Methane derived authigenic carbonate (MDAC) precipitation occurs within marine sediments as a byproduct of the microbial anaerobic oxidation of methane (AOM). While these carbonates form in chemical and isotopic equilibrium with the fluids from which they precipitate, burial diagenesis and recrystallization can overprint these signals. Plane polarized light (PPL) and...
Quantifying the mass transport through marine sediments, and the geochemical response to such flow with numerical models has become a common and powerful approach for geochemical data interpretation. In this dissertation, I developed and applied transport-reaction models to unravel complex and interdependent reactions involving carbon, sulfur and silica transformations in...
The rare earth elements (REEs) have been established as powerful tracers for a range of physiochemical processes occurring in the natural environment. They also hold significant economic importance as many technological advancements are reliant upon the REEs for their unique magnetic, luminescent, and electrochemical characteristics. In sedimentary settings, understanding the...
Given the current state of our oceans, the Pew Oceans Commission (1993) has strongly recommended that increased efforts be made towards ocean literacy. Informal education and outreach programs like the Whale Watching Spoken Here program are important contributors to life-long learning. However, there is little research looking at how these...
The distribution of barite (BaSO₄) in marine sediments has long been studied as a proxy for paleoproductivity. While pure barite is known to be a stable mineral in oxic sediments, it is also known that variations in the Sr/Ba ratio influence its solubility and liability during early diagenesis. To extract...
Nares Strait is one of three main passages of the Canadian Archipelago that
channels freshwater from the Arctic Ocean to the North Atlantic. There are very few
observations regarding the role of this region on the present day Arctic freshwater budget,
and even less regarding the changes in freshwater fluxes...
Large barite (BaSO4) structures mark cold seeps in the southern San Clemente Basin. Barium flux to San Clemente sediments is two to three times greater than fluxes measured in surrounding California Borderland basins. Analyses of sediment trap material, water column samples, sediments and pore water indicate that expected bariumbearing mineral...
The number of Latinx students enrolling in higher education has grown significantly over the past two decades (Jabbar et al., 2019). This study explores a portion of that population by focusing on the experiences of Latinx transfer students at a 4-year institution within the Pacific Northwest of the United States....
This report describes the results of semiquantitative analysis of clay mineral composition by X-ray diffraction. The samples consist of hemipelagic mud and mudstone cored from Hydrate Ridge during Leg 204 of the Ocean Drilling Program. We analyzed oriented aggregates of the clay-sized fractions (<2 μm) to estimate relative percentages of...
The Cooperative Institute for Oceanographic Satellite Studies
(CIOSS) partners with The Science and Math Investigative Learning
Experiences (SMILE) Program to bring ocean sciences and satellite
oceanography to high school students and teachers around the
state of Oregon. This study was conducted as a formative program
assessment during the third year...
Abstract
Current methods employed in the textile industry are unsustainable because they use an abundance of water in the dying process, and discharge the waste into the environment, causing adverse health effect on aquatic life and local communities. The technology that is in place to remove dye from textile effluents...
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Dye Adsorbed (Dist. Water) Dye Adsorbed (Salt Water)
Torres 2012
Methods: F
This study reports on the creation and testing of a model concept-mapping process that will aid the development and documentation of ocean science educational content of The Science and Math Investigative Learning Experiences (SMILE) Program, a pre-college science and math enrichment program based at Oregon State University. The project uses...
Isotopic characterization of carbon in the dissolved inorganic carbon (DIC) pool is fundamental for a wide array of scientific studies directly related to gas hydrate research. In order to generate integrated and internally consistent data of δ¹³C of DIC in pore waters from Hydrate Ridge, we used the modern continuous...
The investigation described in this project will test the hypothesis that fluxes of carbon, barium, manganese, iron and uranium associated with fluid seepage at the San Clemente fracture zone significantly affect the geochemical budgets for these elements, and ultimately result in anomalously high benthic fluxes throughout the San Clemente basin.
Aquatic and riparian systems in the western United States have been highly modified by anthropogenic impacts since Euro-American settlement. Ecological restoration is a practice that has been widely conducted around the world to mitigate the degradation of these systems. The majority of stream restoration efforts have focused on improving in-stream...
