23 results on '"Hamidi Esfahani Z"'
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2. Improvement of Strain Penicillium sp. EZ-ZH190 for Tannase Production by Induced Mutation
- Author
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Zakipour-Molkabadi, E., Hamidi-Esfahani, Z., Sahari, M. A., and Azizi, M. H.
- Published
- 2013
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3. Modelling of simultaneous effect of moisture and temperature on A. niger growth in solid-state fermentation
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Hamidi-Esfahani, Z., Shojaosadati, S.A., and Rinzema, A.
- Published
- 2004
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4. Culture Condition Improvement for Phytase Production in Solid State Fermentation by Aspergillus ficuum Using Statistical Method
- Author
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Jafari-Tapeh, H., primary, Hamidi-Esfahani, Z., additional, and Azizi, M. H., additional
- Published
- 2012
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5. Numerical Simulation of Vacuum Drying by Luikov's Equations
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Nadi, F., primary, Rahimi, G. H., additional, Younsi, R., additional, Tavakoli, T., additional, and Hamidi-Esfahani, Z., additional
- Published
- 2011
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6. Evaluation and Characterization of Vacuum Drying of Date Paste.
- Author
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Ashraf, Z., Hamidi-Esfahani, Z., and Sahari, M. A.
- Subjects
- *
DATES (Fruit) , *FOOD dehydration , *EFFECT of temperature on food , *VACUUM chambers , *MOISTURE content of food , *ARRHENIUS equation - Abstract
The drying behavior and characteristics of date paste were studied at temperatures of 60, 70, and 80°C as thin layer with sample thicknesses of 1, 1.5, and 2 cm in a laboratory scale vacuum chamber. Modeling of drying kinetics of date paste was investigated based on the specific temperatures and sample thicknesses. The experimental moisture loss data were fitted to eight thin layer drying models available in the literature. The modified Henderson-Pabis, Verma, and Jena-Das models showed better fitness to the experimental drying data compared to the other models. The effective moisture diffusivity ranged between 6.0854×10-8 and 4.868×10-7 m2 s-1. Effective diffusivity increased with the increase in temperature and sample thickness. The temperature dependence of effective moisture diffusivity was expressed by an Arrhenius type equation. [ABSTRACT FROM AUTHOR]
- Published
- 2012
7. Numerical Simulation of Vacuum Drying by Luikov's Equations.
- Author
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Nadi, F., Rahimi, G.H., Younsi, R., Tavakoli, T., and Hamidi-Esfahani, Z.
- Subjects
DRYING apparatus ,VACUUM cleaning ,COMPUTER simulation ,MASS transfer ,MATHEMATICAL models of thermodynamics ,HEAT transfer ,MATHEMATICAL models - Abstract
A two-dimensional mathematical model was developed to simulate coupled heat and mass transfer in apple under vacuum drying. Luikov's equations are the governing equations in analyzing heat and mass diffusion problems for capillary-porous bodies. The model considers temperature- and moisture-dependent material properties. The aim of this study is to analyze the influence of some of the most important operating variables, in particular, pressure and temperature of drying air, on the drying of apple. The resulting system of unsteady-state partial differential equations has been solved by a commercial finite element method (FEM) package called FEMLAB (COMSOL AB, Stockholm, Sweden). Simulations, carried out in different drying conditions, showed that temperature is more effective than air pressure in determining the drying rate. A parametric study was also carried out to determine the effects of heat and mass transfer coefficients on temperature and moisture content distributions inside apple during vacuum drying. A comparison between the theoretical predictions and a set of experimental results reported in the literature showed very good agreement, especially during the first 4,200 s, when experimental data and theoretical predictions overlapped and relative errors never exceeded 2%. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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8. Statistical Optimization of Xanthan Gum Production and Influence of Airflow Rates in Lab-scale Fermentor
