Influence of interposition of pink muscle fiber into dorsal ordinary muscle on 5'-IMP degrading activity in various fish species

ABSTRACT: To clarify the cause of differences in the temporal change of K -value among fish species living in the same habitat water temperature, the influence of the interposition of pink muscle fibers into dorsal ordinary muscle on 5'-inosine monophosphate (5'-IMP) degrading activity was examined. Fourteen fish species from the Sakishima Islands (habitat water temperature 28°C) and from Nagasaki (habitat water temperature 17°C) were used for the sample fishes. Each of 5'-IMP and ρ-nitrophenol phosphate (ρ-NPP) degrading activities showed a peak at near pH 8.0 and near pH 5.0, respectively. These activities were somewhat higher in fish from Nagasaki than in fish from the Sakishima Islands. The interposition percentage of pink muscle fibers into dorsal ordinary muscle correlated significantly ( P < 0.05) with the 5'-IMP degrading activity at pH 7.0. Furthermore, the activity at pH 7.0 correlated significantly ( P < 0.001) with the increasing rate of K -value at 32°C (ΔK₃₂). These results suggest that the difference in ΔK₃₂ among fish species in the same habitat water temperature might be caused by differences in 5'-IMP degrading activity because of the differences in the interposition rates of pink muscle fibers into dorsal ordinary muscle.     

Comparison of 5′-inosine monophosphate and p-nitrophenyl phosphate degrading activities among red,pink, and white muscle fibers of cultured carp

ABSTRACT:   As part of a study to clarify the differences in the temporal change in K -value among fish species, the temporal change in K -value and the 5'-inosine monophosphate (5'-IMP) and p-nitrophenol phosphate (p-NPP) degrading activities in the red, pink, and white muscle fibers in the dorsal muscle of the carp were compared. The temporal change in K -value was fastest in red, followed by pink, and white muscle fibers, at both 0°C and 32°C. Moreover, the 5'-IMP and p-NPP degrading activities were highest in red, followed by pink, and white muscle fibers at near optimum pH concentrations. The 5'-IMP degrading activity at pH 7.0 had a positive correlation with the increasing rate of K -value at 32°C for all types of muscle fibers. These results suggest that differences in increasing rates of K -values between red, pink, and white muscle fibers corresponded to the 5'-IMP degrading activities.     

Comparison of characteristics of actomyosin from white, pink, and red muscle fiber types in cultured carp

ABSTRACT: The present study compared and examined the characteristics of actomyosin among white (W), pink (P), and red (R) muscle fiber types in carp (cultured). Both the superprecipitation reaction and the Mg²⁺-ATPase activity of actomyosin became higher with increased Ca²⁺ concentration (pCa 7.0–pCa 5.0) and with decreased adenosine triphosphate (ATP) concentration (3.0–0.5 mM) in all three muscle fiber types. A comparison of the three fiber types shows that the superprecipitation reaction of actomysoin was lower in the order of W < P < R and, in contrast, was higher for Mg²⁺-ATPase activity in the order of W > P > R. A significantly positive correlation between both values was found for each of the three muscle fiber types, but these correlations were clearly different among the three muscle fiber types, and the superprecipitation reaction of actomyosin was lower in the order of W < P < R when Mg²⁺-ATPase activity was at the same level. In conclusion, the characteristics of actomyosin were remarkably different among white, pink, and red muscle fiber types.     

