Showing 7 results for Alizadeh Khaledabad
Volume 15, Issue 85 (3-2019)
Abstract
The aim of the study was to determine the Suitable concentration of Arabic gum, sodium caseinate and beta-cyclodextrin to encapsulation of pomegranate seed oil. For this purpos Beta-cyclodextrin, sodium caseinate and Arabic gum as wall covering by Mixture Design for trapping pomegranate seed oil were used and Then optimized samples with the least turbidity to determine viscosity, encapsulation efficiency, SEM, FT-IR and DLS were choiced. Turbidity of treatments increased at high levels of sodium caseinate as well as in the combination of Arabic gum with beta-cyclodextrin in lack of sodium caseinate. Results of Viscosity showed that the sample containing beta-cyclodextrin-sodium caseinate had a high viscosity than the Arabic gum-sodium caseinate. The maximum encapsulation efficiency was observed in sample containing of sodium casheinate (37.1%) and Arabic gum (62.9%), which had the lowest surface oil. According to the results of DLS , the smallest capsule diameter was related to the sample containing of beta-cyclodextrin and sodium caseinate (439 nm), and had an inverse relationship the diameter of the capsules with the polydispersity index, and values of Zeta potential in the sample containing 62.9% Arabic gum + 37.1% Sodium caseinate was maximum (-25.7). FT-IR results showed the electrostatic interactions in the formation of capsules and their stability. According to SEM images, the capsules irregularly and different morphologically were formed. Therefore, according to the results, 37.1% sodium caseinate and 62.9% Arabic gum is suggested for encapsulation of pomegranate seed oil.
Volume 17, Issue 102 (August 2020)
Abstract
Nowadays, there is a growing demand for the consumption of cold pressed oils. To overcome this problem, new thermal pre-treatments of seeds before pressing have been used. Microwave pretreatment is a modern method that has been presented to obtain high-quality oils with higher oil yield. In the present study, the effect of pre-treatments of pistachio nuts by roasting and microwaving prior to oil extraction by pressing, on the efficiency as well as the quality of the oil was investigated. Pistachio samples were treated with microwave oven (2450 MHz frequency) for 60, 120 and 180 seconds and for oven-pretreatment three levels of temperature (120, 150, and 180°C) for 15 minutes was applied. Also, in order to obtain the real amount of the pistachio oil yield, untreated samples were extracted by solvent. Hot pressing was performed at three temperature levels of 60, 80 and 100°C, to compare with the other thermal pretreatments. All the oil samples were then analyzed for their yield and the quality properties. According to the obtained results microwave and oven pretreatments increased the oil yield and oxidative stability as well as chlorophyll content of the oil. The results showed a decrease in oil acidity of the microwave-pretreated for 180 sec. however, different pretreatment methods had no significant effect (p<0.01) on carotenoid content of the pistachio oil. Totally, microwave pretreatment is an appropriate process before cold pressing of pistachio nuts, which improves the yield and quality properties and oxidative stability of pistachios oil.
Volume 18, Issue 112 (May 2021)
Abstract
The purpose of this study was to investigate the effects of flushing of CO2 / N2 gases at different ratios and gas treatment duration on physicochemical and microbiological properties of raw milk using a combined design. In this research acidity, pH, freezing point, total count, total yeast and mold count and total coliform count were performed on 15 raw milk samples between 9 and 15 minutes after injections. Statistical analysis showed that the combined treatment of nitrogen and carbon dioxide had significant effect on the acidity and pH of raw milk (p˂0.05), so that with increasing the amount of carbon dioxide to 100%, the pH decreased and acidity increased. The combined effect of both gases on the freezing point of raw milk was significant (p˂0.05). Increasing the treatment time of raw milk from 9 to 15 minutes had significant effect (p˂0.05) on reducing the microbial load, but no significant reduction was observed due to the combination of gases. According to ANOVA results, in 100% nitrogen and duration of 15 minutes, the best results in terms of microbiology and chemistry were obtained. The effect of milk treated with a mixture of CO2 and N2 gases on yogurt properties, as a food model, has also been investigated. Yogurt samples were investigated for chemical, microbial, and organoleptic properties during 22 days storage time. The results showed that the raw milk treated with gas mixture did not have an adverse significant effect on the sensory and physicochemical properties of yogurt (p> 0.05). However, yogurt acidity, pH and synthesis were significantly affected during storage time (p˂0.05). Therefore, the application of raw milk treatment with 100% nitrogen gas for 15 minutes can be considered as a bacteriostatic agent in the preservation of raw milk in industrial scale.
