首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 62 毫秒
1.
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   

2.
To characterize post-mortem changes in fish meat quality during chilled and frozen storage, muscle toughness and the connective tissue structure of muscle were compared between two mackerel species, spotted mackerel Scomber australasicus and Pacific mackerel S. japonicus. Measurement of the breaking strength of meat slices from both non-frozen fresh fish and frozen-thawed fish revealed that spotted mackerel meat was softer than Pacific mackerel meat. Under scanning electron microscopic observation, the connective tissue of non-frozen meat of spotted mackerel was thinner than that of Pacific mackerel. In addition, the collagen content in the spotted mackerel meat was lower than that of Pacific mackerel. These findings suggest that connective tissue structure might influence muscle toughness in mackerel.  相似文献   

3.
ABSTRACT

Mariculturing of horse mackerel is not known in the world. Additionally, limited studies exist on quality changes of smoked horse mackerel at refrigerated temperatures. Therefore, in this study, between 1+ and 2-year-old wild and cultured horse mackerels were hot smoked and stored at refrigerated conditions. Chemical, microbiological, and sensory analyses were performed weekly to investigate quality changes and to determine the shelf stability of the products. The results of thiobarbituric acid, trimethylamine, and total bacteria counts were obtained within the acceptable levels. Although the counts of histamine-forming bacteria increased significantly (p < 0.05) during storage, histamine values were well below the permitted limits set by Food and Drug Administration and European Union (EU). Sensory results showed that both storage groups had 3 weeks of shelf life. Total volatile basic nitrogen values supported sensory results. Therefore, the results indicate that culturing of horse mackerel did not alter the quality during storage at 4 ± 1°C.  相似文献   

4.
ABSTRACT:   This study examined the thermal gelation characteristics of myofibrillar protein (MP) and salt-ground horse mackerel surimi that had been mixed with hydroxypropylmethylcellulose (HPMC). Analysis, using thermal scanning rigidity monitor and differential scanning calorimetry, demonstrated that thermal gelation begins in the thermo-reversible HPMC gel used in this study at approximately 60°C. In the rescanning test, first scanning diagrams showed similar pattern, but second scanning diagrams were rather diverse between MP and MP/HPMC mixture. The addition of HPMC increased rigidity of salt-ground surimi and modified the thermal gelation during the heating process, suggesting that certain enhancing effect of gelation occurred when the mixture of MP and HPMC was heated. In the annealing test, the addition of HPMC lowered the breaking force, but increased the gel strength of surimi due to a substantial increase in deformation. Although the strong cross-linking between the two components might not occur during the gelling process, HPMC gel formed at high temperature occupies some space in thermal gel by interacting with proteins and resulted in a combinative gel with a higher rigidity and gel strength at higher temperature.  相似文献   

5.
ABSTRACT: This study attempted to reduce the lipid and water contents in boiled skipjack loins by vacuum treatment and the quality of vacuumed boiled meat was then evaluated during the chilled and frozen storage. The boiled meats were vacuumed at a pressure of 400 Pa for 30 min using a vacuum freeze dryer as an experimental convenience in order to degrease, cool and dehydrate rapidly. The vacuumed boiled meats were stored at 0.0 ± 0.2°C for 10 days and at −20 ± 0.5°C for 90 days. The unvacuumed boiled meats were cooled by air-cooling and stored as the control. Lipid content on a wet basis (w.b.) was reduced as much as 0.5% in the ventral part and 0.4% in the dorsal part of the boiled meats after vacuum treatment. Water content (w.b.) was reduced as much as 2.5% in the ventral part and 3.0% in the dorsal part. The thiobarbituric acid and volatile basic nitrogen values in vacuumed boiled meats were significantly lower ( P < 0.05) than that in unvacuumed boiled meats during storage. Inosine monophosphate (IMP) was only detected as a major nucleotide (about 70%) in boiled meats, and the decomposition of IMP in vacuumed boiled meats was smaller than that in unvacuumed boiled meats during storage. It was concluded that the quality of boiled skipjack loins could be improved by vacuum treatment as a preprocessing procedure in the production of dried skipjack such as katsuobushi .  相似文献   