- Author
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Moshaf, S., Hamidi-Esfahani, Z., and Mohammad Hossain Azizi
- Subjects
lcsh:Biotechnology ,lcsh:TP248.13-248.65 ,Xanthan gum, Second grade date palm, RSM, Xanthomonas campestris, Aeration rate, Lab sclae fermentor - Abstract
The present study was undertaken to investigate and optimize the possibility of xanthan gum production by Xanthomonas campestris PTCC1473 in 500ml shake flasks on the second grade date palm. Using an experimental response surface methodology (RSM) coupled with a central composite design (CCD), three major independent variables (nitrogen source, phosphor source and agitation rate) were evaluated for their individual and interactive effects on biomass and xanthan gum production in submerged fermentation. The optimum conditions selected for gum production were 3.15 g.l-1 for nitrogen source, 5.03 g.l-1 for phosphor source, and 394.8 rpm for agitation rate. Reconfirmation test was conducted, and the experimental value obtained for xanthan production under optimum conditions was about 6.72±0.26 g.l-1, which was close to 6.51 g.l-1 as predicted by the model. A higher yield of biomass production was obtained at 13.74 g.l-1 for nitrogen source, 4.66 g.l-1 for phosphor source, and 387.42 rpm for agitation rate. In the next stage, scale-up from the shake flasks to the 1-L batch fermentors was carried. By using the optimum conditions for xanthan gum, the biomass and xanthan gum concentrations after 72h in three levels of air flow rate (0.5, 1 and 1.5 vvm) were obtained as 3.98, 5.31 and 6.04 g.l-1,and 11.32, 15.16 and 16.84 g.l-1, respectively. Overall, the second grade date palm seemed to exhibit promising properties that can open new pathways for the production of efficient and cost-effective xanthan gum.
9. Optimization of conditions for xanthan gum production from waste date in submerged fermantation
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Moshaf, S., Hamidi-Esfahani, Z., and Mohammad Hossain Azizi
- Subjects
Optimization ,RSM ,Waste date ,Xanthomonas Campestris ,Xanthan gum - Abstract
Xanthan gum is one of the major commercial biopolymers. Due to its excellent rheological properties xanthan gum is used in many applications, mainly in food industry. Commercial production of xanthan gum uses glucose as the carbon substrate; consequently the price of xanthan production is high. One of the ways to decrease xanthan price, is using cheaper substrate like agricultural wastes. Iran is one of the biggest date producer countries. However approximately 50% of date production is wasted annually. The goal of this study is to produce xanthan gum from waste date using Xanthomonas campestris PTCC1473 by submerged fermentation. In this study the effect of three variables including phosphor and nitrogen amount and agitation rate in three levels using response surface methodology (RSM) has been studied. Results achieved from statistical analysis Design Expert 7.0.0 software showed that xanthan increased with increasing level of phosphor. Low level of nitrogen leaded to higher xanthan production. Xanthan amount, increasing agitation had positive influence. The statistical model identified the optimum conditions nitrogen amount=3.15g/l, phosphor amount=5.03 g/l and agitation=394.8 rpm for xanthan. To model validation, experiments in optimum conditions for xanthan gum were carried out. The mean of result for xanthan was 6.72±0.26. The result was closed to the predicted value by using RSM., {"references":["www.Faostat.fao.org","Besbes, S., Hentati, B., Blecker, C., Deroanne, C., Lognay, G., Drira, N.