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The weak gel strength of Dosidicus gigas surimi restricts its applications in surimi products. However, the addition of hydrocolloids effectively improve this drawback. Psyllium husk powder (PHP) contains high levels of dietary fiber and forms a good quality hydrocolloid when dissolved in water. In this study, different concentrations of PHP were mixed with D. gigas surimi, and the cooking properties, gel properties, cold storage changes, water distribution and microstructure of the composite gel imitation noodles were studied. The addition of PHP deepened the color of the samples, and made the surimi obtain ductility and stretchability similar to grain noodles. When the level of PHP was approximately 10%, the water absorption reached saturation, and the water solubility and water-holding capability began to reduce. The gel strength and tensile modulus showed increasing trends, and the relative tensile rate reached the maximum value of 3.08 when 10% PHP was added. After refrigeration, the sample became softer and less viscous. Microstructure observations revealed that as more PHP was added, the surface became smoother and tighter and the gel network was more uniform. Overall, the composite gel imitation noodles formed by the addition of 10% PHP had the best quality.

The Humboldt squid (Dosidicus gigas), is a significant economic species off Peru. The abundance and distribution of the species are highly susceptible to fluctuations in marine environmental conditions. The evolution of mesoscale eddies represents one of the dynamic processes in the ocean, exerting varying degrees of influence on regional biogeochemical processes from generation to dissipation. However, the mechanisms governing the regulation of abundance and spatial distribution of D. gigas off Peru during this evolution remain unclear. Therefore, this study employed normalization techniques and the habitat suitability index (HSI) model, utilizing data from the D. gigas fishery, mesoscale eddies, and marine environmental factors (including sea surface temperature, temperature at 50 m depth, and chlorophyll-a concentration) to analyze the environmental changes and the abundance, spatial distribution, and habitat changes of D. gigas during the evolution of mesoscale eddies. The results indicate that eddies undergo four stages: formation, intensification, maturity, and decay. During eddy evolution, the abundance of D. gigas exhibited an initial increase and a subsequent decrease within cyclonic eddies (CEs), whereas, within anticyclonic eddies (AEs), abundance showed a gradual decline. The outcome of the HSI model revealed that, the habitat suitability and the proportion of suitable habitat areas within eddies were highly consistent with the abundance of D. gigas during all stages of the eddies other than the intensification stage of AEs. The study speculated that both CEs and AEs can create favorable environmental conditions during the maturity stage, thereby leading to an increase in suitable habitat and abundance of D. gigas. These findings emphasize the significant impact of mesoscale eddy evolution on the abundance and habitat distribution of D. gigas. [ABSTRACT FROM AUTHOR]

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The Humboldt squid (Dosidicus gigas), is a significant economic species off Peru. The abundance and distribution of the species are highly susceptible to fluctuations in marine environmental conditions. The evolution of mesoscale eddies represents one of the dynamic processes in the ocean, exerting varying degrees of influence on regional biogeochemical processes from generation to dissipation. However, the mechanisms governing the regulation of abundance and spatial distribution of D. gigas off Peru during this evolution remain unclear. Therefore, this study employed normalization techniques and the habitat suitability index (HSI) model, utilizing data from the D. gigas fishery, mesoscale eddies, and marine environmental factors (including sea surface temperature, temperature at 50 m depth, and chlorophyll-a concentration) to analyze the environmental changes and the abundance, spatial distribution, and habitat changes of D. gigas during the evolution of mesoscale eddies. The results indicate that eddies undergo four stages: formation, intensification, maturity, and decay. During eddy evolution, the abundance of D. gigas exhibited an initial increase and a subsequent decrease within cyclonic eddies (CEs), whereas, within anticyclonic eddies (AEs), abundance showed a gradual decline. The outcome of the HSI model revealed that, the habitat suitability and the proportion of suitable habitat areas within eddies were highly consistent with the abundance of D. gigas during all stages of the eddies other than the intensification stage of AEs. The study speculated that both CEs and AEs can create favorable environmental conditions during the maturity stage, thereby leading to an increase in suitable habitat and abundance of D. gigas. These findings emphasize the significant impact of mesoscale eddy evolution on the abundance and habitat distribution of D. gigas.

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Dosidicus gigas is a kind of low-fat food with poor gel properties. Fermentation has been proved to be an effective food processing method that could improve the gel properties of meat. Here, we inoculated D. gigas with two strains, Lacticaseibacillus casei and Staphylococcus carnosus, that have been approved for use in meat processing, and studied their impact on the quality of the product. Compared with the uninoculated samples, inoculation with L. casei and mixed inoculation with L. casei and S. carnosus were able to significantly reduce pH during fermentation. The plate counting results showed that L. casei may have adapted well to the environment in the inoculated groups, while the growth of Staphylococcus may have been inhibited in the mixed inoculated group. 16s rRNA sequencing confirmed that inoculation significantly altered the bacterial composition of squid surimi sausages. Both inoculation with L. casei and mixed inoculation with L. casei and S. carnosus were able to inhibit the accumulation of the main biogenic amines, and in the mixed inoculated group, the main biogenic amines were lower. Compared with unfermented squid surimi sausages, mixed inoculation changed the texture, gel properties, color, and appearance of squid surimi sausages. These results showed that mixed inoculation can not only ensure safety, but also improve the quality of squid surimi sausages. [ABSTRACT FROM AUTHOR]

