YADH catalyzes the oxidation of ethanol to acetaldehyde using NAD⁺ as a cofactor; the reduction to NADH can be monitored spectrophotometrically at 340 nm. Based on structural similarities to the ribose moiety of NAD⁺, it was hypothesized that sucrose and sucralose could directly interact with the …

The Effects Of Maceration And Enzymes On The Chemical Characteristics Of Hard Apple Cider, Manou De Pelsmaeker

Master's Theses

The purpose of this study was to analyze the effects of maceration and pectinase enzymes on the base chemical, polyphenolic, and volatile characteristics of cider. The apples (Fuji) were milled and macerated for 0, 4, 12, 24, or 36 hours, both with and without an enzymatic pectinase addition. While base chemical characteristics such as sugar content and ABV were unaffected, the acidity of cider was influenced maceration and enzymes. Extended maceration time resulted in lower concentrations of malic acid, and enzymes resulted in a lower pH compared to the control. Polyphenols were extracted during maceration time, resulting in higher concentrations …

Phytochemical Composition And Bioactivities Of Roselle (Hibiscus Sabdariffa L.) Extracts Obtained By Infusion, Ethanolic Maceration, And Maltodextrin-Assisted Drying, Risna Silvianti, Warsito Warsito, Elok Zubaidah, Zubaidah Ningsih, Aqidatul Izza

Karbala International Journal of Modern Science

Roselle (Hibiscus sabdariffa L.) is rich in phenolic compounds and anthocyanins, but the extraction method may influence its chemical composition and biological activity. This study compared hot-water infusion, ethanolic maceration, and maltodextrin-assisted drying. It aimed to examine the relationship between the extraction method, chemical profile, and bioactivity. The resulting extracts (EI, EM, and EP) were analyzed for total phenolic, flavonoid, and anthocyanin, LC-HRMS profiles, and antioxidant capacity by the FRAP assay. Antibacterial analysis was conducted against Escherichia coli (ATCC 25922) and Staphylococcus aureus (ATCC 25923) using agar well diffusion. Cytotoxicity tests (MTT, 24 h) were performed against HT-29, 4T1, …

Caffeine Perceptions And Reality In High School Gymnasts, Gabrielle Steinkopf

InnovateHER Meeting 2026

From years of observation as a high school gymnast, there is a noted “caffeine culture” among gymnasts at my high school. Since gymnastics is a precision sport with not inconsiderable danger, I wondered what impact caffeine ingestion had on athletes. Athletes were asked to give up caffeine during a series of regular season meets, with reflection questions immediately after each meet to assess the impact caffeine might have had on performance vs the gymnasts’ perception of the effects

Advancing Targeted Food Allergen Detection: Extraction Optimization And Sample Preparation Method Comparison Using Lc-Ms/Ms, Zhenhao Wang

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Accurate quantification of food allergens in processed foods by liquid chromatography-tandem mass spectrometry (LC-MS/MS) requires effective protein extraction and sample cleanup. However, no single sample preparation workflow has shown consistent performance across diverse food matrices. This study evaluated extraction buffer formulations and post-extraction cleanup strategies for quantification of milk, soy, and peanut allergens in multiple processed food matrices.

Six extraction buffers with varying combinations of SDS, urea, and thiourea alongside a common Tris-HCl/DTT/PVPP base were evaluated across five food matrices. No significant differences in extraction efficiency were observed among buffer formulations for nonfat dry milk (NFDM), non-roasted soy flour, peanut …

Analysis Of The Flavonoid Composition Of Honey Using High-Performance Liquid Chromatography, Bryce Phillips

Honors Theses

Honey is a naturally occurring substance that has a complex composition including compounds such as flavonoids, that contribute to potential health benefits. Quantitative analysis of flavonoids in honey can be challenging due to their similar structural characteristics, matrix effects, and chromatographic peak separation issues. This study aimed to establish calibration curves for five flavonoids–kaempferol, luteolin, chrysin, myricetin, and quercetin– to estimate their concentrations in five honey samples from varying geographic origins. Liquid-liquid extraction was used to isolate the flavonoids from honey. High Performance Liquid Chromatography was utilized to establish calibration curves and analyze honey samples. The calibration curves assembled demonstrated …

Spectroscopic Characterization And Extraction Optimization Of Catechins In Green Tea, Zach J. Mckinley, Masakatsu Watanabe

SACAD: Scholarly Activities

This research initiative immerses students in a multifaceted analytical chemistry investigation of catechins—polyphenolic antioxidants prevalent in green tea—through the application of both classical and modern techniques. The project emphasizes hands-on experience with real-world sample analysis, method development, and critical data interpretation.

