محمدرضا احسانی

Kopeh cheese is one of the traditional Iranian cheeses. In this study, the effect of ripening time on its physicochemical properties was investigated during 187 days of ripening. The results showed that ripening index and pH increased significantly, while "salt in dry matter" decreased (p <0.05). The maximum delta tangent (TD) ranged from 0.35 to 0.4. The Differential Scanning Calorimeter (DSC) curve showed two exothermic peaks for cheese-extracted fat ripened on days 7, 37, 67, and 127; three exothermic peaks for the sample ripened on 97 days, while two exothermic and endothermic peaks for the sample ripened on 187 days, in the cooling phase. The results of principal component analysis (PCA) showed that PC1 and PC2 divided cheeses into four different groups, and PC3 identified only one group, including cheese day 127, with a high correlation with "moisture in the non-fat dry matter", "salt in dry matter," and "fat in dry matter". Also, they showed a significant correlation with TD (p<0.05). These chemicals had the most important impact on the physical properties of Kopeh cheese.

Nowadays, due to the spread of diseases and their complications as well as the high cost of treatment, the use of functional and healthy foods has been considered by the scientist. In this context, more attention is paid to complications such as infection and disease development due to the spread of free radicals. One of the options currently considered in the prevention, treatment and reduction of disease complications is biologically active peptides extracted from plant and animal sources. In the present study, peptides derived from milk hydrolysis, including peptides derived from whey and lactoferrin combined with vanillin flavors, were investigated in the laboratory to reduce infection and increase the potency of the antioxidant system. Antimicrobial tests against Staphylococcus aureus and Escherichia coli were performed after the preparation of milk hydrolyzed proteins and food supplementation with vanillin flavoring. The antioxidant effects of these peptides individually and along with a mixture of also tested. The results showed that the peptides derived from lactoferrin and whey protein concentrate alone and in combination, had antimicrobial effects at concentrations of 2000, 4000 and 1000 μg / ml, respectively. Also, the results of antioxidant tests in DPPH, ABTS and Reducting power system showed the appropriate ability of these components at 400 mg / ml concentration and the highest antioxidant activity was related to the hydrolyzed whey protein among the components participating in the supplement. Based on the results, it can be concluded that milk-derived peptides with vanillin can be used as an effective supplement to reduce the therapeutic effects in diseases, which will be complemented by animal and clinical studies.

Production of butter from yogurt is a traditional way practiced in many rural regions in Iran. The objective of this study was to isolate and identify the lactic acid bacteria strains with capability of Cholesterol reduction in order to be used as starter in industrial butter production. 10 samples of Iranian traditional butter were collected from local farms across the country. Isolates were identified as LAB based on their Gram reaction, morphology and catalase test in MRS, M17 and MRS with L-Cysteine hydrochloride and L-Mupirocin media. Strains showing high ability of cholesterol reduction and tolerated to bile and acid were then identified by molecular techniques. Finally, the selected strains were used in the formulation of industrial butter production. According to the results of probiotic properties tests, 10 strains showing high ability of cholesterol reduction and tolerated to bile and acid were identified by molecular techniques. The results indicated that 4 isolates belonged to Enterococcus durans, 4 isolates to Lactobacillus, 1 isolate to Pediococcus and 1 isolate to Neoscardovia. Lactobacillus brevis M-4386 4358, Pediococcus pentosaceus M-4384 4336, Neoscardovia arbecensis M-4391 4378 and Lactobacillus pentosus M-4390 4377 were selected to produce industrial butters from cream. The strains used have led to significant changes in the cholesterol content of all samples, and in all samples, cholesterol content was lower than the control. The highest level of cholesterol reduction was achieved in the butter sample prepared by Lactobacillus pentosus M-4390 4377.

