Mantle Muscle Research Articles

Effect of organic salts on setting gels and their corresponding acids on kamaboko gels prepared from squid Todarodes pacificus mantle muscle

The present study evaluated the quality of setting gels prepared by adding sodium acetate, sodium gluconate, sodium citrate, and sodium succinate to Todarodes pacificus mantle muscle meat, and of the acid-induced kamaboko gels produced by soaking the setting gels in their corresponding acid solutions. The breaking strength was the lowest for the setting gel treated with sodium acetate. The pH values of the acid-induced kamaboko gels decreased when soaked in acid, whereas their moisture contents, whitenesses, and breaking strengths increased. The citric acid-induced kamaboko gel had the highest whiteness index and breaking strength among the gels. The sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) patterns did not show large differences among the gels, except for a low-intensity polymer band in the gluconic acid-induced kamaboko gel. Sodium citrate combined with citric acid yielded the best-quality acid-induced kamaboko gel among all the combinations, so this condition was used to study the effect of organic salt levels. The breaking strength increased when a sodium citrate level of up to 3% was used for the sodium citrate-treated setting gel, and 10% for the citric acid-induced kamaboko gel. The SDS-PAGE patterns did not differ among the sodium citrate levels. Egg white and microbial transglutaminase were necessary for citric acid-induced kamaboko gel production.

Effect of lyophilized jumbo squid (Dosidicus gigas) fin and mantle muscle on dough properties and bread baking performance of commercial wheat flour

The effect of 25 and 50 g/kg of lyophilized jumbo squid (Dosidicus gigas) fin (JSF) and mantle muscle (JSM) on dough properties and baking performance of wheat flour were studied. Dough maximum resistance (R max), extensibility, deformation work (Area, 45-min resting time), baking performance, loaf volume, and acceptability were evaluated. JSF (25 g/kg) almost tripled (P≤ 0.05) R maxcompared to control dough, while JSF or JSM (50 g/kg) doubled it (P≤ 0.05). As animal protein increased on blend, extensibility decreased (65.6 ± 4.5 for control versus 39.5 ± 1.4 and 26.7 ± 2.0 for 25 and 50 g/kg JSF, respectively). JSF or JSM (25 g/kg) increased (P≤ 0.05) 2.4 and 1.8 times the control area, respectively. Addition of 50 g/kg JSF or JSM significantly affected specific loaf volume decreasing it. Sensory results showed that a low level powder addition (25 g/kg) could be used for bread production.

II-2. 通電加熱によるイカ筋肉プロテアーゼの活性制御

II-2. 通電加熱によるイカ筋肉プロテアーゼの活性制御

Distribution of APGWamide-immunoreactivity in the brain and reproductive organs of adult Pygmy squid, Idiosepius pygmaeus

The neuropeptide APGWamide is involved in the control of the reproductive behavior in molluscs. Using immunocytochemistry, we investigated the distribution of APGWa-immunoreactive neurons in the brain and reproductive organs of adult male and female specimen of Idiosepius pygmaeus. The study showed that the APGWamide-immunoreactive neurons and fibers are localized in the dorsal basal and vertical lobes of the supraesophageal mass, the palliovisceral lobe of the posterior subesophageal mass and olfactory lobe of the optic tract in male brains, with the highest number of APGWamide-immunoreactive neurons in the palliovisceral and olfactory lobes. In females, only the palliovisceral and olfactory lobes contained APGWa-immunoreactive neurons. The number of APGWamide-immunoreactive neurons in male I. pygmaeus brain is significantly higher than in females. Furthermore, APGWamide-immunoreactive fibers are localized exclusively in male reproductive organs and mantle muscles. Together these data suggest a role for APGW-amide in the control of male reproduction.

