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

M.S.

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

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.

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.

Yes / Background: The omega-3 polyunsaturated fatty acid eicosapentaenoic acid (EPA) and aspirin both have proof of concept for colorectal cancer chemoprevention, aligned with an excellent safety profile. Therefore, we aimed to test the efficacy of EPA and aspirin, alone and in combination and compared with a placebo, in individuals with sporadic colorectal neoplasia detected at colonoscopy. Methods: In a multicentre, randomised, double-blind, placebo-controlled, 2 × 2 factorial trial, patients aged 55–73 years who were identified during colonoscopy as being at high risk in the English Bowel Cancer Screening Programme (BCSP; ≥3 adenomas if at least one was ≥10 mm in diameter or ≥5 adenomas if these were <10 mm in diameter) were recruited from 53 BCSP endoscopy units in England, UK. Patients were randomly allocated (1:1:1:1) using a secure web-based server to receive 2 g EPA-free fatty acid (FFA) per day (either as the FFA or triglyceride), 300 mg aspirin per day, both treatments in combination, or placebo for 12 months using random permuted blocks of randomly varying size, and stratified by BCSP site. Research staff and participants were masked to group assignment. The primary endpoint was the adenoma detection rate (ADR; the proportion of participants with any adenoma) at 1 year surveillance colonoscopy analysed in all participants with observable follow-up data using a so-called at-the-margins approach, adjusted for BCSP site and repeat endoscopy at baseline. The safety population included all participants who received at least one dose of study drug. The trial is registered with the International Standard Randomised Controlled Trials Number registry, number ISRCTN05926847. Findings: Between Nov 11, 2011, and June 10, 2016, 709 participants were randomly assigned to four treatment groups (176 to placebo, 179 to EPA, 177 to aspirin, and 177 to EPA plus aspirin). Adenoma outcome data were available for 163 (93%) patients in the placebo group, 153 (85%) in the EPA group, 163 (92%) in the aspirin group, and 161 (91%) in the EPA plus aspirin group. The ADR was 61% (100 of 163) in the placebo group, 63% (97 of 153) in the EPA group, 61% (100 of 163) in the aspirin group, and 61% (98 of 161) in the EPA plus aspirin group, with no evidence of any effect for EPA (risk ratio [RR] 0·98, 95% CI 0·87 to 1·12; risk difference –0·9%, –8·8 to 6·9; p=0·81) or aspirin (RR 0·99 (0·87 to 1·12; risk difference –0·6%, –8·5 to 7·2; p=0·88). EPA and aspirin were well tolerated (78 [44%] of 176 had ≥1 adverse event in the placebo group compared with 82 [46%] in the EPA group, 68 [39%] in the aspirin group, and 76 [45%] in the EPA plus aspirin group), although the number of gastrointestinal adverse events was increased in the EPA alone group at 146 events (compared with 85 in the placebo group, 86 in the aspirin group, and 68 in the aspirin plus placebo group). Six upper-gastrointestinal bleeding events were reported across the treatment groups (two in the EPA group, three in the aspirin group, and one in the placebo group). Interpretation Neither EPA nor aspirin treatment were associated with a reduction in the proportion of patients with at least one colorectal adenoma. Further research is needed regarding the effect on colorectal adenoma number according to adenoma type and location. Optimal use of EPA and aspirin might need a precision medicine approach to adenoma recurrence. / Efficacy and Mechanism Evaluation Programme, a UK Medical Research Council and National Institute for Health Research partnership. / Research Development Fund Publication Prize Award winner, November 2018.