Protein nanofibers are obtained through heating the globular proteins above their denaturation temperatures at acidic pH. These structures have a length of about 1 μm and a diameter of about 1 to 10 nm and are very anisotropic. The main objective of this study was to produce nanofibrils from whey protein isolates, evaluate their appearance and functional properties in order to use them as ingredients in food. The protein nanofibrils were prepared at 90 °C at the concentration of 20 mg mL-1 then their appearance and functional properties were evaluated at pH 2, 4, and 6. The results obtained by atomic force microscopy showed that by increasing pH, the stability and the content of the produced nanofibrils decreased. Moreover, stable nanofibrils at higher pH values showed higher emulsion capacity and stability and higher solubility percentages. Also by increasing pH, samples opacity and turbidity and color parameters were increased. Nanofibrils also showed better functional properties compared to the control sample (P <0.05). In this way, protein nanofibrils can be commercially suggested as an additive to improve functional properties of food products. Desirable functional characteristics of WPI nanofibrils compared to the unprocessed native whey protein isolate, provides the possibility of their application to improve the qualitative properties of food products and as ingredients in foods for patients and elderly people and dietary and low-calorie foods.

The purpose of this study was to compare the effects of extracted inulin from chicory root and commercial inulin on synbiotic yogurt properties during 21 days at refrigerator storage. Inulin powder from chicory root (0, 1.5, 3 and 4%) and commercial inulin (0, 1, 2 and 3%) were used in synbiotic yogurt containing Lactobacillus acidophilus and Bifidobacterium lactis. The addition of commercial inulin and the extracted inulin powder increased acidity and consequently decreased pH. Adding commercial inulin to milk increased the viscosity and reduced the final product syneresis. The extracted inulin powder at low concentrations had a positive effect on these properties. By increasing storage time, the acidity and syneresis of the synbiotic yogurt increased and pH decreased. The presence of these compounds in milk had a positive effect on the viability of the probiotics bacteria in yogurt, which the effect of commercial inulin on the survival of probiotic bacteria being greater than that of the extracted inulin. Addition of commercial inulin had no significant effect on the color properties of the yogurt samples, while the addition of the extracted inulin powder significantly reduced the brightness index (L*) compared to the control sample and increased the redness (a*) and yellowness (b*) indexes. All sensory properties improved by increasing commercial inulin, whereas 1.5% of the extracted inulin powder had no negative effect on sensory properties of the synbiotic yogurt compared to control.

Essential and minor components of the goat milk are unique ingredients in production of various food products. In this study, characteristics of Nodooshan goat milk were investigated and volatile compounds were identified in traditional Nodooshan goat cheese during ripening.

Physicochemical tests were carried out on raw milk, fresh cheese and ripened cheese in brine. Moreover, lipolysis and analysis of the fatty acid composition and volatile compounds of the various cheese samples were carried out using GC-MS.

Results of the physicochemical tests on fresh raw milk, fresh cheese and ripened cheeses in brine (1 and 2 months) showed that sample appearance, color, smell and taste were according to National Iranian Standards ripened cheese samples were rich in fat, protein, moisture and salt. Analysis of the fatty acid composition demonstrated that the predominant saturated fatty acid content in all samples was palmitic acid (C16:0) and the dominant unsaturated fatty acid in all samples was oleic acid (C18:1). Furthermore, the major volatile components in fresh and ripened cheeses in brine were detected using GC/MS.

Based on results from this study, fatty acid profile of the cheese changes during the ripening. Moreover, variety of the volatile compounds in ripening increases but the number of these compounds decreases.

Spontaneous counter-current imbibition is one of the most important crude oil recovery processes in water-wet fractured reservoirs with low matrix permeability. This paper presents a numerical modeling of imbibition process when water is imbibed by capillarity and gravity forces in to an oil saturated vertical cube core to examine the effect of gravity force on spontaneous imbibition. In this modeling, we assumed that imbibition is a diffusion process. Finite difference implicit method was used to solve the spontaneous imbibition equations. Accuracy of the modeling is investigated with comparison of the modeling results and the experimental data.

In the Northwest part of Iran, a traditional product with high popularity among consumers is produced and is named “Nehre Butter”. This study is concerned to evaluate and compare the nutritional characteristics of this product with the industrial products, with a particular emphasis on the risk factors for cardiovascular disease.
Industrial and traditional butter samples were prepared and fatty acid profile and cholesterol content were measured using gas chromatography and atherogenic and thrombogenic indexes were calculated. In order to investigate the effect of feeding prepared butters, 40 Wistar rats were randomly divided into four groups of ten, including one control group and three groups were treated with fermented cream butter, non-fermented cream butter and traditional butter respectively. The end of the sixty days treatment period, serum cholesterol, triglycerides, LDL-C and HDL-C were measured using colorimetric methods.
The most favourable thrombogenic and atherogenic indexes, hypercholesterolemic/ hypocholesterolemic ratio and cholesterol content were found in the traditional butter. The traditional butter also showed a high percentage of conjugated linoleic acid. In the case of the biological model survey, serum lipids were higher in the traditional butter fed rats as compared to the control, but lower than cream butter fed groups.
This study showed that the traditional butter due to its mild effects on health in comparison with the industrial ones is recommended, although moderate consumption is advised.