\nE., et al. (2005). Voies de valorisation des sous produits de dattes:\nValorisation du noyau. Microbiologie Hygiène Alimentaire, 18, 3-11.","Besbes, S., Cheikhrouhou, S., Blecker, C., Deroanne, C., Lognay, G.,\nDrira, N. E., et al. (2006). Voies de valorisation des sous produits de\ndattes: Valorisation de la pulpe. Microbiologie Hygiène Alimentaire, 18,\n3-7.","Rosalam, S., & England, R. (2006). Review of xanthan gum production\nfrom unmodified starches by Xanthomonas camprestris sp. Enzyme and\nMicrobial Technology, 39, 197-207.","Besbes, S., Drira, L., Blecker, C., Deroanne, C., & Attia, H. (2009).\nAdding value to hard date (Phoenix dactylifera L.): Compositional,\nfunctional and sensory characteristics of date jam. Food Chemistry, 112,\n406-411.","Shu, C. H., & Yang, S. T. (1990). Effects of temperature on cell growth\nand xanthan production in batch cultures of Xanthomonas campestris.\nBiotechnology and Bioengineering, 35, 454-468.","Kalogiannis, S., Iakovidou, G., Liakopoulou-Kyriakides, M., Kyriakidis,\nD., and Skaracis, G. (2003). Optimization of xanthan gum production by\nXanthomonas campestris grown in molasses. Process Biochemistry, 39:\n249-256.","Kamoun, A., Samet, B., Bouaziz, J., & Chaabouni, M. (1999).\nApplication of the rotatable orthogonal center composite design to the\noptimization of the formulation and utilization of a useful plasticizer for\ncement. Analysis, 27, 91-96.","Tait, M. I., and Shutherland, I. W., (1986). Effect of growth condition on\nproduction composition and Viscosity of Xanthomonas campestris.\nExpolysacharide Journal of General Microbiology, 132: 1483-1492.\n[10] Papagianni, M., Psomas, S. K., Batsilas, L., Paras, S. V., Kyriakidis, D.\nA., and Liakopoulou-Kyriakides, M. (2001). Xanthan production by\nXanthomonas campestris in batch cultures. Process Biochemistry, 37:\n73-80.\n[11] Souw, P., and Demain. A., (1980). Role of Citrate in Xanthan\nproduction by Xanthomonas campestris. Journal of Fermentation\nTechnology, 58: 411-416.\n[12] Kurbanoglu, E. B., and Kurbanoglu, N. I. (2007). Ram horn hydrolysate\nas enhancer of xanthan production in batch culture of Xanthomonas\ncampestris EBK-4 isolate. Process Biochemistry, 42: 1146-1149."]}
10. Evaluation and Characterization of vacuum drying of date paste
- Author
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Ashraf, Z., Hamidi-Esfahani, Z., and Mohammad Ali Sahari
11. The influence of co-encapsulated L. plantarum and Silybum marianum seed extract on the physicochemical properties of synbiotic cheese during ripening.
- Author
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Bakhtiyari M, Hamidi-Esfahani Z, and Barzegar M
- Abstract
The effect of Silybum marianum seed extract (SMSE), added freely or in co-encapsulated with L. plantarum (MT, ZH593), on cell survivability, physicochemical and textural parameters in synbiotic cheeses for 60 days at 4 °C were studied. Incorporated cheeses with free, single encapsulated, and co-encapsulated probiotic + SMSE experimented a reduction of 3.19, 1.23, and 0.76 log CFU/mL for the cell survivability and their antioxidant activity reached 15.19, 16.26, and 31.73%, respectively, at the end of the storage. Decrease in hardness, cohesiveness, and springiness of the cheese containing free probiotic + SMSE upon compression during storage revealed proteolysis pattern and pH development being the most effective agents while whey percentage and moisture loss were the most effective agents in the rest of the cheeses. Overall, microcapsules containing L. plantarum and SMSE propose an easy and efficient delivery vehicle for the transition of bio-compounds into cheese as a novel synbiotic food., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors. Published by Elsevier Ltd.)
- Published
- 2024
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12. Continuous decontamination of cumin seed by non-contact induction heating technology: Assessment of microbial load and quality changes.
