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1.
Changes in tissue structure and rheological properties of abalone meat with cold air drying and natural drying were studied. Natural drying took 168 h, while cold air drying took 120 h, which was 71% of natural drying. Nutrition loss of cold air drying abalone meat was less than that of natural drying samples. Muscle fibers in heated samples reassembled, and voids in muscular tissue extended. With drying time increasing, muscle fibers in abalone meat shrank, and the size of aperture among myofibrils decreased. While drying finished, myofibrils in cold air drying abalone meat had a homogeneous network structure, which was fit for water restoration. Rheological properties (elasticity modulus E, viscosity modulus η, and rupture strength) in heated samples were smaller than those in raw samples, while the relaxation time τ was greater. During the drying process, E, η, and rupture strength tended to increase, and the relaxation time τ had no significant regularity changes. Compared with natural drying, the cold air drying had more advantages in actual production as the drying time was shorter, and the drying process and sanitary conditions were easy to control.  相似文献   

2.
SUMMARY: In a study of the relationship between structural changes and rheological parameters of raw and cooked abalone meat, abalone Haliotis discus was cooked in boiling water for 3 h, then cut up and separated into cross- and vertical sections. Structural change was observed using a light microscope and scanning electron micrography. The rheological parameters were obtained by stress-relaxation experiments. Microscopic photography revealed that structural change between muscle fibers in both sections of the cooked meat was greater than that in the raw meat. The elastic modulus and rupture strength in both sections of cooked meat showed no difference between the cross- and vertical sections, and were smaller than those for the raw meat. The relaxation time for the cooked meat was also greater than for the raw meat. These results were mainly because of collagen being gelatinized during heating. These changes were also observed by staining collagen and differential scanning calorimetry.  相似文献   

3.
ABSTRACT:   Horse mackerel and tilapia surimi were subjected to six different heat and pressure treatments in order to compare gelation characteristics of easy- and difficult-setting gels, that is, temperature dependence, by observing rheological properties and microscopic molecular mobility. The stress–relaxation and proton spin–spin relaxation time (1H T 2) of water were measured for all treated gels. Horse mackerel gel demonstrated higher elasticity, large distribution of the stress–relaxation process, and smaller water 1H T 2 than tilapia in both heat and pressure treatments. The water 1H T 2 was steeply increased in the pressure treatment at around 294 MPa for both fishes. In contrast, the 1H T 2 rarely changed in the heat treatment in spite of the considerable change in rheological properties. From the experimental results, it is considered that the gelation of horse mackerel (easy setting) surimi is induced by highly unfolding and re-aggregation of protein, which contributes to the formation of a strong network structure compared with tilapia in both heat and pressure treatments, and that pressure treatments hardly improve the gel strength of tilapia (difficult setting) surimi. The water 1H T 2 measurement was used effectively in order to study gelation characteristics of easy- and difficult-setting fish through observing its molecular dynamics.  相似文献   

4.
Pharmacokinetics of oxolinic acid in gilthead sea bream, Sparus aurata L.   总被引：1，自引：0，他引：1  
This is the first study on the pharmacokinetic parameters of oxolinic acid (OA) in gilthead sea bream, Sparus aurata L. The kinetic profile of OA was studied after a single intravascular injection (20 mg kg−1) in 100 g fish at 20 °C. The distribution half-life ( t 1/2α) and the elimination half-life ( t 1/2β) of the drug were found to be short (0.51 and 12.60 h, respectively). The drug penetration from the plasma to the tissues was adequate as the apparent volume of distribution of the drug at steady-state ( V d(ss)) was found to be 2.11 L kg−1. The mean residence time ( MRT ) of OA was short (14.25 h) and the total clearance rate ( Cl T) of the drug was low (0.15 L kg−1 h−1). The bioavailability ( F %) of OA following oral administration (30 mg kg−1) was also low (14%). Maximum values were observed for muscle at 0.5 h after injection, with levels declining as with subsequent sampling. At the first two time points (0.5 and 1 h) plasma levels of OA were higher than muscle, however, the reverse was evident for subsequent samples. Following oral administration, highest muscle levels were found at 16 h and, with the exception of the 24-h sampling, muscle OA concentrations were higher than plasma at all time points. The fast elimination of OA suggests short withdrawal times with reference to human consumption of treated fish.  相似文献   

