M Seyfzadeh, Gh Zareh Ghashti, Y Moradi, N Mashaeii, M Rahnama,
Volume 9, Issue 2 (4-2020)
Abstract
The purpose of this study was to measure sensory, chemical, microbial, freshness and shelf life of packaged Tilapia fillets by vacuum and modified atmosphere methods compared to fillets packaged by aerobic method at refrigeration. Methods: Treatments consisted of Tilapia fillets packaged by vacuum and modified atmosphere methods. The fillets packaged by aerobic method were as control samples. Findings: TVB-N, PV, TBARS, total bacterial count, Staphylococcus and Pseudomonas bacteria, sensory parameters and freshness showed significant differences in experimental and control treatments (P<0.05). The studied factors did not show significant difference in modified atmosphere treatments compared to vacuum treatments (p> 0.05). Coliform, Escherichia coli and anaerobic bacteria were not observed in experimental and control treatments. Sensory evaluation and frshness were better in modified atmosphere treatment compared to vacuum treatment (p> 0.05). Chemical, microbial, sensory factors and freshness had significantly different in the experimental treatments compared to the control sample (p<0.05). The experimental and control treatments had good quality during 14 and 6 days at refrigeration. Conclusion: Considering the absence of significant differences in microbial and chemical quality of experimental treatments and higher sensory evaluation and freshness of modified atmosphere treatment compared to other treatments, modified atmosphere packaging method is recommended for packing Tilapia fish fillet at refrigerator temperature.
Farzaneh Vardizadeh, Sedigheh Babaei, Mahmood Naseri, Mohammad-Taghi Golmakani, Mina Esmaeili,
Volume 9, Issue 4 (11-2020)
Abstract
In the present study, the structural and antioxidant properties of fucoidan extracted from macroalgae (Sargassum and Padina) from the Persian Gulf coast were evaluated. The fucoidan was extracted by ethanol and hot water and after calculating the extraction yield, DPPH radical scavenging activity, ferric reducing antioxidant power (FRAP), scanning electron microscopy (SEM), and its monosaccharides by HPLC method were examined. The yield of fucoidan in Sargassum (4.2 ± 0.00%) was higher than Padina (2.98 ± 0.28%) (P < 0.05). The IC50 of DPPH free radical scavenging in fucoidan extracted from Sargassum and Padina were 0.1 and 0.14 mg/ ml, respectively, which were higher than BHT as a commercial antioxidant (P < 0.05). The rate of FRAP in both samples increased with an increase in the concentration of fucoidan. The SEM results showed that fucoidan from both macroalgae had strong structural cohesion and irregular surfaces, but Padina had more surface protrusions. The glucose, mannose and xylose sugars in different amounts were detected by the HPLC method, in which the amount of glucose and xylose sugars were higher in the fucoidan derived-Sargassum (P < 0.05). According to the results of the present study, the fucoidan extracted from the Sargassum and Padina can be a good alternative to an industrial antioxidant in food