草鱼不同部位肌肉营养成分、肌纤维特性以及脂肪代谢相关基因的表达

为了探讨草鱼(Ctenopharyngodon idella)不同部位肌肉品质的差异,本研究选取体质量为(1 026.10±145.55)g的草鱼,检测了背部、腹上部、腹底部和尾部肌肉的营养成分、肌纤维组织结构特性以及脂肪代谢相关基因的表达。结果表明,草鱼腹底部肌肉的粗脂肪含量显著高于背部、腹上部和尾部肌肉,而水分含量则显著降低;背部肌肉粗蛋白含量显著高于腹上部、腹底部和尾部肌肉。腹上部肌肉的肌纤维直径显著高于背部、腹底部和尾部肌肉,但其肌纤维密度则显著降低,而最高的肌纤维密度出现在腹底部肌肉;草鱼背部和尾部肌肉肌纤维密度无显著差异。草鱼腹底部肌肉的脂蛋白脂肪酶基因mRNA表达量显著高于草鱼背部、腹上部和尾部肌肉。脂肪酸合成酶和乙酰辅酶A羧化酶α的mRNA表达量在草鱼背部、腹上部、腹底部和尾部肌肉之间无显著差异。研究表明,草鱼不同部位的肌肉营养特性存在显著性差异,肌肉脂肪含量与肌纤维直径呈负相关,与脂蛋白脂肪酶基因的表达量呈正相关。     

Mechanochemical properties of ordinary and dark muscle myosins from seawater fish

Myosin was isolated from two types of muscle, ordinary and dark muscles, of three species of fish living in sea water. The compositions of light chains were visualized by sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and the mechanochemical activity was examined by in vitro motility and ATPase assays. Ordinary muscle myosin of either species had three species of light chain, whereas dark muscle myosin had another two species of light chain judged by SDS-PAGE. Sliding velocity of ordinary muscle myosin was in the range of 4.92–6.89 μm/S, whereas that of dark muscle myosin was in the range of 3.07–4.25 μm/s. Therefore, ordinary muscle myosin showed 1.26–1.95 times higher sliding velocity than dark muscle myosin in either species. The ratios of V_max of actin-activated Mg²⁺-ATPase activity of ordinary to dark muscle myosins were correlated quite well to the ratios of sliding velocity. Activity of ordinary muscle myosin was comparable to that of mammalian fast muscle myosin, but that of dark muscle myosin was twice of that of mammalian slow muscle myosin. These results may reflect the essential role of fish dark muscle myosin always used in slow cruising.     

Muscle fiber types,growth and development in the whole myotome of cultured Pacific bluefin tuna Thunnus orientalis

Following the successful development of Pacific bluefin tuna (PBT) aquaculture, it is of considerable importance to determine the muscle fiber types and their growth patterns for future development. Muscle fiber profiles of dorsal ordinary, lateral ordinary (LO) and dark muscles and their growth patterns in PBT from 3.0 to 54.3 kg body weight were studied. Muscle fibers were histochemically stained for NADH-diaphorase and myosin adenosine triphosphatase activity (mATPase), and immunohistochemically stained with S-58 slow-muscle myosin antibody. All muscle fibers in dorsal and LO muscles showed low NADH-diaphorase activity, and acid-labile (pH 4.0 or 4.3) and alkali-stable mATPase activity. In LO muscle adjacent to dark muscle, three intensities of mATPase activity were observed after acid pre-incubation at pH 4.5 or 5.0, and the activity was related to the muscle fiber diameter. In dark muscle, all small and some large fibers stained intensely for NADH-diaphorase activity, related to their high aerobic metabolism. The high-active fibers with NADH-diaphorase in dark muscle were positive for S-58 antibody. Some large fibers in dark muscle showed intermediate NADH-diaphorase activity and high mATPase activity after alkali pre-incubations. These are fast-twitch oxido-glycolytic fibers in dark muscle and transformed to red muscle fibers with increasing body weight.     

