The aim of this study was to investigate the functional properties of chicken skin gelatin films with varied concentrations of a hydrophilic plasticizer. Gelatin film solutions with different glycerol concentrations A(control), B(5%), C(10%), D(15%) and E(20%), were stirred at 45°C for 20min and oven dried at 45°C. Film characterization determination were included, tensile strength (TS), elongation at break (EAB), water vapor permeability (WVP), solubility, transparency, moisture content, Fourier Transform Infrared Spectroscopy (FTIR), and X-ray Diffraction (X-RD). Glycerol added resulted in improvement of TS and WVP properties. Film B (5% glycerol) demonstrated low EAB (106%), WVP (0.0175 g.mm/h.m2.k.Pa) and solubility (58.64%), but with high TS (3.64 MPa), moisture content (16.0%), UV light transmission (0.04%) and transparency (0.81) compared to films C, D and E. FTIR spectrum analyses demonstrated an aliphatic alcohol group only for Film E (20% glycerol). Hence, chicken skin gelatin film at 5% glycerol concentration showed the most promising potential for industrial food processing applications.
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.
This study investigated consequent functional effects (mechanical and physical) on Gelatin/ CMC/Chitosan composite films from the addition of sorbitol. With glycerol as a plasticizer, solutions for Gelatin/CMC/Chitosan composite films containing graduated sorbitol concentrations (0%, 5%, 10%, 15%, 20%, 25% and 30%), were cast on a petri dish and oven dried at 45˚C. The fabricated films were then characterized for tensile strength, elongation at break (EAB) and puncture resistance (mechanical properties); as well as film thickness, water vapor permeability (WVP), thermal properties, light transmittance and transparency (UV and visible light transmission), biodegradability, and X-ray diffraction (physical properties). Results indicated that by increasing sorbitol concentration, melting point and tensile strength decreased overall (p
Chicken skin gelatin hydrolysates and peptides with angiotensin converting enzyme inhibitory (ACEI) activity were produced enzymatically using alcalase, pronase E, and collagenase before fractionation into