جستجوی مقالات مرتبط با کلیدواژه "پروتئین هیدرولیز شده" در نشریات گروه "پزشکی"

Today, cyanobacteria, which are a group of microscopic algae, have been considered as a protein source for the production of hydrolyzed protein.

The protein extracted from Anabena was hydrolyzed by the alcalase enzyme at 55°C and pH 8 for 8 hours. The amino acid profile of the hydrolyzed protein was analyzed using an RP-HPLC system. The antioxidant properties of the obtained samples were evaluated against DPPH and ABTS free radicals, as well as metal ion chelation. Subsequently, the antibacterial properties of the produced hydrolyzed protein against a number of pathogenic bacteria were investigated.

The amino acid profile of the obtained hydrolyzed protein showed that this sample contained higher amounts than the daily amino acid requirement of children and adults and had significant amounts of essential amino acids. The highest neutralization percentage against DPPH and ABTS free radicals was 88.22% and 68.90% respectively. The highest chelating activity of obtained sample 62.69% was observed at the concentration of 2 mg/ml. Also, the results showed that the highest antibacterial properties of the examined sample against the bacteria Staphylococcus aureus, Listeria monocytogenes, Escherichia coli and Salmonella typhimurium were 6.02, 5.90, 6.30 and 3.80 mm respectively at a concentration of 100 mg/ml liter (P<0.05).

Based on the obtained results, it seems that the protein extracted from Anabena can be used to produce hydrolyzed protein with antioxidant and antibacterial properties and has the potential to be used in food and pharmaceutical industries.

The addition of hydrolyzed germinated mung bean besides affecting the texture of dairy products such as stirred yoghurt and increasing nutritional value because of bioactive components, can be an acceptable substitute for milk proteins and leads to increase the product output. This study was conducted to investigate the effects of hydrolyzed proteins of germinated mung bean on chemical and physical specifications of stirred yoghurt. In this study, hydrolyzed proteins of germinated mung bean (with the portion of 1,2 and 3 percent without MPC) and also 1and1.5 percent of milk protein concentration (MPC) were added. The effects on chemical and physical specifications (pH, acidity, water holding capacity, syneresis, dry matter, minerals, antioxidants activity, viscosity and texture) and sensory evaluation (color, flavor, aroma and total acceptance) were investigated. Samples were evaluated during days of storage (0, 7, 14 and 21 days) at 4℃. Statistical analysis was performed with spss software. The addition of different concentrations of hydrolyzed proteins of germinated mung bean has been prevented pH changes and acidity and decreased syneresis in stirred yoghurt. The results revealed that using hydrolyzed proteins of germinated mung bean can be acceptable substitute for part of milk protein concentration (MPC) in stirred yoghurt.

Encapsulation is a process; by which, a susceptible compound is surrounded with a membrane or matrix that is able to release its contents at a controlled speed under certain conditions. In recent years, popularity of adding bioactive compounds to food products has increased. These compounds are usually sensitive to environmental, processing and/or gastrointestinal conditions. Therefore, encapsulation is an appropriate option to protect these compounds against harsh conditions. Nanoliposomes are made from edible compounds and therefore are common for encapsulation, protection and controlled release of bioactive compounds in foods. The objective of this study was to investigate properties of nanoliposomes loaded with quinoa seed protein hydrolysates.

In this study, nanoliposomes loaded with quinoa seed protein hydrolysates (without and with chitosan coating) were assessed for their particle size, zeta potential and antioxidant activity using DPPH radical scavenging and ABTS radical inhibition activity. Furthermore, effects of six weeks of storage in refrigerator conditions were assessed on the stability and properties of nanoliposomes. Hydrolysis was carried out using alcalase and pancreatin enzymes.

Results showed that particle size increased from nearly 22 nm in control sample to 40 and 70 nm in samples with and without chitosan coating, respectively. Moreover, disintegration index in the sample with chitosan coating (No. 2) was improved, compared to control sample with further uniform distributions. Zeta potential changed from -9 MV in control sample to -4 and 26 MV in samples without and with chitosan coating, respectively. Microencapsulation efficiency over six weeks of storage at refrigerator temperature was 40% in sample No. 1 (sample without chitosan coating) and 65% in sample No. 2 (sample with chitosan coating).