One of the industrial problems is the phenomenon of wax precipitation of oil fractions. One of the ways to prevent wax precipitation is the use of chemical inhibitors to reduce the pour point. Studying the effect of additives on specific oil samples could help in solving the wax precipitation problems at various oil processing stages. Despite the studies that have been done, finding materials that can decrease the pour point and be economically acceptable from one view, and well optimized and acceptable from other chemical and environmental view is still an unsolved problem. So it’s important to use effective materials that can act on preventing wax precipitation,or on decreasing the amount of precipitate, thus as a result it can decrease the pour point temperature. In this study, the effect of industrial polymer additives and surfactants which are economically acceptable on the decrement of pour point temperature was studied using three oil products samples: light diesel, heavy diesel and the fuel oil, products of Esfahan Oil Refining Co. In this study, optimized type and concentration of additive was studied before additive was chosen. The results showed that the copolymer ethylene vinyl acetate 28% at a concentration of 500 ppm reduced the pour point temperature by 12°C for diesel, also the copolymer ethylene vinyl acetate 19% at a concentration of 300 ppm reduced the pour point temperature by 9°C for fuel oil. Also results of this study showed ethylene vinyl acetate copolymer can be used as the pour point depressant of diesel and fuel oil instead of kerosene and other refinery products.

In recent years، substitution of soy milk with cow milk in the individuals'' diet suffering from inflammatory diseases have been considered in clinical studies. However، soy milk is more prone to oxidation compared to cow milk due to its unsaturated fatty acid. Oxidative stability of soy milk fat and its comparison with cow milk fat has been barely discussed in the literature. Present study aimed at comparing the oxidative stability of commercial pasteurized milk and soy milk samples and their fermented counterparts by L. plantarum A7 during 14 days refrigerated period. Commercial pasteurized milk and soy milk with the same concentration of fatty compound were subjected to fermentation using a native lactobacillus strain، Lactobacillus plantarum A7. Peroxide number and thiobarbitoric acid in the four trials including milk، soymilk، fermented milk and fermented soy milk were investigated during 14 days of cold storage in the controlled condition. The results showed that milk and soy milk fermentation by Lactobacillus plantarum significantly reduced the amounts of both oxidative indices. In non fermented products، peroxide value was found to increase by a similar trend، reaching to the pick after five days of refrigeration. No significant difference was observed between such an increase between milk and soy milk. Instead، TBA value was measured at higher level in soy milk samples all through the study period. Discussion and Despite the higher non saturated fatty acid، soy milk appeared to be as sensitive as milk regarding oxidative damage، However، comparing the great impact of fermentation on retarding oxidation، the difference between no fermented products can be regarded as negligible.

The consumption of probiotic products due to their functional effect on the consumers has been increasing in recent years. One of the effects is the production of B group vitamins, specially folic acid and its derivatives by probiotic bacteria. The aim of this study is to examine the growth rate of folic acid in indigenous set and probiotic yogurt. In order to prepare yogurt, milk samples from cow, sheep and goat were provided and microorganisms consisting of Lactobacillus casei (y2b4, JQ41273501) and ordinary yogurt culture (YC-X11) were employed. The samples were incubated for four hoursat 42oC. Folic acid produced during fermentation and storage for 14 days at 4oC were determined using liquid chromatography (HPLC). Furthermore, acidity and pH changes and sensory scores were determined on the first, 7th and 14th days. The ability of folic acid production by indigenous probiotic in all the milk samples (cow, sheep and goat) were observed. The rate of folic acid produced by probiotic bacteria was more than that of set yogurt (P <0.05). pH changes during storage period has a downward trend while the acidity took an upward trend on the 14th day of storage time (P <0.05). In general this study has indicated that indigenous Lactobacillus casei is able to increase the folic acid rate of production up to three times as compared to that produced by the set yogurt. The inoculation of probiotic had no significant effect on the sensory properties of yogurt and an acceptable product has been produced.