El calamar diamante Thysanoteuthis rhombus Troschel, 1857 es un calamar oceánico circum-global, de tamaño grande y relativamente raro de encontrar; sin embargo, en algunas regiones de Asia tiene interés pesquero. Aquí reportamos el primer registro de juveniles de T. rhombus en el Golfo de Tehuantepec, Pacífico Tropical Nororiental, junto con juveniles de Dosidicus gigas (d’Orbigny, 1835) y datos oceanográficos asociados. Los calamares fueron colectados en la zona oceánica con surgencia y frente termohalino y nivel máximo de clorofila-a (5.5 µg/L), a diferencia de la zona nerítica que fue más salada, con mayor nivel relativo de oxígeno y menor nivel de clorofila-a.

Directed formation of the structure of the culture of living cells is the most important task of tissue engineering. New materials for 3D scaffolds of living tissue are critical for the mass adoption of regenerative medicine protocols. In this manuscript, we demonstrate the results of the molecular structure study of collagen from Dosidicus gigas and reveal the possibility of obtaining a thin membrane material. The collagen membrane is characterized by high flexibility and plasticity as well as mechanical strength. The technology of obtaining collagen scaffolds, as well as the results of studies of its mechanical properties, surface morphology, protein composition, and the process of cell proliferation on its surface, are shown in the given manuscript. The investigation of living tissue culture grown on the surface of a collagen scaffold by X-ray tomography on a synchrotron source made it possible to remodel the structure of the extracellular matrix. It was found that the scaffolds obtained from squid collagen are characterized by a high degree of fibril ordering and high surface roughness and provide efficient directed growth of the cell culture. The resulting material provides the formation of the extracellular matrix and is characterized by a short time to living tissue sorption. [ABSTRACT FROM AUTHOR]

Despite concerns about the environmental impact of microplastics (MPs), knowledge of MP contamination levels in pelagic squid is lacking. This study investigated the stomach of an ecologically and commercially important but poorly known squid species, the jumbo squid Dosidicus gigas, found in the tropical and Southern temperate Pacific. We examined the characteristics and spatial distribution of MPs in fifty D. gigas (16.0–37.8 cm mantle length) and assessed potential MP pollution risks. MPs were detected in 50.0% of specimens and had an average abundance of 0.88 ± 1.12 items/individual and 0.24 ± 0.36 items/g stomach weight, and were sized 58.42–2,944.85 μm. The MPs were dominated by polyethylene terephthalate (31.82%) in polymer type, fragments (54.55%) and fibers (43.18%) in shape, and blue (59.59%) in color. All specimens could be evaluated as low risk. No statistically significant correlations were found between the MP abundances and D. gigas stomach weight, stomach fullness index, distance from the coast, and mantle length. While regression analyses showed that fuller stomachs contained larger MPs. Spatial variations in shape and polymer composition suggest that low-density fibrous MPs could be easily transported offshore by upwelling and/or ocean currents. These results indicate intraspecific variation in D. gigas MP contaminants and underscore the need to assess the potential site-specific ecotoxicological consequences of increased plastic pollution to pelagic squid.

Dosidicus gigas is a kind of low-fat food with poor gel properties. Fermentation has been proved to be an effective food processing method that could improve the gel properties of meat. Here, we inoculated D. gigas with two strains, Lacticaseibacillus casei and Staphylococcus carnosus, that have been approved for use in meat processing, and studied their impact on the quality of the product. Compared with the uninoculated samples, inoculation with L. casei and mixed inoculation with L. casei and S. carnosus were able to significantly reduce pH during fermentation. The plate counting results showed that L. casei may have adapted well to the environment in the inoculated groups, while the growth of Staphylococcus may have been inhibited in the mixed inoculated group. 16s rRNA sequencing confirmed that inoculation significantly altered the bacterial composition of squid surimi sausages. Both inoculation with L. casei and mixed inoculation with L. casei and S. carnosus were able to inhibit the accumulation of the main biogenic amines, and in the mixed inoculated group, the main biogenic amines were lower. Compared with unfermented squid surimi sausages, mixed inoculation changed the texture, gel properties, color, and appearance of squid surimi sausages. These results showed that mixed inoculation can not only ensure safety, but also improve the quality of squid surimi sausages.

Neon flying squid Ommastrephes bartramii and jumbo flying squid Dosidicus gigas are two important commercial ommastrephid species in the Pacific Ocean. As short-lived marine species, squids are highly susceptible to changes in climate and marine environments. According to samples collected from the northwest and southeast Pacific Ocean in different years, we explored the growth characteristics of these two squids in terms of their mantle length (ML) distribution and the relationship between mantle length and body weight (LWR), also considering the relative condition factors (Kn), and explored the effects of the El Niño and Southern Oscillation (ENSO) on their growth. The results showed that the ML for O. bartramii and D. gigas had significant differences among different years and different sexes (p < 0.01), and the size of females was larger than that of males. LWR showed that both squids demonstrated a positive allometric growth pattern (b > 3), and parameters a and b were influenced by year and sex. Furthermore, there were significant differences in Kn in both squids for different years and different sexes (p < 0.01), and their interannual fluctuations were quite significant. In conclusion, the alterations in the marine environment caused by climate change had a significant impact on the growth of O. bartramii and D. gigas in this study. ENSO events had opposite effects on the growth of both squid species. [ABSTRACT FROM AUTHOR]