6.
Rigor contraction and quality development were studied during storage of pre-rigor fillets of farmed Atlantic cod (body weight 2 kg). For eight weeks prior to slaughtering, the fish were fed diets containing either 100% fish oil (M-group) or 60% fish oil and 40% soybean oil (S-group). Filleting was performed 0.5 h after slaughtering and the fillets were stored at 6 °C for 48 h post-mortem. The contraction rate was faster for the S-group, but after 48 h storage the contraction was 21% of the initial fillet length for both fish groups. The ATP content analysed 1 h post-mortem was lower of the S-group (4.5 μm g− 1 ww) compared with the M-group (6.1 μm g− 1 ww). After 16 h, the ATP content was similar for both fish groups (1.7-2.2 μm g− 1 ww). The muscle pH analysed 1 h post-mortem was 0.2 unit lower of the S-group (pH 6.9) than of the M-group (pH 7.1). From 8 to 12 h, the pH fell significantly to 6.3 and 6.6 for the S-group and M-group, respectively. From 24 h and onwards, the pH was similar of both fish groups (pH 6.2). Texture development differed significantly due to dietary treatment. The S-group had highest initial breaking force, demonstrating that the texture of this group was firmer immediately after slaughtering. The breaking force of the S-group dropped to a stable level after 4 h, whereas the breaking force of the M-group decreased continuously during the storage period. The breaking force was similar of both groups after 16 h storage. The L*-value (lightness) increased during the first 4-6 h storage. From 8 to 16 h, the L*-value was stable or slightly decreasing. The L*-value was consistently higher of the M-group. In conclusion, dietary inclusion of soybean oil resulted in faster energy depletion post-mortem, faster rigor contraction, faster reduction of the breaking strength and lower L*-values.  相似文献   

7.
CHIE  YONEDA  CHINATSU  KASAMATSU  KEIKO  HATAE  SHUGO  WATABE 《Fisheries Science》2002,68(5):1138-1144
Physicochemical changes of Japanese cockle foot parts occurring during cooking and cold storage at 4°C for 10 days were examined. Raw samples decreased in weight by 27% during cooking at 85°C for 15 s. Both raw and cooked samples decreased in weight to the same extent of 22–23% during the 10-day cold storage. The levels of ATP and related compounds, as well as those of free amino acids, were higher in raw than in cooked samples, although the former were found by sensory evaluation to have a stronger fishy odor. Raw samples started to decrease in ATP content after 5 days of cold storage, showing K' values of 18 and 42% after 5 and 7 days, respectively. The L* value in the Hunter scale color evaluation increased during the cold storage of raw samples, revealing a gradual disappearance of its original purple–gray color. Meanwhile, the L* value of cooked samples remained constant during the cold storage. The tensile strength of cooked samples was significantly higher than those of both raw samples before and after the cold storage, indicating increased toughness by cooking.  相似文献   

8.
ABSTRACT:   Changes in meat firmness and structure of cultured yellowtail at several storage temperatures, from −1.5°C to 10°C, were compared. Firmness decreased less at −1.5°C and 10°C than at the other temperatures. During storage at temperatures from −0.5 to 4.0°C, expansion of intercellular space, which indicates weakening of the connecting force between muscle cells, began to increase after 8 h storage, and the ratio of space to the whole area increased by 3.4–4.9 times after 24 h of storage. However, at −1.5°C and 10°C, the increase of intercellular space was suppressed, and the ratio was 2.4–2.6 times, even after 24 h storage. Collagen fibrils connecting muscle cells disintegrated after 24 h storage at all storage temperatures. Conversely, in 10°C storage, the fine structure of muscle, except for collagen fibrils, was maintained better than at other storage temperatures. These findings indicate that −1.5 and 10°C storage could maintain fish-meat quality for longer periods than storage at −0.5, 1.0, or 4.0°C, the normal refrigeration temperature.  相似文献   