Effects of plasticizer type and concentration on the physicochemical properties of edible film from squid Todarodes pacificus mantle muscle

Physical properties of edible film from squid Todarodes pacificus mantle muscle plasticized with different plasticizers (glycerol, sorbitol, glucose, and fructose) at various concentrations (10%, 20%, and 30% w/w of protein) were determined. The results showed that tensile strength (TS) significantly decreased (P < 0.05) while elongation at break significantly increased (P < 0.05) upon plasticizer addition. Water vapor permeability (WVP) significantly increased (P < 0.05) upon addition of glycerol or sorbitol but significantly decreased (P < 0.05) upon addition of glucose or fructose. Among the plasticizers used in this study, glycerol showed the greatest ability to decrease film TS. However, glycerol-plasticized film was less transparent than those with other plasticizers. Addition of glucose or fructose seemed to decrease the WVP of the film via a Maillard reaction. However, change in film color also occurred to a greater degree than for glycerol- or sorbitol-plasticized film.

Thermodynamic characterization of muscle tropomyosins from marine invertebrates

Structural properties of invertebrate muscle tropomyosin (TM) have not been characterized in detail to date. TMs were thus purified from the mantle muscle of Japanese common squid Todarodes pacificus, the foot muscle of tokobushi abalone Haliotis diversicolor and the tail muscle of kuruma prawn Marsupenaeus japonicus, and investigated for their thermodynamic properties by circular dichroism (CD) spectrometry and differential scanning calorimetry (DSC). From the CD spectrometry data, the apparent melting temperature and the apparent free energy of unfolding at 20°C were calculated to be 43.5°C and 14.5 kJ/mol for the squid TM, 43.0°C and 23.9 kJ/mol for the abalone TM, and 47.3°C and 50.2 kJ/mol for the prawn TM, respectively. From the DSC data, the total free energy of unfolding at 20°C was calculated to be 129 kJ/mol, 253 kJ/mol, and 271 kJ/mol for the squid, abalone, and prawn TMs, respectively. These results suggest that the thermal stability was in the order of prawn TM>abalone TM>squid TM.

Stabilizing effect of Ca2+ on myosin and myofibrils of squid mantle muscle as affected by heating conditions

The suppressive effects of Ca2+ on the thermal denaturation of myosin and myofibrils of squid mantle muscle were compared. The stabilization effect on myosin was smaller than that on myofibrils and was not affected by KCl concentration. The stabilizing effect of Ca2+ on myosin decreased as the heating temperature dropped, showing no stabilization at 20°C, while the effect on myofibrils was the same at all temperatures tested. The stabilizing effect of Ca2+ on myosin disappeared even at 30°C in the presence of sorbitol, where a small inactivation rate was found, while the effect of Ca2+ on myofibrils was equally detected irrespective of the reduction in inactivation rate in the presence of sorbitol. Stabilization of myosin by Ca2+ again appeared even in the presence of sorbitol when the heating temperature was raised to 38°C. It was suggested that Ca2+ confers stabilization on myosin only when myosin is under unstable conditions. The stabilization effect of Ca2+ on myosin was enhanced upon F-actin binding: Ca2+-bound myosin was more significantly stabilized by F-actin binding, and the effect was no longer affected by the conditions for heating.

Effect of setting conditions on mechanical properties of acid-induced Kamaboko gel from squid Todarodes pacificus mantle muscle meat

Squid Todarodes pacificussuwari gels, set at various temperatures and times, and acid-induced kamaboko gel, which was prepared by soaking suwari gel in 5% acetic acid for 20 h, were studied to evaluate the mechanical properties that are affected by setting conditions. Unset squid meat paste did not form a gel when soaked in acetic acid. The breaking strength of both suwari gel and acid-induced kamaboko gel showed a tendency to increase with setting temperature and time. SDS-PAGE analysis of suwari gel and acid-induced kamaboko gel, which were set at various temperatures and times, showed that myosin heavy chain (MHC) was observed at 30°C only for the first hour. The intensity of the MHC band at 30°C gradually decreased with setting time, while the intensity of the polymer band gradually increased with setting time. These results suggest that the protein-protein bonds in suwari gel affect the final texture of acid-induced kamaboko gel. Based on the analysis of the mechanical properties, and in consideration of the fact that the purpose of this experiment was to reduce energy usage, the best setting condition was determined to be 40°C for 3 h.