不同蛋白质与碳水化合物水平对黑鲷肌肉营养组成和质地的影响

为探究日粮中不同蛋白质与碳水化合物水平对黑鲷肌肉营养组成和质地的影响,实验配置了41.0%和37.5%2种蛋白质水平下3种碳水化合物水平(以小麦面粉为碳水化合物源,使用量分别为19%,24%,29%)的实验饲料,分别记为L1(19/41),L2(24/41),L3(29/41),L4(19/37.5),L5(24/37.5),L6(29/37.5)。实验以黑鲷幼鱼[均重(9.95±0.22)g)]为研究对象,投喂上述实验饲料养殖8周后,分析肌肉常规营养与氨基酸组成,测定肌纤维密度,并采用TA.XT plus质构分析仪进行质地多面剖析(TPA)模拟测试。结果显示,不同饲料蛋白质与碳水化合物比例对黑鲷背肌粗蛋白、粗脂肪无显著性影响(P0.05);对背肌谷氨酸、丙氨酸、亮氨酸和蛋氨酸含量均具有显著影响(P0.05),而对其余氨基酸含量与总量均无显著性影响(P0.05);此外,对背肌硬度产生显著性影响(P0.05)。在同一碳水化合物水平下,蛋白质水平降低,背肌硬度、胶性显著减小(P0.05),恢复性显著增大(P0.05);而在同一蛋白水质平下,随着碳水化合物水平升高,背肌硬度、恢复性出现显著性差异(P0.05);蛋白水平降低,肌纤维密度下降(P0.05)。研究表明,2种蛋白质水平下不同碳水化合物水平对黑鲷背肌的常规营养组成无显著性影响,但对氨基酸组成和质地有一定影响。     

Spawning induces a shift in energy metabolism from glucose to lipid in rainbow trout white muscle

Enzymatic changes that occur in the white somatic muscle of rainbow trout (Oncorhynchus mykiss) in response to spawning were investigated, and the evenness of their distribution across the ventral-dorsal plane of this muscle was assessed. Four enzymes that are involved in energy metabolism were measured (phosphofructokinase: glycolytic capacity, 3-hydroxyacyl-CoA dehydrogenase: -oxidation, citrate synthase: citric acid cycle, cytochrome oxidase: oxidative capacity). The enzyme activities were followed in different parts of the white muscle of non-spawning female rainbow trout from May, four months after their first spawning, until December, at second spawning. Samples were taken from white epaxial muscle along the lateral line, on the dorsum, and in between. Samples were also taken from red muscle of non-spawning fish. The isoforms of myosin heavy chains (MyHC) were electrophoretically identified on 6% SDS-PAGE gel to study possible changes in contractile properties of the muscle.Transformation from the non-spawning to spawning phase was associated with dramatic changes in the activity of the enzymes studied in white muscle: glycolytic capacity decreased to less than half, whereas oxidative metabolism increased about two- to four-fold in all areas. Significant quantitative differences in enzyme activities were found between the three epaxial muscle areas: in the non-spawning fish lateral line samples differed from those taken in the other two areas, whereas in spawning fish the dorsal sample difered from the other two. No difference in the expression of MyHC-isoforms was found between spawning and non-spawning fish. Co-expression of both slow and fast isoforms was found in single fibres isolated from red muscle.The results show that the energy metabolism in white muscle of domestic rainbow trout is altered during spawning; i.e., the metabolism becomes increasingly aerobic, with an increased capacity for fatty acid utilization, concomitant with phenotypic changes associated with sexual maturation. These changes are especially pronounced in ventral, superficially located fibres.     

长牡蛎闭壳肌肌纤维的组织学特性

分别利用石蜡切片苏木精-伊红染色法、冷冻切片烟酰胺腺嘌呤二核苷酸四唑氧化还原酶(NADH-TR)组化染色法、肌球蛋白ATP酶染色法对长牡蛎闭壳肌平滑肌和横纹肌进行了组织学特性研究,并比较平滑肌和横纹肌肌纤维组成的差异。石蜡切片结果显示,闭壳肌中平滑肌和横纹肌肌纤维形态结构不同,肌纤维直径、肌纤维密度和横截面积存在显著差异,其中平滑肌肌纤维直径为(5.97±0.631)μm,肌纤维密度为(25 485.65±3917.807)根/mm~2,肌纤维横截面积为(26.25±5.365)μm~2;横纹肌肌纤维直径为(7.41±0.847)μm,肌纤维密度为(16 908.25±3917.807)根/mm~2,横截面积为(40.45±10.083)μm~2。NADH-TR染色结果显示,平滑肌中富含NADH,肌纤维染色较深,呈现深蓝紫色,主要是I型肌纤维,为氧化代谢的慢速收缩型肌纤维;横纹肌染色较浅或者基本不着色,主要是II型肌纤维,为糖酵解代谢的快速收缩肌纤维。ATPase酶染色结果显示,横纹肌ATPase活性强,染色较深,呈现黑色,主要是II型肌纤维;平滑肌中ATPase活性弱,着色浅或基本不着色,主要是I型肌纤维。ATPase酶染色结果与NADH-TR染色结果一致。研究阐明了长牡蛎闭壳肌中平滑肌和横纹肌肌纤维的组织学特性及收缩、代谢特性差异,为深入研究长牡蛎肌纤维生物学特性提供了重要的基础资料,为提高我国贝类肉质品质提供理论依据。     

