The aim of this work was to determine chemical species of arsenic in sea originating certified reference materials. Measurements were done using method of hydride generation. Hydrides were preconcentrated in liquid nitrogen cooled tube and detected using inductively coupled plasma mass spectrometry. During the testing of the method, mutual conversion of arsenic species was observed for inorganic arsenic, monomethyl arsenic and dimethylarsenic. Further study revealed that with presence of matrix and hydrogen peroxide, demethylation occured only in hydride generation phase, not during extraction. Dissociation of hydrogen peroxide in extracts was verified using catalase. End of the demethylation process was proved using measurement with addition of arsenic species standards. The newly invented procedure was used to determine arsenic species in reference materials with sufficient accuracy. Final results are compatible with results from different method, and already published results as well. Key words: speciation analysis, arsenic, hydride generation, seafood, inductively coupled plasma mass spectrometry

Microplastic particles (MPs) are widely distributed in aquatic environments and present a potential risk to marine life. This thesis considers several issues relating to methodologies for sampling and analyzing MPs and the sources and fate of these particles in the marine environment, wild and farmed shellfish, and food webs of southern coastal British Columbia, Canada. Chapter 1 introduces MPs as a contaminant, methodologies for studying them, and reviews what is known about their source, fates, and ecotoxicology in marine environments. Chapter 1 also outlines the goals of this thesis. Chapter 2 compares the potential MP concentration estimates provided by two different seawater sampling methods. Jar samples filtered to 8-µm yielded MP concentrations averaging approximately 8.5 times higher than bucket samples filtered to 63 µm, per L of water (at the site level), driven largely by differences in the number of microfibres. An analysis of MP concentrations and mesh sizes reported in the literature suggests that using a 300–350-µm mesh may underestimate total MP concentrations by one to four orders of magnitude compared with samples filtered through much smaller mesh sizes (e.g., less than 100 µm), and despite the effect of sample volume. Particles less than 300 µm in diameter make up a large component of MPs commonly found in fish and invertebrates. As such, common sampling practices fail to adequately measure a biologically relevant class of MPs, thereby undermining the ability to quantify ecological risk. Chapter 3 determines the influence of shellfish aquaculture activity, and its use of plastic equipment, on MPs in bivalves and their environment by comparing MP concentrations in Manila clams (Venerupis philippinarum) and Pacific oysters (Crassostrea gigas) grown on commercial shellfish beaches with those grown on non-aquaculture beaches from six areas. MP concentrations in water and sediment were also determined in four of the areas. MP concentrations did not differ between shellfish aquaculture and non-aquaculture sites for either bivalve species or for sediment and water samples. Beach sediment type had a minor effect, with more gravelly or sandier beaches associated with higher MP concentrations in oysters or clams, respectively. Oysters on sites using many synthetic anti-predator nets had more MPs than those on sites without any plastic, but analysis of particles using Fourier-transform infrared spectroscopy suggested a predominance of textile fibres including nylon and polyester, which are not typically used in shellfish aquaculture. Chapter 4 uses stable isotope food web analysis and hierarchical Bayesian generalized linear mixed models to explore whether bioaccumulation and biomagnification are occurring in coastal marine food webs at three locations. Bioaccumulation was higher for smaller-bodied suspension feeding animals such as bivalves. However, biomagnification was not occurring in animal digestive tracts, and trophic dilution was demonstrated in fish livers. Trophic transfer was shown to occur between prey and predator for rockfish, but higher concentrations in full stomachs compared with empty ones suggested rapid excretion of ingested MPs. Chapter 5 supplies some general conclusions on the status of MPs in the British Columbian environment, as well as risks to seafood consumers. It also explores future work that will be needed to understand the complex ecotoxicology of MPs. / Graduate / 2022-04-12

Background: The current unsustainable situation of the seafood industry requires innovative solutions and there is an opportunity for companies to provide consumers with plant-based options which would enable them to eat seafood without harming the oceans. However, there are still several barriers keeping consumers from choosing plant-based products, such as limited knowledge, social norms, and cultural settings. Previous studies regarding how a cultural context and storytelling might be used to influence people towards more plant-based eating, especially relating to plant-based seafood are limited. Therefore, it is interesting to examine how companies offering plant-based foods can use culture and certain narratives held by consumers in their branding to integrate them into the Swedish culture and influence consumers towards a more sustainable consumption.   Purpose: The purpose of this study is to investigate what narratives influence consumers, and how companies offering plant-based food can use these narratives to drive a change towards more sustainable consumption among people in Sweden.   Method: Using a semi-structured approach, two focus groups were conducted and two different companies offering plant-based food were interviewed. Furthermore, this qualitative research uses an inductive approach, and the gathered data was later analyzed under a thematic analysis which was the foundation for the conceptual framework.   Conclusion: The myths and narrative towards plant-based substitutes are a noteworthy barrier to adoption, and cultural branding seems to be a favorable strategy for brands offering plant-based food. The findings suggest that culture and childhood experiences have a substantial influence on consumer demand for different types of foods, and that a change in dietary patterns requires a change in the surrounding cultural norms. Brands offering plant-based products need to understand the cultural norms of their target customers and leverage cultural contradictions to offer products that align with personal values.