5.
Commercially, crab meat is obtained by hand-picking after a cooking process, followed by pasteurizing or canning. Jumbo lump is one of the pieces of meat obtained from the blue crab. The aim of this study was to evaluate the effect of the commercial cooking process (boiling and steaming) on the mechanical and functional properties of whole jumbo lump and the gels obtained from cooked and minced jumbo lump from blue crab (Callinectes sapidus). The gels were prepared combining the washing process and microbial transglutaminase. The boiling and steaming processes showed a different effect on the textural and color properties. Whole jumbo lump pieces cooked by immersion in boiling water showed a higher hardness value as compared to steamed jumbo lump pieces, suggesting a different internal structural. The cooking processes used in this study did not modify the water holding capacity, gelling capability, or color of the minced jumbo lump. The addition of microbial transglutaminase to washed minced jumbo lump improved the hardness, cohesiveness, and chewiness of gels elaborated with boiled or steamed jumbo lump, which allowed the textural properties similar to those of the whole jumbo lump.  相似文献   

6.
ABSTRACT:   In order to understand the characteristics of burnt meat in cultured yellowtail Seriola quinqueradiata , fish were kept at two different temperatures (13 and 30°C) and slaughtered by either spinal cord destruction (SCD) or suffocation in air (SA). Early postmortem changes during storage at 32°C were analyzed by rheological, biochemical, and histological methods. The burnt meat (with lightness parameter, L* ≥ 55) was observed at 1-h storage in the SA 30°C group, at 2 h in SCD 30°C, and at 4 h in SA 13°C; meat was normal for the SCD 13°C group until 6 h of storage. Breaking strength scores were higher for the normal meat (200 g/cm2) than burnt meat (70 g/cm2) at 4 h of storage. Expressible water content was higher for the burnt meat than for the normal meat. Adenosine triphosphate concentrations for the SCD groups were higher than for the SA counterparts. Moreover, pH decrease was much faster in the 30°C groups, showing pH 5.6 at 2 h of storage. A negative correlation between the pH and lactic acid contents in muscle ( P  < 0.001) was found. Histological analysis evidenced a larger pericellular area (40%) in the burnt samples than in the normal samples (16%). It was confirmed that a higher fish-keeping water temperature and a stressful slaughter method (faster glycolytic process) were determinative factors that influence the occurrence of burnt muscle in yellowtail, and that the effect of the former is larger than the latter.  相似文献   

7.
ABSTRACT:   An apparatus to measure the locomotor activity of aquatic benthic organisms at variable low light levels was developed and the diurnal behavioral pattern of the abalone Haliotis discus discus was measured at various low light intensities. During the experiment, abalone were exposed to 12 h light–dark cycles of complete darkness, 0 µmol/m2/s throughout the 12 h dark cycle and, during periods I (days 1–8) and III (days 19–26), the 12 h light cycles were set at 10 µmol/m2/s. During period II (days 10–17), abalone were exposed to a light level during the 12 h light cycles of 1 × 10−5, 1 × 10−6, 1 × 10−7 or 1 × 10−8 µmol/m2/s and the changes in locomotor activity assessed. At daytime levels of 1 × 10−5 µmol/m2/s, typical behavioral patterns were observed of high locomotory activity during the night-time cycle. However, at lower light intensities, the distinction between day and night activity patterns became less clear and, at intensities lower than 1 × 10−7 µmol/m2/s, the difference between activity during the light and dark cycles became negligible. Based on this, we conclude that the threshold of light level perception in relation to locomotor activity is approximately 1 × 10−7 µmol/m2/s. The significance of these results in relation to the entrainment of behavior in abalone is discussed.  相似文献   

8.
The pharmacokinetic properties of flumequine following a single intravascular injection (10 mg kg–1 fish) were studied in sea bass, Dicentrarchus labrax (L.), 120 g held at 18 °C. The absorption half life ( t 1/2α) and the elimination half life ( t 1/2β) of the drug were calculated to be 1.05 and 10.71 h, respectively. Tissue penetration of flumequine seemed to be moderate because both the apparent volume of distribution of the drug at steady-state ( V d(ss)) and the extensive apparent volume of the central compartment ( V c) were found to be small (1.51 and 0.626 L kg–1). The mean residence time ( MRT ) was short (09.73 h) and the total clearance (CLT) of the drug was rapid (0.156 L kg–1 h–1).  相似文献   