Novel Design for a Biomimetic Water-Jetting Propulsion Vehicle Actuated by SMA Wires

An experimental biomimetic water-jetting propulsion vehicle for robot cuttlefish is presented. Firstly the cuttlefish swimming mode and mantle muscle structure is analyzed as the theory basis. Secondly the vehicle is designed and manufactured. The vehicle is actuated by SMA wires. Through rational structural design, it can achieve flexible water-jetting propulsion like cuttlefish mantle. Thirdly the geometrical model of the biomimetic mantle cross section is built. At last, the performance of the propulsion machine is tested by experiment. The experimental results are mainly about the response curves of the mantle outside diameter, the strain of SMA wire and the swimming displacement with time. The maximum contractive distance of the biomimetic mantle along the vertical direction is 6 mm, the maximum strain of SMA wire is -1.8 %. The maximum swimming speed is 45 mm/s.

Utilization of Oryzacystatin for Regulating the Ripening of Squid Shiokara, a Traditional Japanese Salted and Fermented Seafood

Shiokara is a fermented seafood composed of sliced squid mantle muscle ripened with fresh squid liver. Preliminary sensory evaluation by using the ranking test revealed that the hardness of squid muscle in shiokara was reduced within 7 d of ripening. During the process of ripening, muscle proteins were digested by proteinases present in squid liver. The degradation of paramyosin and myosin heavy chain was observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The hardness of squid mantle muscle in shiokara was reduced with the degradation of paramyosin and myosin heavy chain. This degradation was mainly caused by E-64-sensitive cysteine proteinases. To control the hardness of shiokara, we used rice seed oryzacystatin, which suppresses proteolysis by papain-like cysteine proteinases. When oryzacystatin was added 4 d after the start of shiokara ripening, the muscle protein degradation stopped, without further muscle softening. These results show that oryzacystatin is useful to control the ripening of shiokara by regulating its hardness.

Predator cues alter the timing of developmental events in gastropod embryos

Heterochrony, differences in the timing of developmental events between descendent species and their ancestors, is a pervasive evolutionary pattern. However, the origins of such timing changes are still not resolved. Here we show, using sequence analysis, that exposure to predator cues altered the timing of onset of several developmental events in embryos of two closely related gastropod species: Radix balthica and Radix auricularia. These timing alterations were limited to certain events and were species-specific. Compared with controls, over half (62%) of exposed R. auricularia embryos had a later onset of body flexing and an earlier occurrence of the eyes and the heart; in R. balthica, 67 per cent of exposed embryos showed a later occurrence of mantle muscle flexing and an earlier attachment to, and crawling on, the egg capsule wall. The resultant developmental sequences in treated embryos converged, and were more similar to one another than were the sequences of the controls for both species. We conclude that biotic agents can elicit altered event timing in developing gastropod embryos. These changes were species-specific, but did not occur in all individuals. Such developmental plasticity in the timing of developmental events could be an important step in generating interspecific heterochrony.

Proteomic Interrogation of Venom Delivery in Marine Cone Snails: Novel Insights into the Role of the Venom Bulb

Cone snails of the genus Conus are predatory marine gastropods mainly found in the shallow waters of the tropics and warm temperate seas. To prey on other marine organisms including fish, cone snails have evolved complex venoms synthesized and delivered by a highly sophisticated venom apparatus. Upon prey discovery, the venom is perfused through a harpoon-like radula tooth and rapidly injected into the prey to cause paralysis. While the venom components of cone snails have been intensively characterized, the mechanism of venom translocation and loading prior to and during injection remains elusive. The involvement of the venom bulb, a muscular dilation of the venom gland has been suggested, however evidence is sparse. Here, we use a combination of proteomics, molecular biology, and morphological examination to elucidate the potential role of the venom bulb in venom translocation and delivery. Analysis of the venom bulb proteome clearly demonstrated a function of this organ in muscular movement and, more interestingly, in burst muscle contraction. Morphological examination revealed high structural similarities to the mantle muscle of squids, animals known for their rapid escape response. We sequenced and further characterized arginine kinase, a key protein of rapid muscular movement in invertebrates and show high concentrations of this enzyme in the bulb when compared to the venom gland and the foot muscle. Proteins characteristic for venom biosynthesis were low in abundance. On the basis of our findings, we suggest that the bulb of cone snails is a highly specialized organ of venom translocation. Delivery of venom is driven by burst contractions of the bulb rapidly forcing the venom through the radula tooth into the prey.

