聚磷酸盐在单冻鱿鱼肉片生产中的应用

本文通过试验和方差分析,研究了不同盐类及其浓度和浸泡时间对鱿鱼肉片保水性的影响。结果表明,鱿鱼肉片的最适保水工艺条件是:食盐浓度0.5％,三聚磷酸盐0.5％,浸泡时间7-8h。     

Effects of the extensive culture system as finishing production strategy on biometric and chemical parameters in rainbow trout

The effect of finishing extensive farming period, to reduce fat content and manipulate the fatty acid profile of fish muscle, was evaluated in rainbow trout. Fish were stocked in an artificial lake, in which fish were fed only on naturally available nutrients with no supply of artificial feed, for different lengths of time from 0 to 120 days. No weight loss was noted during the whole finishing period while total length increased from 228±7 to 269±3 mm and the condition factor decreased from 1.41±0.04 to 0.89±0.02. The total fat content of the fillets decreased considerably from 4.7±0.6% at the beginning to 2.4±0.4% and 0.7±0.2% after 45 and 120 days respectively. Fillet fatty acid composition was affected by the time of stocking in the extensive farm. In contrast to the reduction in C18:1n‐9, C18:2n‐6, total monounsaturated fatty acid and total n‐6 percent values, an increase in the C20:5n‐3, C22:6n‐3, total polyunsaturated fatty acid and total n‐3 percent values was observed. It was shown that while other finishing strategies for salmonids have some disadvantages, the extensive culture system seems to be a potentially useful tool for increasing the general quality of the end product.     

Use of bioluminescent Salmonella enterica serovar Enteriditis to determine penetration in tumbled and hand-tumbled marinated chicken breast fillets

Migration of bacteria into tumbled chicken breast fillets was investigated using a bioluminescent strain of Salmonella Enteriditis. Tumbling (6 rpm; 0 to 30 min) resulted in the introduction of bacteria into the muscle interior at every time period measured and at a higher frequency (72%) than marination (38%; samples placed in brine, and manually turned every 2 to 3 min) alone. The frequency of penetration was greatest after 20 min for the marinated meat and after 30 min for the tumbled chicken breast fillets. The results illustrate the usefulness of the bioluminescent method to track bacterial migration and compare processes such as tumbling and marinating.     

Fillet Quality and Processing Attributes of Postsmolt Atlantic Salmon,Salmo salar,Fed a Fishmeal‐free Diet and a Fishmeal‐based Diet in Recirculation Aquaculture Systems

Many studies have evaluated the adequacy of alternate ingredient diets for Atlantic salmon, Salmo salar, mainly with focus on fish performance and health; however, comprehensive analysis of fillet quality is lacking, particularly for salmon fed these diets in recirculation aquaculture systems (RAS). To this end, a study was conducted comparing fillet quality and processing attributes of postsmolt Atlantic salmon fed a fishmeal‐free diet (FMF) versus a standard fishmeal‐based diet, in replicate RAS. Mean weight of Atlantic salmon fed both diets was 1.72 kg following the 6‐mo trial and survival was >99%. Diet did not affect (P > 0.05) processing and fillet yields, whole‐body proximate composition(fat, moisture, protein), fillet proximate composition, cook yield, fillet texture, color, or omega‐3 fatty acid fillet content, including eicosapentaenoic acid and docosahexaenoic acid levels. Whole‐body ash content was greater in salmon fed the FMF diet. The FMF diet resulted in a wild fish‐in to farmed fish‐out ratio of 0:1 per Monterey Bay Aquarium's Seafood Watch criteria due to its fishmeal‐free status and use of lipids from fishery byproduct. Overall, fillet quality and processing attributes were generally unaffected when feeding a diet devoid of fishmeal to postsmolt Atlantic salmon cultured in RAS. [Correction added on 7 September 2017, after first online publication: the P value in Abstract has been changed from “P < 0.05” to “P > 0.05”.].     

Dummy regression analysis for modelling the nutritionally tailored fillet fatty acid composition of turbot and sole using gilthead sea bream as a reference subgroup category

Farmed turbot and sole were sampled at different stages of the production cycle for analysis of fillet lipid content and fatty acid (FA) composition. The entire data set along with our own published data on gilthead sea bream were fitted to dummy regression equations with turbot and sole as dummy variables, gilthead sea bream as a reference subgroup category, and diet FA composition and fillet lipid content as independent variables. The relative contribution of each independent variable to the total variance was found to vary within and among FAs and fish species, but strong correlation coefficients (0.76 <  r² > 0.99) were found for almost all of the FA equations, including saturated FAs, monoenes and long‐chain polyunsaturated fatty acids (PUFA) of n‐3 and n‐6 series. Given the differences in lipogenic activities of the fish species, major interaction effects between fillet lipid content and dummy variables were found for monoenes and saturated FAs. The proposed equations (hosted at www.nutrigroup-iats.org/aquafat ) were able to fit different proportions of EPA, DPA and DHA underlying the fish species differences in FA desaturation/elongation pathways. The robustness of the model was proven with extra data from the three fish species, allowing a close linear association near to equality for the scatter plot of observed and predicted values.     