- Author
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Rahmati E, Khoshtaghaza MH, Banakar A, Ebadi MT, and Hamidi-Esfahani Z
- Abstract
Over the past few decades, the demand for high-quality food has increased steadily. Therefore, it is essential to develop innovative technologies that effectively reduce microbial load while minimizing any negative effect on the quality of spices. The objective of this study was to determine the efficacy of a self-designed non-contact induction heating system using contaminated cumin seeds. The non-contact induction heating decontamination process was performed at different temperatures of 115, 135 and 155°C and durations (45, 60 and 75 s) through continuous process (screw conveyor) in Pyrex cylinder chamber. Various parameters including microbial load, color characteristics, essential oil content, surface morphology, sample temperature, and energy consumption were analyzed as dependent variables in the study. The results showed that the treatment combination (155°C - 60 s) reduced the aerobic plate count from 6.21 to 2.97 CFU/g. Mold, yeast and coliforms in the treatment combination (155°C-45 s) were also reduced by 3.26 and 3.6 CFU/g, respectively. The total color difference of the samples increased due to the degradation and alteration of pigments at high temperatures. However, no statistically significant disparity in essential oil content was observed between the treatment groups and the control group. The quantities of essential oil components in the cumin seeds were determined to align with the ISO standard, with the primary constituents identified as follows: Terpinen-7-al γ (38.98%), Cumin aldehyde (20.75%), γ-Terpinene (18.81%), β-Pinene (13.66%), and p-Cymene (6.2%). In summary, non-contact induction heating system shows promise as an effective technology for surface decontamination of spices. The acquired findings contribute to a deeper understanding of the impact of the induction heating process on both the microbial contamination levels and the quality attributes of cumin seeds. This scientific knowledge serves as a foundational framework for the prospective adoption and integration of this technology on a larger industrial scale., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)
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- 2024
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13. Evaluation of MicroRNA-125b-5p and Transcription Factors BLIMP1 and IRF4 Expression in Unsolved Common Variable Immunodeficiency Patients.
- Author
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Hamidi Esfahani Z, Yazdani R, Shahkarami S, Babaha F, Abolhassani H, Sadr M, Pourfathollah AA, and Aghamohammadi A
- Subjects
- Adult, Biomarkers metabolism, Case-Control Studies, Down-Regulation, Epigenesis, Genetic, Female, Gene Expression Regulation, Humans, Interferon Regulatory Factors metabolism, Male, Positive Regulatory Domain I-Binding Factor 1 metabolism, Up-Regulation, Common Variable Immunodeficiency genetics, Interferon Regulatory Factors genetics, MicroRNAs metabolism, Positive Regulatory Domain I-Binding Factor 1 genetics
- Abstract
Common variable immunodeficiency (CVID) is the most prevalent form of symptomatic primary humoral immunodeficiencies characterized by failure in the final differentiation of B lymphocytes. The majority of CVID cases have no identified genetic defect, and epigenetic alteration could be involved in the pathogenesis of CVID. Hence, we aimed to evaluate the expression of hsa-miR-125b-5p -and, B lymphocyte-induced maturation protein-1(BLIMP-1) and interferon regulatory protein-4 (IRF-4) in a group of CVID patients with no definitive genetic diagnosis in comparison with healthy individuals. Ten CVID patients (all known genes excluded) and 10 age and sex-matched healthy controls participated in the study. B lymphocytes were isolated and expression of miR-125b-5p, IRF4, and BLIMP1 were evaluated by real-time polymerase chain reaction (RT-PCR). Moreover, B cell subsets were analyzed by flow cytometry. The results showed that the relative expression of miR-125b-5p in CVID patients was increased while it was decreased for the BLIMP1 and IRF4 transcription factors compared with the healthy controls. Although a reduction was observed in switched and non-switched memory B cells among all high-miR patients, these subsets were decreased in patients with normal miR expression (71.0% and 85.0%, respectively). Our results suggest that overexpression of miR-125b-5p affects the terminal differentiation of B cells in a selected group of CVID patients by downregulating the BLIMP-1 gene and more intensively for the IRF-4 gene expressions.
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- 2021
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14. Statistical optimization of arachidonic acid synthesis by Mortierella alpina CBS 754.68 in a solid-state fermenter.