Fish muscle: the exceptional case of notothenioids

Fish skeletal muscle is an excellent model for studying muscle structure and function, since it has a very well-structured arrangement with different fiber types segregated in the axial and pectoral fin muscles. The morphological and physiological characteristics of the different muscle fiber types have been studied in several teleost species. In fish muscle, fiber number and size varies with the species considered, limiting fish maximum final length due to constraints in metabolites and oxygen diffusion. In this work, we analyze some special characteristics of the skeletal muscle of the suborder Notothenioidei. They experienced an impressive radiation inside Antarctic waters, a stable and cold environment that could account for some of their special characteristics. The number of muscle fibers is very low, 12,700–164,000, in comparison to 550,000–1,200,000 in Salmo salar of similar sizes. The size of the fibers is very large, reaching 600 μm in diameter, while for example Salmo salar of similar sizes have fibers of 220 μm maximum diameter. Evolutionary adjustment in cell cycle length for working at low temperature has been shown in Harpagifer antarcticus (111 h at 0°C), when compared to the closely related sub-Antarctic species Harpagifer bispinis (150 h at 5°C). Maximum muscle fiber number decreases towards the more derived notothenioids, a trend that is more related to phylogeny than to geographical distribution (and hence water temperature), with values as low as 3,600 in Harpagifer bispinis. Mitochondria volume density in slow muscles of notothenioids is very high (reaching 0.56) and since maximal rates of substrate oxidation by mitochondria is not enhanced, at least in demersal notothenioids, volume density is the only means of overcoming thermal constraints on oxidative capacity. In brief, some characteristics of the muscles of notothenioids have an apparent phylogenetic component while others seem to be adaptations to low temperature.     

Comparison of the proximate compositions,breaking strength and histological structure by the muscle positions of the full-cycle cultured Pacific bluefin tuna <Emphasis Type="Italic">Thunnus orientalis</Emphasis>

ABSTRACT:   Using the skeletal muscle of full-cycle cultured Pacific bluefin tuna (body weight: 13.1 ± 2.6 kg, cultured for about 21 months), the proximate compositions, breaking strength and histological structure of the front and rear parts of the dorsal ordinary muscles (FD-OM and RD-OM) and the ventral ordinary muscles (FV-OM and RV-OM) were compared. The FV-OM showed low moisture, protein, ash and high fat contents ( P  < 0.05, respectively) for the other three positions. The breaking strength of FD-OM, RD-OM and RV-OM increased up to 15–18 h and decreased later. However, the breaking strength of FV-OM was maintained during chilled storage. The pH of all muscles decreased up to 15 h, and then stayed at pH 5.7–5.8. However, the pH of FV-OM stayed at a higher level (pH 5.9). The histological structure observed by optical microscopy showed a space extension among muscle cells after 24 h in all positions, and these results were also supported by image analysis.     

