Elham Ranjbar Nedamani; Alireza Sadeghi Mahoonak; Mohammad Ghorbani; Sharlot Jakobson; Vahid Khori
Abstract
Introduction: Proteins are being hydrolyzed to generate various properties such as antioxidant activity and nutritional values. Enzymatic hydrolysis is carried out in milder condition and is more controllable. The produced protein hydrolysates’ properties are dependent to the hydrolysis condition. ...
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Introduction: Proteins are being hydrolyzed to generate various properties such as antioxidant activity and nutritional values. Enzymatic hydrolysis is carried out in milder condition and is more controllable. The produced protein hydrolysates’ properties are dependent to the hydrolysis condition. So by optimizing the hydrolysis conditions, proteins with higher antioxidant abilities are achieved. Response surface method is a statistical way to optimize and model the process more efficiently. The aim of present study was to optimize and model the hydrolysis condition to produce and antioxidant protein hydrolysate with high nutritional value from Cajanus cajan by pepsin. Materials and methods: First, Cajanus cajan’s proteins solubility was measured. After reaching the pHs with the most and least solubility, protein extraction was carries out by using NaOH and HCl. Enzyme concentration (1, 2, 3%), temperature (30, 35, 40 °C) and time (2, 3.5, 5 h) as independent variables were given to the Design Expert software and protein hydrolysis was done in a shaker incubator according to the 20 treatments suggested by the software. 1, 1- diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, hydroxyl radical scavenging activity, Reducing power and total antioxidant activity were measured as dependent variables. Antioxidant assays were modeled by the software and the optimum condition was evaluated. The obtained optimum condition was validated by repeating the antioxidant assays for the protein hydrolysate produced in the optimum condition. The amino acid profile of the protein hydrolysate was measured using HPLC-MS and chemical score was measures. Then, the molecular weight distribution of the protein concentrate and protein hydrolysate was evaluated by FPLC. Chemical composition of the samples was also measured. Results & discussion: The optimum condition for achieving antioxidant protein hydrolysate was enzyme concentration 2.15%, temperature 39.99 °C and time 4.52 h. Model validation results for this point were including DPPH scavenging activity 58.49%, reducing power 0.31 nm, hydroxyl radical scavenging activity 38.2% and total antioxidant capacity 0.63 nm. The protein concentrate consisted of 215.84 mg/g hydrophobic and 57.04 mg/g of them were aromatic amino acids. These amino acids are responsible for antioxidant activity of the protein hydrolysates. Chemical scores for essential amino acids were good. Most of the peptides in the protein hydrolysate had molecular weights below 10 kD that is considered to have antioxidant activities. Hydrolysis also increased the protein and ash content while fat and water content decreased compared to the Cajanus cajan’s flour and protein concentrate. Results showed that Cajanus cajan’s protein hydrolysate can be a good source of antioxidants and play a positive role in human nutrition.
Marjaneh Alinejhad; Bahareh Shabanpour; Reza Safari; Mozhgan Alinejhad; Hassan Nasrollahzadeh Saravi
Abstract
The objective of this study was to produce fish peptone from tuna (Thunnus tonggol) viscera, by Alcalase. Response Surface Methodology (RSM) was employed for optimizing the temperature and pH. Hydrolysis was done in different tempratures (50-65˚C) , pH (8-8. 5) and selected 13 treatments. Samples with ...
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The objective of this study was to produce fish peptone from tuna (Thunnus tonggol) viscera, by Alcalase. Response Surface Methodology (RSM) was employed for optimizing the temperature and pH. Hydrolysis was done in different tempratures (50-65˚C) , pH (8-8. 5) and selected 13 treatments. Samples with higher value of protein were used instead of the standard peptones which applied in commercial media for Listeria monocytogenes. Based on the three-dimensional graphs, the optimum condition for temperature and pH were determined to be 50˚C and 8. 5 respectively. The results showed that the highest (76. 89 g/l) and the lowest (38. 54 g/l) rates of protein content were related to pH 8 at 57˚C and pH 8 at 50˚C. Maximum bacterial growth rate was related to pH 8 at 65˚C. Results also showed that tuna (Thunnus tonggol) viscera can be used as low cost nitrogen sources for Listeria monocytogenes growth media.