- Author
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Ghobadi Z, Hamidi-Esfahani Z, and Azizi MH
- Abstract
Arachidonic acid (ARA) is an omega-6 fatty acid that plays a major role in human health. The present study optimizes the production of ARA by the soil fungus Mortierella alpina CBS 754.68 on oil cakes. In the first step, the best substrate was chosen from four oil cakes, namely soybean, sunflower, olive, and colza oil cakes, of which sunflower oil cake showed the highest yield. In the next step, screening tests were performed using the Plackett-Burman design. Seven variables (substrate particle size, moisture content, time, temperature, yeast extract, glucose, and glutamate) were investigated (each taking values of +1 and -1). Among these variables, time, temperature, and substrate particle size significantly affected ARA production ( p < .05), so they were further investigated in the optimization step. The optimal fermentation time, temperature, and substrate particle size calculated by response surface methodology were 8.75 days, 18.5°C, and 1.3 mm-1.7 mm, respectively. Under these conditions, M. alpina was predicted to produce 4.19 mg of ARA/g dry weight of substrate (DWS). The actual yield, determined in evaluation tests, was 4.48 ± 0.16 mg ARA/g DWS, which shows the accuracy of the model. In the final step, the effect of the aeration rate on producing ARA was investigated in a packed-bed solid-state fermenter under the determined optimal conditions. In this stage, the highest ARA yield was 10.13 ± 0.26 mg/g DWS, approximately double that of the optimization step, and this confirms that aeration increases ARA production by M. alpina ., Competing Interests: The authors declare no conflicts of interest., (© 2021 The Authors. Food Science & Nutrition published by Wiley Periodicals LLC.)
- Published
- 2021
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15. Enzymatic production of xylooligosaccharide from date ( Phoenix dactylifera L.) seed.
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Ataei D, Hamidi-Esfahani Z, and Ahmadi-Gavlighi H
- Abstract
Date palm ( phonix dactylifera L .) is an important tropical fruit growing in central and southern regions of Iran. Date seed is composed of cellulose, hemicellulose, and lignin, that make it an excellent candidate for xylooligosaccharide (XOS) production. In this study, two different protocols are used for the extraction of hemicellulose from date seeds. In the first protocol, hemicellulose (xylan1) was extracted by 2.25 M alkaline solution at room temperature for 24 hr. In the second protocol, date seed was treated with LCHTA (low concentration, 0.1 M, high temperature, 80°C, alkaline solution) for 3 hr, and thereafter, hemicellulose (xylan2) was extracted by 2.25 M alkaline solution at room temperature for 24 hr. The carbohydrate units of xylan1 and xylan2 were qualified and quantified by HPAEC- PAD. Side groups of xylan1 and xylan2 were detected by FTIR. In the next step, xylan1 and xylan2 were exposed to two commercial endoxylanases namely veron 191 and pentopan mono BG. Temperature, pH, time, and enzyme dosage of hydrolyzation were optimized to maximize XOS and minimize xylose. The results showed that the enzymes successfully hydrolyzed xylan2 and produced XOS, but cannot hydrolyze xylan1. Pentopan mono BG and veron 191 produced the highest amount of XOS after 4 (1.17 mmol/g) and 6 hr (1.13 mmol/g) of incubation, respectively. Conversion factors of xylan2 to XOS for pentopan mono BG and veron were 0.41 and 0.36, respectively. This study presence the possible prebiotic properties of date seed XOS and its application in functional foods., Competing Interests: The authors declare that they have no conflicts of interest., (© 2020 The Authors. Food Science & Nutrition published by Wiley Periodicals LLC.)
- Published
- 2020
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16. A new case of congenital ficolin-3 deficiency with primary immunodeficiency.