Muscle fiber growth in olive flounder,Paralichthys olivaceus: Fiber hyperplasia at a specific body weight period and continuous hypertrophy

The objective of this study was to investigate muscle fiber growth‐related attributes, especially fiber hyperplasia and hypertrophy, and their relation to growth characteristics in olive flounder. After a conditioning period, juvenile olive flounder (214 g of initial body weight) were weighed after 0, 4, 8, 12, and 24 weeks of a feeding trial and were selected based on mean body weight at each period (G1, G2, G3, G4, and G5, respectively). During the 3.0‐fold increase in body weight (363.1–1,071 g, p < 0.001), the fiber area was increased approximately 2.2 times (p < 0.05), and the median area increased from the G1 to G5 groups (p < 0.05). The G3 group exhibited a greater fiber number than the G2 group (p < 0.05) as the G3 group exhibited a higher percentage of smaller fiber and mosaic hyperplasia. In addition, a higher percentage of centered nuclei and deoxyribonucleic acid amount in the G2 group were accompanied by an increase in fiber number in the G3 group. Therefore, the muscle growth of olive flounder was influenced by continued fiber area growth and a significant number increase by mosaic hyperplasia during a specific period (G2 to G3 groups; from 512.7 to 670.3 g).     

Biochemical differences in lateral muscle of wild and farmed gilthead sea bream (series Sparus aurata L.)

Red and white muscle from specimens of wild and farmed gilthead sea bream (Sparus aurata) were analyzed for histochemical ATPase activity, total protein content, fatty acids, trace element concentrations and myosin isoforms. The fibre type composition of muscle samples was confirmed histochemically by the ATPase reaction, which did not show any differences between the two groups of animals. Myosin ATPase activities, myosin and protein yields were significantly higher in white muscle than in the red muscle and for the red muscle the latter two parameters were higher in wild fish. Fatty acid profiles revealed differences between the two groups of animals, probably because of the fatty acid composition of the diets. Zinc, copper and iron concentrations were higher in red muscle than in white muscle; muscles from wild fish were significantly richer in trace elements. No separation of fast and slow heavy chains of myosin could be obtained on SDS-gel electrophoresis, but two dimensional electrophoresis revealed the presence of three light chains in white muscle (LC1F, LC2F, LC3F), and two main types in red muscle (LC1S, LC2S). Small, variable percentages of LC3F were found in the red muscle samples, especially in the wild fish. It is concluded that the different environmental conditions, experienced by wild and farmed fish, have significantly influenced the biochemical composition of their lateral muscle.     

Possible degradation of type I collagen in relation to yellowtail muscle softening during chilled storage

ABSTRACT:   In this paper, the detection of type I collagen degradation during the softening phenomenon of yellowtail muscle, was examined. Acid soluble collagen was isolated from dorsal ordinary muscle at death and after 24-h chilled storage. In the abundant ratio of subunit components, an increase in β12 chain (5.4 points) and a decrease in components with molecular weights larger than γ chain (7.0 points) after 24-h chilled storage, was found. Type I collagen was detected in the alkali-soluble fraction by SDS-PAGE. Its amount calculated from hydroxyproline contents in alkali-soluble fraction was increased from 0.097 mg/g muscle to 0.155 mg/g muscle during 24-h storage. The increased alkali-soluble collagen (0.058 mg/g muscle) was about 1.4% of whole collagen. These results suggest that a slight decomposition of type I collagen of yellowtail muscle may occur and subsequently becomes alkali-soluble corresponding to postmortem softening.     

The changes in proximate compositions and glycogen contents in the dorsal ordinary muscles of the full-cycle cultured Pacific bluefin tuna Thunnus orientalis occurring with growth

ABSTRACT:   Using full-cycle cultured (FC) Pacific bluefin tuna (body length [BL], 42.6–66.4 cm; body weight [BW], 1.66–7.40 kg, n  = 15), the changes in chemical compositions and histological structure of the cephalal parts of the dorsal ordinary muscles (DOM) occurring with growth were investigated. A positive correlation ( r  = 0.9644, P  < 0.05) was observed between BL and BW with growth. The protein, lipid and ash contents of DOM and condition factor did not change with growth. However, the glycogen content of DOM increased ( P  < 0.05) from approximately 55 cm (BL) in this study. Using optical microscopic photographs, the various shapes of muscle fibers were observed and it was noted that the muscle fiber diameter increased ( P  < 0.05) with growth. Using transmission electron microscopic observation, many glycogen granules were observed in muscle fibers (especially, side of connective tissue) of DOM throughout the growth stage in this study. These results indicate that the glycogen content of DOM of FC Pacific bluefin tuna increases before the lipid with growth.     

