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

No description available.

<p>För den som vill fiska i Strömmen är det bara att ta sitt fiskespö och gå dit, fisket har varit fritt för allmänheten sedan 1436. Men sportfisket är inte okontroversiellt, all lax och öring i Strömmen är inplanterad och hotar de naturliga fiskbestånden i länet. Och man bör akta sig - fiske kan vara beroendeframkallande.</p>

Anserine and carnosine are water-soluble dipeptides that have antioxidant properties and are found in the skeletal muscle of mammals and fishes. These dipeptides are removed through the washing process in surimi production. The objective of this research was to determine the concentration of anserine and carnosine in surimi wash water (SWW) at all stages of surimi processing, and undertake preliminary methods to remove and concentrate the two dipeptides and study the effect of surimi wash water extract on color. Wash water samples were collected from a local surimi plant. The samples were treated by the following methods: centrifugaion, heat-treatment at 60, 80 and 100°C and filtration using different ultrafiltration (UF) membranes. The concentrations of the protein and the two dipeptides were analyzed using Lowry and high performance liquid chromatography with a fluorescent detector, respectively. Iron content was determined in SWW samples using atomic absorption spectrometry and colorimetry. Effect of SWW extract and other antioxidants on the color of fresh-farmed salmon were studied using color parameters-hue angle, chroma and lightness. Results showed that there was a trend: content of protein and dipeptides (anserine and carnosine) in SWW (raw) was higher in the first two stages of surimi processing. In the second set of experiment, where different heat treatments were used, it was found that the proteins and dipeptides showed similar trends. Additionally, 80°C followed by 100°C treatment were effective in removal of proteins and recovery of dipeptides. Among UF treatments, 1K molecular weight cut-off membrane was the most effective in recovery of dipeptides. Iron was less than 1 ppm in all SWW samples. Color measurement of fresh farmed salmon patties revealed that treatments of SWW extract (1%) in addition to other food antioxidants such as butylated hydroxy toluene and camosine (1%), mamtained salmon color until day 5. Therefore, SWW extract at lower concentrations may have an economical and potential use as a food antioxidant. / Graduation date: 2000

Protein solubility of Pacific whiting muscle with isoelectric point at pH 5.5 was significantly affected by pH. The highest breaking force was measured from fish proteins treated at pH 11, while high deformation values were obtained at pH 2 and 11. Texture of gels made using the conventional method were quite inferior to gels made using fish proteins treated at pH 2 or 11, while color of conventional gels was significantly better than the other treatments. SDS-PAGE revealed that fish proteins were highly denatured during acid or alkali treatment. High cathepsin B-like activity was detected from acid-aided fish proteins. Strong cathepsin L-like activity was found in fish proteins treated at pH 10.5, which corresponded with the lower breaking force and deformation obtained from those samples. Disulfide bonds contributed to high texture value in fish proteins treated at pH 11. Physicochemical characteristics of sarcoplasmic proteins (SP) from rockfish and their interaction with Alaska pollock surimi (myofibrillar proteins) were investigated. Solubility of SP was significantly suppressed at acidic pH (2-4) plus high salt concentration (0.5 M NaCl). This was also supported by SDS-PAGE results (extensively degraded SP). DSC results revealed SP gave three endothermic transitions. The least amount ofproteins was lost when treated at pH 2 or 3 followed by precipitation at pH 5.5. SP did not enhance the gelation properties of myofibrillar proteins, but positively contributed to gelation with myofibrillar proteins when compared to sucrose. Myofibrillar proteins were primary components contributing to heat-induced gelation. Salt effect on acid- or alkali-treated surimi gel was investigated. Good gels were obtained without salt using acid- and alkali-treated fish proteins. Their texture properties decreased as NaCl content increased, unlike conventional surimi gels. Consequently, NaCl did not solubilize myofibrillar proteins once the fish proteins were treated by acid or alkali. Solubility was apparently not a key factor for the texture properties of acid- or alkali-treated surimi. Transglutaminase-mediated setting reaction was partially inactivated during acid or alkaline treatment. Acid-treated surimi gel gave the best color properties. / Graduation date: 2003

The effect of salt (0, 0.9, 1.7, 2.5%) and pH (range 4 to 10) on surimi gels made from Pacific Whiting (Merluccius productus) was investigated. Gel-forming ability was measured by the torsion test. In general, surimi gels increased in gel strength with increased pH. Breaking shear stress increased to a greater degree than breaking shear strain above pH 7.0. The increase in gel strength was greater at higher pHs for gels made without salt than those made with salt. At neutral pH, the salted surimi showed greater gel forming abilities than the unsalted whiting surimi. Poor gels were formed at low pH (pH 4 to 6) for both the salted and no-salt surimi. These results demonstrated that pH and salt concentration had an interactive effect on the gel-forming ability of the Pacific whiting surimi and that improved gel strength at low salt levels might be obtained by increasing the pH. / Graduation date: 1993

Thesis (Ph.D.)--University of British Columbia, 2004. / Adviser: Dianne Newell. Includes bibliographical references.

Thesis (Ph.D.)--University of British Columbia, 2000. / Adviser: Tony Pitcher. Includes bibliographical references.

För den som vill fiska i Strömmen är det bara att ta sitt fiskespö och gå dit, fisket har varit fritt för allmänheten sedan 1436. Men sportfisket är inte okontroversiellt, all lax och öring i Strömmen är inplanterad och hotar de naturliga fiskbestånden i länet. Och man bör akta sig - fiske kan vara beroendeframkallande.

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