The aim of the present study is to report on the physicochemical characterization of shortfin scad (Decapterus macrosoma) waste hydrolysate (SWH) enzymatically prepared using alcalase. The characterization incorporates chemical composition (moisture, protein, fat, ash), protein concentration, molecular weight (SDS- PAGE), amino acid composition, solubility and structure properties of shortfin scad waste hydrolysate (SWH) via Fourier transform infrared (FTIR) spectroscopy. SWH contains an average of 5.06 ± 0.47% moisture, 73.08 ± 1.54% protein, 7.55 ± 0.90% fat and 10.40 ± 0.13% ash, with a high protein concentration (30.80mg/ ml). The SDS-PAGE result showed that molecular weight of SWH was less than 17kDa. The amino acid composition of SWH was found to be high in glutamic acid/glutamine (12.39 ± 0.59%) and aspartic acid/asparagine (7.89 ± 0.18%), followed by glycine (7.15 ± 0.39%), lysine (6.80 ± 0.15%), arginine (6.38 ± 0.08%), and leucine (5.99 ± 0.10%). Fourier transform infrared (FTIR) spectra showed that SWH presented a similar structure to that shortfin scad waste (SW). In addition, protein solubility in SWH increased to 92.98% by increasing pH level (pH 4 to pH 10). These findings demonstrate the promising potential of shortfin scad waste hydrolysate for the application as natural bioactive sources due to high protein content and concentration, lower molecular weight, high solubility, and high percentage of essential amino acids which fulfil adult human requirements.
This study aims to optimize enzymatic hydrolysis process for producing angiotensin I-converting enzyme (ACE) inhibitory peptides from protein hydrolysate of shortfin scad (Decapterus Macrosoma) waste (SWH). The enzymatic hydrolysis conditions, namely the temperature (40, 50, 60°C), time (B: 60, 120, 180 min), pH (C: 7, 8, 9) and enzyme substrate concentrations (D: 1, 2, 3%) on yield, degree of hydrolysis (DH) and ACE-inhibitory activity were analysed. Responses were optimized using the response surface methodology (RSM) by employing four factors, 3-levels and the Central Composite Design (CCD). The optimized conditions were further validated to indicate the validity of the prediction model. The optimal conditions obtained for the hydrolysis conditions were at temperature of 50°C, time of 60 min, pH of 9 and enzyme to substrate concentration of 2.92%. The experimental result for yield was lower than the predicted value, as generated by RSM. However, the degree of hydrolysis of SWH was higher than the predicted value. The ACE inhibitory activity of SWH was 79.34%, and showed lower than the predicted value. Therefore, the optimized conditions of SWH served as good conditions for the production of bioactive peptide with high ACE inhibitory activity.