جستجوی مقالات مرتبط با کلیدواژه "ترکیبات فلاونوئیدی" در نشریات گروه "صنایع غذایی"

Phenolic compounds are known as a base of many functional foods due to their antioxidant properties and salutary effects. Phenolic compounds mainly found in plant sources. Agricultural wastes are one of the cheapest sources for getting phenolic compounds. Pistachio is considered one of the most important agricultural products in Iran. Study on the different parts of solid wastes generated from pistachio processing is worthy due to containing valuable compounds. On the other hand, using novel techniques such as supercritical CO2, subcritical water, pulsed electric fields, etc., have gained more attention in the past few years. These technologies do not have side effects on the raw materials and final products; do not use chemical solvents such as hexane, methanol, acetonitrile, etc., in comparison to traditional extraction methods with the long time needed and using chemical solvents with hazardous effect on consumers. In this study, the subcritical water extraction method as a green technology was used for the extraction of phenolic compounds from pistachio hull using y response surface methodology.

In this study antioxidant properties of phenolic compounds extracted from pistachio hull by subcritical water fluid were evaluated. The extraction process is done at 120– 180 Celsius degree, pressure 10– 50 bar and ratio 1:10– 1:30 (sample to solvent) by using the subcritical water fluid method. The total phenolic compound, flavonoid compounds, reduction power, radical scavenging, and stability power of soybean edible oil were determined for each treatment. The stability power of extracts in soybean measured with rancimat test at 110 Celsius degree and airflow of 20 litter per minute. Comparison and statistical analysis for optimization of results accomplished using response surface methodology (RSM) by design expert software 7.0.0 version. After optimization, the results for optimum treatment were compared with BHT, ascorbic acid, and alpha-tocopherol. This comparison was done for reduction power, stability power, and radical scavenging ability.

The results showed that the total phenolic compounds changed from 7671.43 to 8903.57 mg Gallic acid equivalent per 100 g dry matter. Reduction power increased by increasing temperature from 120 to 150 Celsius degree and after that decreased. The effect of pressure on the phenolic compounds wasn’t remarkable. The amount of flavonoid compound was between 142.87 and 290.21 mg equivalent catechin per 100 g dry material. The most effective parameter among investigated parameters (temperature, pressure, and ratio), was temperature. The pressure of extraction in subcritical water extractions did not have any significant effect and every change in laboratory results was very small The best results were observed at 147 Celsius degrees, pressure 10 bar, and 1:19 ratio. In these optimum conditions, the amount of total phenolic compounds, total flavonoid compounds, stability power, radical scavenging power, and reduction power was 2497.8 mg gallic acid per 100 g dry material, 267.99 mg flavonoid compounds catechin equivalent per 100 g dry material, 7.44 h, 1370.77 ppm, and 362.94 ppm respectively. Reduction and stability power with radical scavenging ability of pistachio hull extracts were very near to BHT as well as a synthetic antioxidant. Results showed that the extracts obtained from pistachio hull by subcritical water had high amount of phenolic compounds and had the same antioxidant properties as the synthetic antioxidant BHT

In this research, the physicochemical and antimicrobial properties of propolis from honeybee beehives around Mashhad and the content of active compounds in propolis were determined by high pressure liquid chromatography (HPLC) both quantitatively and qualitatively. Physicochemical properties of the propolis sample (such as ash, moisture, soluble solids and insoluble solids and existing metal elements) were measured. The total phenolic and flavonoids compounds in the ethanolic extract of propolis were 40.126 mg/g (gallic acid) and 26.46 mg/g (quercetin), respectively. Antimicrobial tests showed that the minimum inhibitory concentration (MIC) of the extract against Staphylococcus aureus was 100 mg/mL, while in the applied concentration MIC did not achieve against Escherichia coli. Also, the results of the minimum bactericidal concentration (MBC) test indicated that propolis extract on Staphylococcus aureus had only inhibitory effects. Evaluation of the content of phenolic and flavonoid compounds in propolis extract by HPLC indicated that the flavonoid compounds included flavones (13.33 mg/g), flavonoids (6.375 mg/g), flavonols (8.235 mg/g) and flavanones (16.825 mg/g). Based on the results, propolis can be used in various food and pharmaceutical industries.

Nowadays due to undesirable effects of synthesis antioxidant, food industry has paid more attention to the natural antioxidants. In this study, Phenolic compounds of Rosa canina L. as a natural source of antioxidant was extracted with methanol 80%, ethanol 50% and water in three times (6, 12 and 24 hours) and then Total Phenolic contents were determined by Folin Ciocaltue assay and flavonoid contents were measured. Also the antioxidant activity of extracts was assessed through DPPH (2, 2-diphenyl-1- picrylhydrazyl) radical-scavenging activity, reducing power assay and total antioxidant activity in different concentration and compared to synthetic antioxidants, BHA and BHT. The results of this study showed that solvent was effective on extraction of phenolic compounds significantly and Methanol 80% was optimum solvent in extraction of phenolic and flavonolid compound from Rosa canina L. methanolic extract of Rosa canina fruit had highest total phenol (235.29 ± 7.80 mg gallic acid per g dry extract) and flavonoid (14/00 ± 0.21 mg quercetin per g dry extract) contents. Methanol extract had lowest IC50 in DPPH radical-scavenging activity (48.06 mg/ ml), reducing power (73.00 mg/ml) and total antioxidant capacity (218.72). In most cases antioxidant activity of extract was higher as compared to BHA. Extracts showed antioxidant activity in a concentration-dependent way. Result of this study showed that Rosa canina fruit is a potential source of natural antioxidants but more investigation was suggested to use of them as a preservative in food products.