Jumbo squid Dosidicus gigas play a critical role in the marine ecosystems and are an important commercial species in the East Pacific. Generally, three size groups have been distinguished on the basis of the mantle length (ML) of an adult. Here, fatty acid (FA) analyses of muscle tissues were used to explore the feeding strategies of D. gigas off the Peruvian exclusive economic zone in terms of different size groups and sexes. There was no significant difference in fatty acid composition between the small- and medium-sized groups, whereas the large-sized group differed significantly from other groups. The higher content of C20:4n6 and (C18:2n6 + C18:3n3) indicates that the large-sized group may feed more frequently in nearshore and deep waters. Furthermore, the niches of the three size groups were consistent with the results of fatty acid composition, with the large-sized group occupying the widest trophic niche, followed by the medium-sized group and then the small-sized group. In addition, there was evidence of trophic niche overlap between the small and medium groups. In terms of sexual variability of the small and medium groups, the fatty acid composition significantly differed between females and males. In terms of sexual variation of the large group, the fatty acid composition between females and males was similar, indicating that similar feeding strategies may be adopted by them. This study revealed the variability of the feeding strategies of three size groups of D. gigas off the Peruvian exclusive economic zone. [ABSTRACT FROM AUTHOR]

Con el objetivo de obtener un producto de buenas características fisicoquímicas, microbiológicas y sensoriales, apto para el consumo humano, se realizó el estudio experimental de un proceso de hidrólisis enzimática, utilizando músculo cocido de calamar gigante Dosidicus gigas (Orbigny 1835). Para este fin, se evaluó la interacción idónea entre la proporción de enzima alcalina (Delvolase)/proteína del sustrato (1,6%; 2,4% y 3,2%) y la relación agua/sustrato (1/1 y 1/2), sometiendo cada tratamiento al método de secado por aspersión y, bajo esta condición, se determinó sensorialmente su aceptabilidad. La prueba con mejor calificación sensorial mostró una proporción de enzima/proteína del sustrato de 3,2% y una relación agua/sustrato de 1/2. El análisis proximal del producto presentó valores en proteínas de 79,22 ± 0,1 %; humedad entre 4,47 ± 0,2 %; grasa en 4,30 ± 0,2 %; cenizas entre en 4,10 ± 0,2 % y 7,91 ± 0,5 % de carbohidratos. El producto hidrolizado tuvo un grado de hidrólisis de 12,8 % con pesos moleculares entre 36 y 116 kDa, según lo indicado por el gel de poliacrilamida PAGE-SDS al 15%. Finalmente, el análisis microbiológico mostró ausencia de microorganismos patógenos, lo que garantizó la inocuidad del producto en aras de su consumo.

This study aimed to investigate the effect of temperature and time changes in two typical thermal processing procedures, frying and baking, on squid quality. Increasing the frying/baking temperature and prolonging the time significantly impacted color, L* value decreased over time, and a* value increased (P < 0.05). Total nitrogen, non-protein nitrogen, and cadaverine levels increased significantly after thermal process (P < 0.05), whereas histamine levels increased and subsequently reduced, which was attributed to the process of lipid oxidation. The concentration of pyrazine was dramatically increased (fried: 3.01 ∼ 1468.27 µg/kg; baked: 0.00 ∼ 836.14 µg/kg). The hierarchical cluster analysis was applied to analyze the complicated raw data of squid in order to evaluate the quality under different frying/baking conditions. Squid, whether fried or baked, took on a deeper color, contained more protein per unit weight, and tasted more desirable, although the histamine levels rose at certain temperatures as well. This study indicated the appropriate cooking methods and conditions could help to preserve nutrition while keeping histamine levels under control.

The synchronous response of the spatial distribution pattern of Dosidicus gigas and Trachurus murphyi habitat along the Chilean waters to different-intensity El Niño events was examined based on the habitat suitability index (HSI) models inclusive with the key environmental factors of sea surface height anomaly (SSHA), sea surface salinity (SSS), water temperature at 400-m depth (Temp_400 m) for D. gigas, sea surface temperature (SST), mixed layer depth (MLD), Temp_400 m for T. murphyi, and Niño 1 + 2 index. Results showed that all the environmental factors except MLD were significantly correlated with the Niño 1 + 2 index. Compared with weak (WE) and moderate (ME) El Niño events, the suitable range of SSHA and SSS for D. gigas decreased, resulting in a decreased suitable habitat area and increased poor habitat area during the strong (SE) El Niño years. In space, the suitable habitat of D. gigas was mainly distributed in north-central Chile with an east–west strip pattern; it decreased significantly in the northwestern waters off Chile and moved southwestward under SE El Niño events. For T. murphyi, the ME El Niño events yielded a contracted suitable range of water temperature and MLD decreased, consequently leading to a decreased suitable habitat area and increased poor habitat area of T. murphyi compared to WE and SE El Niño events. The suitable habitat of T. murphyi was mainly distributed in the 42°–47°S area and varied non-significantly during the WE and SE El Niño events; however, it clearly decreased in the southwest area of Chile and shifted northeastward under ME El Niño events. Our results indicated that El Niño events with different intensities strongly affected the habitat pattern of D. gigas and T. murphyi off Chile by changing the regional marine environment.

