No description available.

No description available.

The purpose of this research was to determine the feasibility of pasteurizing crabmeat in retort pouches compared to cans. Retort pouches and cans were packed with various amounts of crabmeat, pasteurized to an internal temperature of 185°F (85°C) for 1 min, and subsequently cooled. The criteria for evaluation were total processing time, process lethality (F value), microbiological stability and sensory evaluation. Pasteurizing crabmeat in retort pouches resulted in total processing times that were significantly less (P ≥ 0.05) than cans. Also, pasteurizing to targeted F values provided a more rapid and efficient way to achieve equivalent processes. Thus, equivalent can processes were given to pouches in significantly less (P ≥ 0.05) time. Microbial loads were reduced by greater than 99% in both pouches and 65 cans following pasteurization to a target F value (F⁶⁵₁₈₅ = 24). This reduction was maintained during 6 months storage at 36°F (2.2°C). Sensory evaluations conducted over a 6 month period indicated no real preference for crabmeat packaged in retort pouches or cans. However, crabmeat packed in pouches was significantly better (P ≥ 0.05) on some weeks. Hedonic scores indicated meat in both types of containers were acceptable for the duration of the study. It was concluded that packaging and pasteurizing crabmeat in retort pouches is an acceptable, if not superior, method of pasteurization. / Master of Science

In response to water quality deterioration caused by clam processing effluent, the Virginia State Water Control Board is imposing much greater effluent discharge limitations on the industry. Meeting these limits will require increased wastewater treatment and decreasing the water volume of water used and the loading of organic material and suspended solids. Disposal of sludges and solid wastes also present problems to the industry. Three processing plants were studied to characterize the nature, sources and variations in waste generation and to evaluate potential solutions. Wastewater is generated throughout the processing plants from washing operations, from splashing and overflow of tanks and flumes and from cleanup operations. Wastewater generation varied from plant to plant and at each plant over time, ranging from 80,000 gallons to almost 350,000 gallons per day and as high as 40,000 gallons per hour. The organic loading in wastewater ranged as high as 15,000 mg/L COD and averaged 3000-7000 mg/L. Total suspended solids loading ranged as high as 29,000, and were usually between 1,000 and 10,000 mg/L. Anaerobic digestion and composting of solid wastes were evaluated by bench scale experiments. Anaerobic digestion can provide reduction in COD of 75% and generate usable biogas. Composting can be used to stabilize sludges and solid wastes with destruction of the organic fraction in seven days. The proposed 90 mg/L BOD and 90 mg/L TSS limitations are not significantly stricter than the limitations imposed on similar plants in other areas. / Master of Science

Least cost formulations for surimi seafood were studied by linear programming (LP) and nonlinear programming (NLP). The effects of water and starches on functional properties of Alaska pollock and Pacific whiting surimi gels were investigated. Six starches (modified potato starch, potato starch, modified wheat starch, wheat starch, modified waxy corn starch, and corn starch) and their mixtures were used as ingredients. Mixture and extreme vertices design were used as experimental designs. Canonical models were applied to the optimization techniques. Blending different kinds of surimi showed linear trends for each functional property, so that LP was successfully employed to optimize surimi lots. Strong interactions were found between surimi and starch or in starch mixtures. Two optimum solutions, obtained from LP and NLP, were compared in this study. Corn starch and modified waxy corn starch greatly improved the functional properties. / Graduation date: 1997

Four experiments were conducted with crab processing waste. Addition of 1.5% propionic/formic acid prevented degradation up to 14 d. Desirable fermentation was achieved when 32% of the treated crab waste was ensiled with 32% straw, 16% molasses, and 20% water with or without .1% microbial inoculant. The pH of the silage was lowered and high concentration of lactic acid was observed. Use of .2% NaOCl or .4% H₂O₂ retarded spoilage of crab processing waste up to 7 d. Ensiling of the treated waste (32%), straw (32%), molasses (16%), and H₂0 (20%) indicated that the chemical used in preservation enhanced fermentation. Addition of .4% NaOCl and 1.5% acetic acid to the crab processing waste retarded degradation up to d 4. The trimethylamine (TMA) concentration and NH₃ evolution were highest for the untreated waste while the lowest concentration for TMA and NH₃ evolution were observed for the NaOH-treated waste. Addition of 1% NaNO₂ or combination of .4% NaOCl/CaOCl (1:1, w/w) preserved the waste for up to 10 d. The evolution of NH₃ and H2₂S, and TMA concentration were lowest for the waste treated with 1% NaNO₂. Apparent digestibility of DM, organic matter, CP, energy, NDF, ADF, cellulose and hemicellulose decreased linearly (P<.01) with level of crab waste-straw silage in diets containing 0, 50, and 100% crab waste-straw silage. Nitrogen retention increased linearly (P<.05) with level of crab waste-straw silage. The apparent absorption was higher (P<.01) and retention was positive (P<.05) for Ca, Mg, Na, K, Cu and Fe with sheep fed the highest level of crab waste-straw silage. Daily gain, feed efficiency and carcass characteristics tended to be higher for steers fed 30% crab waste-straw silage, dry basis. The flavor and overall desirability of cooked meat were not adversely affected by feeding up to 30% crab waste-straw silage, dry basis. Modifying the existing methods of quantifying chitin showed that initial decalcification or deprotinization of the samples with chemicals are not necessary. Similar values were obtained for chitin when ADF/ashing method was compared to the ADF/deacetylation method. These methods prevented loss of chitin during preparation. Digestibility of chitin was higher (58%) for sheep fed 100% crab waste-straw silage compared to the value of 37% in sheep fed 50% crab waste-straw silage. When ADF/ashing method was used in quantifying chitin, higher disappearances were obtained for samples containing 100% crab meal kept in the rumen or incubated in vitro for 72 h. / Ph. D.

