Physicochemical Changes of Connective Tissue Proteins in Jumbo Squid (Dosidicus gigas) Muscle During Ice Storage

Abstract

Connective tissue (CT) proteins in jumbo squid (Dosidicus gigas) play an important role because they are the responsible for the union between various cells; hence, there is a close relationship between their functions and muscle firmness during ice storage. In this study, the thermal resistance and solubility of the CT extracted from the fins, mantle and arms of jumbo squid during ice storage (20 days) was evaluated. The CT was fractionated based on solubility [NaCl‐soluble (SSCT) and insoluble (ICT)]. The solubility of the CT was affected during ice storage. An increase in the thermal resistance of the SSCT after 10 days with a subsequent decrease was found in the mantle. Furthermore, the ICT was thermally more resistant than the SSCT in all the anatomical regions. Finally, the electrophoretic profile revealed that structural changes occurred, causing changes in its solubility, due to an increase in the thermal resistance. Practical Applications Jumbo squid (Dosidicus gigas) is an important seafood resource in Mexico, which is commercialized primarily iced and fresh‐frozen. Its muscle connective tissue (CT) has different physicochemical characteristics that differ from other seafood products; it is thermally more resistant and might be responsible for the textural changes during ice storage. Moreover, specific studies about the behavior of CT proteins in such organism may result in improved post‐catch management of jumbo squid muscle, focused on the processing of the species in the food industry or anywhere that CT proteins are used as raw material. The main objective of this research is to investigate solubility changes and thermal resistance of CT proteins of iced jumbo squid mantle.

Effect of cooking on physicochemical and structural properties of jumbo squid ( Dosidicus gigas ) muscle

“…Therefore, in each anatomical region, the myofibrils (mainly composed by myosin and actin) and contractile connective proteins (such as collagen and elastin) have different supra‐organizational rearrangements. Fins and arms contain a major proportion of collagen than mantle (Osuna‐Amarillas et al, ; Torres‐Arreola, Pacheco‐Aguilar, Sotelo‐Mundo, Rouzaud‐Sández, & Esquerra‐Brauer, ), in which this connective protein serves as scaffold of actomyosin complexes, and also surely was contributed to prevent hydrolysis and loss of squid muscle proteins throughout cooking process.…”

“…Torres‐Arreola et al () reported major amount of connective tissue (collagenous proteins) in muscle from fins and arms than in mantle. Besides, it has been reported that crosslinking degree of collagen in jumbo squid muscle plays an important role during post‐catch management (Osuna‐Amarillas et al, ).…”

“…Fibers from arm muscle suffered more structural damages than that in the other two anatomical regions, due probably to its proper structural structure, which is more heterogeneous compared to mantle and fins. Moreover, collagen fibers could play an important role during the heating process, thus arms has been reported as the anatomical region with the highest collagen content in jumbo squid (Osuna‐Amarillas et al, ; Torres‐Arreola et al, ). Therefore, further studies will be necessary to confirm how the heating process affects collagen fibers integrity in squid tissues.…”

Relationship between muscle texture and the crosslinking degree of collagen fibers from octopus ( Octopus vulgaris ), guitarfish ( Rhinobatos productus ), and cazon ( Mustelus lunulatus )

“…Octopus displayed the highest IC content, followed by guitarfish and, finally, cazon with the least amount. These changes in solubility can be attributed to the crosslinking degree of the CT fibers, affecting the collagen solubility of the evaluated species (Osuna‐Amarillas et al, ; Ramírez‐Guerra, Fimbres‐Romero, et al, ). Moreover, these dissimilarities in the collagen solubility could be related to the firmness differences detected in the muscle of each organism.…”

“…Figure shows peaks around 97–205 kDa. Collagen molecule consists of three polypeptide chains (α, approximately 100 kDa) (Badii & Howell, ), which depending on the intramolecular crosslinking degree, can be extracted as β‐chain (two α‐chains linked by covalent bonds), a phenomenon related to the protein aggregation during postcapture management (Osuna‐Amarillas et al, ; Torres‐Arreola et al, ). Although, it may also depend on the evaluated species (age, size, sex, and habitat) (Ando et al, ).…”