Jumbo squid (Dosidicus gigas) plays an important role in food webs throughout the eastern Pacific; however, its trophic ecology is complex, because it is a highly migratory and opportunistic predator. In this study, δ13C and δ15N values were measured along the lateral wall of lower beak to investigate the ontogenetic and spatiotemporal feeding strategy shifts of jumbo squid, respectively. Both year and area had significant influences on δ13C (p < 0.01), while sex and stage had no significant influence on δ13C (p > 0.05). All explanatory variables (sex, stage, year, and area) had significant influences on δ15N (p < 0.05). The differences of niche among life stages indicated that the habitat and feeding habit were likely changed with the growth of individuals. Compared with normal years, the habitat of squids might change during the El Niño year. However, during the strong El Niño year, habitat location changed and niche size decreased compared to normal years. The trophic niche of D. gigas differed between different areas. Stable isotopes in early life stages were most effective for distinguishing different geographic populations. Females and males were likely to inhabit similar geographic areas throughout ontogeny. Unexpectedly, we found evidence to suggest females may have larger habitats and wider trophic niche than males. This study revealed the ontogenetic and spatiotemporal plasticity of habitat and feeding strategy of D. gigas.

Neon flying squid (Ommastrephes bartramii) and jumbo flying squid (Dosidicus gigas) are two commercially essential oceanic squids in the Pacific Ocean. An in-depth understanding of the mechanisms of their annual and interannual abundance fluctuations under environmental and climate variabilities can ensure ration and suitable management. Thus, the annual and interannual abundance fluctuations of the stock of the western winter-spring cohort of O. bartramii and D. gigas off Peru Exclusive Economic Zone (PEEZ) waters and their association with habitat temperature variabilities are explored in this study based on the historical Chinese Squid-jigging fishery data from 2003 to 2020. The habitat temperature variabilities were defined as the effective principal components of the SST at the squids’ two important habitats (spawning and feeding ground) through life histories according to the principal component analysis. The Hodrick—Prescott filter analysis was conducted to quantify the annual and interannual fluctuations of abundance and habitat temperature variabilities. Furthermore, the generalized additive model (GAM) was employed to investigate their associations. The results demonstrated different but not synchronous trends of abundance for O. bartramii and D. gigas. Regarding O. bartramii, the interannual abundance first decreased (2003∼2013) and then increased (after 2014). For D. gigas, the interannual abundance kept decreasing within 2003∼2020. Their annual trends have presented large fluctuations over years. The results of GAM indicated that using habitat temperature variabilities only can trace the abundance trend of O. bartramii and D. gigas at an interannual but not annual scale. Further studies verified that Pacific Decadal Oscillation (PDO) is a crucial factor affecting the interannual abundance trend of these two squids through the habitat temperature variabilities. However, this study indicates that the habitat temperature variabilities not only are related to other large-scale factors, which are not investigated currently at an interannual scale, but also, are combined with other small- or middle-scale factors at an annual scale on their impacts to the abundance fluctuations of these two squids. Therefore, in order to better explain the mechanisms of annual and interannual abundance fluctuations of O. bartramii and D. gigas under environmental and climate variabilities, the importance of combining other potential factors into consideration is highlighted.

In this study, the eddy characteristics on the fishing ground of the Humboldt squid (Dosidicus gigas) in the eastern equatorial Pacific Ocean were detected based on geometrical characteristics with the flow field during April–June 2017. The influence of the eddies on the biophysical environment, D. gigas abundance, and habitat distribution were explored. The habitat was identified by fishery data, sea surface temperature (SST), vertical water temperature, and chlorophyll-a (Chl-a). Results indicated that the eddy lifetime was relatively short, with only three eddies persisting for more than 2 weeks. The number of eddies in each month showed a similar variability trend with the monthly average catch per unit effort (CPUE) of D. gigas. Two eddies were taken with a lifetime of above 2 weeks, which revealed that the environmental conditions around the eddies significantly changed. When the eddy persisted for 8–10 days, SST and vertical temperature gradually decreased, but Chl-a significantly increased. The habitat quality of D. gigas gradually increased, and the gravity center of the fishing ground was consistent with eddy movement. The eddy-induced Ekman pumping led to the transportation of deep waters with rich nutrients into the euphotic layer, promoted the reproduction of bait organisms, and yielded favorable water temperature conditions for D. gigas. These environmental changes aided the formation of high-quality habitats, which increase D. gigas abundance and catch and drive the shift of the gravity centers of fishing grounds with the eddy. Our findings suggested that eddy activities have significant impacts on D. gigas abundance and habitat distribution.

