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There have been tremendous changes in aquatic food products over the past 25 years based on seafood research. The future of seafood research over the next 25 years is difficult to predict, but the ...

A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method for salmon species identification was optimized for use with U.S. commercial products. Reference specimens of six salmonid species were collected and morphologically verified. A 463- to 464-bp fragment of the mitochondrial tRNAGlu/cytochrome b gene was PCR-amplified, digested with two restriction enzymes (Sau3AI and NlaIII), and analyzed with agarose gel electrophoresis. All six species were successfully differentiated with this method and the restriction digest was shortened to 1 h rather than overnight. A decision-making flowchart was developed based on these results that allows for species diagnosis within two–three steps. After the method was optimized, it was tested with a variety of commercial salmon products (n = 29), including canned, smoked, jerky, and fresh fillet samples. Salmon species identification was successful for all 14 smoked and fresh/frozen fillet products, with the possibility of same-day species d...

Changes in the fatty acid composition of 13 bled and blast-frozen U.S. West Coast albacore tuna (Thunnus alalunga) were determined following custom-canning and 5 weeks of canned storage. In accordance with typical custom-canning procedures, no additional packing materials were used, and the product did not undergo a precooking step. Raw albacore tuna was found to be rich in n-3 polyunsaturated fatty acids (PUFAs), with an average of 9.1% (% wt of total fatty acids) EPA and 33.8% DHA. Canning and short-term storage did not cause major fluctuations in the fatty acid profiles of the albacore tuna, with no significant changes in the total fractions of saturated fatty acids (30–31%), monounsaturated fatty acids (19%), PUFAs (50%), or n-3 PUFAs (46–47%). On a tissue weight basis, U.S. West Coast albacore tuna was found to contain high levels of total n-3 PUFAs, with 3.3 g/100 g tissue in raw tuna and 4.0–4.1 g/100 g tissue in products that were canned and stored for 5 weeks.

The effects of processing and storage on cadmium (Cd) levels in Pacific oysters (Crassostrea gigas) were examined. The oysters were 2.75 yrs old and were analyzed for Cd at various points in the processing line including: shucked (S), shucked and drained (SD), and shucked, drained, washed and jar-packed (S-WJ). The effects of high pressure processing (HPP) followed by washing and jar-packing were also examined. Jar-packed oysters from groups S-WJ and HPP were held under refrigerated storage and were analyzed at 0, 5 and 10 days. Some processing methods had significant effects on the Cd levels in oysters. Draining nectar from the oysters resulted in significant increases in Cd concentrations, followed by significant decreases as a result of washing and jar-packing. HPP-treated oysters that were washed and jar-packed showed further decreases in Cd. Ten days of jar-packed storage resulted in a gradual decrease in wet weight Cd concentration for both the HPP (from 1.1 to 0.8 mg/kg) and the S-WJ group...

Intrinsic characteristics of sardines harvested off the Oregon-Washington coast were determined. The lipid content was initially low (6.79%) in the beginning of the season in June, significantly increased to 22.95% in mid-August, and decreased slightly by the end of September. An inverse correlation (R2 = −0.90) was found between lipid and moisture content. Triacylglycerides were the predominant lipid fraction, while the phospholipids fraction was the lowest. Analysis showed that 20:5n3 was the most abundant fatty acid in sardine oil followed by 16:0 and 22:6n3 fatty acids. The level of 20:5n3 fatty acid was slightly higher in August-September than earlier in the season.

Two hundred and thirty-nine albacore tuna (Thunnus alalunga) were troll-caught in the mid-Pacific Ocean and off the US Pacific Coast from June to November 2003. Catch location, harvest date, and sea surface temperature were recorded for individual fish, and lipid and moisture content in the white muscle were determined. The average weight of the alba-core was 6.07 kg and lipid content was highly variable (0.67–18.74%). There was an inverse correlation between the lipid and moisture content of albacore (R2 = 0.93), and percent lipid increased slightly in fish caught later on in the season (R2 = 0.24). Geographical Information Systems (GIS) software was used to determine correlations between lipid content and geographic location. Lipid content varied considerably among tuna caught at similar latitudes; however, most fish caught below 40°N had a lipid content of less than 10%, while the fish with the highest lipid content (13–19% lipid) were all harvested above 40°N.