9.
ABSTRACT:   Suppressive effects of non-ionic (sorbitol, maltose, and trehalose) and ionic (Na-glutamate, Na-acetate, Na-sulfate, and ammonium sulfate) compounds on the thermal inactivation of myosin subframgent-1 (S-1) and myofibril Ca2+-ATPase were compared. All compounds suppressed S-1 denaturation. When myofibrils were used (at 0.1 M KCl), sugars and sugar alcohol (non-ionic compounds) suppressed denaturation similar to S-1, while Na-glutamate, Na-acetate, and Na-sulfate weakly suppressed them. Ammonium sulfate accelerated denaturation, but suppressed denaturation when heated in 2 M KCl, at which myosin lost protection by F-actin. It was thus concluded that ionic compounds affected the denaturation of myofibrils in two ways; suppression as established with S-1, and acceleration as a result of loss of protection by F-actin caused by increase in ionic strength.  相似文献   

10.
Viable, diploid gynogenetic (gynogenotes) paddlefish Polyodon spathula were produced by activating eggs with ultraviolet-irradiated shovelnose sturgeon Scaphirhynchus platorynchus spermatozoa and heat shocking. Without irradiation treatment, sturgeon spermatozoa appeared to activate the eggs (up to gastrulation), but did not result in any viable hybrids. Experiment 1 determined that heat-shock treatment of 35 C for a 2-min duration within the interval of 2–22 min post-activation resulted in highest yield of gynogenotes (12–19%) from eggs incubated at 18 C. Experiment 2 applied the heat shock treatment at 35 C from 14.0 to 28.0 min in 2-min intervals after activation at 18 C for a larger scale of gynogenetic production. Both experiments showed that the best yields of gynogenotes were obtained when the heat shock treatment occurred at 16, 18, and 20 min after activation. When these times were expressed in terms of τ0. units (duration of one mitotic cycle of synchronous cell division related to water temperatures), optimal activations were 0.26, 0.29, and 0.32τ0 (τ0@ 18 C = 63.5 min). Experiment 3 tested the utility of τ0. at two different pre-shock incubation water temperatures of 18 C and 16 C, and determined that there was no significant interaction in percentage of viable gynogenotes between two different incubation temperatures and the mitotic intervals (0.21, 0.26, 0.31, 0.36, 0.41τ0) tested. Best survival of gynogenotes occurred when eggs held at either pre-shock incubation water temperatures were shocked at 0.26τ0 All gynogenotes examined were histologically confirmed to have ovarian tissue and were determined to have similar oocyte development to that of normal female (control) paddlefish.  相似文献   

11.
A feeding experiment was carried out to evaluate two natural diets versus a formulated feed on the performance of weaning red abalone Haliotis rufescens . Four treatment diets were then investigated: a formulated diet; plantlets from culture Macrocystis pyrifera, Porphyra columbina from natural beds; and a mixed diet consisting of a blend of fresh P. columbina together with the formulated diet. This study was performed in a shallow aquaculture system with a horizontal water flow. After 90 days, significant differences were observed between treatments. The highest growth was obtained with Porphyra (3.3 mm month−1), followed by the mixed diet (2.6 mm month−1), then Macrocystis (2.1 mm month−1) and lastly the formulated diet (1.4 mm month−1). Moreover, after the diets were tested for stability and remnant nutrients after a 12-h water immersion, a positive trend appeared to be related to the protein/energy (P:E). It is concluded that fronds of P. columbina resulted in the best diet for weaning H. rufescens under horizontal water flow systems, even if apparently the water stability of the formulated diet had a negative impact on abalone performance, particularly due to a poor nutrient retention capacity. Therefore, formulated diets should be improved before being recommended for weaning red abalone.  相似文献   

12.
The relative contribution that solid waste or 'sludge', which accumulates at the bottom of abalone ( Haliotis midae L.) tanks, makes to dissolved ammonia has not been established. Sludge was allowed to accumulate in 10 fully stocked abalone tanks, fed a formulated feed (Abfeed®; Marifeed, South Africa), for 24 days. Sludge was subsequently siphoned from five of these tanks. Total ammonia nitrogen (TAN) production and toxic, free ammonia nitrogen (FAN) were recorded in the tanks from which sludge was removed and compared with those from which sludge was not removed over the subsequent 50 h. Tanks with neither abalone nor sludge present were used as a control. The mean production of TAN (±standard deviation) was an average of 44% higher in tanks from which sludge was not removed compared with those from which it was, indicating that the sludge was a significant contributor to dissolved ammonia in the tanks. The toxic FAN concentrations were correspondingly higher in tanks with sludge present (2.3±0.3 μL−1) compared with cleaned tanks (1.9±0.1 μL−1). Our results indicate that regular removal of sludge from abalone tanks should significantly reduce the dissolved ammonia levels, thereby improving water quality in the culture environment.  相似文献   

