S. Bahram , S.r. Javadian , M. Abdollahi ,
Volume 8, Issue 1 (3-2019)
Abstract
In this study, the physical and mechanical properties of tragacanth film incorporated with different antioxidant compounds including Hypericum perforatum extract, Ferulago angulata extract and vitamin C 25% (w/v) were studied. Adding Hypericum perforatum extract, Ferulago angulata extract and vitamin C reduced the moisture content and the solubility of the tragacanth film (p<0.05). The lowest amount of the solubility was observed in the tragacanth film containing vitamin C (51.59%) and Hypericum perforatum extract (52.05%). The amount of water vapor permeability (WVP) decreased in the tragacanth film containing vitamin C (1.68±0.06×10-7 gs-1m-1Pa-1 ), and in the films containing extracts increased significantly (p<0.05). Adding both extract and vitamin C to the tragacanth film decreased the mechanical properties of the film. Also, the lowest amounts of opacity were observed in the tragacanth film and tragacanth film containing vitamin C 1.72 and 0.98, respectively (p<0.05). The lowest amount of light transmission was observed in the tragacanth film containing Hypericum perforatum and Ferulago angulata extract (p<0.05).
Volume 19, Issue 128 (10-2022)
Abstract
In this study, the extract of Hypericum Perforatum aerial organs was prepared by hydro alcoholic solvent and the extract was coated in calcium alginate nanoparticles and the antimicrobial properties of the extract and nanoparticles on four gram-positive, gram-negative yeast and mold groups were investigated and Nanocapsules containing extract were evaluated on the shelf life of white cheese. To prepare Nano-extracts, the emulsion production method of alginate-calcium Nanocapsules containing the extract was used. The production of Nanocapsules containing the extract was done by adding calcium chloride nanoparticles to the alginate Nanoemulsion containing the extract in a ratio of 1 to 6 for 4 hours. To prepare the cheese, Staphylococcus aureus, Escherichia coli, and Candida albicans yeast are inoculated separately into the milk at a rate of 103 CFU / ml and then added calcium chloride, Rennet enzyme, extract and Nanocapsules containing extract to milk were done and the microbial properties of the cheese samples were evaluated on the day of production and up to seven days after. The results of particle size determination, particle size dispersion index, and potential and efficiency of encapsulation for the production of Nanocapsules containing Hypericum Perforatum extract and its microscopic examination confirmed the production of nanoparticles with appropriate efficiency of encapsulation. Also, the results showed that for all three microorganisms tested, the sample containing Nano-extract was able to reduce about one logarithmic cycle of the inoculated microorganism and during the shelf life of gram-positive, gram-negative and yeast had a downward trend (P <0.05). The results of the present study showed that using plant extracts containing antimicrobial compounds such as extracts of aerial organs of Hypericum Perforatum plant, especially in Nanoparticle and in appropriate quantities, as an alternative to synthetic preservatives, produce a healthy food product and with longer shelf life, it will be possible.
Volume 19, Issue 130 (12-2022)
Abstract
In the present study, the use of the ultrasonic apparatus has been investigated in the extraction process of Hypericum perforatum L. flowers. The effect of methanol to water ratio (24.77, 35, 50, 65, and 75.22 percent), time (1.59, 5, 10, 15, and 18.40 minutes), and temperature (24.77, 35, 50, 65, and 75.22 °C) on the extraction of phenolic compounds, flavonoids and antioxidant activity of the extract using two methods of 2,2-diphenyl-1-picrylhydrazyl (DPPH%) and (FRAP) Ferric Reducing antioxidant power (FRAP) were studied using the response surface method and central composite design. The results of RSM showed that the highest extraction efficiency was obtained at 50% methanol/water ratio, 70 °C, and 15 min. Under optimal conditions, the corresponding values for total phenol content, total flavonoid content, and antioxidant assays of %DPPH and FRAP were 28.46 (mg gallic acid equivalent (GAE) g-1 dry weight (DW)), 19.75 (mg quercetin g−1 DW), 89.23 (%DPPH), and 3.57 FRAP µmol Fe++ /g DW respectively. In addition, results express the effectiveness of the proposed conditions and reliability of central composite design analysis on the extraction of phenolic antioxidants from H. perforatum flowers. Using ultrasonic is a low-cost, simple, and efficient method for the extraction of phenolic antioxidants, which increases the extraction efficiency and thermal protection of phenolic antioxidants.
Volume 20, Issue 143 (11-2023)
Abstract
In this study, the effect of ultrasound pretreatment (at 40 kW power, for 20 min) with single partial solvent including water and ethanol and two partial solvents containing water/ethanol in the form of 30% (water): 70% (ethanol) and 60% (water): 40% (ethanol), were considered on the extraction efficiency, total phenolic and flavonoid compounds, as well as the free radical inhibition rate of the St. John’s wort (Hypericum perforatum L.) extract. In order to analyze the data, a completely randomized design was used in three replications, and the comparison of means was done by Duncan's multi-range test, at the probability level of α=1%, and using SPSS 14. Based on the results, the highest amount of extraction efficiency (18.3 %), total phenolic (0.295 mg GAE/g dw) and flavonoid (0.105 mg QE/g dw) compounds and the inhibition rate of free radicals (84.21 %) was measured in the samples pre-treated with ultrasound along with two partial solvents [30% (water): 70% (ethanol)] and the lowest amount of extraction efficiency (4.21%), total phenolic (0.051mg GAE/g dw) and flavonoid (0.0115 mg QE/g dw) compounds as well as free radical inhibition rate (47.53 %) was specified in water (100 %) solvent.