High Pressure Processing (HPP) run at 275 and 310 MPa for 2, 4, and 6 min and heat treatments at 90°C for 35 min were applied to minced albacore muscle (Thunnus alalunga). Effects on protein solubility, thermal stability, total sulfhydryls and fluid retention were measured. Treatments reduced (p < 0.05) protein solubility, with heat showing an 89% reduction versus 60.3 ± 5.3% reduction for HPP treatments. HPP increased thermal stability of most proteins, shifting their endotherms towards higher temperatures, but only myosin showed an enthalpy change higher than control. Heated proteins did not exhibit an endotherm peak indicating total protein denaturation and showed less total sulfhydryl content and the highest liquid holding capacity (p < 0.05).

Mercury is a toxic heavy metal released into the environment from both natural and anthropogenic sources. It is of great interest to consumers as to whether it can cause neurological effects at low dose levels. The effects of organic mercury exposure at high levels have been demonstrated in several large-scale poisonings, particularly those in Japan and Iraq in the 1950s, ′60s and ′70s. These epidemics showed that organic mercury, in sufficient concentrations, is a potent neurotoxin that is especially harmful to the developing nervous system. Since the most common form of human exposure to organic mercury is through fish consumption, several epidemiological studies have examined the relationship between maternal fish intake and health effects in humans, especially the fetus. Levels of mercury in fish vary depending on factors such as: trophic level in the food chain, size, and habitat location. For this reason, it is important to gather information on mercury levels in different types of fish in ...

The acid soluble collagens (ASC) and pepsin soluble col-lagens (PSC) of albacore tuna and silver-line grunt skin, by-products from frozen fish fillet industry, had been extracted, purified and characterized. Analysis of the collagens by SDS-PAGE indicated the absence of a disulfide bond, which is a characteristic of type I collagen. They also contained different subunits, a, β and ?. At least two different a chains, a1 and a2, were presented. The proportion of ? trimer in ASC was higher than in PSC. This caused reduced solubility of ASC, whereas, PSC were lower molecular weight and had fewer crosslinks, which resulted in increased solubility. Collagen water solubility was lower than in 0.5 M acetic acid, but the solubility increased as the temperature increased. Denaturation temperature (Td) of silver-line grunt collagen was slightly higher than albacore tuna collagen, but about 7–9°C lower than calfskin collagen.

Electron beam (e-beam) irradiation to reduce spoilage bacteria and Listeria monocytogenes on cold-smoked salmon was studied. Salmon fillets were inoculated with L. monocytogenes (4.4 × 103CFU/g) and exposed to e-beam radiation at doses of 1, 2, and 4 kGy. The e-beam irradiated samples were stored at 5>C and tested for psychrotrophs, mesophiles, and L. monocytogenes on days 1, 8 and 28. Total bacterial populations on cold-smoked salmon were reduced by e-beam processing but increased during storage. inoculated salmon were reduced by 2.5 log CFU/g with a low e-beam dose of 1.0 kGy and were completely eliminated by e-beam doses of 2.0 kGy and greater. E-beam irradiation could be used to reduce bacterial contamination and increase safety of cold-smoked fish. Further studies are needed to evaluate the effects of e-beam irradiation on sensory characteristics of processed fish.

Intrinsic quality characteristics, including lipid, moisture, and fatty acid content, of West Coast albacore tuna (Thunnus alalunga) was investigated. West Coast albacore tuna were troll caught off the Oregon coast, delivered to the Oregon State University Seafood Laboratory, held at -30°C and analyzed for lipid distribution in different areas of the muscle. Additional albacore were troll caught off the Oregon coast and analyzed fresh for fatty acid content. Core samples were taken from six designated body zones of the fish. The lipid content ranged from 3.9 ± 0.2 to 36.3 ± 1.1%, with a distribution of higher lipid towards the head and lower lipid towards the tail. Total omega-3 content averaged approximately 40% of the identified fatty acids for each body zone, with average omega-3 (g/100 g tissue) ranging from 2.1 ± 0.5 to 3.5 ± 0.4. An inverse correlation (R2 = −0.95) was found for lipid and moisture content.

A trend in new food product development is the growing participation of chefs within an organizational framework known as Culinology(r). Culinology(r) is defined as the fusion of culinary/chef skills and technical/scientific skills. Combining culinary expertise with food science is expected to produce more creative and financially successful products. This concept paper develops ideas for embedding the culinary framework into a broader interdisciplinary and multisector system for designing and developing new food products from publicly managed natural resources. Initial results from implementing the first stage of this framework are provided for West Coast albacore tuna.

