Squid Mantle Research Articles

Quality of Refrigerated Squid Mantle Cut Treated with Mint Extract Subjected to High-Pressure Processing.

Squid (Loligo vulgaris) is commonly prone to spoilage, leading to a short shelf-life. High-pressure processing (HPP) can play a role in maintaining the quality and freshness of squid. Along with HPP, food preservatives from natural sources such as mint extract (ME), which are effective, safe, available, and cost-effective, are required. The present study aimed to investigate the combined effect of ME and HPP on the quality of refrigerated squid mantle cuts (SMC) over a period of 15 days. The time-kill profiles of ME and planktonic cell inactivation by HPP were assessed. ME (400 mg/L) inhibited bacterial growth, while planktonic cells treated with HPP (400 MPa) exhibited a reduction at 5 min. Physicochemical and microbial qualities of SMC treated with ME (0, 200, 400 mg/L) followed by HPP (0.1, 200, 400 MPa) for 5 min were monitored during refrigerated storage. Samples treated with ME (400 mg/L) and HPP (400 MPa) exhibited lower weight loss, cooking loss, pH changes, volatile base content, microbial counts, and higher textural properties than other samples. Based on next-generation sequencing results, Brochothrix campestris from family Listeriaceae was the predominant spoilage bacteria in treated sample after 12 days of storage. Therefore, ME and HPP combined treatments exhibited effectiveness in extending the shelf-life of refrigerated SMC.

Effects of Heating Treatment on the Physicochemical and Volatile Flavor Properties of Argentinian Shortfin Squid (Illex argentinus).

In this study, the effect of different heating temperatures (80, 90, 100, and 121 °C) on the physicochemical and volatile flavor properties of fried mantles (Argentinian shortfin) was investigated. The squid mantles were soaked in a maltose syrup solution (20% w/v) for 10 s and fried in soybean oil for 10 s (160 °C), vacuum-packed, and processed at different temperatures for 10 min. Then, the squid mantles were subjected to colorimetric analysis, sensory evaluation, free amino acid analysis, and texture profile analysis. In addition, the volatile organic compounds (VOCs) in the squid mantles were analyzed. The results revealed that lower treating temperatures (80 and 90 °C) improved the chromatic and textural properties, along with organoleptic perception. Additionally, the content of amino acid in the squid mantles treated at 121 °C was significantly lower than that of the samples treated at other temperatures (p < 0.05). Headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) was used to detect 41 VOCs, including their monomers and dimers. Among these detected VOCs, the contents of alcohols, ketones, and pyrazines were positively correlated with temperature. However, the content of aldehydes in the squid mantles gradually decreased as the heating temperature increased (p < 0.05). The combined HS-GC-IMS and E-nose results revealed that the lower temperatures (80 and 90 °C) were more suitable for flavor development and practical processing. This study provides valuable information for properly controlling the heating process of squid products, as well as flavor and practical applications for the aquatic industry.

A Comprehensive Investigation of Tenderization Methods: Evaluating the Efficacy of Enzymatic and Non-Enzymatic Methods in Improving the Texture of Squid Mantle — A Detailed Comparative Study

AbstractIn this study, enzymatic [papain (P), bromelain (B), and A. oryzae-derived fungal protease (FP); enzyme ratios: 0.012 (v/v), 38 °C, 50 min] and non-enzymatic [control (C; saline), mineral water (95%)–lemon juice (5%) (ML) (1/2:w/v), 38 °C, 50 min)] tenderizing methods on European squid mantle (Loligo vulgaris Lamarck, 1798) were investigated. Scanning electron microscope (SEM) imaging, water holding capacity (WHC), cooking loss (CL), total free amino acids (TFAA), total soluble protein (TSP), hydroxyproline (Hyp), and Fourier-transform infrared spectroscopy (FTIR) analyses were performed on uncooked samples. pH, water activity (aw), color, nutritional changes, amino acids (AA), total volatile basic-nitrogen (TVB-N), Warner-Bratzler shear (WBS), texture profile analysis (TPA), and sensory evaluations were performed on both uncooked and cooked samples. A significant decrease in protein content was observed in group P (12.86%) compared to untreated (U) squid (15.16%). During frying, group P absorbed more cooking oil (8.37%) than the other groups. A higher degree of hydrolysis was observed in the enzymatically tenderized groups than in non-enzymatic groups, and a shift in secondary protein structures in favor of random coils. Hydrolysis was confirmed by Hyp and AA analyses. The total AA content order was found as B &lt; P &lt; FP &lt; C &lt; ML &lt; U. ML and FP groups have relatively higher total bitter and umami AA compositions, especially in uncooked samples. FP and ML groups had more favorable results across all analyses, especially in terms of the sensory results, nutritional values, and TPA results of cooked samples. It is concluded that both methods are very convenient regarding industrial usage.