The objectives of this research were to use trained sensory panels to identify key sensory profiling characteristics of freshwater prawns, develop and test price elicitation methods using the trained panels and gather freshwater prawn pricing information. Prawns were procured through a reputable producer and delivered to the Department of Food Science, Nutrition & Health Promotion at Mississippi State University. A trained sensory panel was utilized to develop descriptive terms to express key attributes of freshwater prawns. Trained panelists evaluated both raw and cooked product forms for 40 and 83 attributes, respectively. At the end of the sensory evaluation of the products, trained panelists also completed a willingness-to-pay ballot. Results determined sensory attributes for both raw and cooked prawns and the value of the raw product form.

Numerous food-borne illnesses are associated with fish and shellfish annually due to consumers choosing to eat seafood raw or undercooked and consumers not properly handling and preparing seafood. The 2009 FDA Food Code suggests intact fish and shellfish should be cooked to an internal temperature of 63°C to target Salmonella spp. Selected fish and shellfish were cooked to 64°C ± 1 and 74°C ± 1 and evaluated for consumer acceptability, characteristics of doneness at temperature endpoints, and physical changes of texture (TPA, KSC, and WB), color, and cook loss. Temperature endpoints represented the recommended internal temperature and ten degrees higher to increase lethality of Salmonella spp. Differences (p < 0.05) in texture were determined among the methods and products tested. However, consumer acceptability (n = 50) for fish and shellfish products (salmon: baked, poached; tilapia: baked, pan-fried; and shrimp: boiled) cooked to 64°C ± 1 and 74°C ± 1 were liked equally (p > 0.05), with mean hedonic scores falling between 6 (like slightly) and 7 (like moderately). A trained descriptive panel (n = 7) reviewed visual and non-oral texture indicators of doneness to distinguish 64°C ± 1 and 74°C ± 1. Firmness and shape of shrimp, separation between muscle flakes and fillet edge color of baked tilapia, and firmness and edge color of the fillet for baked salmon were identified as indicators to determine doneness. Overall, 74°C could be recommended as the internal temperature for cooking fish/shellfish such as salmon, tilapia, and shrimp without diminishing eating quality or acceptability. / Master of Science in Life Sciences

While investigating the gruesome death of a marine biologist, a by-the-book biracial detective and a jaded Tribal officer uncover a conspiracy surrounding a sea cucumber poaching ring on the reservation. Inspired by actual events.

Consumers regularly decide to consume fish and shellfish raw or undercooked, which can cause foodborne illness due to product contamination or unsafe handling by the consumer.  In order to be considered safe for consumption, intact fish and shellfish should be prepared to an internal temperature of 63"C, according to the 2009 FDA Food Code, with Salmonella spp. as the target organism.  Focus groups (5 groups, 32 participants) were conducted to determine consumer beliefs and concerns regarding fish and shellfish safety and preparation.  Transcripts of focus groups where coded for themes, which were then grouped into categories.  Nine categories emerged including:  experience, trust, confidence, quality of product, motivation, concerns, cooking procedures, cooking instructions, and knowledge.  Emerging themes were used to help develop educational materials to increase consumer ability to properly prepare fish and shellfish.  In a separate experiment, participants (n=6) cooked salmon (baked, broiled), tilapia (baked, broiled), and shrimp (broiled, boiled) according to cookbook-based directions.    Internal temperatures of products were recorded, with 33.3% of products cooked to a temperature less than 63"C.  A group training session was held, during which participants received additional visual and non-oral cues to determine when products were prepared to 63"C and safe food handling practices.  After training, participants prepared the same products.  Participants demonstrated improved food safety behaviors and were more successful at cooking products to temperatures "63"C (94.4% of products).  Improved cooking instruction and educational materials may reduce the risk of foodborne illness from undercooked fish and shellfish. / Master of Science in Life Sciences