Commercially important pelagic squid such as jumbo squid Dosidicus gigas play a key role in energy and nutrient transfer in marine ecosystem. Geographic variations in the foraging strategy of D. gigas can provide valuable information on cephalopod trophic diversification and adaption to natural and anthropogenic impacts. Here, we used a novel combination of stable isotope (SI) and fatty acid (FA) analyses of muscle tissues and morphometric measurements of feeding apparatuses to evaluate spatial patterns of habitat and resource use of D. gigas collected from three main fishing grounds in the tropical and southern temperate Pacific Ocean. Results showed that the δ13C and δ15N values were different among geographic stocks within D. gigas, possibly because of site-specific dietary sources and isotopic baseline values. Spatial variabilities in FA profiles/biomarkers, combined with SI results, suggests two foraging patterns: utilization of resources mainly from oceanic food webs or from both neritic and oceanic food webs. This behavior likely promotes the site-specific trophic niche width, increases adaptation to inhabiting oceanographic conditions, and could be driven by differences in feeding apparatuses morphology, body size, and trophic position. These results emphasize the dietary flexibility of D. gigas and their important ecological roles in ecosystems as cross-biome trophic linkages. Trophic diversification of pelagic squid like D. gigas may have important implications for their population dynamics, ecological associations, and subsequent management.

The process of thermal gelation involves protein denaturation, leading to the exposure of functional groups to form new interactions; these conformational changes favour protein-water- protein interactions and help to stabilise the gel. It is known that in muscle proteins, myofibrillar proteins such as myosin are responsible for the main functional properties; however, in invertebrate species, actin and paramyosin exert an influence on the rheological properties of the gels. Therefore, in the present work, the gelling property of the actomyosin-paramyosin complex was studied. There were significant differences (p < 0.05) in hardness and water-retention capacity, which was higher for actomyosin-paramyosin isolate (API) than for mantle proteins (MP). This may have been due to its structure being more porous than that of MP, which is agglomerated. The API system favoured protein-protein and water-protein interactions; these formed stronger cross-links, which in turn favoured gelling. Moreover, the presence of sarcoplasmic proteins may be more of a physical-chemical impediment rather than hydrolysis caused by endogenous proteases. [ABSTRACT FROM AUTHOR]

The present study investigated the flavour characteristics and key volatile components of fermented squid (Dosidicus gigas) as well as their formation mechanism by three different starter cultures of lactic acid bacteria (LAB) and natural squid. The sensory assessment, volatile compounds, as well as the amino acids of the mixed fermented squid were detected using pickled brine as samples of fermented squid. A total 88 types of volatile compounds were found in four samples by 0–72 h of fermentation. After fermentation by LAB, the volatile compounds of squid showed that the fermented squid with different started cultures differed mainly in terms of numbers of alcohols, ketones, and esters. Furthermore, the amounts of volatile compounds among three starter cultures were also obviously different. Gas Chromatography-Mass Spectrometer (GC-MS) analysis indicated that the mixed fermentation process contained relatively higher (+)-limonene (11.71%) (lemon scent) and 3-hydroxy-2-butanone (5.72%) (creamy taste). These compounds were not detected in the control group. The main flavour compounds of nonanal and 2, 4-decadienal were gradually reduced. Meanwhile, 2, 3-butanedione, 2-heptanone, 2-pentylfuran, and nonanoic acid are the key flavour components. The total principal component is 94.01%, which were clarified by electronic nose in combination with principal components analysis. After mixed fermentation by LAB, the total amino acid (TAA) content reached 85.36 g/100 g, which was almost twice the amount of the control, especially in aspartate, glutamate, and threonine. Our results indicated that LAB has obvious effects on deodorization and flavour promotion during the fermentation of squid. This study provided an important basis for the further development and utilization of squid.

Ommastrephid squids are short-lived ecological opportunists and their recruitment is largely driven by the surrounding environment. While recent studies suggest that recruitment variability in several squid species can be partially explained by environmental variability derived from synoptic oceanographic data, assessment of ommastrephid stocks using environmental variability is rare. In thisstudy, we modified asurplus production model to incorporate environmental variability into the assessment of threeommastrephid squids (Ommastrephes bartramii in the northwest Pacific, Illex argentinus in the southwest Atlantic and Dosidicus gigas in the southwest Pacific). We assumed that the key environmental variables—suitable sea surface temperature on spawning grounds during the spawning seasons and feeding grounds during the feeding seasons—have effects on the carrying capacity and the instantaneous population growth rate, respectively, in the surplus production model. For each squid stock, the assessment model with environmental variability had the highest fitting accuracy and the lowest mean squared error and coefficient of variation, and the management reference points based on the optimal model were more precautionary. This study advances our understanding of the interactions between the environment and ommastrephid squid population dynamics and can therefore improve the management of these commercially valuable stocks with a short life cycle.