Comparison of physicochemical and volatile flavor properties of neon flying squid (Ommastrephes bartramii), jumbo squid (Dosidicus gigas), and Argentine shortfin squid (Illex argentinus) during chilled storage.

The difference and similarities in the physicochemical and volatile flavor properties were determined in neon flying squid (OB), jumbo squid (DG), and Argentine squid (IA) mantles during 8 days of chilled storage. Physicochemical analysis indicated the chilled conditions induced rapid increases in pH value, total volatile basic nitrogen (TVBN), and carbonyl and malondialdehyde (MDA) content of the three squid species. In addition, myofibrillar protein (MP) content decreased and springiness in the OB, DG, and IA mantle samples declined with the extension of storage time. Importantly, OB mantles presented less chemical stability than the other two squid samples during 8 days of chilled storage. In addition, histological observations suggest DG mantle tissues presented more compact structures than those of the other two samples. Volatile flavor analysis showed propionaldehyde, 3-pentanone, trimethylamine, 3-furanmethanol, 2-methyl butyric acid, and 2-butanone were highly abundant in the squid mantles after storage, likely resulting from decomposition, oxidation, and degradation of proteins and lipids in the squid mantle, which varied with different squid species. The findings provide insight into the performance of three squid species during chilled storage.

Squid/synthetic polymer double-network gel: elaborated anisotropy and outstanding fracture toughness characteristics

The hierarchical anisotropy of a biotissue plays an essential role in its elaborate functions. To mimic the anisotropy-based functions of biotissues, soft and wet synthetic hydrogels with sophisticated biotissue-like anisotropy have been extensively explored. However, most existing synthetically manufactured anisotropic hydrogels exhibit fundamental anisotropy and poor mechanical toughness characteristics. In this paper, natural/synthetic hybrid double-network (DN) hydrogels with hierarchical anisotropy and high toughness characteristics are reported. These DN gels are prepared directly by using a squid mantle as an anisotropic soft bioproduct for the primary network and polyacrylamide (PAAm) as a synthetic polymer for the secondary network. The obtained squid/PAAm DN gel maintains the complex orientation of the muscle fibers of the squid mantle and exhibits anisotropic, enhanced mechanical properties and excellent fracture resistance due to its unique composite structure. This hybrid strategy provides a general method for preparing hydrogels with elaborated anisotropy and determining functions derived from the anisotropy.

Evaluating the effects of nanoparticles combined ultrasonic-microwave thawing on water holding capacity, oxidation, and protein conformation in jumbo squid (Dosidicus gigas) mantles

Magnetic nanoparticles (MNPs) have a dual role in acting as magnetic and sonosensitizer agents, which can combine the synergistic effects of microwave and ultrasonic waves. To study the effects of MNPs combined ultrasonic-microwave thawing (NUMT) on the water holding capacity (WHC), oxidation of protein and lipid, and protein conformation, jumbo squid mantles were subjected to cold storage thawing (CST), MNPs combined ultrasonic thawing (NUT), MNPs combined microwave thawing (NMT) and NUMT. Results showed that NUMT treatment had a higher WHC, lower oxidation, effectively reduced myofibrillar protein aggregation and degradation, and stabilized the structure of the protein of the jumbo squid. The muscle fiber structure of NUMT treated jumbo squid mantles was dense, orderly with a smooth surface, and the fiber network gaps were small and uniformly distributed. This study shows that NUMT can ameliorate the thawing qualities of jumbo squid, and is an effectively thawing method.