Thesis (M.A.)--Memorial University of Newfoundland, 2005. / Bibliography: leaves 148-162.

The research pursued relates to the establishment of interrelationship between various factors affecting chitin extraction, and combination of optimum levels of factors required to maximize the yield of chitin extraction. Optimization of chitin extraction was carried out using crab, lobster, and shrimp solid wastes. The study was divided into two stages: (a) optimization of chitin extractability with respect to particle size; (b) optimization of demineralization and deproteinization stages in lobster chitin extraction using Response Surface Methodology. Particle size had a significant effect on crab and lobster chitin extractability; a particle size of 2.0mm gave the highest yield in chitin extraction. The mean yield of chitin from crab and lobster at particle size of 2.0mm were 28.8% and 23.2%, respectively. Shrimp chitin extractability was not affected by particle size with the mean yield being 25.2%. Response Surface Methodology was used to determine simultaneous effects of (a) concentration of extractant; (b) shell:extractant ratio; (c) temperature of extraction; and (d) time of extraction on deproteinization and demineralization stages of chitin extraction and hence yield of chitin. All variables had an effect on demineralization and deproteinization yields. Maximum demineralization was predictable by a multi-factor model consisting of a combination of concentration of HCl, shell:extractant ratio, temperature and time of extraction. (Abstract shortened by UMI.)

JS McMillan Fisheries Ltd. (JSM) is a Vancouver-based company with operations in nearly all levels of the commercial fishing industry, from supply through distribution. The heart of the operation is the processing facilities where freshly caught Pacific salmon are prepared for sale to end consumers and institutional buyers. As the operations of JSM evolved, the decision making for allocating a catch of salmon with varying characteristics amongst a set of final products has become too complex and time consuming. The focus of this study is to determine an effective and efficient method for JSM to allocate daily a fresh salmon harvest between the various products they produce on a daily basis. The goal is short-term production planning, to allocate the catch among the products in such a manner that the profit potential of the catch is maximized, i.e. prepare a production schedule that maximizes the total profit over the planning horizon. Additional goals of this project include: automation of the decision making process for the catch allocation, "what if" planning, decreasing expert dependency, reducing decision making time, and building a practical and innovative decision support tool. In order to solve this problem efficiently and effectively, optimization models were developed for allocating the catch to the end products. A corresponding decision support tool was built for the end-users at JSM.

Chitin is a polysaccharide found in abundance in the shell of crustaceans. In this study, chitin was first extracted from shrimp waste material previously demineralized, using proteolytic enzymes, i.e., chymotrypsin and papain. The conditions used for the deproteinization were optimized with respect to 3 factors, viz., pH, temperature, and enzyme to waste (E/W) ratio, using response surface methodology (RSM). / In a second part of the study, chitosan was prepared from chitin by partial deacetylation and its capacity to preserve whole and headless fresh shrimps was evaluated. The shrimps (Pandalus borealis) were dipped in chitosan (1 and 2% w:v), and stored on ice. Chemical indicators such as pH, drip loss, total volatile bases (TVB), nucleotide degradation, and sensory indicators of appearance (including melanosis) and odor, as well as total microbial counts were monitored during 20 days. / As a third and final part, the antimicrobial properties of chitosan were evaluated using several microorganisms implicated in food spoilage and/or food poisoning outbreaks, especially those associated with fish and seafood products. Chitosan prepared from crab offal and used in the previous study on shrimp preservation was compared with commercially available chitosan from Sigma Chemical Co. (St-Louis, MO). (Abstract shortened by UMI.)