Volume 18, Issue 113 (july 2021)
Abstract
The aim of this research was to investigate the feasibility of composite and laminated chitosan (CH) and whey protein isolate (WPI) film preparation which was containing cumin essential oil and chitosan nanofiber. Production of composite film was possible by decreasing WPI pH to below its isoelectric pH. Double-layer was also prepared by pouring WPI solution on dried CH film. amount of active agent and nanofiller was fixed (125 mg/100ml) and only the effect of CH/WPI ration and film type (laminated or composite) on the properties of films was arudied by RSM analytical method. The color, watercontact angle, moisture absorption, solubility, water vapor permeability and mechanical properties of films were determined. By using desirability function and according to the results, optimum formulation of composite film (65.14% WPI and 34.85% CH) and laminated film (49.01% WPI and 50.99% CH) was achieved. Microstructure of optimized films was analyzed by FTIR, FE-SEM and XRD tests. Results of FE-SEM indicated a heterogenous stracture in composite film but without any phase separation. Also, at the laminatred film good attachment between two layers of CH and WPI was observed. Semi-crystalline stracture of composite film was approved by XRD analysis and there was no detectable difference between peak intensity and crystalline stracture of composite and laminated film. there was a slight difference in the FTIR spectra of composite and laminated films. According to the results, the characteristics of composite film in comparison to laminated film had better accordance with the used prediction model. But the laminated film exhibited better morphological characteristics and could be suggested for preservation of different foods due to its high potential for use in food packaging.
Volume 19, Issue 126 (August 2022)
Abstract
The aim of this study was to prepare antimicrobial and antioxidant films based on wheat gluten and Heracleum persicum essential oil, magnesium oxide nanoparticles and polypyrrole were used to improve the structure of films. Response surface statistical design was used to investigate the effect of the essence, magnesium oxide nanoparticles and polypyrrole on the physicochemical properties of the films. According to the obtained results, moisture absorption, solubility and water vapor permeability of the films decreased with increasing the content of essential oil and pyrrole. Increasing the amount of essential oil and pyrrole in the film structure improved the mechanical properties of the films. Then, the optimal films (containing 12% essential oil, 0.904% magnesium oxide and 0.2 pyrrole) were studied to evaluate the structural and antimicrobial properties. The antibacterial, antioxidant and electrical conductivity of the film was greatly increased in the presence of all three additives of essence, magnesium oxide nanoparticles and polypyrrole (P <0.05). Gluten-essence-MgO-PPy (Glu-E-MgO-PPy) composite film had the highest antioxidant and antibacterial properties. The optimal film had higher antibacterial activity against Escherichia Coli ATCC13706 compared with Staphylococcus aureus ATCC6538. SEM images showed that the essence and polypyrrole strengthened the gluten film structure and made it more resistant to the passage of water vapor. FTIR spectra confirmed the electrostatic interactions between gluten and essence and polypyrrole. The results of thermal analysis showed that polypyrrole greatly increased the thermal resistance of the film and the nanoparticles had little effect on the thermal resistance. The results of this study showed that composite and bioactive film with three important properties of electrical conductivity, antibacterial and antioxidant has the potential to be used as an active and intelligent film in the packaging of perishable food products.
Volume 19, Issue 133 (February 2023)
Abstract
Encapsulation is an effective method to increase the viability of probiotic bacteria. The aim of this research is to determine the optimal formulation for microencapsulation of Lactobacillus acidophilus PTCC 1643 with soy protein isolate, xanthan gum and fructooligosaccharide as wall materials by freeze drying method. For this purpose, 19 treatments with Combine design were prepared by Design expert software. Encapsulation efficiency, particle size, zeta potential, and probiotic viability, FTIR and SEM tests were performed on the samples. The optimal sample was selected based on the lowest zeta potential and particle size, and the characteristics of microcapsules were determined by the aforementioned tests. The results showed that probiotic viability increased and decreased with increasing concentration of soy protein isolate and xanthan gum, respectively. The particle size of the samples also increased with increasing the concentration of soy protein isolate. In general, according to the protective effect of xanthan gum, soy protein isolate and fructooligosaccharide on probiotics, it can be concluded that these compounds can be used as a wall for coating to enrich food products.
Volume 20, Issue 145 (March 2024)
Abstract
This study was carried out with the aim of covalent immobilization of Aspergillus oryzae beta-galactosidase and Bacillus licheniformis protease on multi-walled amino-carbon nanotubes. In this method, fractional 2k design was used to study the effect of seven continuous factors (activation pH, glutaraldehyde molarity, activation time, buffer solution pH, buffer solution molarity, MWCNT-NH3-glutaraldehyde amount and stabilization time) on the stabilization efficiency and enzyme activity. . Design-expert software was used to analyze data and draw graphs. The results showed that the aforementioned factors predict the level of enzyme activity of Bacillus licheniformis protease and Aspergillus oryzae beta-galactosidase with correlation coefficients of 0.80 and 0.92 at the rate of 77 and 88%, respectively. Also, the correlation coefficient of the covalent fixation efficiency model of Aspergillus oryzae beta-galactosidase and Bacillus licheniformis protease on multi-walled carbon nanotubes was 0.89 and 0.82, respectively, and the studied factors were able to determine the covalent fixation beta efficiency, respectively. Aspergillus oryzae galactosidase and Bacillus licheniformis protease on multi-walled amino-carbon nanotubes predict 83 and 77%, respectively.