Ascaridoid nematodes infecting commercially important marine fish and squid species from Bangladesh waters in the Bay of Bengal

Parasitic ascaridoid nematodes occur in a wide range of marine organisms across the globe. Some species of the anisakid family (Ascaridoidea: Anisakidae) can cause gastrointestinal disease in humans (i. e. anisakidosis). Despite their importance as potentially hazardous parasites, the occurrence and infection characteristics of ascaridoids are still poorly known from many host species and geographical areas. This study investigated the diversity and infection levels of ascaridoid parasites in various commercial fish and squid host species off Bangladesh. Fish and squid specimens were visually inspected for nematodes using the UV-press method. Nematodes were assigned to genus level based on morphology and identified by sequence analyses of the entire ITS region and partial 28S rDNA and mtDNA cox2 genes. Third-stage larvae (L3) of Anisakis typica occurred at low prevalence (P = 10% and 8%, respectively) in the viscera of Selar crumenophthalmus and Trichiurus lepturus, while Hysterothylacium amoyense occurred in the viscera of Sardinella fimbriata (P = 1%) and the viscera and muscle of Harpadon nehereus (P = 32%) and T. lepturus (P = 76%). Lappetascaris sp. Type A L3 occurred in the mantle of the squid Uroteuthis duvaucelii (P = 11%). Anisakis and Lappetascaris species, and H. amoyense were firstly identified in the Bay of Bengal. The potentially zoonotic A. typica was only found in fish viscera. Hysterothylacium amoyense and Lappetascaris sp., both generally regarded as non-zoonotic, occurred at low prevalence in the muscle or mantle of fish or squid, respectively. Since consumption of raw or lightly processed seafood seems to be rare in Bangladesh, the risk of acquiring anisakidosis from consuming fishery products from off Bangladesh appears to be low. Due to its reddish appearance, the visual presence of H. amoyense larvae in fish flesh may represent a food quality issue.

Interaction of Squid (Dosidicus giga) Mantle Protein with a Mixtures of Potato and Corn Starch in an Extruded Snack, as Characterized by FTIR and DSC

The majority of snacks expanded by extrusion (SEE) are made with vegetable sources, to improve their nutritional content; it has been proposed to incorporate squid (Dosidicus gigas), due to its high protein content, low price and high availability. However, the interaction of proteins of animal origin with starch during extrusion causes negative effects on the sensory properties of SEE, so it is necessary to know the type of protein–carbohydrate interactions and their effect on these properties. The objective of this research was to study the interaction of proteins and carbohydrates of SEE elaborated with squid mantle, potato and corn. The nutritional composition and protein digestibility were evaluated, Fourier transform infrared (FTIR) and Differential Scanning Calorimetry (DSC) were used to study the formation of protein–starch complexes and the possible regions responsible for their interactions. The SEE had a high protein content (40–85%) and biological value (&gt;93%). The melting temperature (Tm) was found between 145 and 225 ◦C; the Tm values in extruded samples are directly proportional to the squid content. The extrusion process reduced the amine groups I and II responsible for the protein–protein interaction and increased the O-glucosidic bonds, so these bonds could be responsible for the protein–carbohydrate interactions.

A Collagen Basketweave from the Giant Squid Mantle as a Robust Scaffold for Tissue Engineering.