Edible film from squid ( Todarodes pacificus) mantle muscle

Mantle muscle meat of Japanese common squid ( Todarodes pacificus) was used to produce edible films in this study. The solubility of squid mantle muscle proteins increased upon addition of NaCl and organic salts (Na-citrate, Na-benzoate, Na-acetate and Na-tartrate). At concentrations below 2%, among organic salts, Na-citrate appeared to have the highest ability to dissolve proteins. Film-forming solutions were prepared by dissolving squid mantle meat in 0.5% or 1% salt solutions at neutral pH. Physical properties and SDS–PAGE of the films were determined. The film-forming solution prepared with 0.5% Na-citrate gave the transparent film with the highest tensile strength and least degradation of myosin heavy chain. Organic salt type at the same concentration had no significant effects ( p ⩾ 0.05) on water vapour permeability (WVP) of the films. The films showed excellent UV barrier properties. In addition, organic salts gave no significant effects ( p ⩾ 0.05) on light barrier properties and transparency of the films except for NaCl and Na-tartrate which were crystallised during the drying process. These results suggested that Na-citrate is the most useful for producing the edible films from squid mantle muscle among the organic salts examined in this study.

Effect of phospholipid n‐3 polyunsaturated fatty acids on rat lipid metabolism

AbstractIt has been demonstrated that the amount and type of dietary fat are factors involved in the risk of arteriosclerosis and coronary or cerebral artery disease through lipid metabolism. In this study, we investigated the effects of phospholipids (PLs) containing n‐3PUFAs on lipid metabolism in rats. PLs containing n‐3PUFAs were prepared from squid (Todarodes pacificus) mantle muscle. Groups of male Wistar rats were fed AIN93G diet containing soybean oil (SO, 7%), fish oil (1.2%) + SO (5.8%), soybean PLs (1.8%) + SO (5.2%), or PLs containing n‐3PUFAs (1.8%) + SO (5.2%). The following indicators were assayed as indexes of lipid metabolism: TAG and cholesterol in serum and liver, fecal cholesterol, bile‐acid excretion, and liver mRNA expression levels of genes encoding proteins involved in cholesterol homeostasis. Serum and liver TAG contents decreased significantly in the group fed PLs containing n‐3PUFAs as compared to other groups, accompanied by a significant decline in the expression level of sterol regulatory element binding protein‐1c. The decrease in cholesterol content in the group fed PLs containing n‐3PUFAs was due to the increase in fecal cholesterol excretion and the increase of mRNA expression levels of ATP‐binding cassette (ABC) G5 and ABCG8 in liver.Practical applications: PLs containing n‐3PUFAs decreased serum and liver TAG contents compared with that induced by soybean PLs. Further, PLs containing n‐3PUFAs can induce a reduction in serum and liver cholesterol concentrations as well as the triglyceride‐reducing effect of conventional n‐3PUFAs containing TAG. In other words, dietary n‐3PUFAs contained in PLs can prevent life‐style diseases such as hyperlipidemia, arteriosclerosis and coronary, or cerebral artery disease more effectively than TAG containing n‐3PUFAs. Therefore, it is expected that the risk of lifestyle diseases would be decreased if PL containing n‐3PUFAs can be supplied routinely. In this study, PLs containing n‐3PUFAs were prepared from squid mantle muscle. On an industrial scale, such PLs can be produced from various unused resources and waste materials of fisheries. We conclude that highly functional foods could be developed based on the findings of this study, and would be available for health promotion worldwide.