Bubble growth is one of the key parameters in solution gas drive modeling study. It is required that the dominant forces to be specified and calculated appropriately for the bubble growth modeling. In addition, performance capability and reliability of experimental models of bubble growth should be specified before consideration. In this paper, mechanisms of bubble formation, bubble growth and gas phase flow in solution gas drive process in heavy oil reservoirs are studied. Also, various theories with different correlations and assumptions are presented.

During the recent years، a great deal of food studies has been dedicated to anti -oxidant properties of the food constituents and in this relation various laboratory methods have been used for evaluating anti -oxidant property in various foods. In the present study، four methods for measuring anti-oxidant capability including ascorbat auto-oxidation inhibition، the scavenging effect for DPPH free radical، the hydrogen peroxide scavenging activity، and reducing activity were compared for investigating anti -oxidant properties of commercial ultra heated (UHT) milk and soy milk as well as the products resulted form their fermentation. For fermentation، a human isolated strain of Lactobasillus، Lactobasillus plantarum A7 was used. The obtained results were affected by the type of applied method. The results from various methods did not agree in some cases. Among the four compared methods، The scavenging effect from DPPH free radical and reducing activity were more coordinated in comparison with other evaluative methods. Nonetheless The scavenging effect for DPPH free radical was considered as the best method used in this study. Based on the both tests results، anti –oxidant capability was measured in UHT soy milk more than milk. Using all the four methods، considerable decrease in anti –oxidant capability was observed with fermentation of soy milk.

Lipolysis during cheese ripening is one of the main biochemical reactions. In pasteurization natural lipase present in milk becomes inactive. Therefore lipolysis occurs in Iranian cheeses at low level. The aim of this study is to accelerate the ripening of traditional and ultra-filtered Feta cheeses by lipolysis and evaluate the effect on the microbiological characteristics of the cheeses. Aspergillus niger encapsulated lipase was prepared according to Sol-Gel method. For producing cheeses after milk fat standardization where the pasteurization was carried out at 75 °C for 15 s, the milk was cooled and the starter, rennet and lipase were added in three forms of encapsulated, encapsulated with arabic gum and non- encapsulated to the traditional and UF-Feta cheeses. The amount of added lipase to curd or retentate was 4 g/100kg. The lipolysis development and evaluations of chemical, microbial and sensory characteristics were performed during the 60 days of ripening. On the 15th day of ripening period the lipolysis development and chemical compounds observed had significant differences at the P< 0.05 between the traditional and UF- Feta cheeses. The microbial counts were negative after 15 th day.Encapsulated lipase treatment of UF-Feta cheeses had the highest sensory score. Accelerated lipolysis in cheese might be regarded as a ripening indicator. Production of free fatty acid and hygroscopic additive like arabic gum had prevention effect on microbial counts in the final product and improved the sensory properties.

In this paper, the development of a new potassium carbonateon alumina support sorbent prepared by impregnating K2CO3 with an industrial grade of Al2O3 support was investigated. The CO2 capture capacity was measured using real flue gas with 8% CO2 and 12% H2O in a fixed-bed reactor at a temperature of 65 °C using breakthrough curves. The developed sorbent showed an adsorption capacity of 66.2 mgCO2/(gr sorbent). The stability of sorbent capture capacity was higher than the reference sorbent. The SO2 impurity decreased sorbent capacity about 10%. The free carbon had a small effect on sorbent capacity after 5 cycles. After 5 cycles of adsorption and regeneration, the changes in the pore volume and surface area were 0.020 cm3/gr and 5.5 m2/gr respectively. Small changes occurred in the pore size distribution and surface area of sorbent after 5 cycles.