9.
ABSTRACT:   The optimal water temperature in seed germination and the upper critical water temperature in seedling growth were determined for Zostera marina collected from Ise Bay, Japan. The relationship between the seed germination rates and seed storage period (0, 30 and 60 days at 0°C) was also examined. The optimal water temperature for seed germination was in the range from 10 to 15°C regardless of the storage periods, in which germination rates ranged from 35 to 57%. Seedlings grown from seed up to 10 cm in total length were cultured for 1 week under various water temperatures to measure their relative growth rates. The optimal water temperature in growth was in the range from 20 to 25°C; relative growth rates ranged from 2.0 to 2.6%. Seedlings could survive up to a water temperature of 28°C, but most seedlings withered at 29 or 30°C. The optimal water temperatures for seed germination and seedling growth were related to the seasonal changes of water temperature at the sampling site. Although seedlings were rarely observed in the field in summer, they can grow at temperatures as high as 28°C. Therefore, Z. marina may extend its distribution as far as where the summer water temperature is lower than 28°C.  相似文献   

10.
The distribution of egg and larvae of mackerel, horse mackerel, sardine, hake, megrim, blue whiting and anchovy along the European Atlantic waters (south Portugal to Scotland) during 1998 is described. Time of the year, sea surface temperature and bottom depth are used to define the spawning habitat of the different species. Mackerel, horse mackerel, and sardine eggs and larvae presented the widest distribution, whereas megrim and anchovy showed a limited distribution, restricted to the Celtic Sea and the Bay of Biscay respectively. Correspondingly mackerel, horse mackerel and sardine showed the highest aggregation indices. Blue whiting larvae were found at the lowest temperatures, whereas anchovy eggs and larvae were found in the warmest waters. The analysis is a basis for evaluation of ongoing changes in the pelagic ecosystem of the north‐east Atlantic.  相似文献   

11.
To elucidate the structural changes in pink (P), white (W), and red (R) muscles during storage in ice, we measured the breaking strength and changes in pericellular connective tissues of cultured carp. The breaking strength just after killing was highest in R muscle (1.00 ± 0.20 N), lowest in W muscle (0.37 ± 0.07 N), and intermediate (0.84 ± 0.12 N) in P muscle. During the storage period, the breaking strength decreased first in R muscle, then in P muscle, followed by W muscle. The diameter of muscle fibers was greater in W muscle (113 ± 15 μm) than in P muscle (72 ± 3 μm) and R muscle (48 ± 2 μm). Destruction of the honeycomb structure of the pericellular connective tissue occurred most rapidly in W muscle and most slowly in R muscle. These results suggest that the interposing of P muscle fibers in the dorsal ordinary muscle contributes to the acceleration of post-mortem tenderization in fish.  相似文献   

12.
SUMMARY: The study on K value change at low temperature storage had been carried out down to a temperature of −40°C, however, there was no evidence about this reaction rate if the temperature were lowered below the storage temperature normally used especially for tuna meat (−60oC). The rate of K value change ( kf ) of yellowfin tuna ( Thunnus albacares ) meat was determined during storage at a wide temperature range (20°C to −84°C). The logarithm of K '(= 100 − K value) was used in this study and its plot against storage time yielded a straight line, which indicated an apparent first-order reaction for all temperature storage. Furthermore, physicochemical characterization of water in tuna muscle was carried out using Differential Scanning Calorimetry (DSC) at very low temperature. The temperature dependence of this reaction was analyzed by an Arrhenius's plot that resulted in two break points. The first break point occurring at freezing point might be due to the freeze effect. The second break point was at −10°C. The reaction rate change steeply declined at the temperature range of −70°C to −84°C, and was thought to be related to glass transition which may occur in the fish sample.  相似文献   