Yes / The seAFOod polyp prevention trial was a randomised, placebo-controlled, 2 × 2 factorial trial of aspirin 300 mg and eicosapentaenoic acid (EPA) 2000 mg daily in individuals who had a screening colonoscopy in the English Bowel Cancer Screening Programme (BCSP). Aspirin treatment was associated with a 20% reduction in colorectal polyp number at BCSP surveillance colonoscopy 12 months later. It is unclear what happens to colorectal polyp risk after short-term aspirin use. To investigate colorectal polyp risk according to the original trial treatment allocation, up to 6 years after trial participation. All seAFOod trial participants were scheduled for further BCSP surveillance and provided informed consent for the collection of colonoscopy outcomes. We linked BCSP colonoscopy data to trial outcomes data. In total, 507 individuals underwent one or more colonoscopies after trial participation. Individuals grouped by treatment allocation were well matched for clinical characteristics, follow-up duration and number of surveillance colonoscopies. The polyp detection rate (PDR; the number of individuals who had ≥1 colorectal polyp detected) after randomization to placebo aspirin was 71.1%. The PDR was 80.1% for individuals who had received aspirin (odds ratio [OR] 1.13 [95% confidence interval 1.02, 1.24]; p = 0.02). There was no difference in colorectal polyp outcomes between individuals who had been allocated to EPA compared with its placebo (OR for PDR 1.00 [0.91, 1.10]; p = 0.92). Individuals who received aspirin in the seAFOod trial demonstrated increased colorectal polyp risk during post-trial surveillance. Rebound elevated neoplastic risk after short-term aspirin use has important implications for aspirin cessation driven by age-related bleeding risk. ISRCTN05926847. / Efficacy and Mechanism Evaluation Programme. Grant Number: NIHR128210.

Yes / Aspirin and eicosapentaenoic acid (EPA) reduce colorectal adenomatous polyp risk and affect synthesis of oxylipins including prostaglandin E2. We investigated whether 35 single nucleotide polymorphisms (SNPs) in oxylipin metabolism genes such as cyclooxygenase [PTGS] and lipoxygenase [ALOX], as well as 7 SNPs already associated with colorectal cancer (CRC) risk reduction by aspirin (eg. TP53; rs104522), modified the effects of aspirin and EPA on colorectal polyp recurrence in the randomised 2x2 factorial seAFOod trial. Treatment effects were reported as the incidence rate ratio (IRR) and 95% confidence interval (CI) by stratifying negative binomial and Poisson regression analyses of colorectal polyp risk on SNP genotype. Statistical significance was reported with adjustment for the false discovery rate as the P and q value. Five hundred and forty-two (of 707) trial participants had both genotype and colonoscopy outcome data. Reduction in colorectal polyp risk in aspirin users compared with non-aspirin users was restricted to rs4837960 (PTGS1) common homozygotes (IRR 0.69 [95%CI 0.53,0.90]; q=0.06), rs2745557 (PTGS2) compound heterozygote-rare homozygotes (IRR 0.60 [0.41,0.88]; q=0.06), rs7090328 (ALOX5) rare homozygotes (IRR 0.27 [0.11,0.64]; q=0.05), rs2073438 (ALOX12) common homozygotes (IRR 0.57 [0.41,0.80]; q=0.05), and rs104522 (TP53) rare homozygotes (IRR 0.37 [0.17,0.79]; q=0.06). No modification of colorectal polyp risk in EPA users was observed. In conclusion, genetic variants relevant to the proposed mechanism of action on oxylipins are associated with differential colorectal polyp risk reduction by aspirin in individuals who develop multiple colorectal polyps. SNP genotypes should be considered during development of personalised, predictive models of CRC chemoprevention by aspirin. / Funder(s): Efficacy and Mechanism Evaluation Programme (EME) Award Id(s): NIHR128210. Funder(s): NIHR Senior Investigator grant. Funder(s): Cancer Research UK (CRUK) Award Id(s): C23434/A24939. Funder(s): European Union-BBSRC (UK) Award Id(s): BB/P028233/1.

Seafood transportation/distribution has become an important activity in the seafood industry due to increasing global demand for fresh seafood. Providing good quality seafood to consumers requires appropriate handling and packaging technology. The purpose of this research is to study the effect of various combinations of insulation and coolant quantities on temperature distribution within a seafood shipping container and packaging cost. A three-dimensional transient heat transfer model was developed to predict the temperature distribution in a fish shipping container. The finite element method was used to develop the model. An eight-noded isoparametric hexahedron element was selected. The geometric configuration of the fish shipping container and the physical and thermal properties of the materials used for packaging were the input parameters of the model. The model validation was performed in two stages to ensure component-wise validation. The first stage was for the case with no ice. The second stage was for the case with ice. The results from the model were compared to those obtained through experiments. Predicted and observed temperatures showed good agreement. The temperature predictions were within 2 °C for the case with no ice and 3 °C for the case with ice. The effect of a polyethylene/aluminum foil laminated bag on the temperature distribution in the shipping container was studied for the case with no ice. The temperatures of high density polyethylene, which simulated fish, were reduced by approximately 3 °C (maximum) due to the low emissivity of aluminum foil. The model was applied to study the effect of various combinations of insulation and coolant quantities on the temperature distribution and the packaging cost. It was found that the fish container with 1.70 cm thick polystyrene and 10 kg of ice can be used for a required shipping time of 24 hours whereas the fish container with 2.54 cm thick polystyrene and 10 kg of ice can be used for a required shipping time of 48 hours under the simulated transport conditions used in this study. / Ph. D.