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Babaha F, Abolhassani H, Hamidi Esfahani Z, Yazdani R, and Aghamohammadi A
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- Child, Preschool, Complement Pathway, Mannose-Binding Lectin genetics, Diagnosis, Differential, Humans, Male, Meningitis, Pyelonephritis, Seizures, Exome Sequencing, Frameshift Mutation genetics, Lectins genetics, Lupus Erythematosus, Systemic diagnosis, Primary Immunodeficiency Diseases diagnosis
- Abstract
Objectives: Human Ficolin-3 ( FCN3 ) is an oligomeric-structured lectin encoded by the FCN3 gene with a pivotal role in the lectin complement pathway. It has anti-microbial activities against bacterial and viral infections and restrains opportunistic pathogens. Mutation in the FCN3 gene is associated with variable clinical manifestations particularly immunologic (infections and autoimmunity) and neurologic complications., Methods: In this study, we report a 5-year-old boy with a biallelic mutation in the FCN3 gene using clinical and immunological and genetic evaluations (whole exome sequencing)., Results: Our case is the first national and the eighth case worldwide with a confirmed frameshift mutation associated with Ficolin-3 deficiency. He manifested refractory seizures since early infancy, meningitis, pyelonephritis and was diagnosed with severe primary immunodeficiency., Conclusion: Our case and literature review indicate Ficolin-3 deficiency should be considered in early-onset, premature neonate with a bacterial infection, neurological manifestation and systemic lupus erythematosus like presentations.
- Published
- 2020
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17. Isolation and identification of lactic acid bacteria with phytase activity from sourdough.
- Author
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Mohammadi-Kouchesfahani M, Hamidi-Esfahani Z, and Azizi MH
- Abstract
Wholemeal bread is strongly recommended due to its nutritional value. However, whole-grain foods contain a high level of phytic acid, an antinutritional factor that decreases the mineral bioavailability. The objective of this study was isolation and identification of lactic acid bacteria with phytase activity to find a suitable starter for bread-making. Wheat-legume sourdoughs were prepared by the back-slopping procedure. Lactic acid bacteria were isolated from the sourdough of wheat flour-mung bean, and their phytase activity was tested in the solid and liquid media. Out of the nine phytase-active isolates in the solid medium, only three isolates produced extracellular phytase in the liquid medium with activity ranging from 16.3 to 53.2 (U/ml). These isolates belonged to species Weissella confusa mk.zh95 and Pediococcus pentosaceus . The highest phytase activity was found for Weissella confusa mk.zh95 . Weissella confusa mk.zh95 is considered an interesting source of phytase during cereals and legumes fermentation which improves the bioavailability of minerals., Competing Interests: The authors declare that they have no conflicts of interest., (© 2019 The Authors. Food Science & Nutrition published by Wiley Periodicals, Inc.)
- Published
- 2019
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18. Optimization of cellulase production under solid-state fermentation by a new mutant strain of Trichoderma reesei .
- Author
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Darabzadeh N, Hamidi-Esfahani Z, and Hejazi P
- Abstract
Nowadays, the use of agricultural by-products, as the cheap substrate for the production of value-added products, is of high interest for the researchers and practitioners. Cellulase is a relatively expensive and a very important industrial enzyme where in this study was produced form rice by-products under solid-state fermentation. A new mutant of Trichoderma reesei was used for cellulase production. The effective variables were initially screened by "Plackett and Burman design." Afterward, the main variables including moisture content, P source, incubation temperature, and incubation time were optimized by "one factor at a time design." Finally, the resulting variables including 74% for moisture content, 2 g/L for K
2 HPO4 , 30°C of incubation temperature, and 4 days of incubation time were reported as the ultimate optimal condition for cellulase production., Competing Interests: The authors declare that they have no conflict of interest.- Published
- 2018
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19. Efficacy of Bacillus subtilis and Bacillus amyloliquefaciens in the control of Aspergillus parasiticus growth and aflatoxins production on pistachio.