Metabolic physiology of the Humboldt squid, Dosidicus gigas: Implications for vertical migration in a pronounced oxygen minimum zone

The Humboldt (or jumbo) squid, Dosidicus gigas, is an active predator endemic to the Eastern Pacific that undergoes diel vertical migrations into a pronounced oxygen minimum layer (OML). Here, we investigate the physiological mechanisms that facilitate these migrations and assess the associated costs and benefits. Exposure to hypoxic conditions equivalent to those found in the OML (∼10 μM O 2 at 10 °C) led to a significant reduction in the squid’s routine metabolic rate (RMR), from 8.9 to 1.6 μmol O 2 g −1 h −1 ( p < 0.05), and a concomitant increase in mantle muscle octopine levels (from 0.50 to 5.24 μmol g −1 tissue, p < 0.05). Enhanced glycolitic ATP production accounted for only 7.0% and 2.8% at 10 °C and 20 °C, respectively, of the energy deficit that resulted from the decline in aerobic respiration. The observed metabolic suppression presumably extends survival time in the OML by conserving the finite stores of fermentable substrate and avoiding the accumulation of the deleterious anaerobic end products in the tissues. RMR increased significantly with temperature ( p < 0.05), from 8.9 (at 10 °C) to 49.85 μmol O 2 g −1 h −1 (at 25 °C) which yielded a Q 10 of 2.0 between 10 and 20 °C and 7.9 between 20 and 25 °C ( p < 0.05). These results suggest that 25 °C, although within the normal surface temperature range in the Gulf of California, is outside this species’ normal temperature range. By following the scattering layer into oxygen-enriched shallow water at night, D. gigas may repay any oxygen debt accumulated during the daytime. The dive to deeper water may minimize exposure to stressful surface temperatures when most prey have migrated to depth during the daytime. The physiological and ecological strategies demonstrated here may have facilitated the recent range expansion of this species into northern waters where expanding hypoxic zones prohibit competing top predators.

APPLICATION OF ORGANIC ACIDS FOR TEXTURE MODIFICATION OF OCTOPUS (OCTOPUS VULGARIS) MUSCLE

ABSTRACT The effect of using organic acids to tenderize octopus (Octopus vulgaris) muscle during heat processing was investigated. They can decrease the stability and increase the solubility of the collagen that is responsible for the toughness of the octopus muscle. Acetic, lactic or citric acid was added at 0.05 and 0.1 M levels during the heat processing of octopus. Toughness was assessed by measuring the force required for a 2‐mm probe to fully penetrate a 5‐mm thick mantle muscle segment using a TA‐XT2i texture analyzer. Addition of the organic acids resulted in significant tenderization compared with the untreated control. No difference in the tenderizing effect of acetic, lactic and citric acids was observed. Differences in the cooking yield of the octopus were observed to be caused by the lowering of the pH of the muscle by the citric acid.PRACTICAL APPLICATIONSThe effect of the application of organic acids on octopus muscle was investigated. Based on the results of the study, application of acetic or lactic acid in low concentrations can significantly reduce toughness of octopus muscle and, thus, decrease the duration of the heat processing required to achieve the desired texture, without compromising the yield of the processed product and, thus resulting in significant cost and energy savings.

Relationship between Tissue Structural Collapse and Disappearance of Flesh Transparency during Postmortem Changes in Squid Mantles

This study evaluated the relationship between squid flesh transparency and muscle tissue microstructure. Squid mantle muscle was stored at 4 degrees C after being transported for 2 h by 4 different transportation methods used commonly in Japan (Group 1: live squid packed in ice-cold seawater; Group 2: live squid packed at 4 degrees C; Group 3: squid killed immediately after harvest and packed at 4 degrees C; Group 4: live squid packed in a fish tank containing seawater). Parameters of muscle tissue transparency were measured by an image analysis of digital images of squid muscle tissue. The mantle muscle tissue was observed under a transmission electron microscope to determine the postmortem structural changes at the cellular level. The ATP content of muscle tissue and rupture energy of squid flesh were also measured. As a result, the transparency of squid flesh and the ATP content of the muscles showed the same pattern of change in degree as time passed. The values of these parameters were highest in the group of squid killed immediately followed in order by those transported live, the refrigerated squid, and squid stored in ice-cold seawater. The mantle muscle tissue started to lose its transparency when the ATP in the muscle tissue started to decline. Disintegration of squid muscle tissue structure at the cellular level during storage under refrigeration for 24 h (4 degrees C) was observed in all methods of transportation. This suggested that destruction of the squid muscle tissue structure by autolysis is remarkably fast. The muscle tissue structure disintegrates due to decomposition of the muscle proteins, and muscle transparency is lost because the entire muscle develops a mixed coarse-minute structure.

