Morteza Mohammadi; Mohammad Ghorbani; Alireza Sadeghi Mahoonak; Adel Beigbabaie; Samira Yeganeh zad
Abstract
Introduction: 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 ...
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Introduction: 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. Materials and Methods: 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. Results and Discussion: 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 smallThe 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
Food Biotechnology
Negin Ghazanfari; Seyed Ali Mortazavi; Farideh Tabatabaei Yazdi; Morteza Mohammadi
Abstract
Introduction: One of the most important challenges facing medical science is infectious diseases and poisoning, which in turn increases the production and consumption of new and common antibiotics. With theover use of common antibiotics, we are witnessing the spread of antibiotic-resistant microbial ...
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Introduction: One of the most important challenges facing medical science is infectious diseases and poisoning, which in turn increases the production and consumption of new and common antibiotics. With theover use of common antibiotics, we are witnessing the spread of antibiotic-resistant microbial species, which makes the treatment of infectious diseases long and costly. Natural compounds of plant origin (essential oils and extracts) have been used to kill or at least prevent the growth of pathogenic microorganisms. These compounds, which are naturally present in plant tissues, are probably produced as part of their defense mechanisms against microbial invasion. Plant-based antimicrobials have therapeutic potential and are not only effective in treating infectious diseases, but also reduce the large number of side effects that are often associated with synthetic antimicrobials. Essential oils are complex mixtures of volatile, aromatic, low molecular weight and hydrophobic compounds present in various parts of aromatic plants, including leaves, flowers, seeds, sprouts and shoots. Among these plants, we can mention the coriander plant. Coriander (Coriandrum sativum L.) is an annual, herbaceous, aromatic plant belonging to the Apiaceae family. Coriander has a long history of nutritional and therapeutic use. This plant is a rich source of aromatic compounds and essential oils that have antibacterial, antifungal and antioxidant effects and is used in the preparation of various foods as a spice. Materials and Methods: The tested coriander seeds were obtained from Khorasan Razavi province, Mashhad city. Antioxidant-free soybean oil was obtained from the Seh Gol Khorasan vegetable oil factory. Total phenolic content (TPC), Radical scavenging ability (DPPH assay), Oxidative stability index (OSI), Peroxide value (PV), Minimum inhibitory concentration (MIC) and Minimum bactericidal concentration (MBC) of essential oil were measured on a number of bacteria causing infection and food poisoning. The compositions of essential oils were identified by Gas Chromatography-Mass Spectrometry (GC-MS). Results and Discussion: Most of the constituents of coriander seed essential oil were oxygen monoterpene compounds. Essential oils that have a higher percentage of oxygenated compounds are more important than other compounds in terms of aroma, strong odor, as well as antimicrobial and antioxidant power, so they are considered more valuable essential oils. Analysis of microbial test results showed that coriander seed essential oil had a relatively strong and good effect against the studied Gram-positive bacteria, so that the essential oil inhibited the growth of Staphylococcus aureus even at low concentrations. This essential oil had good antioxidant activity in the thermal stability of soybean oil. Coriander seed essential oil as an antioxidant compound was able to increase the oxidative stability of soybean oil under oxidative acceleration conditions. The results showed that total phenolic compounds were 0.161 mg GAE/100g, IC50 for essential oil was 30.981 mg/ml and thermal stability of soybean oil treated with coriander seed essential oil was 5.17 h. The results of microbial tests showed that Gram-positive bacteria was more sensitive to Coriander seed oil than Gram-negative bacteria. The most important constituents of coriander seed essential oil were Linalool (49%), Terpinolene (7%) and α-Pinene (6.8%).