Nanotechnology has the potential to introduce revolutionary changes to several areas of oil and gas industry such as exploration, production, enhanced oil recovery, and refining. In this paper, the effect of different concentrations of Fe2O3 nanoparticles as a catalyst on the heavy oil viscosity at various temperatures is studied. Furthermore, the effect of a mixture of Fe2O3 nanoparticles and steam injection on heavy oil recovery is studied in laboratory. The experimental tests show that some of these nanoparticles decrease the heavy oil viscosity less than 50% at certain concentrations at different temperatures. The reason for this viscosity reduction is that, similar to a catalyst, thesenanoparticles activate some reactions. Our results of steam injection tests show that the injection of a Fe2O3 nanoparticle mixture increases heavy oil recovery because of cracking reactions which crack the C-S, C=C, and C≡C bonds of the heavy components of heavy oil and change them to light components.

Despite significant roles of leadership capabilities in social and professional effectiveness and efficiency، most academic curricular programs including food science and technology disciplines، merely focus on technical knowledge and skills. Meanwhile، interdisciplinary and multisectoral nature of food as well its key role in human right، individual health and well-being، and national development necessitates to be integrated with leadership skills. This study was conducted in 2008 to determine leadership educational needs among Iranian food science and technology specialists. Both qualitative and quantitative research techniques were employed to assess the situation and needs. Qualitative data were collected through in-depth interview with 9 ‘key informant leaders’ from different sectors، i. e. academia، government، industry and nonprofit institutions as well as participatory observations to two leadership training programs in South-East Asia and Europe. Quantitative survey was performed using a pre-tested 20-item questionnaire. The questionnaire developed to explore ‘level of importance’ and ‘present status’ of 20 leadership skills and capabilities among 84 food science and technology specialists، between 25-45 years of age، from different disciplines and sectors. Cronbach’s alpha test confirmed the questionnaire reliability. Data derived from questionnaire survey were used to calculate the «educational opportunity scores» using the Ulwick equation. The formula reveals which participants’ needs are the most important but least satisfied. The Paired-t test was employed to compare differences of means of «importance» and «status» for each leadership skills. Ranking of educational opportunities was done using Freidman analysis of variance test. All statistical analyses were performed at α=0. 05 using Excel and SPSS softwares. According to both qualitative and quantitative studies، effective team-building، evidence-based decision-making، and creativity and innovation were found as the most limiting leadership capabilities among food science and technology specialists in Iran. There is however a number of differences between two research methodologies in selecting other leadership skills which are prioritized to be developed. While the qualitative study put its emphasis on effective communication، flexibility، holistic view، and crisis resolution، the quantitative survey prioritizes industrial strategies، motivation، trust building and ethics. Bench marking with two visited programs in South-east Asia and Europe also show that two of these skills، i. e. effective team-building and creativity، possess important places in the program schedules. Both quantitative and qualitative studies reveal limitations in leadership skills among food science and technology specialists in Iran. Therefore، development of training programs focusing on core capabilities based on transformational leadership framework as well as some more specialized allied-food skills is recommended.

Edible films and coatings are developed to improve quality and to extend shelf-life of food products. In this study، soy protein isolate was obtained from defatted soy flour by alkaline extraction and acid precipitation. Then edible films were prepared from soy protein isolate. The effects of protein concentrations and two plasticizers of glycerol and sorbitol on some physical and mechanical properties of the films were evaluated، using response surface methodology (RSM). The results showed that tensile strength، opacity، thickness and water vapor transmission rate (WVTR) were increased، while elongation of the films decreased by protein concentration. Increasing the concentration of glycerol and sorbitol increased WVTR، elongation، total color difference (ΔE)، thickness and opacity، while declined tensile strength of the films. The model developed by RSM for the physical and mechanical properties of the films had high coefficient of multiple determination (R2 >0. 87) and significant F values. The models suggested that the concentration of soy protein and the type and concentrations of the plasticizers are the most influential factors with significant effects on the properties of soy protein isolate films.

Absorption of flavor compounds from food into the package is one of the interactions which occur between food and packaging material. This phenomenon is of high importance، because absorption of flavors into the packaging material could diminish the flavor intensity of the product as well as loss of mechanical/border properties of the packaging material، so the final loss of quality in the food product will be appear. Absorption of menthol (mint flavor agent) from yogurt drink into the PET was studied at three storage temperature (4، 25 and 45°C). Solvent extraction method used for extraction of menthol from PET bottle and dispersive liquid-liquid mixroextraction used for preconcentration of extracted solution before instrumental analysis by GC. Quantification of menthol performed using gas chromatograph coupled with FID detector. The results showed that the absorption of menthol into the packaging material is a time and temperature dependent phenomenon so that the content of menthol absorbed into bottle increases with elevation in time and temperatures. The mathematical model represented fickian diffusion in the absorption of menthol into polyethylene terephthalate bottles.