Bleeding of Farmed Atlantic Cod: Residual Blood,Color, and Quality Attributes of Pre- and Postrigor Fillets as Affected by Perimortem Stress and Different Bleeding Methods

The main objectives of the study were to (a) assess the effect of perimortem stress on blood drainage, (b) compare the efficiency of gill cutting and direct gutting as bleeding methods, and (c) compare pre- and postrigor filleting strategies for presence of residual blood in Atlantic cod fillets. Anesthetized cod had significantly higher drainage of blood compared to stressed fish. Nevertheless, the visual assessments of residual blood were not affected by stress or bleeding method. Some minor, but significant, differences between pre- and postrigor fillets were found. Stressed fish were initially less light in color than those unstressed, but after ice storage there was no noticeable difference. However, initially, the largest difference in fillet color was due to different bleeding methods. Fillets cut from fish subjected to gill cutting were lighter and less red in color than those bled by direct gutting. After 7 and 21 days of storage, the color differences observed in fresh and salted fillets, respectively, were mainly due to the different rigor status when they were filleted, indicating that fillets cut postrigor were superior to fillets cut prerigor. Prerigor filleting resulted in lower water holding capacity after ice storage in anesthetized, direct gutted cod.     

Effects of Phosphate Type on the Quality of Vacuum-Tumbled Catfish Fillets

The objective of this study was to determine the effects of various agglomerated phosphate blends on the quality of vacuum-tumbled catfish fillets. Catfish fillets were tumbled with a brine solution at 15% over initial, raw weight prior to tray-packing and storage at 4°C for 10 days. Fillets were evaluated for protein exudate, tumbling yield, color, pH, cooking loss, tenderness, purge loss, and shelf life. A specific blend of agglomerated sodium phosphates (AGSP) that contains mono-, tri-, and polyphosphates had significantly less protein (p < 0.05) exudate and significantly higher pH (p < 0.05) than other treatments. All phosphate treatments significantly increased (p < 0.05) tenderness and significantly decreased (p < 0.05) purge loss, but agglomerated phosphate blends significantly decreased (p < 0.05) cooking loss and yellowness. Psychrotrophic plate counts for all phosphate treatments were similar to the control at each storage time. All phosphate treatments improved the yield and quality of catfish fillets, but the use of AGSP may optimize quality attributes.     

Tub gurnard Chelidonichthys lucerna L.: a new fish species suitable for farming? First answers evaluating the growth of juveniles reared at different stocking densities,welfare and fillet quality

A trial was conducted to evaluate the growth performance and survival of Chelidonichthys lucerna. A total of 13 352 180‐days old juveniles (5.5 ± 2 g; 5 ± 1 cm) were reared at two different densities (A‐EXP = 68 fish m^?3; B‐FFA = 15 fish m^?3) in eight tanks (four tanks per group) for 360 days. The welfare status and meat quality of fish were evaluated for the A‐EXP and B‐FFA groups in comparison with wild‐caught fishery gurnard (C‐WID). The survival rate was high for both A‐EXP (79%) and B‐FFA (93.5%). B‐FFA fish had the highest specific growth rate (1.16 vs. 1.07; P < 0.05), and were heavier than A‐EXP fish (321 ± 40 g vs .239 ± 44 g; P < 0.01). Rearing conditions did not affect blood metabolites, except for glucose concentrations, which were higher in C‐WID (P < 0.05). The meat quality traits showed that reared groups were fatter (2.8–3.2%) than C‐WID (0.94%); total n‐3 fatty acids (19.02–19.26%) were lower in reared groups than C‐WID (29.99%); and EPA + DHA were similar in all groups (15.1–16.61% vs. 27.99%). Despite the good growth and survival, the final mean weight was below that requested by the market (400–500 g). Future research efforts should focus on reducing the feed conversion rate (3:1).     

罗非鱼片在食盐溶液中的渗透脱水规律研究

研究了质量分数(10%、20%、30%)、温度(10、20、30℃)及厚度(3、5mm)对罗非鱼片在食盐溶液中的渗透脱水和盐吸收量随渗透时间而变化的影响规律。试验结果表明,鱼片的脱水量及盐的吸收量均随渗透温度的升高而增加。食盐的质量分数是决定鱼片是否脱水的关键因素,鱼片在10%的食盐溶液中表现为吸水,而在质量分数超过20%的食盐溶液中表现为脱水,质量分数越高,则鱼片失水量越多,同时溶质获得量也越高。较薄鱼片的渗透脱水和溶质获得量均高于较厚鱼片。     

Quality of raw and smoked fillets from clinically healthy Atlantic salmon,Salmo salar L., following an outbreak of pancreas disease (PD)

Pancreas disease (PD) is a viral disease of farmed salmonid fish, which causes huge economic losses. Pathological changes in skeletal muscle, pancreas and heart are hallmarks of PD. Stakeholders in the fish‐smoking industry have claimed that fillets from PD‐affected Atlantic salmon, Salmo salar L., are of poor quality. We therefore examined harvest‐ready, clinically healthy Atlantic salmon from a population of fish previously affected by PD. Histopathological changes in skeletal muscle tissues ranged from minor to severe. Fillet quality measurements showed that fish with severe skeletal muscle changes provided a paler raw fillet and a yellowish and harder cold‐smoked fillet than normal. PD had no significant effect on fillet gaping, bacteriological quality or off‐odour development during storage. An unexpected finding was a significant subendocardial fibrosis in 23% of the PD‐affected fish. The latter may indicate susceptibility to stress‐related heart failure.