Changes in the pericellular connective tissue and breaking strength of the three types of muscles of the cultured carp Cyprinus carpio during storage in ice

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.     

Changes in Volatile Compounds of Dark and Ordinary Muscles of Yellowtail (Seriola quinqueradiata) During Short-Term Cold Storage

ABSTRACT

Changes in volatile compounds in dark and ordinary muscle of yellowtail during 2 days of refrigerated storage at 5°C were investigated. Twenty-seven compounds were identified in ordinary muscle and 39 in dark muscle during 2 days of storage at 5°C. Thirteen compounds at Day 0 of storage and 29 compounds at Day 2—such as 2,3-pentadione, 1-penten-3-ol, (Z)-2-penten-1-ol, and (E,Z)-2,4-heptadienal—identified in the dark muscle showed significantly higher values compared to ordinary muscle. Levels of thiobarbituric acid-reactive substances (TBARS) in dark muscle were significantly higher than those in ordinary muscle throughout 2 days of storage period, and a significant increase in TBARS occurred in just dark muscle at Day 2 of storage. In ordinary muscle, viable cells remained at the same order of magnitude as their initial values for 2 days. Eight aldehydes in ordinary muscle and 25 volatile compounds in dark muscle increased significantly without microbial action prior to increase in TBARS during short-term cold storage. Principal component analysis of the volatile compounds in dark and ordinary muscle was able to differentiate between different storage time samples of same muscle type as well as different muscle samples of same storage time.     

Changes in Biochemical Compositions and Quality of White Shrimp (Litopenaeus vannamei) During Storage

ABSTRACT

To understand biochemical characteristics, storage stability, and freshness indicators of white shrimp (Litopenaeus vannamei), changes in extractable nitrogenous compounds, microbial count, and sensory rating of white shrimp during storage at 25 and 4°C were investigated. Free amino acids showed a slow increase during storage at 25°C, but no obvious change was found at 4°C. Adenosine triphosphate (ATP) and adenosine diphosphate (ADP) were found at initial stage and decreased rapidly after storage. Both inosine 5′-monophosphate (IMP) and adenosine monophosphate (AMP) increased and then decreased during storage. Inosine, hypoxanthine, and the K-value gradually increased with time. The levels of total volatile basic nitrogen (TVB-N), NH₃, and trimethylamine (TMA) of white shrimp increased with storage time at 25 and 4°C. The TVB-N, NH₃, TMA, inosine, hypoxanthine, and K-value could be considered as freshness indicators of white shrimp during storage. However, the total plate count did not corroborate the acceptability recommended limits for white shrimp during storage. The sensory evaluation, associated with TVB-N, TMA, and K-value, showed the quality was unacceptable after 6 h storage at 25°C and 7 days at 4°C.     

不同脆化阶段草鱼肌肉的显微结构观察和质构特性分析

脆肉鲩作为广东特色水产品之一,其养殖中常出现"不脆"、"半脆"现象,严重制约其产业发展。为探索可鉴定脆度的指标,文章结合生产(饲喂120 d蚕豆+30 d饲料),每30 d采集1次肌肉,检测其感官脆度、肌纤维结构、质构特性的变化。随着脆化时间增加,蚕豆组草鱼感官脆度不断增加(P0.05),肌纤维直径逐渐减小、密度逐渐增大(P0.05);60 d后蚕豆组草鱼质构特性(硬度、弹性、咀嚼性、内聚性、胶黏性)均显著高于对照组(P0.05)。转投30 d饲料对感官脆度、肌纤维结构、质构特性均无显著影响(P0.05)。相关性分析表明,硬度、弹性、咀嚼性、胶黏性与感官脆度的相关性更高(R~20.90,P0.05)。结果表明,硬度、弹性、咀嚼性、胶黏性可用于脆肉鲩的脆度评价,转投30 d饲料不影响其脆度。