Many trace elements (e.g., Zn, Cd, Mo) are essential phytoplankton micronutrients, making them crucial to the marine ecosystem and ultimately the carbon cycle. Because of this association trace metals are also utilized in paleoceanographic studies (e.g., Mo, Cd). However, not much is known about what controls the cycling of these...
To assist with risk-assessment with deepwater and ultra-deepwater prospects for offshore energy extraction as well as provide a useful tool for oil spill response, a spatially-explicit model was developed for comprehensive simulations of a blowout event from the wellhead to final fate and degradation. The Blowout and Spill Occurrence Model...
Brooks Island, located in central San Francisco Bay, California, currently supports the largest breeding colony of Caspian terns (Hydroprogne caspia) in the Bay Area, and is one of several proposed relocation sites for some Caspian terns from the world's largest colony in the Columbia River estuary of Oregon. Juvenile salmonids...
This thesis develops a manual for interpreters at six National Park Service areas established to preserve and interpret fossils of the Cenozoic Era: Fossil Butte National Monument (Wyoming), John Day Fossil Beds National Monument (Oregon), Badlands National Park (South Dakota), Florissant Fossil Beds National Monument (Colorado), Agate Fossil Beds National...
Hydroxylamine is a constituent of the nitrogen cycle which has been shown to be an intermediate in both nitrification and nitrate reduction in several in-vitro studies. However, there have been no investigations into the concentrations and distributions of hydroxylamine
in the marine environment. The purpose of this work was to...
Ocean Drilling Program (ODP) Leg 204 to Hydrate Ridge, located on the continental slope offshore Oregon (USA), was the first drilling expedition dedicated to understanding gas hydrate processes in accretionary complexes and provided a testbed for a number of different techniques for estimating the gas hydrate content of sediments. It...
Oxygen and strontium isotopic composition of sedimentary pore fluids obtained by drilling at the Chile Triple Junction have been used to obtain information on the diagenesis and transport mechanisms of fluids. Samples were collected from three sites located on an east-west transect of the pre-collision zone (Sites 859, 860, and...
The isotopic compositions of interstitial waters collected from Hydrate
Ridge during Ocean Drilling Program Leg 204 were measured to
evaluate the fluid evolution of this accretionary prism. At shallow
depths, the dissolved Cl- concentrations and δD and δ¹⁸O values of the
interstitial water reflect changes in the salinity and the...
We report on geochemical data from anoxic sequences of the Nicobar Fan, recovered during International Ocean Discovery Program (IODP) expedition 362 to the Sumatra subduction zone. Analyses include strontium and carbon isotope composition of pore fluids, elemental and isotopic composition of carbonate concretions, and whole sediment analyses.
Biogeochemical mechanisms employed by key organisms, or symbiotic associations of organisms, transform the function and structure of their environment through processes recognized as ecosystem engineering. This dissertation seeks to investigate organism-ecosystem interactions that serve globally significant ecological functions in marine systems and impact how systems respond to environmental change. Using...
While water scarcity and energy demand are continuously increasing in the world, alternative sources are needed to meet the requirement of a growing population. Microbial Fuel Cell (MFC) is a sustainable technology that converts organic matter in wastewater into electricity, thus it can be a potential alternative source for water...
Despite more than two centuries of exploration, including more than six million deep wellbores with depths exceeding 40,000 feet in some parts of the world, our ability to constrain subsurface processes and properties remains limited. Characteristics of the subsurface vary and can be analyzed on a variety of spatial scales....
Marine sediments contain an abundance of methane that is biologically produced
and plays a significant role in the global carbon cycle. Microbes responsible for the
carbon cycle in marine sediments, and the processes that they carry out, need to be
characterized in order to fully understand the role of this...
In this thesis I present the results of a comprehensive assessment of the Pacific-North American (PNA) teleconnection pattern in general circulation models (GCMs) and a regional climate model (RCM). The PNA teleconnection pattern is a quasi-stationary wave field over the North Pacific and North America that has long been recognized...
The overall purpose of this research is to assess the Oregon public's capacity to address water resources disturbances through civil society. According to scientists and resource managers, Oregon's water resources are over taxed and at risk, with future projections placing additional stress from climate change and population growth. Oregon's 2009...
