Sharif Digital Repository

Probiotics are defined as essential live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. In order to provide health benefits for probiotic bacteria it has been recommended that they must be present at a minimum level of 106 CFU/g of food product or 107 CFU/g at point of delivery or be eaten in sufficient amounts to yield a daily intake of 108 CFU. Several studies have shown that certain strain of lactic acid bacteria, such as Bifidobacterium bifidum and Lactobacillus acidophilus prevent some diseases linked to the gastro-intestinal tract. however, many reports have demonstrated their poor survival and stability. Their survival in the... 

In this study, Pseudomonas aeruginosa BBRC-10036 was used for lipase production. The organism secreted the enzyme extracellulary. First of all, effect of initial pH of the culture broth on lipase activity was studied in order to determine the optimum condition for lipase production. After production, this enzyme must be separated from culture and after that the enzyme must be purified for using in analysis and industry. Different methods are used for purification of the enzyme. In this research, first precipitation was used and then this lipase has been purified by Ion exchange Chromatography leading to 2.33- fold purification and 11.47% recovery. In precipitation by acetone, maximum... 

Xanthan is a water-soluble anionic polysaccharide that is produced by anaerobic fermentation using the bacterium Xanthomonas campstris. Xanthan is used in various industries, including food industry and oil industry because of its appropriate rheological properties. For this reason, various studies have been done on the production and recovery of xanthan. In this study conditions for recovery of xanthan gum were investigated and optimized by response surface methodology. Initially xanthan production under optimal conditions that determined in previous studies i.e. YM broth at 30 ⁰C without pH control was performed. After production, the gum separation was investigated using food solvents... 

Oil refineries, petrochemical factories and oil platforms produce a large amount of oily wastewater every day. If these wastewaters are released in environment, it can damage soil and water seriously. Although, Biological treatment of oily wastewaters is a well-established method for remediation of these wastes, efficiency of conventional systems such as Activated Sludge, aren’t very high. Also these systems have many problems such as instability during hydraulics shocks and bulking phenomena. the hybrid bioreactor system are designed to increase the efficiency of treatment by allowing greater organic loads, increasing microbial concentration by using attached and suspended bacteria, and... 

Fats and oils are one of the main human food diet components that provide the necessary fatty acids for our body. So the fatty acids available in consuming oils are so important. In this research the mixture of palm and sunflower oils with different compounds: (80:20, 60:40, 50:50, 40:60, 20:80) were used for preparing free- trans shortening by interesterification. For this purpose a special stabilized lipase (Lipozyme TLIM) were used and performed the physicochemical properties: free fatty acids, peroxide value, iodine value, slip melting point, solid fat content, P-anisidine value, soap, oxidative stability at 110 0C, and the profile of fatty acids on the primitive blends and final samples... 

Environmental problems have been one of the considerable issues since the irreversible characteristics of nature and its effect on human life were recognized. Scientists have proposed a variety of solutions in order to overcome such problems. Green marketing can be regarded as one of the solutions in this area. Similar to most other issues, this concept has been noticed less in developing countries compared to developed countries. Therefore, researchers in this study conducted a comprehensive research on the concept of green marketing in Iran focusing on consumers’ behavior.
To achieve relevant results, two types of research were conducted: qualitative and quantitative. The results of... 

After primary and secondary recovery processes more than 50 percent of oil remains in reservoirs. Therefore for more recovery from these reservoirs, methods of enhanced oil recovery should be applied.In this paper the effect of nanoparticles of SiO2 in size of 14 nm, on wettability is investigated. Using this nanoparticle, the wettability of carbonate rock in reservoirs could be changed and alter from oil-wet or mix-wet to water-wet. To assess this, hydrophilic changes of sandstone core and carbonate core are studied using the contact angle test. The same test is done on the carbonate core saturated with brine and oil that had received injection with brine and nanoparticles of SiO2 with two... 

In this project we focused on Ultrasonic waves as novel, effective and well-controllable means for cell wall disruption and disintegration to provide faster and more complete penetration of solvent into cellular materials and improve sugar mass transfer and extraction from sugarcane and sugar beet. Impact of frequency, temperature, power density and reactor shape on Ultrasonic wave efficiency in extraction process has been investigated and the result was utilized to design a semi-pilot reactor. In the optimum situation, sucrose extraction from sugarcane improved to 4.51 gr/100 ml H2O that had a significant increasing from 2.1 gr/100 ml H2O extraction in thermal only process at 70 °C. Optimum... 

Enzymes, the nanometric biocatalysts that play a key role in biochemical reactions of living cells and bio-organisms, offer various applications including biosensing, bioremediation and chemical synthesis. A simple bio-conjugation procedure to surround a single horseradish peroxidase (HRP) enzyme molecule with dendritic polyester macromolecules (Polyester-32-hydroxyl-1-carboxyl bis-MPA Dendron, Generation 5) was proposed in this project. The characterization of resultant nanoparticles entitled HRP dendrozyme, was performed by TEM, DLS, GPC and FTIR spectroscopy. The results showed that HRP nanoparticles were spherical in shape and have an average size of 14 nm in diameter. Furthermore,... 

Xanthan gum is a water-soluble exo-polysaccharide. It is produced industrially from carbon sources by fermentation using the gram-negative bacterium Xanthomonas campestris. There have been various attempts to produce xanthan gum by fermentation method using bacteria and yeast by using various cheap raw materials. In this study the cultural conditions for xanthan gum production by Xanthomonas campestris were investigated and optimized by response surface methodology, to maximize cell and xanthan production in batch experiments using YM broth without pH control. The individual and interactive effects of three independent variables (carbon source concentration (40-80 g/l), nitrogen source... 