13.
We examined the distribution and migration of age-0 jack mackerel in the East China Sea (ECS) and Yellow Sea, based on data from seasonal bottom trawl surveys. Sampling was conducted at 79–161 stations during five cruises in spring (April–June), early summer (May–July), late summer (August–October), autumn (October–December), and winter (January–February). During early summer, jack mackerel (mean 92 mm fork length), which were estimated to have hatched in the southern East China Sea (SECS) during winter, began to occur abundantly, especially along the shelf-break region of the central East China Sea (CECS). In late summer, the distribution center of young fish (mean 126 mm) shifted northward into the shelf region of northern East China Sea (NECS), corresponding with the rise of bottom water temperature and high prey abundance. In winter when the bottom water temperature declined in the shelf region, the distribution center of jack mackerel (mean 144 mm) shifted southward, with high densities occurring in the SECS and CECS. In spring, overwintering jack mackerel that had become age-1 (mean 175 mm) were distributed abundantly along the shelf-break region of the ECS. On the other hand, jack mackerel were only sporadically found, generally at low densities, in the Yellow Sea during all seasons. High densities of jack mackerel were largely restricted to areas of >15°C bottom water temperature during all seasons. Our results indicate that the seasonal shifts of the 15°C isotherm of the bottom layer and the food conditions are significant environmental factors determining the migration of jack mackerel within the ECS.  相似文献   

14.
ABSTRACT:   The addition of microbial transglutaminase (MTGase) to salted squid muscle paste greatly strengthened the elasticity of the thermal gel, which was produced by the preferential cross-linking of myosin heavy chains through a two-step heating process that consisted of setting at 40°C and subsequent heating to 80°C or 90°C. Starch increased the breaking strength of thermal squid gels, but decreased the deformation. Thus, the starch-added gels became harder and less elastic. Although, when both MTGase and starch were added to squid muscle paste, the changes in viscoelastisity and myosin cross-linking reaction were similar to those with MTGase alone during setting, the storage and loss moduli of the paste sharply increased with an increase in starch content above 70°C. Subsequently, the thermal gel texture became more brittle or breakable than gels prepared by setting with MTGase only.  相似文献   

15.
The effect of temperature on the swimming performance of jack mackerel Trachurus japonicus was examined in a flume tank by measuring the swimming endurance time and heart rate. The lower swimming performance was observed at 10°C (the lowest temperature tested), manifesting as the shortest endurance time and the slowest maximum sustained speed. ECG measurements of the heart rate under free-swimming conditions at zero flow velocity revealed a temperature effect, with 25.3 beats/min observed at 10°C, 38.9 at 15°C, and 67.2 at 22°C. The heart rate also increased with swimming speed to maximum levels of 60, 125, and 208 beats/min, respectively, at these three temperatures. Heart rate recovery times measured after the fish had been swimming at prolonged speed tended to increase with temperature, while a negative correlation resulting in relatively short recovery times was observed after swimming at close to the burst swimming speed at each water temperature.  相似文献   

16.
The aim of the present study was to evaluate the effects of various sous-vide time–temperature regimes and their interactions on quality parameters of Atlantic mackerel (Scomber scombrus) during chilled storage. The mackerel ?llets were exposed to sous-vide treatment at 60, 75, and 90°C for 10, 15, and 20 min and further stored for 1, 3, and 7 days at 4 ± 1°C before analysis. Changes in pH, water content and cook loss, amount of water- and salt-soluble proteins, texture, and color parameters, as well as accumulation of lipid oxidation products in sous-vide-cooked mackerel were assessed. Sous-vide cooking time and temperature had the lowest contribution to the formation of primary and secondary products of lipid oxidation, as well as increase in yellowness of the fish flesh due to their accumulation; whereas duration of chilled storage led to a significant increase in oxidation and yellowness (p < 0.05). Duration of chilled storage also affected structural and textural properties of the fish muscle, leading to a decreased cook loss. At the same time, sous-vide cooking decreased the firmness of the fish muscle. Duration of chilled storage was found to have the highest significant effect (p < 0.001) on all physicochemical characteristics of sous-vide-cooked mackerel.  相似文献   

17.
Jiang  Yan-Rong  Yoshida  Asami  Ohta  Megumi  Gao  Yi-Li  Noguchi  Erika  Kuwahara  Koichi  Hara  Kenji  Osatomi  Kiyoshi 《Fisheries Science》2023,89(1):93-100