With an ever-growing urban population there is a continued interest in urban agriculture as a viable option to improve access to fresh produce and enhance food security in an increasingly urbanized world. As the primary method of urban agriculture in the United States, community gardens also provide a range of...
The research and analysis presented in this dissertation illustrate how individuals enact lived religion as they seek to navigate social inequalities. The enactment of lived religion involves directing attention towards orientations. I use the term orientations in the sense articulated by Ahmed (2004), to allude to how bodies are situated...
The working hypothesis for this study is that the introduction of GIS technology into the ancient procedures of map-making has changed the map-making context sufficiently to require a revision of the way we think about, learn from, and use maps, specifically in the public involvement process in natural resource management....
We present a kinetic model based upon pore water data collected from eight sites drilled
during the second Ulleung Basin gas hydrate drilling expedition (UBGH2) in 2010.
Three sites were drilled at locations where acoustic chimneys were identified in seismic
data, and the rest were drilled on non-chimney (i.e. background)...
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, with a kinetic modeling approach 2
3
Wei-Li Hong
1
, MartaE. Torres
1
, Ji-Hoon Kim
2
, Jiyoung
Sedimentary pore fluids from the Chile Triple Junction were sampled in situ, and analyzed for their noble gas composition. ³He/⁴He and ⁴He/Ne ratios were used to evaluate the fraction of helium in the samples that originated from mantle and radiogenic sources. The results show no primordial helium in samples recovered...
Methane fluxes into the oceans are largely dependent on the methane phase as it migrates upward through the sediments. Here we document decoupled methane transport by gaseous and aqueous phases in Storfjordrenna (offshore Svalbard) and propose a three-stage evolution model for active seepage in the region where gas hydrates are...
Recent studies have suggested that the marine contribution of methane from shallow regions and melting marine-terminating glaciers may have been underestimated. Here we report on methane sources and potential sinks associated with methane seeps in Cumberland Bay, South Georgia's largest fjord system. The average organic carbon content in the upper...
Drilling in the Cascadia accretionary complex enable us to evaluate the contribution of dehydration reactions and gas hydrate dissociation to pore water freshening. The observed freshening with depth and distance from the prism toe is consistent with enhanced conversion of smectite to illite, driven by increase in temperature and age...
The significance of the various carbon cycling pathways in driving the sharp sulfate methane transition (SMTZ) observed at many locations on continental margins is still a topic of debate. Unraveling these processes is important to our understanding of the carbon cycle in general and to evaluate whether the location of...
We present a kinetic model based upon pore water data collected from eight sites drilled
during the second Ulleung Basin gas hydrate drilling expedition (UBGH2) in 2010.
Three sites were drilled at locations where acoustic chimneys were identified in seismic
data, and the rest were drilled on non-chimney (i.e. background)...
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RUNTIME
time_units years
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timestep_init 1.E-12
time_tolerance
We present a kinetic model based upon pore water data collected from eight sites drilled
during the second Ulleung Basin gas hydrate drilling expedition (UBGH2) in 2010.
Three sites were drilled at locations where acoustic chimneys were identified in seismic
data, and the rest were drilled on non-chimney (i.e. background)...
We present a kinetic model based upon pore water data collected from eight sites drilled during the second Ulleung Basin gas hydrate drilling expedition (UBGH2) in 2010. Three sites were drilled at locations where acoustic chimneys were identified in seismic data, and the rest were drilled on non-chimney (i.e. background)...
Marine sediments are vast sources and reservoirs of methane, a potent greenhouse gas. Most of this methane is anaerobically oxidized by archaea before it can reach the overlying ocean, though the efficiency of this process often depends on methane fluxes and mechanisms of fluid transport. Anaerobic methanotrophic archaea, or ANME,...
Hydrate Ridge is an accretionary thrust ridge located on the lower slope of the central Cascadia convergent margin. Structural mapping based on two-dimensional and three-dimensional multichannel seismic reflection profiles and gridded bathymetry coupled with deep-towed sidescan sonar data and Ocean Drilling Program (ODP) biostratigraphy suggests that seafloor fluid venting patterns...
Total organic carbon (TOC) content of marine sediments represents residual carbon, originally derived from terrestrial and marine sources, which has survived seafloor and shallow subseafloor diagenesis. Ultimately, its preservation below the sulfate reduction zone in marine sediments drives methanogenesis. Within the gas hydrate stability zone (GHSZ), methane production along continental...