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Summary: Only 50%–60% of total seafood catch is used for human consumption, seafood processing being considered as one of the main sources of by‐products. Among marine species, jumbo squid (JS; Dosidicus gigas) represents the most important squid fishery, showing an increasing economic interest in many countries. As for any other marine species, the regular cleaning, dressing and processing produce high quantities of by‐products (skin, head, fins, viscera, tentacles, unclaimed mantle, etc.) that are rich in many nutrients (proteins, lipids, minerals, vitamins, enzymes, biopolymers, etc.). This review compiles information about extraction and employment of JS by‐products with the aim of enhancing their economic value and reduce environmental drawbacks. A special emphasis is given to the relevance in developing methods susceptible to transform by‐products into useful and profitable products susceptible to be applied in several industries such as food, medicine, agrochemical or pharmaceutical. Future possible trends for widening this profitable use are mentioned. [ABSTRACT FROM AUTHOR]

Gelatines from three different jumbo squid (Dosidicus gigas) by-products (fins, arms, and skin) were compared based on their chemical and biochemical properties (amino acid composition, molecular weight distribution, and in vitro digestibility), antioxidant capacity (ABTS+ and ORAC assays) and effect on oxidative stress biomarkers (serum antioxidant capacity (TAC) and serum malondialdehyde levels (MDA)) in healthy rats. Gelatine from the skin showed the highest polar and imino amino acid contents and a higher proline hydroxylation degree. Gelatine β-component was not detected in either fins or arms. These differences may explain the higher in vitro digestibility and higher antioxidant capacity (before and after digestibility) of the skin gelatine. Fin gelatines decreased TAC-ORAC values. All obtained gelatines decreased the MDA levels. Jumbo squid gelatine, administered during feeding, may help decrease a breakdown product of spontaneous lipid peroxidation in serum.

Objetivo: Realizar un análisis bioeconómico de la pesquería de calamar gigante Dosidicus gigas en el noroeste de México. Metodología: La dinámica poblacional del recurso fue modelada con el algoritmo de Schaefer (1954) usando dos pares de valores de la tasa intrínseca de crecimiento poblacional (r) que representa el aumento de una población en un período determinado y de la capacidad de carga del ambiente (k): r = 1.23-1, k = 243,836 t y r = 1.68 año-1, k =190,468 t. Se emplearon datos oficiales de capturas anuales de 1974-2012 y de esfuerzo pesquero de 2010-2012 para pangas y barcos, ya que 2012 es el último año con capturas comerciales, previo al colapso de la pesquería que inició en 2013 y que a la fecha permanece. Los costos de operación y precios de venta del producto fueron obtenidos mediante entrevistas con productores pesqueros de la región. Se aplicaron el modelo biológico de Schaefer y el modelo bioeconómico de dos flotas compitiendo por un stock, con poder de pesca y costos de operación y valor del producto diferentes.Resultados: El esfuerzo aplicado en 2012 estaba cerca del esfuerzo necesario para obtener el máximo rendimiento económico fMRE en ambas flotas, y el esfuerzo total autorizado estaría operando en condiciones económicas sub-óptimas entre el esfuerzo en el máximo rendimiento económico fMRE y el esfuerzo en equilibrio bioeconómico fEB, alcanzando un equilibrio poblacional EP en 34 % de k, independiente de los valores de r y k utilizados. La biomasa en equilibrio económico BEEC estimada fue muy baja, del orden de 16 % de k para pangas y de 32 % de k para barcos: Las pangas se ubicaron por debajo del punto de referencia límite PRL de 20 % de k establecido en la Carta Nacional Pesquera de México 2012 (Diario Oficial de la Federación, 2012) para varias especies.Limitaciones: No hay datos posteriores a 2012; Se asume un coeficiente de capturabilidad constante. Conclusiones: De existir una capturabilidad denso-dependiente, la biomasa estimada debió estar más baja que la pronosticada por el modelo biológico de 19 %, lo que implica que se pudo haber llegado al fMRE de las pangas, en un nivel de biomasa de riesgo para el stock.

ABSTRACT. The jumbo squid Dosidicus gigas is the most abundant cephalopod species in the southeastern Pacific Ocean, which supports the biggest cephalopod fishery in the world. Due to its growing economic importance, the population growth and distributional expansion of this squid is being increasingly studied. Nevertheless, some basic features of the biology of D. gigas are still unknown or have been poorly investigated. In this review we summarize the known information regarding the biology and ecology of this species in the southeastern Pacific Ocean; we focus on the Chilean region in order to propose hypotheses and research lines for a better understanding the life history of this organism. Available data on the size structure, reproduction and genetics of D. gigas allows us to propose hypotheses related to the squid's life history traits. Based on the current literature and publications of colleagues, we propose two hypotheses regarding the effect of spatial variation on the life history of D. gigas. Hypothesis 1: Squids mature at large sizes and spawn in oceanic waters with warm temperatures where paralarvae and juveniles develop. Immature squids migrate near shore to feed, grow and mature, and then return to the offshore sites to spawn. Hypothesis 2: Alternatively, juvenile D. gigas in the oceanic zone do not migrate to coastal waters and mature at small sizes compared to individuals living near the coast that mature at larger size and migrate to oceanic waters to spawn. We provide background information about the feeding behavior and parasitism of this species, suggesting that D. gigas is an important trophic link in the southeastern Pacific marine ecosystem. However, more studies on the feeding habits, reproduction and parasite load are needed not only to test hypotheses proposed in this study, but also to advance the overall knowledge of this species.