Catechins were extracted from various commercial green tea products, including loose leaves, powders, and dietary supplements, by trituration with ethyl acetate followed by solvent partitioning using a methanol and water solution. The resulting extracts were analyzed using UV-Visible spectroscopy to quantify catechin content. Selected samples were further characterized by liquid chromatography–mass spectrometry (LC-MS), confirming both the identity and purity …

Identification Of Covalent Catechin Adducts Of Enoyl-Acp Reductase (Fabi) From E. Coli Using Mass Spectrometry, Francisco G. Atwi, P. M. Joyner, Rustin Ghidari

Seaver College Research And Scholarly Achievement Symposium

Enoyl-ACP reductase (FabI), an enzyme which is inhibited by catechin, is essential for lipid biosynthesis in bacteria (E. coli). Another FabI inhibitor, triclosan, has strong antibacterial effects,1 but overuse can be detrimental to the environment. Flavonoids, a class of dietary compounds, are known to have potent inhibitory effects on FabI and other kinases.2,3,4 Adducts form as a result of the biochemical reaction between flavonoids and cysteine, a modification which can be verified by m/z shifts on the mass spectra.5 Samples of E. coli protein with overexpressed FabI are utilized: the wild type with ordinary primary structure, and mutant type lacking …

Detection And Quantification Of Allergen Cross-Contact In Shared Frying Oil Using Targeted Mass Spectrometry, Francisca Asigri

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Cow’s milk and egg allergies are prevalent IgE-mediated food allergies that pose significant public health concerns worldwide. Although strict avoidance remains the primary management strategy, unintended exposure can still occur through allergen cross-contact, particularly in commercial and industrial food operations that utilize shared frying oils. The objective of this study was to identify and quantify allergen transfer in shared frying oil and assess the robustness of existing targeted mass spectrometry methods (LC-MS/MS) for detecting milk and egg proteins in heated oil matrices.

Heated oil spikes were developed by incorporating non-fat dry milk (NFDM) and whole egg powder (WEP) into oil …

Alkaline And Acid Extraction Of An L-Tryptophan–Sunflower Flour Red Colorant: Production, Characterization, And Utilization, Spencer Nguyen, Marissa Wong, Lilian Were Senger

Food Science Faculty Articles and Research

The objective was to produce and characterize a red colorant resulting from interaction of sunflower-derived chlorogenic acid with L-tryptophan/Trp and to evaluate its applications. Yield, intensity, solubility, stability, protein, and metal content of colorants from pH 9 and pH 11 lyophilized sunflower flour- Trp colorants were measured. Red color formation took < 3 h with alkalization and subsequent acidification. The sunflower flour: Trp mixture ratio that produced the greatest redness was 10:2. The highest red pigment was in supernatants and not the precipitates. The red colorant intensity and solubility were highest at neutral pH when compared to acidic pH solutions. The color stability of the new red colorant in icing and refrigerated whole milk matrices, when assessed weekly for a month, showed no color change in refrigerated milk. After 30 min of incubation at 63 °C, pinkness in milk remained unchanged or increased. The pink color, however, faded in icing over time due to exposure to light. The present study established a new natural red colorant developed from sunflower protein-Trp mixtures at alkaline pH, as well as its application in icings and whole milk for commercial strawberry milk products. This colorant could serve as a replacement for the synthetic petroleum-based Red 3.

Research Progress In Antagonistic Bacteria Against Staphylococcus Aureus, Caiqi Wang, Yuansong Ma, Xinrui Zhao, Pei Zhou, Sifan Lu, Yuxin Li, Yinbiao Xu

Journal of Food Science and Biotechnology

Staphylococcus aureus,a common Gram-positive foodborne pathogen,is ubiquitous in the human skin and respiratory tract.It can cause pneumonia,pleurisy,endocarditis,food poisoning,sepsis and other infectious diseases.The widespread and long-term use of antibiotics has aggravated the antibiotic resistance of Staphylococcus aureus.In particular,the emergence of multi-drug resistant strains has greatly reduced the therapeutic effect.Therefore,developing new antibacterial means to replace or assist existing antibiotics has become an urgent need.Microbial natural products are important resources for the development of new antibiotics,and antagonistic microorganisms play an important role.This paper reviewed the species of antagonistic bacteria against Staphylococcus aureus,the types of antibacterial active substances,and the commonly used screening methods of …

