PHYSICO‐CHEMICAL AND FUNCTIONAL PROPERTIES OF PROTEINS OF TILAPIA (OREOCHROMIS MOSSAMBICUS)

Abstract

The properties of total proteins from fresh tilapia (Oreochromis mossambicus) have been assessed. The meat had high moisture (81.34%) and low lipid (<1%) content. The nitrogen solubility index, with water as solvent, showed minimum solubility of 25.52% of total nitrogen at pH 6.0. The solubility profile of total proteins as a function of molar concentration of sodium chloride indicated maximum solubility at 0.8 M and thereafter it decreased. The total proteins comprised three different fractions as revealed by gel filtration profile. The high molecular weight component was more predominant. The sodium dodecyl sulphate polyacrylamide gel electrophoresis pattern revealed multiple bands in the molecular weight range of 205–18 kDa. Higher value of adenosine triphosphatase (ATPase) activity (4.1 µg Pi/mg of protein/min) obtained in the present study may be due to combination of sarcoplasmic and myofibrillar ATPase activity. High modori‐inducing proteases (MIPase) activity at 55C was observed in the muscle extract that might interfere in the gelling ability. The gel‐forming ability of tilapia meat was found to be moderate as indicated by large strain and small strain test. PRACTICAL APPLICATIONS Tilapia is one of the growing aquacultured species all over the world. In India, the mossambique Tilapia (Oreochromis mossambicus) was introduced in inland water bodies like reservoirs to boost the production. Because of its prolific breeding habit and occupation of similar trophic niches, this species has overpopulated many bodies of water. Hence, there is growing need to utilize this species for surimi production and, consequently, generate more revenues for the inland fisheries sector. Knowledge of the physicochemical and functional properties of this species would help in understanding its suitability in surimi production. The rheological properties like dynamic viscoelastic behavior, flow profile, Ca‐ATPase activity, and MIPase activity would shed light on the final gel strength of the surimi prepared from this species, and also indicate the guidelines for ameliorating the quality of the gel by addition of different concentrations of cryoprotectants or change of washing cycles.

Protein Degradation and Instrumental Textural Changes in Fresh Nile Tilapia (Oreochromis niloticus) during Frozen Storage

“…; Murthy et al . ). The total crude protein content observed in the fish muscle is comparable with other tilapia species and fresh water fishes (Akande ).…”

“…Murthy et al . () reported a pH of 7.0 in fresh tilapia meat. In this study, the TPC, TBA and TVBN levels of the raw material used were found to be below the approved food standards limit.…”

Quality of Ready to Serve Tilapia Fish Curry with PUFA in Retortable Pouches

“…Studies on the biochemical composition of the tilapia fish meat revealed higher moisture content and lower fat content. Many researchers have indicated that tilapia fish is a lean variety, where fat content is less than 2% (Zain 1979; Akande 1989; Asiedu and others 1991; Ninan and others 2008; Murthy and others 2010). The total observed crude protein content in the fish muscle is comparable to other tilapia species and fresh water fishes (Zain 1979; Akande 1989; Arekere 1993; Siddaiah 1994).…”

“…Fresh tilapia meat had a pH of 6.8, TBA value of 0.57 ± 0.01 mg%, total volatile base nitrogen (TVBN) content of 3.57 ± 0.10 mg% and TPC of 4.9 × 10 4 CFU/g. Murthy and others (2010) reported a pH of 7.0 in fresh tilapia meat. The higher pH value observed in the present study may be due to the observation and recording of the results during rigor or post rigor period.…”

Aislamiento y caracterización parcial de miosina del manto de calamar gigante (Dosidicus gigas)

“…La actividad ATPasa de miosina de calamar gigante (Dosidicus gigas), detectada en el presente estudio (Tabla 1), es mayor a la reportada para la proteína extraída de otras especies, como bacalao (Gadus morhua), con~0,47 µmol Pi/min/mg proteína (Riebroy et al, 2009), vieira (Patinopecten yessoensis) con 0,86 µmol Pi/min/mg proteína (Araki & Hasegawa, 2000) y tilapia (Oreochromis mossambicus) con 4,1 µmol Pi/mg proteína/min (Murthy, Panda, & Shamasundar, 2011). Esta diferencia pudiera estar relacionada con las necesidades fisiológicas de esta especie.…”