Modori-inducing proteinases (MIPs) in horse mackerel and the effect of sodium citrate on the modori phenomenon were investigated. Cysteine protease caused the modori phenomenon only at 60 ℃, while metalloproteinase caused it at both 60 ℃ and 70 ℃. Moreover, the autolysis of myofibrillar proteins was mainly inhibited by ethylene diamine tetra-acetic acid (EDTA), verifying the existence of insoluble metalloproteinase. From the results comparing thermal gel properties and protease activities, we confirmed that increased activity of insoluble metalloproteinase corresponded to the weakening of the thermal gel. Thus, insoluble metalloproteinase was the major MIP in horse mackerel. Moreover, sodium citrate could markedly inhibit insoluble metalloproteinase activity at 60 ℃. The addition of sodium citrate significantly improved the breaking force of the thermal gel at 60 ℃ and 70 ℃, suggesting that sodium citrate could suppress the modori phenomenon by inhibiting insoluble metalloproteinase. Therefore, it is desirable to use sodium citrate in horse mackerel surimi-based products to prevent the modori phenomenon.

  相似文献   

18.
ABSTRACT: An ice-nucleating bacterium, designated MACK-4, was isolated from ice-stored mackerel ( Scomber australasicus ) and identified as a Pseudomonas fluorescens . The optimal temperature and pH for its growth in nutrient broth with 2.5% glycerol (NB-G) were 15°C and 6.5, respectively. The maximal ice-nucleating activity (INA) was obtained after 54 h incubation at 15°C. However, the INA was almost completely lost after 48 h incubation at 25°C or higher. The growth and INA decreased with increase of NaCl added in NB-G within 0.0–4.0%. The INA of MACK-4 was very stable at 5–25°C, pH 4.0–9.5, while that of isolated ice-nucleating matter from MACK-4 was stable at 5–25°C, pH 5.5–9.0.  相似文献   

19.
We describe the seasonal migrations of Argentine chub mackerel ( Scomber japonicus ) into the fishing ground in relation to sea surface temperature conditions and analyse the temperature evolution during the fishing season on the basis of 1955–97 time-series. The upper temperature limit for the presence of schools was around 19°C. At higher values, most schools leave coastal waters (< 50 m) for the shelf. An inverse relationship was observed between catches per unit of effort (CPUE) of the inshore fishery and sea surface temperature. The highest standardized CPUE values corresponded to temperatures lower than 19°C. Above this temperature, the probability of obtaining a standardized CPUE higher than 1 was extremely low, and the standard deviations were minimal. The economic benefit from catches was also analysed through the different months of the fishing season. It was found that the mean benefit corresponding to temperatures lower than 19°C exceeded approximately 15 times that obtained at higher temperatures. A simple fishing strategy was proposed to the commercial fleet in order to improve the economic benefit of the catches. The migratory pattern followed by mackerel during the spawning period was also analysed in relationship to other environmental factors like food availability. Zooplankton composition, size structure and abundance in coastal and shelf waters are described, and their implications for feeding ecology of larvae and adults of the species are discussed.  相似文献   

20.
The effects of temperature on growth, food-conversion ratio (FCR) and feeding intensity of juvenile dusky kob Argyrosomus japonicus (23.7±2.6 g fish−1) were assessed over the temperature range 17.5–28.5 °C in a 42-day growth trial. Growth increased with increasing temperature up to an optimum after which it declined. Specific growth rates were 2.05% and 1.2% day−1 for the fastest (25.3 °C) and the slowest (17.5 °C) treatments respectively. Food-conversion ratio peaked at a lower temperature than growth. Optimal (0.72 kg kg gain−1) and least efficient (1.40 kg kg gain−1) FCR were found at 21.7 and 17.5 °C respectively. Feeding intensity was linearly related to temperature within the range of 17.5–28.5 °C. These results corresponded to the thermal preference (25–26.4 °C) and natural temperature distribution (12–28 °C) of South African dusky kob. Determination of the temperature range that does not limit growth is a prerequisite to assess the relationship between growth and environmental variables such as light intensity, feeding regime and stocking density. Consequently, experiments to determine the effects of these environmental variables on growth and aquaculture potential of dusky kob should be conducted at 24–26 °C.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号