13.
Abstract:   Age, growth and sexual maturity of the fan ray Platyrhina sinensis in Ariake Bay, Japan were determined from specimens collected from May 2002 to September 2006. Age determination was conducted by vertebral centrum analysis using soft X-radiography. Annual band pair deposition was determined by marginal increment and edge analyses. The von Bertalanffy growth model best described the overall pattern of growth for both males and females (males L ∝  = 455.2, k  = 0.56, t 0 = −1.09; females L ∝  = 555.8, k  = 0.28, t 0 = −1.77; L ∝ is the theoretical asymptotic total length in mm, k is the growth rate coefficient and t 0 is the theoretical time at zero length). Parameter estimates suggest that females attain a larger asymptotic total length and grow more slowly than males. The observed maximum ages were 5 years for males and 12 years for females. Age at 50% sexual maturity was 2.1 years for males and 2.9 years for females. The results indicate that this species is relatively fast-growing, short-lived and early maturing compared with many batoid species.  相似文献   

14.
ABSTRACT:   The effect of salt concentration on the thermal denaturation profile of myosin in walleye pollack and carp myofibrils was compared by studying the subfragment-1 (S-1) and rod denaturation rates upon heating. Species-specific denaturation mode observed at 0.1 M KCl was no longer detected when samples were heated above 0.5 M KCl, where S-1 and rod denaturation rates were identical to each other. As the heating of the chymotryptic digest of myofibril formed practically no rod aggregates, S-1 denaturation in a form of myosin was the rate limiting step for rod aggregate formation. As the aggregate formation by rod was remarkably suppressed by lowering the temperature, the free movement of myosin tail upon heating was suggested to play an important role in the rod aggregate formation in a high salt medium.  相似文献   

15.
ABSTRACT:   A field experiment was conducted in the Matsumae area of Hokkaido, Japan, during June and July 2002, to investigate the effects of different entrance designs on the catch efficiency of fish traps by fishing with commercial traps (entrance inclination angle [α] = 37°; funnel length of entrance [ L f ] = 22 cm) and experimental traps. The experimental traps were of the same size and similar design as commercial traps, with different entrance inclination angles (trap E1: α = 46°; E2: α = 27°; E3: α = 0°; all L f  = 22 cm) or funnel lengths (E4: α = 37°, L f  = 8 cm). In total, 2200 fish during 200 trap hauls were captured. The catch was significantly higher using both traps E2 and the commercial trap than with trap E3 ( P  < 0.05), and the catch of trap E2 was higher than that of the commercial trap. There were no significant differences in mean fish body length or the frequency distributions of body length among trap types (E1, E2, E3 and commercial). The funnel length of the entrance also affected the catch of traps. Trap E4 had significantly higher catches than the commercial trap ( P  = 0.04) when traps were deployed for a 1-day soak time. Fish body length frequency distributions did not differ between trap E4 and the commercial trap. The results showed that catch can be greatly affected by trap entrance designs.  相似文献   

16.
The feasibility of obtaining a similar growth response from juvenile pink abalone Haliotis corrugata at a research laboratory and a hatchery, when using natural feeds was evaluated. Four macroalgae, Egregia menziesii , Eisenia arborea , Macrocystis pyrifera , Gracilaria sp., and the surfgrass Phyllospadix torreyi were used as feeds. Response patterns of abalone were very similar at both facilities in terms of final length, weight, and survival, varying from 13.0 to 15.50 mm, 0.31 to 0.52 g, and 60.0% to 78.6%, respectively. Better growth was obtained when E. menziesii , M. pyrifera , and Gracilaria sp. were offered. Poor results were obtained with surfgrass. The feed conversion ratio was determined at the laboratory and did not vary significantly, ranging from 42.3 to 199.0; although a significant inverse correlation was observed with growth rate. Growth in length and weight and survival rates varied within 1.6–20.2 μm day−1, 0.123–1.664 mgday−1, 0.4–0.64%day−1, respectively. Mean growth rate in length (14.7μm day−1) and weight (1.18 mg day−1) at the hatchery were significantly higher than that obtained at the laboratory (9.4 μm day−1 and 0.77 mg day−1), which is most likely a consequence of more suitable water temperature at the hatchery. Mean survival rate was significantly higher at the laboratory (53.1%day−1) than at the hatchery (46.1%day−1).  相似文献   

