Quantification of Water-Soluble Protein from Snakehead Fish (Channa striata) by Bradford UV–Vis and FTIR Profiling

Snakehead fish (Channa striata) is widely recognised as a nutritionally valuable aquatic resource and is frequently associated with protein-rich traditional preparations. This study aimed to quantify the water-soluble protein fraction of C. striata using Bradford UV–Vis spectrophotometry and to characterise the corresponding functional groups by Fourier Transform Infrared (FTIR) spectroscopy. The fish flesh was processed to obtain an aqueous (water-soluble) protein isolate, and protein concentration was determined using the Bradford method with UV–Vis measurement at 595 nm. Functional-group profiling of the isolate was subsequently evaluated by FTIR to verify spectral features consistent with protein/peptide structures. The Bradford assay indicated a protein level of 460.6 ± 0.958 mg/g, corresponding to 46.06% within the analysed fraction. FTIR analysis revealed characteristic protein-related bands, including Amide A at 3266.43 cm⁻¹, Amide I at 1635.92 cm⁻¹, and Amide III at 1318.95 cm⁻¹, supporting the presence of peptide bonding patterns in the isolate. Collectively, these findings demonstrate that C. striata yields a measurable water-soluble protein fraction quantifiable by Bradford UV–Vis and confirmable at the functional-group level by FTIR, providing a practical analytical basis for further standardisation and quality-oriented studies.