Sediments at the southern summit of Hydrate Ridge display two distinct modes of gas hydrate occurrence. The dominant mode is associated with active venting of gas exsolved from the accretionary prism and leads to high concentrations (15%–40% of pore space) of gas hydrate in seafloor or near-surface sediments at and...
Sporosarcina pasteurii is known to produce calcite or biocement in the presence of urea and Ca²⁺. Herein, we report the use of novel ultramicrosensors such as pH, Ca²⁺, and redox sensors, along with a scanning electrochemical microscope (SECM), to monitor a real-time, bacteria-mediated urea hydrolysis process and subsequent changes in...
Full Text:
, Yvan Allau2, Circe
Verba3, Frederick Colwell2, MartaE. Torres2, Dipankar Koley1,*
1 Department of
The isotopic composition of the dissolved inorganic carbon (DIC) collected at sites of active methane discharge on Hydrate Ridge, Oregon, reveals anaerobic methane oxidation mediated by bacteria, with δ13CDIC reaching values as low as –48‰ in the upper 4 cm of the sediment. In spite of the high sulfide levels...
Analytical challenges in obtaining high quality measurements of rare earth elements (REEs) from small pore fluid volumes have limited the application of REEs as deep fluid geochemical tracers. Using a recently developed analytical technique, we analyzed REEs from pore fluids collected from Sites U1325 and U1329, drilled on the northern...
Geophysical and biogeochemical processes associated with fluid venting from active and passive continental margins will receive significant scientific and economic attention
into the next century and are of major societal relevance. An important unknown among these interrelated processes is the role played by methane gas hydrates, at and below the...
Coring at ODP Sites 859, 860, and 861 near the Chile Triple Junction failed to recover anticipated gas hydrate that was inferred
to be present from two lines of geophysical evidence: pre-cruise observation of a weak to strong bottom simulating reflector (BSR)
marking the predicted base of the gas-hydrate stability...
Sporosarcina pasteurii is known to produce calcite or biocement in the presence of urea and Ca²⁺. Herein, we report the use of novel ultramicrosensors such as pH, Ca²⁺, and redox sensors, along with a scanning electrochemical microscope (SECM), to monitor a real-time, bacteria-mediated urea hydrolysis process and subsequent changes in...
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. Thurber,b Yvan Allau,b
Circe Verba,c Frederick Colwell,b MartaE. Torresb and Dipankar Koley*a
Sporosarcina pasteurii is known to produce calcite or biocement in the presence of urea and Ca²⁺. Herein, we report the use of novel ultramicrosensors such as pH, Ca²⁺, and redox sensors, along with a scanning electrochemical microscope (SECM), to monitor a real-time, bacteria-mediated urea hydrolysis process and subsequent changes in...
A massive release of methane on the Cascadia Hydrate Ridge was documented
during a ROPOS program in August 1998, consistent with previously reported
observations in 1996. An extensive survey of the seafloor revealed that the
seeps lie within a narrow band trending 109 degrees. This feature parallels larger
mounds imaged...
The extensive reduction in adult Pacific lamprey (Entosphenus tridentatus) counts at many hydroelectric dams in the northwestern USA signals a substantial decline in lamprey numbers across the entire region in the past 40 to 50 years. Among the many potential causes of this decline, obstruction of migration routes has likely...
Silicic volcanism in the central Oregon Cascade range has decreased in both the size and frequency of eruptions from its initiation at ~40 Ma to present. The reasons for this reduction in silicic volcanism are poorly constrained. Studies of the petrogenesis of these magmas have the potential for addressing this...
The marine environment is under increasing pressure from human activities worldwide, particularly in coastal waters, creating a need to better understand fine-scale distributions of highly mobile species that occur in the area, as they are frequently most threatened. Harbor porpoise (Phocoena phocoena) occur frequently in Oregon’s nearshore habitat, but due...
Bacillus subtilis α-amylase was used to hydrolyze
starch from peeled and whole potatoes (Solanum tuberosum).
Effect of gelatinization temperature, pH, enzyme concentration,
temperature of hydrolysis and presence of calcium
ions were investigated. Optimum conditions for hydrolysis
were when α-amylase levels were 0.3 percent of the starch
concentration in the presence...