- Author
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Siahmoshteh F, Siciliano I, Banani H, Hamidi-Esfahani Z, Razzaghi-Abyaneh M, Gullino ML, and Spadaro D
- Subjects
- Antifungal Agents metabolism, Aspergillus metabolism, Iran, Mycelium growth & development, Aflatoxins analysis, Aspergillus growth & development, Bacillus amyloliquefaciens metabolism, Bacillus subtilis metabolism, Biological Control Agents metabolism, Mycotoxins analysis, Nuts microbiology, Pistacia microbiology
- Abstract
Pistachio (Pistacia vera) is an important nut for its economic, nutritional and health aspects but it can be contaminated by aflatoxigenic fungi in the field and during storage. Biological control could be considered as an alternative to chemical treatment. In this study, we evaluated the antifungal and anti-mycotoxigenic capability of two Bacillus spp. both in vitro and on pistachio kernels. In in vitro conditions, both strains were able to reduce the mycelial growth and they were able to degrade the four aflatoxins during the first three days after inoculation. AFG
1 and AFG2 were rapidly degraded within two days of incubation with the bacterial strains. No aflatoxin was found in the bacterial cell walls, permitting exclusion of mycotoxin adsorption and hypothesis of an in vitro biodegradation as a mode of action. The cultivar of pistachio most susceptible to fungal colonization was 'Ahmad-Aghaei', selected among four main Iranian cultivars. A. parasiticus was able to grow and produce aflatoxins on pistachios, but at longer inoculation periods, a natural decrease of aflatoxins was registered. Both strains were able to reduce the fungal incidence and number of spores on pistachio with a stronger effect during the first 5dpi. The effect on aflatoxin content in vivo was less pronounced than in vitro, with a maximum effect at 8dpi. At longer times, there was a contrasting effect due to the lower activity of Bacillus spp. in stationary phase and higher growth of Aspergillus species. This consideration could explain the lack of aflatoxin reduction at 12dpi. Both bacterial strains showed good antifungal activity and aflatoxin reduction in in vitro conditions and on pistachio kernels. Altogether, these results indicate that Bacillus species could be considered as potential biocontrol agents to combat toxigenic fungal growth and subsequent aflatoxin contamination of nuts and agricultural crops in practice., (Copyright © 2017. Published by Elsevier B.V.)- Published
- 2017
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20. Effects of concentration method and storage time on some bioactive compounds and color of jujube ( Ziziphus jujuba var vulgaris ) concentrate.
- Author
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Shams Najafabadi N, Sahari MA, Barzegar M, and Hamidi Esfahani Z
- Abstract
Jujube extract was concentrated by various heating methods including vacuum, microwave and conventional heating. The effect of concentration methods and storage time (for 90 days at 4 °C) on total phenolic and total monomeric anthocyanin contents, individual anthocyanins, individual organic acids, and color values of jujube concentrate was investigated separately. The desired level of concentration (65.0 °Brix) was achieved in 45, 96 and 117 min by the microwave, vacuum and conventional heating methods, respectively. The concentrate obtained with microwave method had the highest total phenolic content (159.32 mg GAE/g DW) and total monomeric anthocyanin content (48.84 mg cyn-3-glu/100 g DW) in comparison to the other methods at the beginning of storage. Hunter color parameters ( L* , a* and b* ) decreased significantly with increasing the time of storage in all cases; however, this effect was more obvious in the vacuum heating. Cyanidin-3,5-diglucoside was determined as the major anthocyanin in all concentrates, while its degradation was more pronounced in the conventional heating (25.59%) comparing to the microwave (11.14%) and vacuum methods (17.59%) during the 90-day storage. The jujube concentrate prepared with the microwave method had the highest organic acid contents (e.g. malic, citric, succinic and ascorbic acids) as compared to the other methods. Thus, according to the results, the heating method and storage time had significant effects on the bioactive compounds and color values of jujube concentrate. In general, microwave energy could be successfully used in production of jujube concentrate followed by 90-day storage.