It has been shown that lactic fermentation of both milk and soy milk could boost their ant oxidative properties، in our previous study، using a native strain of lactobacillus planetarium for ultra-high-temperature (UHT) processed milk and soy milk fermentation، resulted in an increase in anti-oxidative properties of UHT milk، where the output was opposite for UHT soy milk. Since the obtained results were not expectable، here، in this study the effect of fermentation of the given samples were studied using three different lactobacillus strains as well as using less heated commercial milk and soy milk. The objective of the present study was to compare the lactic fermentation effects on anti-oxidative properties of sterilized and pasteurized milk and soy milk using three different lactobacillus strains. Commercial UHT milk and soy milk and their pasteurized type of products were used; Lactobacillus acidophilus، Lactobacillus Plantarum and Lactobacillus Rhamnosus were used as the lactic cultures and DPPH radical scavenging effect was applied as anti-oxidative index. The DPPH radical scavenging effects of unfermented UHT and pasteurized soy milk were obtained as 31. 8 ± 6. 7 and 35. 9 ± 1. 0، respectively; such data، for milk were shown to be 15. 0 ± 2. 3 and 15. 2 ± 2. 4. For both UHT and pasteurized milk، by individual usage of all three strains، fermentation increased the anti-oxidative index. Accordingly، despite different types of fermenting microorganism، the average of the observed data were 24. 4 ± 4. 0and 25. 1 ± 5. 2; however، in sterilized soy milk، DPPH (1، 1-diphenyl-2-picrylhydrazy) radical scavenging activity decreased to 24. 4 ± 12. 1، whereas the pasteurized one showed a considerable increase in this property up to the value of 45. 0 ± 3. 5 after fermentation. Difference in fermenting microbial stains did not make significant difference on the change in antioxidant properties of soy and soymilk. The results of this study confirmed our previous results that lactic fermentation would reduce the anti-oxidative characteristic of UHT soy milk. The type of thermal processing must be considered as the main reason; the fact that after fermentation، the pasteurized soy milk just showed as increase in anti-oxidative property as the milk samples.

Liposomes are closed continuous bilayer structures made mainly of lipid and/or phospholipid. Nowaday, application of liposomes as a nano carrier of ripening accelerated cheese enzyme in cheese production and ripening are suggested. Application of recent methods of liposome production such as Pro-liposome and Heating methods caused addition of encapsulation acceleration of cheese ripening enzyme in the curd without any worry about harmful residue in liposome. Utilization of enzyme-loaded liposome caused protection of enzyme from loss in whey, target association of liposome with casein micelles. Therefore, without any bitterness and yield reduction, control ripening acceleration was achieved. Usage of recent production of liposome method introduce a new research to Iranian researcher about target proteolysis and lipolysis in traditional Iranian cheese with emphasis about consumer right

This is a study aimed to investigate the effect of lactic acid bacteria including Lactobacillus acidophilus and Sterptococcus thermophilus (as thermophilic culture), Lactococcus lactis subsp. lactis, cremoris and diacetylactis, Leuconostoc citrovorum (as mesophilic culture), Lactobacillus acidophilus, Lactobacillus casei, Bifidobacterium lactis and a mixed culture of L.acidophilus, L. casei and B. lactis on fatty acid profile, conjugated linoleic acid (CLA) and atherogenic index (AI) of butter. Fatty acid analysis with gas chromatography indicated that application of thermophilic and mixed culture decreased the ratio of saturated to unsaturated fatty acid; whereas, the butters made with L. acidophilus had the highest content of CLA. Moreover, AI in the samples prepared with thermophilic cultures was the least. Sensory evaluation of the treatments revealed no significant differences (p> 0/05) in appearance and color. However, the butters prepared with thermophilic and mesophilic cultures had more desirable taste in comparison with the samples made with L. acidophilus, L. casei and B. lactis. From the nutritional point of view, the adverse effect of butter could be diminished via the application of selected lactic acid bacteria.