The growing applications of tissue engineering technologies warrant the search and development of biocompatible materials with an appropriate strength and elastic moduli. Here, we have extensively studied a collagenous membrane (GSCM) separated from the mantle of the Giant squid Dosidicus Gigas in order to test its potential applicability in regenerative medicine. To establish the composition and structure of the studied material, we analyzed the GSCM by a variety of techniques, including amino acid analysis, SDS-PAGE, and FTIR. It has been shown that collagen is a main component of the GSCM. The morphology study by different microscopic techniques from nano- to microscale revealed a peculiar packing of collagen fibers forming laminae oriented at 60–90 degrees in respect to each other, which, in turn, formed layers with the thickness of several microns (a basketweave motif). The macro- and micromechanical studies showed high values of the Young’s modulus and tensile strength. No significant cytotoxicity of the studied material was found by the cytotoxicity assay. Thus, the GSCM consists of a reinforced collagen network, has high mechanical characteristics, and is non-toxic, which makes it a good candidate for the creation of a scaffold material for tissue engineering.

Gastrophysical and chemical characterization of structural changes in cooked squid mantle.

Squid (Loligo forbesii and Loligo vulgaris) mantles were cooked by sous vide cooking using different temperatures (46°C, 55°C, 77°C) and times (30 s, 2min, 15min, 1 h, 5h, 24h), including samples of raw tissue. Macroscopic textural properties were characterized by texture analysis (TA) conducted with Meullenet-Owens razor shear blade and compared to analysis results from differential scanning calorimetry. The collagen content of raw tissues of squid was quantified as amount of total hydroxyproline using ultra-high-performance liquid chromatography. Structural changes were monitored by Raman spectroscopy and small-angle X-ray scattering and visualized by second harmonic generation microscopy. Collagen in the squid tissue was found to be highest in arms (4.3% of total protein), then fins (3.0%), and lowest in the mantle (1.5%), the content of the mantle being very low compared to that of other species of squid. Collagen was found to be the major protein responsible for cooking loss, whereas both collagen and actin were found to be key to mechanical textural changes. A significant decreased amount of cooking loss was obtained using a lower cooking temperature of 55°C compared to 77°C, without yielding significant textural changes in most TA parameters, except for TA hardness which was significantly less reduced. An optimized sous vide cooking time and temperature around 55-77°C and 0.5-5h deserves further investigation, preferably coupled to sensory consumer evaluation. PRACTICAL APPLICATION: The study provides knowledge about structural changes during sous vide cooking of squid mantle. The results may be translated into gastronomic use, promoting the use of an underutilized resource of delicious and nutritious protein (Loligo vulgaris and Loligo forbesii).

The Hydration Characteristics, Structural Properties and Volatile Profile of Squid (Symplectoteuthis oualaniensis) Mantle Muscle: Impacts of Steaming, Boiling, and Sous Vide Cooking.

Herein, the effects of boiling (BO), steaming (ST), and sous vide (SV) on the hydration characteristics, structural properties, and volatile profile of squid (Symplectoteuthis oualaniensis) mantle muscle (SMM) were investigated. Three cooking methods resulted in a dramatic decrease in proton mobility and freedom of protons, the relaxation time T2 decreased after cooking, and the water binding in the SMM was closer, but the SV treatment could retain more water in the SMM. SV resulted in a lower cooking loss (10.8%) than ST (49.0%) and BO (36.7%). Samples treated with SV had a better color and texture, the secondary structure β-fold of the squid protein was damaged by cooking to a certain extent, and the damage degree was BO > ST > SV. Compared with BO and ST, SV treatment caused more damage to the myosin heavy chain, paramyosin, and actin in SMM, improved the tenderness of SMM, and resulted in more regular internal reticular structures and less formation of fibrous structures. Cooking methods can significantly affect the volatile components of SMM, resulting in increasing volatile components or generating new volatile components in SMM including 2-methylbutanal, ethyl 2-methylpropanoate, acetic acid, and propyl methyl ketone in ST and BO samples and 2-methylbutanal, hexanal, and 2,3-pentanedione in SV samples. Therefore, SV resulted in the best quality squids and has substantial industrial application potential.