This study examines the possibility of using a hand-held ultrasonic device to provideinformation about the composition of North Pacific albacore (Thunnus alalunga). The ultrasonic velocity and attenuation coefficient (1-6 MHz) of albacore samples of varying composition was measured over the temperature range 5 to 30EC. The lipid, protein, ash and moisture content of the same fish were measured using standard methods. Ultrasonic velocity versus temperature profiles were dependent on fish composition and could therefore be used to provide information about composition. Ultrasonic attenuation measurements were too variable to use as a means of providing information about fish composition. The availability of a hand-held ultrasonic device that is simple to use would be useful for grading albacore according to their composition.

HACCP was implemented in the U.S. in December, 1997. A survey from the FDA Office of Seafood, after the first 6 months, showed mixed results regarding successful implementation. Four major issues have developed from the initial FDA inspections. They include: parasites in seafood, histamine monitoring, lethality of cook, and Clostridium botulinum in vacuum packed containers. This paper will summarize these issues focusing on presentations and discussions from the Seafood Hazard Analysis HACCP Research Meeting held in Astoria, OR, September 23-24, 1998.

Pacific whiting showed high levels of proteolytic activity compared with other species, i.e., rockfish and squawfish. A wide variation of activity was found in individual whiting. The level of protease activity was highly correlated with the number of white pseudocysts in the muscle. Although correlation of proteolytic activity with black pseudocysts was low, higher activity was observed in tissue infected with black pseudocysts when compared to tissue without black pseudocysts. The protease activity of intact flesh was decreased by 83% during surimi processing.

A consumer sensory evaluation of three types of fresh salmon (wild chinook, farmed chinook, farmed Atlantic) was undertaken. Eleven attributes related to flavor, texture and color were selected for analysis. Statistical tests showed that delicate/fresh fish flavor had the strongest effect in impacting overall enjoyment. A linear regression model was designed to determine the effects of eleven sensory attributes on enjoyment. Four flavor and two texture attributes were significant in impacting overall enjoyment. Results indicated that consumers were able to differentiate between the salmon types by several attributes.

Stabilized mince (SM) was made from fresh Pacific whiting mixed with varying levels of sucrose (6 to 12% w/w) including 0.2% w/w polyphosphates. SM samples were maintained in frozen storage and used at different time intervals for surimi production. Comparisons with control surimi made from fresh mince showed that acceptable surimi can be produced from SM stored at -20°C with cryoprotectant levels at 6% w/w sucrose and 0.2% w/w polyphosphates. There was a slight decrease in whiteness in surimi made from the SM samples when compared to the control. Surimi yields from SM were comparable to yields of surimi made from fresh mince.

The iced storage characteristics of freshwater Northern squawfish (Ptychocheilus oregonensis) were investigated and the proximate composition and physical nature of squawfish were determined. Quality changes were monitored over 24 days of storage by chemical, physical, microbiological, and sensorial methods of analysis. The Torrymeter readings, K values, and descriptive sensory evaluation demonstrated that squawfish kept well in ice for 15 days. The torsion test results showed that squawfish exhibited good gel forming ability and decreased only 10% of the original value after 24 days of iced storage. An evaluation of the methods used to assess fish quality was made.

The effects of varying concentrations of salt and pH on the gel strength of Pacific whiting (Merluccius productus) surimi were investigated. Surimi gels were made with and without the protease inhibitor beef plasma protein (BPP). Gel strength was measured by torsion and reported as shear stress and shear strain. In general, surimi gels increased in gel strength with increased pH. Stress increased to a greater degree than strain about pH 7. Water holding capacity values increased up to pH7 and than leveled off. Surimi gels made with low salt (0.9%) or not salt had greater stress values that the higher salt surimi gels in the alkaline pH range. The results demonstrated that the effects of salt and pH are interactive on gels strength for Pacific whiting surimi

The potential of using the torsion test and differential scanning calorimetry (DSC) to determine the effect of frozen storage on protein denaturation in fish fillets was investigated. Pacific whiting fillets were stored for 12 weeks at three temperature conditions: -20¦C, -8¦C, and at a level varying between 0 and -8¦C. Salt soluble protein (SSP) extractability and Ca++-ATPase activity were used to evaluate the torsion test and DSC. The shear strain value of the torsion test provided a good correlation with SSP extractability, Ca++-ATPase activity, and myosin transition enthalpy as measured by DSC. Therefore, shear strain can be considered as a useful tool for the determination of protein denaturation in Pacific whiting during periods of frozen storage. Because Ca++-ATPase activity, shear stress and shear strain, and myosin transition enthalpy all decreased within one week, protein deterioration in frozen Pacific whiting appears to be rapid at the temperatures tested.

(2007). Dr. Robert Price. Journal of Aquatic Food Product Technology: Vol. 15, No. 4, pp. 1-2.