An instrument was constructed to measure molecular fluorescence (FL) or chemiluminescence (CL) and absorbance (ABS) simultaneously. The lower, middle, and upper portions of the test solution are probed to obtain ABS, FL, and CL data. Optical fibers are used extensively. The ABS and FL or CL spectra are acquired in...
Anthropogenic activities have posed many threats to the oceans and marine life. Understanding how individuals are affected and physiologically respond to these threats is crucial and allows for management and conservation applications. I evaluated the overall health condition of a subpopulation of gray whales (Eschrichtius robustus) along the Oregon coast,...
A commercially important polyelectrolyte, xanthan, was chosen for
a systematic analysis of the relationship between molecular
conformation and surface properties. In the first study the effects
of ionic strength, xanthan concentration and temperature on the
xanthan molecular conformation were investigated by potentiometric
titration. The effects of the same factors and...
In addition to well established properties that control the presence or absence of the hydrate stability zone, such as pressure, temperature, and salinity, additional parameters appear to influence the concentration of gas hydrate in host sediments. The stratigraphic record at Site 17A in the Andaman Sea, eastern Indian Ocean, illustrates...
Log and core data document gas saturations as high as
90% in a coarse-grained turbidite sequence beneath the gas
hydrate stability zone (GHSZ) at south Hydrate Ridge, in the
Cascadia accretionary complex. The geometry of this gas-saturated
bed is defined by a strong, negative-polarity
reflection in 3D seismic data. Because...
The validation and potential use of mathematical models to estimate the
shelf-life of refrigerated food exposed to temperature abuse and basing such
estimations on microbial growth was analyzed. Combined heat transfer, microbial
growth models, and non-parametric statistical procedures formed a computer-based
predictive tool to assess shelf-life and estimate the accuracy...
Analytical chemistry is an essential qualitative and quantitative tool to describe foods and biomaterials and their changes during production, processing and distribution. In this work, rapid analytical procedures for the extraction and quantification of components in fluid milk and diatom fermentation broth were developed. Analytical methods to measure the concentration...
Clostridium perfringens is the causative agent of a wide variety of diseases in animals and humans. C. perfringens can produce more than 15 toxins. However, individual strains produce a subset of these toxins. Although a small percentage of C. perfringens isolates (mostly belonging to type A) produce C. perfringens enterotoxin...
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Mahfuzur R. Sarker J. Antonio Torres
Clostridium perfringens is the causative agent of
Sea otters (Enhydra lutris) used to exist along coastlines throughout much of the North Pacific Ocean. During the Maritime Fur Trade, sea otters were extirpated from much of their historic range, including Oregon. There is renewed interest in reintroducing sea otters to Oregon. Managers seek improved understanding of the potential...
Understanding prey quality and prey selection by predators is critical for management efforts aimed at identification and protection of essential habitats and prey. Marine predators must make daily foraging choices in a heterogenous and dynamic environment in order to meet the high energetic demands of migration, reproduction and foraging. With...
Citizen science work has built the foundation of much of our knowledge on regional-scale large cetacean spatial patterns through historical whaling data. Historical whaling data on sperm whales was used as an example to show the type of ecological questions large-scale, long-term citizen science datasets can address. Results from the...
About 48 million cases of Foodborne illnesses (FBIs) are estimated to occur every year in the US. These are diseases caused by contamination of foods with bacteria, viruses, protozoa, parasites and toxic chemicals. Clostridium difficile infections (CDIs) are an important health-care and community associated problem. Since C. difficile spores have...
The lag phase, the specific growth rate, the minimum a [subscript w]
required for growth and the temperature characteristic of
Fsendomonas fluorescens, Brochothrix thermosphacta, Salmonella
typhlmurium, Streptococcus faecalis and, Staphylococcus aureus
have been studied in liquid model media under controlled temperature
and a [subscript w] conditions. The results show that...
Chitosan has been proposed as a "natural" coagulating agent to solve wastewater problems. The main hindrance in this commercial chitosan application has been its low cost effectiveness. The hypothesis in our research is that chitosan complexes with natural polyanions is more effective than chitosan alone, particularly in recovering low concentration...