The differences of muscle proteins between neon flying squid (Ommastrephes bartramii) and jumbo squid (Dosidicus gigas) mantles via physicochemical and proteomic analyses

Neon flying squid (OB) and jumbo squid (DG) mantles were evaluated to reveal the similarities and differences in their physicochemical features and protein abundances. Microstructural results indicated that the OB mantle exhibited numerous myofibril fragments and disordered microstructures after frozen storage compared with DG tissues. Chemical analysis suggested that freezing resulted in a rapid decrease in myofibrillar protein (MP) content, Ca2+-ATPase activity, and total sulfhydryl content, and promoted the increase in carbonyl content of MPs in both OB and DG. While, DG presented better MP stability than OB muscle after 120 days of frozen storage. Label-free proteomic analysis detected 24 down- and 33 up-regulated differentially abundant proteins (DAPs) in OB and DG mantles. Identified DAPs including isocitrate dehydrogenase and malic enzyme initiated a rapid decrease in the MP properties in OB samples. Moreover, DAPs were related to cytoskeleton function, including paramyosin, tropomyosin, and troponin C, which improved the stability of DG in response to freezing-induced changes.

Interaction of Squid (Dosidicus giga) Mantle Protein with a Mixtures of Potato and Corn Starch in an Extruded Snack, as Characterized by FTIR and DSC.

The majority of snacks expanded by extrusion (SEE) are made with vegetable sources, to improve their nutritional content; it has been proposed to incorporate squid (Dosidicus gigas), due to its high protein content, low price and high availability. However, the interaction of proteins of animal origin with starch during extrusion causes negative effects on the sensory properties of SEE, so it is necessary to know the type of protein–carbohydrate interactions and their effect on these properties. The objective of this research was to study the interaction of proteins and carbohydrates of SEE elaborated with squid mantle, potato and corn. The nutritional composition and protein digestibility were evaluated, Fourier transform infrared (FTIR) and Differential Scanning Calorimetry (DSC) were used to study the formation of protein–starch complexes and the possible regions responsible for their interactions. The SEE had a high protein content (40–85%) and biological value (>93%). The melting temperature (Tm) was found between 145 and 225 °C; the Tm values in extruded samples are directly proportional to the squid content. The extrusion process reduced the amine groups I and II responsible for the protein–protein interaction and increased the O-glucosidic bonds, so these bonds could be responsible for the protein–carbohydrate interactions.

SMA active fiber pumps inspired by the squid mantle

Squid possess a mantle that is able to quickly compress an internal fluid, thus providing a jetting locomotion that enables them to be the fastest aquatic invertebrates. The mantle possesses a complex collagen fiber and muscular system, and the primary propulsion is accomplished through circumferential muscles (90°) contracting around the mantel. In addition, jetting is enhanced through elastic energy stored in the helically-wound IM-1 collagen fibers. The angles of these fibers have been measured between 28° and 32° in different species of squid. Inspired by the muscular fiber configuration found in the mantle of squid, novel pumps that use shape memory alloy (SMA) active fibers oriented at precise angles around a cylindrical shell are investigated through experiments and analytical studies. A thermomechanical model of an SMA fiber is presented and the parameters are identified through experiments. Using the thermomechanical model of the SMA fiber, an analytical model of the SMA active fiber pump is presented and is validated through experiments. Results show that maximum pumping power and efficiency is achieved for pumps when the matrix modulus is less than the fiber modulus and the optimal fiber wind angle is ±55°. When the matrix modulus is similar to the fiber modulus, maximum pumping performance is achieved with a wind angle of ±90°, similar to the angle of the circumferential muscles in the squid mantel.

Vibrio fischeri Amidase Activity Is Required for Normal Cell Division, Motility, and Symbiotic Competence.