The population dynamics of jumbo squid Dosidicus gigas from northwest Mexico was evaluated for the period 1974-2012 using Schaefer's model, where model parameters were estimated with the catch maximum sustainable yield method (Catch-MSY) using two prior intrinsic population increase rate (r) range values (1.0 to 2.0 and 1.5 to 2.0). Estimated parameters with both prior r ranges were 1.23 and 1.68 yr-1 for r and 243,836 and 190,468 ton for carrying capacity (k), respectively. Corresponding management quantities were 75,147 and 80,098 ton for the maximum sustainable yield (MSY) and 121,918 and 95,234 ton for the biomass at MSY (BMSY). Estimated jumbo squid biomass dropped below the BMSY after 2003, and near to 0.2 k in 2012. The Schaefer's model showed that declines in estimated biomass were preceded by catches that exceeded the MSY. Strong El Niño-Southern Oscillation events can change the availability of jumbo squid in northwest Mexico through migratory processes and phenotype changes in maturation size, but stock biomass variability is most likely to be caused by fishing. [ABSTRACT FROM AUTHOR]

El propósito de la investigación fue determinar la composición proximal y propiedades funcionales del surimi liofilizado de calamar gigante (Dosidicus gigas). Se elaboró surimi a partir de calamar gigante y fue liofilizado hasta obtener surimi en polvo para evaluar sus características y propiedades funcionales. El contenido de proteínas fue 58,7% y carbohidratos 30,5%. La solubilidad proteica en agua y sal (3%) fueron 21,1% y 40,6% respectivamente, siendo estos valores superiores a surimi en polvo de especies comerciales. La capacidad de gelificación fue 2,4% y la capacidad emulsificante fue 79,9% a una concentración del 1,0%. El color en la escala de Hunter fue L*: 91,5; a*: 0,5; b*:7,0. El surimi en polvo de calamar gigante fue considerado como un polvo proteico funcional debido a su contenido porcentual proteico, y tuvieron buenas características tecnológicas y de gran potencial en la industria alimentaria.

Jumbo squid (Dosidicus gigas) is one of the largest cephalopods, and represents an important economic fishery in several regions of the Pacific Ocean, from southern California in the United States to southern Chile. Large and considerable discards of this species, such as skin, have been reported to constitute an important source of potential by-products. In this paper, a shotgun proteomics approach was applied for the first time to the characterization of the jumbo squid (Dosidicus gigas) skin proteome. A total of 1004 different peptides belonging to 219 different proteins were identified. The final proteome compilation was investigated by integrated in-silico studies, including gene ontology (GO) term enrichment, pathways, and networks studies. Potential new valuable bioactive peptides such as antimicrobial, bioactive collagen peptides, antihypertensive and antitumoral peptides were predicted to be present in the jumbo squid skin proteome. The integration of the global proteomics results and the bioinformatics analysis of the jumbo squid skin proteome show a comprehensive knowledge of this fishery discard and provide potential bioactive peptides of this marine by-product.

The present study investigated the flavour characteristics and key volatile components of fermented squid (Dosidicus gigas) as well as their formation mechanism by three different starter cultures of lactic acid bacteria (LAB) and natural squid. The sensory assessment, volatile compounds, as well as the amino acids of the mixed fermented squid were detected using pickled brine as samples of fermented squid. A total 88 types of volatile compounds were found in four samples by 0-72 h of fermentation. After fermentation by LAB, the volatile compounds of squid showed that the fermented squid with different started cultures differed mainly in terms of numbers of alcohols, ketones, and esters. Furthermore, the amounts of volatile compounds among three starter cultures were also obviously different. Gas Chromatography-Mass Spectrometer (GC-MS) analysis indicated that the mixed fermentation process contained relatively higher (+)-limonene (11.71%) (lemon scent) and 3-hydroxy-2-butanone (5.72%) (creamy taste). These compounds were not detected in the control group. The main flavour compounds of nonanal and 2, 4-decadienal were gradually reduced. Meanwhile, 2, 3-butanedione, 2-heptanone, 2-pentylfuran, and nonanoic acid are the key flavour components. The total principal component is 94.01%, which were clarified by electronic nose in combination with principal components analysis. After mixed fermentation by LAB, the total amino acid (TAA) content reached 85.36 g/100 g, which was almost twice the amount of the control, especially in aspartate, glutamate, and threonine. Our results indicated that LAB has obvious effects on deodorization and flavour promotion during the fermentation of squid. This study provided an important basis for the further development and utilization of squid. [ABSTRACT FROM AUTHOR]

Age determination of the jumbo squid ( Dosidicus gigas) has been successfully carried out over its geographic range based on the use of the rings present in the statoliths. In this study, we propose an additional method to identify ages of D. gigas off the Ecuadorian and Chilean Exclusive Economic Zones (EEZs) waters by using upper beak rostrum sagittal section (RSS) analysis. Our results show periodic growth increments and occasional checks located in the RSS surface. Growth increments meet at the internal rostral axis in the shape of chevron, and the marks in the hood are more discernable and clearer than in the crest. As has been suggested for octopi, checks are thought to represent temperature oscillation and reproductive events. Growth increments are laid down in the RSS daily, and numbers were similar to the numbers of increments used to determine age in statoliths. There was a significant regional difference in age but not in increment width when mantle length effects were considered, where squid off the warm Ecuadorian EEZ waters had a shorter lifespan and higher somatic growth in mantle length than those in the temperate Chilean EEZ waters. [ABSTRACT FROM AUTHOR]