- Published
- 2017
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21. Effect of potassium sorbate on antimicrobial and physical properties of starch-clay nanocomposite films.
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Barzegar H, Azizi MH, Barzegar M, and Hamidi-Esfahani Z
- Subjects
- Aluminum Silicates pharmacology, Anti-Infective Agents pharmacology, Aspergillus niger drug effects, Aspergillus niger physiology, Clay, Physical Phenomena, Sorbic Acid pharmacology, Starch pharmacology, Treatment Outcome, Aluminum Silicates chemistry, Anti-Infective Agents chemistry, Food Packaging methods, Nanocomposites chemistry, Sorbic Acid chemistry, Starch chemistry
- Abstract
Using fresh foods which undergo the least processing operations developed widely in recent years. Active packaging is a novel method for preserving these products. Active starch-clay nanocomposite films which contained potassium sorbate (PS) at a level of 0, 5, 7.5 and 10 g PS/100 g starch were produced and their physical, mechanical and antimicrobial properties were evaluated. In order to evaluate antimicrobial properties of films Aspergillus niger was used. The results showed that 5% of the PS did not produce antimicrobial property in the film, but by increasing the content of the additive in film formulation, antimicrobial effect increased. PS increased water permeability and elongation at break of the films, but decreased tensile strength. The rate of PS migration into the semi-solid medium in starch-nanocomposites was lower than starch films. This shows that nanocomposite films could retain their antimicrobial property for longer time., (Copyright © 2014 Elsevier Ltd. All rights reserved.)
- Published
- 2014
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22. Expression analysis for genes involved in arachidonic acid biosynthesis in Mortierella alpina CBS 754.68.
- Author
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Samadlouie HR, Hamidi-Esfahani Z, Alavi SM, and Varastegani B
- Subjects
- Carbon metabolism, Genes, Fungal, Nitrogen metabolism, Real-Time Polymerase Chain Reaction, Arachidonic Acid biosynthesis, Biosynthetic Pathways genetics, Gene Expression Profiling, Mortierella genetics, Mortierella metabolism
- Abstract
The time courses for production of fungal biomass, lipid, phenolic and arachidonic acid (ARA) as well as expression of the genes involved in biosynthesis of ARA and lipid were examined in Mortierella alpina CBS 754.68. A significant increase in the arachidonic acid content in lipids that coincided with reduced levels of lipid was obtained. Reduced gene expression occurred presumably due to the steady reduction of carbon and nitrogen resources. However, these energy resources were inefficiently compensated by the breakdown of the accumulated lipids that in turn, induced up-regulated expression of the candidate genes. The results further indicated that the expression of the GLELO encoding gene is a rate-limiting step in the biosynthesis of ARA in the early growth phase.
- Published
- 2014
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23. Evaluation of culture conditions for cellulase production by two Trichoderma reesei mutants under solid-state fermentation conditions.
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Latifian M, Hamidi-Esfahani Z, and Barzegar M
- Subjects
- Bioreactors, Mycology methods, Cellulase biosynthesis, Fermentation, Mutation, Trichoderma genetics, Trichoderma metabolism
- Abstract
Response surface methodology (RSM) was used to evaluate the effects of fermentation parameters for cellulase production by Trichoderma reesei QM9414 and T. reesei MCG77 in solid-state fermentation using rice bran as substrate. Initial pH, moisture content and temperature were optimized using filter paper activity (FPA) as response. Statistical analysis of the results for T. reesei QM9414 showed that only moisture content had significant effect on cellulase activity and had a linear effect on enzyme activity (maximum enzyme activities were obtained at 70% moisture content). The results for T. reesei MCG77 showed that temperature and moisture content were the most significant parameters for cellulase activity. The optimum cellulase production was in the temperature range of 25-30 degrees C and moisture content between 55% and 70%. After the optimization, the FPA in T. reesei MCG77 was increased by 2.5 folds compared to that of T. reesei QM9414.
- Published
- 2007
- Full Text
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