Soheyl Reyhani Poul, Ali Jafarpour, Reza Safari,
Volume 5, Issue 4 (3-2017)
Abstract
Abstract
The aim of this study was to hydrolysis of rainbow trout viscera by application of flavourzyme, papain and pepsin enzymes and compare the functional and antioxidant properties of these three types of proteins. At the same time, the maximum degree of hydrolysis and nitrogen recovery was recorded for the hydrolysate produced by flavourzyme (23.12 ± 1.05% and 55.64 ± 0.68% respectively). In all pH values tested (apart pH 8 and 10), hydrolysate produced by flavourzyme showed the highest solubility compared to other proteins (p<0.05). In addition, emulsion activity (apart from pH 4) and emulsion stability index (apart from pH 8) in this protein were higher in comparison with two other proteins (p<0.05). To compare the antioxidant properties of hydrolysate, the inhibition capability of scavenging of 2,2 diphynyl-1-picrylhydrazyl (DPPH) free radicals and reduction capacity of iron (III), were measured. As a result, hydrolysate produced by pepsin showed highest DPPH scavenging power (83.59 ± 2.27 %) and iron (III) reduction power (0.886 ± 0.013 absorbtion in 700 nm).This study showed that the proteins produced from the substrate has favorable properties and various factors, including the type of enzyme used greatly affect these properties.
M. Esmaeili Kharyeki , M. Rezaei, S. Khodabandeh , A. Motamedzadegan,
Volume 7, Issue 1 (3-2018)
Abstract
Aims: Skipjack tuna has the highest level of catch rate among tuna all over the world. Its head contains about 64% protein. Many Protein Hydrolysates and peptides obtained from various marine sources have a high antioxidant power. The aim of this study was to investigate the antioxidant activity of Protein Hydrolysate in Skipjack tuna head.
Materials & Methods: In this experimental study, 30 Skipjack tunas were investigated. At first, the amount of different compounds (protein, fat, ash, and moisture) was evaluated in the raw material; then, the hydrolysis process was performed by Alcalase enzyme and the hydrolysis degree of the protein hydrolysate was evaluated at different times. The antioxidant activity of the protein hydrolysate mixture was measured by DPPH radical scavenging activity, iron revival power, and ABTS radical inhibitory activity. For data analysis, the analytical tests were used.
Findings: The main part of the fish head was protein and it had high levels of ash. The degree of hydrolysis increased with increasing time and was it significant at 15, 60, and 120 minutes (p<0.05), but not significant at 120 and 240 minutes (p<0.05). DPPH radical scavenging activity increased with increasing hydrolysis time and there was a significant difference in all samples obtained from different times (p<0.05). The iron reduction capacity of the protein hydrolysate samples increased with increasing the hydrolysis time, and the highest amount was at 240 minute. The samples obtained from different times had a significant difference in iron reduction capacity (p<0.05). Increasing the concentration of protein hydrolysate increased inhibitory activity (p<0.05).
Conclusion: Protein hydrolysate in Skipjack tuna head has a high antioxidant activity and can be used in food products to increase oxidation stability.