Probiotics Regulate Gut Microbiota And Immune Homeostasis To Prevent And Treat Food Allergy : A Review, Yao Chen, Zumeng Xia, Yijin Yang, Lianzhong Ai, Guangqiang Wang, Yan Zhang, Zhen Luo, Yong Zhou, Yongjun Xia

Journal of Food Science and Biotechnology

Food allergy (FA) is a common immunological disorder,and its pathogenesis is primarily associated with a complex regulatory process involving CD 4+ T cells in the immune system,such as the polarization of Th 2 cells and the imbalance between Treg/Th 17 cells.The balance of intestinal immune cells plays a critical role in the development of FA,while dysbiosis of the gut microbiota may disrupt this balance,thereby contributing to the onset of FA.Probiotic intervention targeting the gut microbiota can directly or indirectly influence the functions of immune cells to regulate immune responses,representing a promising approach for the prevention and treatment of FA.The authors …

Research Progress Of Gc-Ms-Based Metabolomics In Fermented Cereal Foods, Haichen Liu, Chang Liu, Hongyan Huo, Hui Xu, Shunxi Zhu, Lei Liu, Kui Zou

Journal of Food Science and Biotechnology

As an emerging discipline,metabolomics has gradually become the focus of food science research.Among numerous metabolomics analysis methods,gas chromatography-mass spectrometry (GC-MS ) has attracted much attention for its wide application.Fermented cereal foods occupy an important position in global dietary culture and are an indispensable type of foods in peopl e’s daily lives.The author reviewed the application of GC-MS based metabolomics for the development of fermented cereal foods,covering sample preparation,metabolite extraction,data analysis,and practical application in fermented cereal foods.Moreover,this paper elaborated on the advantages and limitations of GC-MS-based metabolomics in fermentation,aiming to provide a reference for further exploring the principles of food fermentation …

Mechanism Of The Effect Of Microwave Heating On The Degradation Of Fructans In Steamed Cakes Prepared With Saccharomyces Cerevisiae, Xiaoyue Ying, Yuan Tao, Yuan Yuan, Ziting Li, Bowen Yan, Jianxin Zhao, Wei Chen, Daming Fan

Journal of Food Science and Biotechnology

[Objective ] This study aimed to investigate the effect of microwave heating on the fructan mass fraction in steamed cakes prepared with Saccharomyces cerevisiae and elucidate the molecular mechanism of the activation of invertase by microwave.[Method ] Steamed cakes were prepared under varying microwave power density (3.40~5.10 W/g ) and heating time (2~5 min ),and the fructan mass fraction was compared between steamed cakes prepared by microwave heating and conventional steaming.The activity of invertase from Saccharomyces cerevisiae was measured under microwave heating and water bath heating conditions.Molecular dynamics simulations were performed to explore the invertase-kestose interactions under microwave fields.[Result ] …

Differences In Important Chemical Components And Free Radical Scavenging Activities Of The Ginger Germplasm Resources From Fujian, Meichun Chen, Enquan Lin, Xuefang Zheng, Zuliang Li, Bo Liu, Jieping Wang

Journal of Food Science and Biotechnology

[Objective ] This study aims to analyze the important chemical components of different ginger germplasm resources from Fujian and evaluate their comprehensive quality and free radical scavenging activities.[Method ] Gas chromatography-mass spectrometry (GC-MS ) and liquid chromatography-quadrupole-time of flight-mass spectrometry (LC-QTOF-MS ) were employed to determine the importance chemical components in 13 ginger germplasm resources.Differences in the chemical compounds were analyzed by the cluster analysis and principal component analysis (PCA ).The free radical scavenging activities of the ginger germplasm resources against ABTS+ were further evaluated.[Result ] A total of 65 chemical compounds were identified from the 13 ginger germplasm resources,including …

Cyanidin- 3-Glucoside Ameliorates Ocular Surface Dysfunction In Rats With Dry Eye Disease, Ke Zhang, Ziyu Liu, Zhangben Yao, Peng Zhang, Lei Tian, Ying Jie, Yong Wang

Journal of Food Science and Biotechnology

[Objective ] Studies have shown that cyanidin- 3-glucoside (C3G),the main component of black rice anthocyanins,exhibits protective effects on retina and retinal pigment epithelium (RPE ) cells.However,there is a lack of in vivo evidence regarding the efficacy of C 3G in alleviating dry eye disease (DED ),which limits its application in ocular surface disorders.This study aims to investigate the protective effects of C 3G on DED in rats.[Method ] 24 Wistar rats were randomly assigned into control,model,and C 3G groups.In model and C 3G groups,a DED model was established by subcutaneous injection of scopolamine hydrobromide (4 times daily for 28 d).The …