Showing 5 results for Antioxidant Property
Sara Tavvafi, Seyed Fakhreddin Hosseini, Reza Hassan Sajedi,
Volume 13, Issue 1 (1-2024)
Abstract
In the present study, the green tiger shrimp (Penaeus semisulcatus) processing wastes were hydrolyzed by alcalase in an enzyme-to-substrate ratio of 1: 100 under optimal conditions of temperature (55°C) and pH (7.5) for 16 hours, and the degree of hydrolysis was investigated. Also, the hydrolyzed sample during 300 minutes of hydrolysis, was fractionated by ultracentrifugal members having molecular mass cutoffs of 3, 10, and 30 kDa, and four peptide fractions were obtained. Then, the antioxidant activity (DPPH and ABTS free radicals scavenging activity) and the antihypertensive properties of hydrolysate and peptide fractions were measured at different hydrolysate concentrations. The degree of hydrolysis was the highest (31.86 ± 0.95%) at a hydrolysis time of 60 minutes. The results of DPPH radical scavenging activity showed that the peptidic fraction <30 kDa exhibited the highest scavenging activity compared to the other fractions (69.61 ± 0.15% at a concentration of 10 mg/mL). The highest rate of ABTS radical scavenging activity was also observed for the sample <30 kDa at a concentration of 2 mg/mL (99.38 ± 0.15%). Measuring the inhibitory activity of angiotensin-converting enzyme I (ACE-I) also revealed that although all samples could inhibit ACE (inhibitory activity between 12-53%), the highest inhibitory rate belonged to the peptide fraction <30 kDa (53.23%). In general, the results of this study showed that the peptides obtained from the hydrolysis of green tiger shrimp waste can be used as a natural antioxidant in the formulation of nutraceuticals.
Volume 17, Issue 108 (1-2021)
Abstract
Background and purpose: In recent years, the use of natural substances such as essential oils and extracts has been emphasized in place of chemical preservatives in the food industry. green walnut skin is an agricultural waste that, due to its phenolic compounds, can be considered as a natural combination containing biological properties, and it reduces many of the incurable diseases and prevents the oxidation of lipids and is used as antimicrobial factors. In this study, the content of phenolic compounds, antioxidant and anti - bacterial properties of methanolic extracts of green walnut skin was investigated.
Materials and Methods: Extraction was carried out using both soaking and soxhelt methods in 60% and 80% methanol solvent. The amount of phenolic compounds of the extract was determined by spectrophotometric method.
The anti-radical activity of the extract was evaluated by DPPH radical inhibitory test. Antibacterial activity of the extract was investigated by disc diffusion method against Salmonella typhimurium, Shigella dysentery and Listeria monocytogenes. Collected data were analyzed using SPSS software and Duncan test.
Results: The total phenol content for soaking and soxhlet methods was respectively 17.81 and 89.07, according to Gallic acid equivalent, based on mg / g of sample. EC50 amount of green walnut skin was 0.15 mg / ml. The Remarkable antimicrobial activity was observed against all studied bacteria. MIC was between 1.625 and 1.25 and MBC between 1.2 and 2.5 mg / ml.
Conclusion: The results of this study showed that methanolic extracts of green walnut skin are a potential source of bioactive compounds with antioxidant and antimicrobial properties that can be used in the food and medicine industry to protect human health.
Volume 18, Issue 116 (10-2021)
Abstract
The toxic effects of synthetic antimicrobial and antioxidant compounds have led to an increase in the use of natural types, such as plant extracts. In this study, the antimicrobial effect of Lawsonia inermis aqueous extract was investigated against Escherichia coli, Salmonella typhimurium, Staphylococcus epidermidis, and Listeria innocua, by disc diffusion agar, well diffusion agar, minimum inhibitory concentration, and minimum bactericidal concentration methods. The higher concentrations of the extract showed higher antimicrobial effects against S. epidermidis and L. innocua compared to E. coli and S. typhimurium. Moreover, the total phenolic and flavonoids contents of the extract were 59.45±1.12 mg gallic acid per gram of extract and 40.35±0.70 mg quercetin per gram of extract, respectively. The antioxidant properties of aqueous extract were measured based on the DPPH and ABTS free radical scavenging activities. It was found that the antioxidant activity increased significantly as a function of L. inermis aqueous extract concentration. The antimicrobial and antioxidant properties of L. inermis leaf aqueous extract could make it a natural bioactive compound to be used as in food and medicinal products.
Volume 21, Issue 148 (5-2024)
Abstract
AbstractPeptides obtained from protein hydrolysis have many bioactive properties and have strong antioxidant activity against free radicals and prevent oxidation processes that cause damage to biological macromolecules and degradation and loss of food quality. Due to the large amount of rice production in the world, a large amount of rice bran is produced and available. As a suitable and cheap protein source, rice bran can be used for the production of plant-derived peptides. Optimizing conditions of enzymatic hydrolysis of rice bran protein by alcalase enzyme was done with the aim of achieving maximum antioxidant properties. In order to check the antioxidant activity of the obtained peptides, iron 3 reduction power tests and DPPH free radical inhibitory activity and total antioxidant activity were used. In order to optimize the process, Design Expert software and response surface method were used with three independent variables: enzyme concentration to substrate 1-3%, temperature 40-55 degrees Celsius and hydrolysis time 30-210 minutes. The optimal treatment was obtained under the determined conditions including temperature of 51.5 degrees Celsius, time of 131.5 minutes and concentration of enzyme to substrate of 3%, which has maximum DPPH free radical inhibition of 37.172%, total antioxidant activity of 1.109% and reductiveness of 2.084%. The obtained results showed that the hydrolysis process of rice bran protein by alkalase enzyme has led to the production of peptides with high and significant antioxidant properties that can be used in the production of useful foods and pharmaceutical industries and can also replace synthetic antioxidants.
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Volume 21, Issue 154 (12-2024)
Abstract
Considering the sensitivity of apple fruit to many pests and diseases and the sensitivity of consumers to synthetic pesticides, the use of plant essential oils has increased to increase the lifespan of various horticultural products, including apples. In this research, total phenol, total flavonoid and antioxidant properties of Elettaria cardamomum essential oil were investigated. In addition, the antimicrobial property of this essential oil was evaluated on a number of fungi that cause spoilage of apple fruit, including Penicillium expansum, Botrytis cinerea, and Alternaria alternata. The phenol and flavonoid content of E. cardamomum essential oil was equal to 69.60 mg of gallic acid per gram of essential oil and 27.40 mg of quercetin per gram of essential oil, respectively. The amount of antioxidant property of E. cardamomum essential oil in DPPH and ABTS free radical inhibition method was obtained as 57.30% and 63.60%, respectively. In the investigation of the antifungal property, the largest inhibition zone was observed in P. expansum by disk diffusion and agar well methods, and the minimum inhibitory concentration for P. expansum and B. cinerea fungi was 8 mg/ml and minimum fungicidal concentration was 64 mg/ml. Considering the high antioxidant and antifungal properties of E. cardamomum essential oil, it can be used as a suitable alternative to synthetic fungicides.