Partial characterization of an effluent produced by cooking of Jumbo squid ( Dosidicus gigas) mantle muscle

Jumbo squid ( Dosidicus gigas) mantle muscle was cooked simulating industrial procedures (95 °C × 25 min, 1.2:5 muscle:water ratio). The effluent produced was analyzed for chemical and biochemical oxygen demands (COD and BOD 5, respectively), proximate analysis, flavor-related compounds (free amino acids, nucleotides and carbohydrates) and SDS–PAGE. The COD and BOD 5 exhibited variation among samplings ( N = 3) (27.4–118.5 g O 2/L for COD and 11.3–26.7 g O 2/L for BOD 5). The effluent consisted of 1% total solids, 75% of which represented crude protein. Sixty percent of the total free amino acid content, which imparts flavor in squid species, corresponded to glutamic acid, serine, glycine, arginine, alanine, leucine and lysine. The nucleotide concentration followed this order, Hx ≫ ADP > AMP > ATP > IMP > HxR. The variation observed in the present work was probably due to physiological maturity differences among the squid specimens (i.e., juvenile versus mature). Solids present in squid cooking effluent could be recovered and potentially used as flavor ingredients in squid-analog production by the food industry.

Hot-water solubility of mantle collagens in several cephalopod molluscs

The mantle muscles of five cephalopod species, Todarodes pacificus, Photololigo edulis, Sepioteuthis lessoniana, Sepia esculenta, and Sepia longipes, were extracted with 0.1 M NaOH to prepare crude collagen fiber, called ‘residue after alkali extraction’ (RS-AL). Solubility of the collagens in water was examined in the temperature range 20–90°C. The collagens showed a similar tendency in solubility, which gradually increased depending on the treating temperature, and the values at 40–90°C were constantly less than 47.0% for all the species examined. In addition, the collagens were estimated to denature in the approximate temperature range of 37.5–42.5°C. These results suggest that the collagens in RS-AL from these species may have relatively high resistance to hot-water extraction even after their denaturation.

Lipid composition and diet inferences of abyssal macrourids in the eastern North Pacific

The lipid compositions of 2 abyssal macrourids, Coryphaenoides armatus and C. yaqui- nae, from the eastern North Pacific were examined and used to infer diet. The resulting fatty acid (FA) profiles are the first published for C. yaquinae and among the first for abyssal fishes. They indicated a greater proportion of polyunsaturated FAs and lower monounsaturated FAs than shallower living con- geners, suggestive of homeoviscous adaptations to great pressure. Cholesterol was the predominant sterol, which is frequently the case for exclusively car- nivorous species. Comparisons of macrourid FA pro- files were made to those of benthic prey and epipelagic carrion sources, including the Humboldt squid Dosidicus gigas captured in surface waters of the abyssal study site. The FA profiles of macrourid muscle were very similar to those of squid mantle muscle. The FA profiles of macrourid liver and swim- bladder were similar to benthic crustaceans, whole squid, squid digestive gland and the epipelagic fish Trachurus symmetricus. For both tissues, the FA pro- files of echinoderms were the most different. These comparisons suggest a strong link to carrion and ben- thic crustaceans and a weak one to echinoderms, the dominant megafauna at the study site and in most of the abyssal ocean. These results support previous stomach content and stable isotope analyses, reinforc- ing the hypothesis that there are closer food web ties between abyssal fishes and epipelagic nekton than to many abyssal benthic groups.