N-Acetylmuramoyl-l-alanine amidases are periplasmic hydrolases that cleave the amide bond between N-acetylmuramic acid and alanine in peptidoglycan (PG). Unlike many Gram-negative bacteria that encode redundant periplasmic amidases, Vibrio fischeri appears to encode a single protein that is homologous to AmiB of Vibrio cholerae We screened a V. fischeri transposon mutant library for strains altered in biofilm production and discovered a biofilm-overproducing strain with an insertion in amiB (VF_2326). Further characterization of biofilm enhancement suggested that this phenotype was due to the overproduction of cellulose, and it was dependent on the bcsA cellulose synthase. Additionally, the amiB mutant was nonmotile, perhaps due to defects in its ability to septate during division. The amidase mutant was unable to compete with the wild type for the colonization of V. fischeri's symbiotic host, the squid Euprymna scolopes In single-strain inoculations, host squid inoculated with the mutant eventually became colonized but with a much lower efficiency than in squid inoculated with the wild type. This observation was consistent with the pleiotropic effects of the amiB mutation and led us to speculate that motile suppressors of the amiB mutant were responsible for the partially restored colonization. In culture, motile suppressor mutants carried point mutations in a single gene (VF_1477), resulting in a partial restoration of wild-type motility. In addition, these point mutations reversed the effect of the amiB mutation on cellulosic biofilm production. These data are consistent with V. fischeri AmiB possessing amidase activity; they also suggest that AmiB suppresses cellulosic biofilm formation but promotes successful host colonization.IMPORTANCE Peptidoglycan (PG) is a critical microbe-associated molecular pattern (MAMP) that is sloughed by cells of V. fischeri during symbiotic colonization of squid. Specifically, this process induces significant remodeling of a specialized symbiotic light organ within the squid mantle cavity. This phenomenon is reminiscent of the loss of ciliated epithelium in patients with whooping cough due to the production of PG monomers by Bordetella pertussis Furthermore, PG processing machinery can influence susceptibility to antimicrobials. In this study, we report roles for the V. fischeri PG amidase AmiB, including the beneficial colonization of squid, underscoring the urgency to more deeply understand PG processing machinery and the downstream consequences of their activities.

Physicochemical characterization of sous vide cooked squid (Loligo forbesii and Loligo vulgaris) and the relationship to selected sensory properties and hedonic response

The present study aims at promoting the use of squid in Scandinavia, a currently unexploited, and possible sustainable source of protein, available in the local waters. By a gastrophysical approach, the effects of sous vide cooking time and temperature on the mantle of squid (Loligo forbesii and Loligo vulgaris) were quantitatively assessed to obtain good eating quality, evaluated by Danish consumers (n = 141) coupled to physicochemical characterisation by texture analysis (TA) using the Warner-Bratzler shear blade and by differential scanning calorimetry (DSC). Consumers rated the squid samples well above neutral for the most liked samples, indicating a possible market for squid among Danish consumers. A positive hedonic rating of squid was found to be independent of gender and familiarity with eating squid, but some dependence of age was identified where the “younger” half of the consumers (<50 years) rated the squid higher in hedonic response with regards to taste. According to Danish consumers, squid mantle meat should be cooked long enough for it to be tender, but not too long, resulting in an extensive softness and compromised taste. A desirable texture and taste were obtained at the expense of cooking loss, which increased with extended cooking, which may negatively impact juiciness. However, it was found that cooking at lower temperatures (46–55 °C) significantly decreased cooking loss, while in some cases, possessed similar physicochemical textural attributes (55 °C) as squid cooked at a higher temperature of 77 °C. Indicatively, a sous vide cooking temperature of 55 °C seems to be an acceptable compromise to obtain both a pleasant texture and sufficient juiciness.

Dietary fatty acid analyses of the squid Idioteuthis cordiformis: further evidence for predation on deepwater sharks