L-Asparaginase has two major uses. For decades it has been known and used as an antitumor agent. Besides, it has been introduced as a food processing aid in the last trench against acrylamide formation in foods. Here, we have produced extracellular L-Asparaginase from Candida utilis and studied the parameters surrounding its production. Thus, two species of yeast were cross-examined: Saccharomyces cerevisiae (BBRC 30006) and Candida utilis (ATCC 9950). Moreover, the most suitable method for detecting and determining L-Asparaginase activity was investigated and selected for this purpose which is via L-Aspartate determination with Hydroxylamine. Furthermore, six deferent parameters of... 

With the rapid development of biotechnology, peptide and protein drugs are now playing an increasingly important role in therapeutics. Compared with chemical drugs, peptide and protein drugs have some limitations such as low stability and rapid deactivation. Biodegradable and biocompatible polymeric micro carriers have been shown to have a high potential for the delivery of peptides and proteins. Among these polymers, alginate has been widely investigated as a biomaterial. Alginates are natural polysaccharide polymers isolated from brown seaweed. Bovine serum albumin (BSA) loaded calcium alginate microspheres produced in this study by a modified w/o emulsification method. The influence of... 

Natural tissues of body consist of Extra Cellular Matrix (ECM) and cells. Scaffold produces a temporary matrix for cells and facilitates oxygen and nutrients transport which enhances tissue regeneration. Therefore, attempts in regeneration of tissues and organs by scaffolds attracted great interest in today’s researchs. Choosing scaffold fabrication method and its polymer type, play a key role in scaffold specifications as they determine scaffold properties. In this project electrospinning was chosen as the scaffold fabrication method which is because of the unique properties of scaffolds fabricated by this method and also its ability in producing micro and nano fibers. At first set of... 

Nowadays with the extension of industry and factories as well as different kinds of plants, a wide range of pollution and circumference hazardous has been entered to the people`s life. Industrial wastewater has been always a threat for health of our environment and efforts for reducing its dangerous effects are still under studies. Dairy wastewater is one of the main branches of food industrial pollutions and it has been studied in this specific project. The goal was to reduce the Chemical Oxygen Demands (COD) of dairy wastewater with oxidation of Titanium Dioxide Nanophotocatalyst oxidation under UV irradiation. Among the various methods for synthesizing of this Nanophotocatalyst, the... 

In this project an enzymatic peroxidase biosensor based on two naono structured material 1-Polyaniline nananofibers 2-Polyethylene glycol-Poly citric acid copolymer was studied for phenol detection.Polyaniline nanofibers and poly ethylene glycol-poly citric acid copolymer were synthetized by chemical polymerization.Electrochemical behaviors of these biosensors were studied using cyclic voltammetry (CV) and amperometric techniques. The amperometric response of the coated electrodes is highly stable with 92% of the initial activity remaining after 5 determinations. These phenol biosensors show an oxidation peak at 0.55V. The amperometric response for phenol biosensor based on Polyaniline... 

Many chemicals exist in the petroleum wastewater, whose disposal into the environment can result in environmental pollutions and serious damages to the ecosystem.Since conventional treatment processes are not sufficient to achieve the water quality requirements, advanced treatment processes are required. In this study, Hybrid Membrane Bioreactor (HMBR), Rotating biological contactor with packing (RBCp) coupled with an external membrane, is used for synthetic petroleum wastewater treatment. Biodegradability of chemical oxygen demand (COD) and that of total petroleum hydrocarbon (TPH) were evaluated and compared for different hydraulic retention times (HRTs) and petroleum pollution... 

Major bone defects resulted from diseases or hurts that can not heal naturally, requaire bone transplantation. golden standard for transplantation is autologus one but it has some disad-vantages such as economic burden, the lack of graft source, surgery on patient, and so on. so exploring altrnative ways led to exploit stem cells.traditionally bone marrow mesenchymal stem cells (MSCs) used for stem cell-bsaed bone regeneration. bone marrow aspiration to aquaire stem cells is painfull and give a population of cells such as hematopoetic cells that requaire to seperate and can not be handled in first passages. MSCs can be substituted by multipotent adipose tissue-derived stem cells (ADSCs) in... 

In this research, Response Surface Methodology was applied to study the effects of Na-Montmorillonite and glycerol on some functional properties of corn starch films. Films were prepared by casting method according to central composite design. No antimicrobial activities were observed against Escherichia coli and Staphylococcus aureus. The minimum of hydrophilicity and the maximum of tensile strength were obtained by maximization of clay and minimization of plasticizer in the considered range, which resulted in minimum transparency. Biodegradation of corn starch/glycerol/Na-MMT nanocomposites by soil burial according to ASTM D6400 and enzymatic degradation tests were carried out for up to 6... 

Peppermint oil is one of the most often used food ingredients and it is volatile. Many common procedures such as microencapsulation have been used for protecting volatile food ingredients. For this research, L-menthol was chosen as the core material to be encapsulated. L-menthol is responsible for the minty flavor and cooling sensation of food and pharmaceutical products. The encapsulation of L-menthol was prepared by complex coacervation, using gum Arabic and gelatin as wall material and tannic acid as cross-linking agent. The effect of various processing parameters, including wall material, core material, tannic acid and tween¬80 concentrations, on particle size and efficiency was...