Here we summarize the current knowledge on the transfer and accumulation of harmful algal bloom (HAB)-related toxins in cephalopods (octopods, cuttlefishes and squids). These mollusks have been reported to accumulate several HAB-toxins, namely domoic acid (DA, and its isomers), saxitoxin (and its derivatives) and palytoxin (and palytoxin-like compounds) and, therefore, act as HAB-toxin vectors in marine food webs. Coastal octopods and cuttlefishes store considerably high levels of DA (amnesic shellfish toxin) in several tissues, but mainly in the digestive gland (DG)—the primary site of digestive absorption and intracellular digestion. Studies on the sub-cellular partitioning of DA in the soluble and insoluble fractions showed that nearly all DA (92.6%) is found in the cytosol. This favors the trophic transfer of the toxins since cytosolic substances can be absorbed by predators with greater efficiency. The available information on the accumulation and tissue distribution of DA in squids (e.g., in stranded Humboldt squids, Dosidicus gigas) is scarcer than in other cephalopod groups. Regarding paralytic shellfish toxins (PSTs), these organisms accumulate them at the greatest extent in DG >> kidneys > stomach > branchial hearts > posterior salivary glands > gills. Palytoxins are among the most toxic molecules identified and stranded octopods revealed high contamination levels, with ovatoxin (a palytoxin analogue) reaching 971 μg kg−1 and palytoxin reaching 115 μg kg−1 (the regulatory limit for PlTXs is 30 μg kg−1 in shellfish). Although the impacts of HAB-toxins in cephalopod physiology are not as well understood as in fish species, similar effects are expected since they possess a complex nervous system and highly developed brain comparable to that of the vertebrates. Compared to bivalves, cephalopods represent a lower risk of shellfish poisoning in humans, since they are usually consumed eviscerated, with exception of traditional dishes from the Mediterranean area.

Four oceanic squid species, Ommastrephes bartramii, Dosidicus gigas, Sthenoteuthis oualaniensis and Illex argentinus, not only support important commercial fisheries, but also play a vital role in their marine ecosystems. It is therefore important to identify them in the analyses of their predators’ stomach contents as this can yield critical information on the trophic dynamics of ecosystems. Hard beaks of the four species frequently found in their predators’ stomachs can be used to identify them. In this study, to remove the effect of size differences among individuals, measurements of upper and lower beaks were standardized with an allometric model. A discriminant analysis was carried out to compare morphological differences among the four species and between the sexes for each species. The upper rostral width and upper rostral length showed the greatest interspecific variation in the beak morphological variables of the four Ommastrephidae. The linear discriminant functions of beak morphological variables were developed for the four Ommastraphidae, which resulted in a rate of correct species classification of over 97%. Sexual dimorphism was also found in the beak morphology of O. bartramii and I. argentinus. This study suggests that morphological variables can be used to reliably classify Ommastrephidae at genus level, which can help identify the specie in the stomachs of cephalopod predators. This helps to improve the understanding of the role cephalopods play in their marine ecosystems.

Acoustic surveys for assessing the biomass and distribution of the jumbo squid (Dosidicus gigas) and the lightfish (Vinciguerria lucetia) were carried out in the Humboldt Current System of Peru in 2007 and 2008. At the same time, 937 jumbo squid were caught and their stomach contents analyzed. The diet of the jumbo squid was dominated by mesopelagic fish. The first component of their fish diet was V. lucetia and the second component was the myctophid fish Diogenichthys laternatus. Acoustic biomass estimates of these species show that V. lucetia is an important component in aggregative structures in the Humboldt Current System of Peru and its distribution and movements are closely related to the migratory movements of the jumbo squid. The trophic relationship observed between D. gigas and V. lucetia promotes an increase in jumbo squid biomass and, has a positive trophic effect on the ocean ecosystem.

The jumbo flying squid Dosidicus gigas is widely distributed in the eastern Pacific Ocean and supports an important fishery. Although many studies have been carried out on the biology of this species, limited biological information is available in the waters outside the Exclusive Economic Zone of Chile (EEZ) (20°S-41°S and 74°30’W-84°W). Three surveys were conducted in this area by the Chinese squid jigging vessels during the period from April 2006 to May 2008. The majority of the catch in the survey was from the two areas defined by 37°30’-41°S and 78°30’-80°W and by 25°-30°S and 76°-77°30’W. The sex ratio (M: F) of the catch was 1: 2.48. The mean mantle length (ML) was 376 mm for males with a range of 257-721 mm and 388.7 mm for females with a range of 236-837 mm. Two distinguished size classes, medium- and large-sized groups, were identified in this study with the medium-sized group (350-450 mm ML) consisting of 89% of the total catch. The sizes at first sexual maturity were 638 mm ML for females and 565 mm ML for males. This study suggests that all the individuals examined were hatched from March 2007 to February 2008, indicating that D. gigas might spawn all year around with a peak spawning time from November 2007 to January 2008. Most of the stomachs analyzed had food remains. The preys included three major groups: fish (mainly lanternfish), cephalopods and crustaceans, but D. gigas was the dominant species in the stomach contents, showing strong evidence of cannibalism. The information obtained from this study improves our understanding of the fishery biology of D. gigas off Chile.