17.
ABSTRACT:   The aim of this study was to establish effective procedures for chromosome manipulation in greenling Hexagrammos otakii Jordan et Starks, which has enormous aquacultural potential. To accomplish this, temperature-dependent measurements of the mitotic intervals (τ0) were carried out. The τ0 in this fish was determined by averaging the duration of the first and third embryonic divisions at temperatures ranging 5–25°C. At higher temperatures, eggs developed faster and underwent more identical development. For greenling, τ0 were 341.1 ± 3.60 min at 5°C, 275.5 ± 4.53 min at 10°C, 189.7 ± 6.93 min at 15°C, 99.2 ± 8.27 min at 20°C and 34.2 ± 8.74 min at 25°C. There were strong, negative correlations between the τ0 and water temperatures at all temperatures studied ( Y  = −79.3 X  + 425.3, R 2 = 0.9968, where Y is the mitotic interval and X is the temperature).  相似文献   

18.
ABSTRACT:   Age and growth of alfonsino Beryx splendens (Lowe) were studied using counts of presumed daily incremental growth rings on the transverse section of otoliths of fish collected from the Kanto District, central Japan. Microstructural growth increments were observed from the core to the outermost margin of the broadest of approximately 50 branches formed on the surface of an otolith. Of 98 otoliths examined, 46 were readable. The number of increments and fish lengths ranged from 448 (218 mm fork length [FL]) to 3701 (411 mm FL). The ages of these fish were estimated to be 1 year, 2 months and 10 years, 2 months, respectively, assuming that an increment was formed daily. The von Bertalanffy growth equation combined for males and females was expressed as follows: L t  = 542 {1 −  exp  [−0.133( t  + 2.00)]}, where L t is fork length (mm) at yearly age t . The results of the present study were compared with those of other researchers who had studied alfonsino from central Japan.  相似文献   

19.
Volutharpa ampullacea perryi (false abalone) meats were water cooked at 75–100°C for 5–60 min, and the changes in weight loss, pH, color, in vitro digestibility, texture, microstructure, and sensory characteristics were investigated. The weight rapidly decreased in the initial cooking and decreased slightly with the extension of both heating temperature and time. Obvious differences in color were found compared between the raw and cooked meats with respect to ΔL*, Δa*, and Δb* values. Digestibility was significantly improved with the thermal treatments. Textual properties, such as hardness, springiness, chewiness, and resilience, improved with the increasing of thermal intensity, but reduced with overcooking, and the variations were further confirmed by the scanning electron microscopy analysis. The samples boiled at 90–95°C for 10–15 min and 100°C for 5–10 min acquired better acceptance in the sensory evaluation. The complex relationship among cooking conditions and physicochemical and histological characteristics of meat as well as the consumer perceptions was illuminated by the principal components regression analysis. These results could provide useful information for quality control in V. a. perryi meat cooking.  相似文献   

20.
Abstract  Culture-based fish yield in non-perennial reservoirs of Sri Lanka was related to reservoir morphometry and stocking density. The reservoirs were stocked mainly with fingerlings of one Chinese and three Indian major carp species, common carp, Cyprinus carpio L., and the genetically improved farmed tilapia strain of Nile tilapia, Oreochromis niloticus (L.), at four pre-determined species combinations and a range of stocking densities [ SD (fingerlings ha−1)]. Twenty-three reservoirs were harvested successfully at the end of the culture period of 2002–2003. Basic limnological and morphometric parameters, including shoreline development ( D L ) and shoreline area ratio ( R LA ), were estimated for each of the 23 reservoirs. Bray–Curtis similarity and non-metric multidimensional scaling using mean values of limnological data revealed that reservoirs could be ordinated into two major clusters, one with intact sample distribution due to similar trophic characteristics and the other with scattered sample distribution. Reservoirs in the cluster with similar trophic characteristics showed significant correlation ( P  < 0.05) between R LA and total fish yield ( Y ). A multiple regression equation, Y  = −693 + 4810  R LA  + 0.484 SD , was generated to estimate fish harvest in relation to SD .  相似文献   

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