Soluble surimi wash water (SWW) proteins could be recovered using chitosan (Chi) complexed with alginate (Chi-Alg) generating co-products for feed formulations. Chi with a degree of deacetylation (DD) of 84% complexed with Alg at a mixing ratio (MR) of 0.2 was used to study Chi-Alg concentration and treatment time protein...
Edible coatings controlling preservative migration from
surface to food bulk could inhibit surface microbial growth
which is often the main cause of spoilage for many food
products. In this project we focused our attention upon
methylcellulose, hydroxypropyl methylcellulose, and chitosan as
the structural component for such edible films. These films...
The distribution of mobile marine predators often reflects underlying dynamic ecological processes. The geographical focus of this PhD is the South Taranaki Bight (STB) of New Zealand, where wind-driven coastal upwelling generates productivity and prey to support a blue whale foraging ground. The STB is also New Zealand’s most industrial...
The use of edible coatings in combination with antimicrobial
agents enhances the microbial stability of foods. In this study we
evaluated the potassium sorbate and sorbic acid permeability of an
edible methylcellulose (MC) - palmitic acid (PA) film with a MC:PA
ratio of 3:1.
Permeability cell measurements were used to...
Species conservation depends on robust population assessment. Data on population abundance, distribution, and connectivity are critical for effective management, especially as baseline information for newly documented populations. I describe a pygmy blue whale (Balaenoptera musculus brevicauda) population in New Zealand waters with year-round presence that overlaps with industrial activities. This...
Quantitative procedures were developed to determine the effect of variability in the model parameters required for the estimation of microbial shelflife and thermal processing time. Monte Carlo simulations combined with these predictive models were implemented in Microsoft Excel™. In the first study,
predictive models were used for shelf-life predictions based...
Equipment and procedures for the rapid measurement of the water vapor
permeability of polymer films and food coatings has been evaluated. The
method uses an electronic sensor to measure the concentration increase in
water vapor diffusing through a film into a chamber of known volume. Air of
known humidity is...
Spores of foodborne pathogens such as Clostridium botulinum, Clostridium perfringens and Bacillus cereus are widely distributed in nature. Presence of those spores in food products, particularly C. botulinum spores in vacuum packed, ready-to-eat low-acid products, is a great safety concern. The research here described is a first effort towards understanding...
The desire to understand the spatial and temporal drivers of animal behavior and distribution relative to scale is central to movement ecology. Optimal foraging theory states that a predator should continue exploiting a patch until it is no longer profitable to do so. As human developments increasingly encroach on the...
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Leigh G. Torres
The desire to understand the spatial and temporal drivers of animal
Automation of Capacitor Discharge Welding (CDW) has not been investigated in
industry due to the limited understanding of the process. The US Department of Energy's Albany Research Center (ALRC) has done an extensive study of the process and reported applications of welds in the manufacture of electro-mechanical products such as...
Understanding residents’ perceptions of and support for tourism is essential for sustainable tourism development and management. Research has shown that perceptions of tourism impacts are related to residents’ support for tourism. It is generally accepted that perceived tourism impacts predict support for tourism, as explained by social exchange theory. However,...
The biogeochemical processes that occur in marine sediments on continental margins are complex; however, from one perspective they can be considered with respect to three geochemical zones based on the presence and form of methane: sulfate-methane transition (SMTZ), gas hydrate stability zone (GHSZ), and free gas zone (FGZ). These geochemical...
Research on cetacean foraging ecology is central to our understanding of their spatial and behavioral ecology. Yet, functional mechanisms by which cetaceans detect prey across different scales remain unclear. Here, I postulate that cetaceans utilize a scale-dependent, multimodal sensory system to assess and increase prey encounters. I review the literature...
Abstract
Current methods employed in the textile industry are unsustainable because they use an abundance of water in the dying process, and discharge the waste into the environment, causing adverse health effect on aquatic life and local communities. The technology that is in place to remove dye from textile effluents...
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of Acid Green 3 Dye
By
Martine Torres
An Undergraduate Thesis Submitted
Flavored milk is a growing category for dairy products; however, it is a perishable product that is subject to microbial spoilage which can lead to a negative consumer experience and lead to lost sales. Flavored milk processors communicated unique spoilage events related to their products, including color loss of strawberry...