Encapsulation of hydrolyzed quinoa proteins using nanoliposome and its coating with chitosan improve various characteristics of nanoliposomes such as particle size, decomposition index and zeta potential, improving particle stability by decreasing its release rate during storage and causing high storage ability of the active compounds in nanoliposome structures.

Protein hydrolysates are compounds with low molecular weight that after entering the body are easily absorbed and play important biological roles in cellular levels. The most important functions of bioactive compounds are antioxidant, antimicrobial, anticancer activities and enhance the immune system. The main objective of this study was to produce cotton seed protein hydrolysate using pepsin enzyme that was optimized by response surface methodology. The factors investigated in this study were temperature (30-40◦C), time (2-5h) and enzyme/substrate ratio (0.5-2%) in order to obtain maximum antioxidant activity. The antioxidant activities were investigated using 1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging capacity, total antioxidant capacity, reducing power and chelating activity. All of the experiments were designed according to the central composite design. Each of the studied variables had a significant effect on the responses (p<0/05). The optimal conditions to achieve maximum antioxidant activity were temperature of 31.1◦C, time of 5h and enzyme/substrate ratio of 1.75%, respectively. Under these conditions, (DPPH) free radical scavenging capacity, reducing power, chelating activity, total antioxidant capacity and degree of hydrolysis were 83%, 0.158 Å, 70%, 1.99 mmol α- tocopherol/mL and 31.75%, respectively. Cotton seed protein hydrolysates have exhibited good antioxidant activity and might be employed as a natural antioxidant in food products and formulations.

Background and Biological studies on marine fauna, especially invertebrates, has significantly increased in recent years which led to the identification of many different bioactive compounds. The sea cucumber are echinoderms with a very muscular body wall that contains 70% collagen and is considered a rich source of protein. Based on recent researches on bioactive compounds extracted from sea cucumber, it was found to have cytotoxic, antioxidant, anti-tumor, and anti-coagulation properties.
In this experimental study, enzymatic hydrolysis method was used to study the anticoagulant properties of hydrolysates protein in muscles of sea cucumber. Finally, the anticoagulant properties of hydrolysates protein on the human blood plasma was examined by the Activated Partial Thromboplastin Time anticoagulant test (APTT) in two concentrations (90 and 130 µg/ml), and Prothrombin Time (PT) in different concentrations (220, 440, 670, and 900 µg/ml).
The total amount of hydrolysates protein was found to be 55.8 mg/g in wet tissue. The results of anti-coagulation assays showed that the hydrolysates protein of the sea cucumber muscle contains anticoagulant properties on human blood plasma and could prolong the clotting time.
Peptides from the hydrolysis in sea cucumber muscle have anticoagulant properties as already reported for heparin-like compounds.

Somesynthetic antioxidants namely BHA and BHT are used as food additives in order to improve the quality and shelf life of food. Although these antioxidants exhibit higher antioxidant activity as compared to the natural antioxidants such as ascorbic acid, but in relation to their safety and related aspects to health, there is a cause for concern. Therefore the use of natural antioxidants to replace the synthetic antioxidants is considered as an important aspect and research concerned with this matter has been regarded quite important. Peptides obtained from proteins hydrolysis are examples of natural antioxidants that have been discussed in recent researches. In this study protein hydrolysate was produced from soya protein isolate using Alcalase 2.4l and the effect of different hydrolysis conditions such as temperature, time and enzyme/substrate ratio, on degree of hydrolysis and antioxidant activity of the product were investigated in a completely randomized design and then the Fe++ chelating activity and reducing power of protein hydrolysate was evaluated. The highest degree of hydrolysis was observed at 55°C after 210 minutes with the enzyme/substrate ratio of 90 Anson unit/ Kg substrate that was 30.27 %. Under these conditions, the Fe++ chelating activity reached its maximum concentration, whereas the Fe+++ reducing power showed the absorption of 0.15 that indicated lower value as compared to the highest obtained reducing power. The protein hydrolysate obtained from soya can act as a natural antioxidant with a high nutritional value and other biological properties and in appropriate concentrations might act as the synthetic antioxidants.