Idioteuthis cordiformis is the largest deepwater mastigoteuthid squid in the southern Pacific Ocean. Signature fatty acid (FA) and lipid class analysis was carried out on the digestive gland, fins and caecum oil of 18 individuals of I. cordiformis caught in the waters off southern Australia during late 2004. Lipid classes varied between the tissues and oil samples, with sex not being an important factor. The presence of hydrocarbons within the digestive gland and caecum was noteworthy, as high proportions of this lipid class are generally only common in the livers of many deepwater sharks. Monounsaturated FAs dominated the digestive gland and caecum oil, while the fin had high values of both saturated and polyunsaturated FAs. FA profiles of I. cordiformis were compared to profiles of potential prey species (sharks, small and large fish, crustaceans and squid) using Bray-Curtis similarity coefficients. Analysis of the digestive gland and caecum oil FA profiles revealed a close match with the following prey: myctophids (Lampanyctodes australis, Electrona paucirastra, Symbolophorus barnardi), the dragon fish Stomias boa, the smooth oreo Pseudocyttus maculatus and the deepwater sharks Etmopterus baxter, Dalatias licha, Centroselachus crepidater, Centroscymnus coelopsis and Centrophorus zeehaani. The fin FA profile did not match closely to any potential prey and was most similar to other squid mantle tissue. Based on the results of this study, I. cordiformis has a broad diet spectrum of teleost fish and deepwater sharks and occupies a high trophic position.

Effect of the application of ultrasound on sarcoplasmic proteins from giant squid (Dosidicus gigas) mantle

This research studies the application of ultrasound (US) on sarcoplasmic proteins from giant squid (Dosidicus gigas) mantle and its effect on its functional properties. US was applied during 30, 60 and 90 s. A decrease was observed in the emulsifying activity index (EAI), an increase in the emulsifying stability index (ESI), an increase in the foaming capacity (FC) and a decrease in the foaming stability (FS). In addition, the application of US increased the surface hydrophobicity (So) and decreased the viscosity with the increase in temperature. Functional properties of sarcoplasmic giant squid mantle proteins increase with the application of ultrasound.

Carotenoid feed supplementation in Argentine penaeoid shrimp broodstock

This work aimed to improve reproductive maturation in two penaeoid species (Artemesia longinaris and Pleoticus muelleri) by using carotenes added in artificial feeds and comparing antioxidant activity and carotenoids profiles. Immature females were kept for 45 days at salinity 33, temperature at 18°C, pH 7, 12:12 h photoperiod, ammonium &lt;0.2mg L-1 and seawater exchanged at 100% per day. Feeding regimes consisted of 50% fresh frozen ingredients (clam muscle and squid mantle) and 50% dry pellets. For each species, three pelletized feeds were tested, one as a control (C) and two supplemented each one with 300 mg astaxanthin (A) and β-carotene (B) kg-1 of diet. At the end of the trials, ovaries, midgut gland, and integument were sampled. In both species, the addition of carotenoids improved ovarian development: 100% of females fed A or B diets were mature, but of the females fed with diet C only 75% (P. muelleri) and 64% (A. longinaris) matured. Ovaries of mature females exhibited the highest concentration of carotenoids. The abundance of free astaxanthin regarding total carotenes, suggests that excess of free astaxanthin could be biotransformed to esterified astaxanthin. The scavenging properties were evaluated against the stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical by electron resonance spectroscopy (EPR). For all feed treatments, the extracts exhibited strong DPPH scavenging activity, without significant differences among them.

The development of marine biomaterial derived from decellularized squid mantle for potential application as tissue engineered urinary conduit

Tissue engineering is focusing research effort on search for new biomaterials that might be applied to create artificial urinary conduit. Nevertheless, the demanding biomechanical characteristics necessary for proper conduit function is difficult to be replicated. In this study, we are introducing novel marine biomaterial obtained by decellularization of squid mantle derived from Loligo vulgaris. Squid mantles underwent decellularization according to developed dynamic flow two-staged procedure. Efficacy of the method was confirmed by computational dynamic flow analysis. Subsequently Decellularized Squid Mantle (DSM) underwent extensive histological analysis and mechanical evaluation. Based on gained biomechanical data the computational modelling using finite element method was utilized to simulate behavior of DSM used as a urinary conduit. Taking into account potential application in reconstructive urology, the DSM was then evaluated as a scaffold for urothelial and smooth muscle cells derived from porcine urinary bladder. Conducted analysis showed that DSM created favorable environment for cells growth. In addition, due to polarized structure and natural external polysaccharide layer, it protected seeded cells from urine.