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Your search keyword '"Najafpour-Darzi, Ghasem"' showing total 28 results
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28 results on '"Najafpour-Darzi, Ghasem"'

23. Turning Waste into Wealth: Optimization of Microwave/Ultrasound-Assisted Extraction for Maximum Recovery of Quercetin and Total Flavonoids from Red Onion (Allium cepa L.) Skin Waste.

Author

Velisdeh, Zeinab Jabbari, Najafpour Darzi, Ghasem, Poureini, Fatemeh, Mohammadi, Maedeh, Sedighi, Armin, Bappy, Mohammad Jabed Perves, Ebrahimifar, Meysam, and Mills, David K.

Subjects
RESPONSE surfaces (Statistics), ONIONS, ANALYSIS of variance, BIOACTIVE compounds, REGRESSION analysis, ETHANOL
Abstract

This study optimized the extraction conditions to maximize the recovery yields of quercetin and total flavonoids from red onion skin waste using sequential microwave/ultrasound-assisted extraction. Five effective factors of quercetin extraction yield were investigated using response surface methodology. The method was successfully performed under optimal 60 s microwave irradiation conditions followed by 15 min sonication at 70 °C with 70% (v/v, water) ethanol with a solvent-to-solid ratio of 30 mL/g. The variance analysis of the model for both quercetin (Y1) and total flavonoid (Y2) recovery from DOS demonstrated that ultrasound temperature (X2) was the most highly significant and influential factor, with a p-value of <0.0001 for both responses. Additionally, three key interaction terms—X1X2, X2X4, and X2X5—were identified as highly significant, further underscoring the critical role of ultrasound temperature in optimizing the extraction process for both quercetin and total flavonoids. The maximum recovery yields of quercetin and total flavonoids from red onion skin were 10.32% and 12.52%, respectively. The predicted values for quercetin (10.05%) and total flavonoids (12.72%) were very close to the experimental results. The recovery yields obtained from different extraction methods under the identical experimental conditions mentioned earlier were ultrasound/microwave-assisted extraction (7.66% quercetin and 10.18% total flavonoids), ultrasound-assisted extraction (5.36% quercetin and 8.34% total flavonoids), and microwave-assisted extraction (5.03% quercetin and 7.91% total flavonoids). The ANOVA confirmed highly significant regression models (p-values < 0.0001), with an insignificant lack of fit (p = 0.0515 for quercetin, p = 0.1276 for total flavonoids), demonstrating the robustness and reliability of the optimization. This study provides valuable insights for improving the extraction of bioactive compounds, which is critical for developing effective cancer treatments and advancing medical research. Additionally, the model shows potential for scaling up food processing applications to recover valuable products from red onion skin waste. [ABSTRACT FROM AUTHOR]

Published
2024
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27. Biosynthesis of exopolysaccharide from waste molasses using Pantoea sp. BCCS 001 GH:a kinetic and optimization study

Author

Niknezhad, Seyyed Vahid, Kianpour, Sedigheh, Jafarzadeh, Sina, Alishahi, Mohsen, Najafpour Darzi, Ghasem, Morowvat, Mohammad Hossein, Ghasemi, Younes, Shavandi, Amin, Niknezhad, Seyyed Vahid, Kianpour, Sedigheh, Jafarzadeh, Sina, Alishahi, Mohsen, Najafpour Darzi, Ghasem, Morowvat, Mohammad Hossein, Ghasemi, Younes, and Shavandi, Amin

Abstract

The bacterium Pantoea sp. BCCS 001 GH produces an exopolysaccharide (EPS) named Pantoan through using sugar beet molasses (SBM) as an inexpensive and widely available carbon source. This study aims to investigate the kinetics and optimization of the Pantoan biosynthesis using Pantoea sp. BCCS 001 GH in submerged culture. During kinetics studies, the logistic model and Luedeking-Piret equation are precisely fit with the obtained experimental data. The response surface methodology (RSM)-central composite design (CCD) method is applied to evaluate the effects of four factors (SBM, peptone, Na2HPO4, and Triton X-100) on the concentration of Pantoan in batch culture of Pantoea sp. BCCS 001 GH. The experimental and predicted maximum Pantoan production yields are found 9.9 ± 0.5 and 10.30 g/L, respectively, and the best prediction factor concentrations are achieved at 31.5 g/L SBM, 2.73 g/L peptone, 3 g/L Na2HPO4, and 0.32 g/L Triton X-100 after 48 h of submerged culture fermentation, at 30 °C. The functional groups and major monosaccharides (glucose and galactose) of a purified Pantoan are described and confirmed by 1HNMR and FTIR. The produced Pantoan is also characterized by thermogravimetric analysis and the rheological properties of the biopolymer are investigated. The present work guides the design and optimization of the Pantoea sp. BCCS 001 GH culture media, to be fine-tuned and applied to invaluable EPS, which can be applicable in food and biotechnology applications.

Published
2022

28. Towards a novel pullulan and pullulan-enteric hard capsules: Study of drug release and crucial capsule features

Author

Aghajannataj Ahangarkola, Faezeh, Najafpour-Darzi, Ghasem, and Ramezani Kalmer, Ramin

Abstract

Pullulan, a natural polymer, is often used as a plant-based alternative polymer for gelatin to produce hard capsules. To the best of our knowledge, there have been negligible studies on the performance of enteric pullulan capsules. Hence, this paper describes a new formulation for enteric pullulan hard capsules that can resist the acidic environment of the stomach and release the drug in the small intestine without the need for an exterior coating. This formulation consists of three polymers, including pullulan, Eudragit L100, and κ-carrageenan, which are used to develop resistance against acid and facilitate gelation to form capsules. With regards to the humidity assessment of target hard capsules, it is estimated that the prepared capsules possess an appropriate potential for target utilizations. The capsules were tested using esomeprazole as a model drug for dissolution testing. The results demonstrated that the enteric hard-shell capsules remained stable for 2 h in 0.1 N HCl at a pH of 1.2 and then ruptured upon entering a phosphate buffer (simulated small intestine) medium at a pH of 6.8. The FESEM and cross-sectional analysis revealed that no drug was released due to the absence of pores on the surface. Rheological examinations also revealed that the prepared solution have a desirable property. It is certified that the NMR spectrum proposes the existence of crosslinking and polymerization of pullulan which signifies appropriate existing interactions polymeric binders and gelling agent. TGA and DSC evaluations are in well accordance with the strong cross-linked structure generated by comprising pullulan polymer with the Eudragit pH-sensitive Polymer. Overall. this new formulation has potential feature for utilization in drug delivery systems where controlled release is desired, especially for drugs that are sensitive to acidic environments in the stomach.

Published
2024
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