Research Article
Maryam Ghaderi; Alireza Sadeghi Mahoonak; Mehran Alami; Morteza Khomeiri; Rahil Rezaei
Abstract
In this study, total phenolics and flavonoids content, antiradical and antimicrobial activity of methanolic extract of two Iranian acorn varieties, namely Quercus.castaneifolia var castaneifolia and Quercus.branti var persica were evaluated. Total phenolic and flavonoid content and extraction yield of ...
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In this study, total phenolics and flavonoids content, antiradical and antimicrobial activity of methanolic extract of two Iranian acorn varieties, namely Quercus.castaneifolia var castaneifolia and Quercus.branti var persica were evaluated. Total phenolic and flavonoid content and extraction yield of methanolic extract of castaneifolia variety (MC) were significantly higher than that of the extract of persica variety (MP). Extracts were also tested for their antioxidant activities using scavenging activity of 2, 2-diphenyl-1-picrylhydrazyl and compared with synthetic antioxidant namely BHA and BHT. EC50 values for MC, MP, BHA and BHT were 42.84, 70.40, 89.46 and 41.73 mg/ml, respectively. The extracts also showed good antimicrobial activity against all of tested microorganisms and the tested gram-negative bacteria was more resistant to the inhibitory effect of extracts. The ranges of minimum inhibitory concentration (MIC) of the extracts were 0.312-5 and 1.25-5 mg/ml for MC and MP, respectively. There was no difference between the MIC of MC and MB extract against Salmonella typhi and Shigella dysenteriae but MC extract showed the strongest activity on Escherichia coli and Yersinia entrocolitica at lower concentration. MP extract at concentration of 5mg/ml had bactericidal effect on all of gram negative bacteria (except Citrobacter). The most efficient bactericidal activity of MC extract was against Bacillus cereus, with MBC = 0.312 mg/ml while Shigella dysenteriae had the highest MBC (10mg/ml). A high-performance liquid chromatography was used for determination of phenolic acids of extracts. gallic, caffeic, p-coumaric and cholorogenic acid were found in MC and Gallic, caffeic, cholorogenic and sirinjic acid were detected in MP extract.
Keywords: Acorn fruit, Antimicrobial activity, Gallic acid, Methanolic extract, Phenolic Compounds
Research Article
Elham Zaerzadeh; Seyed Ali Mortazavi; Mahmoud Reza Jafari; Sima Afsharnejad; Farideh Tabatabaei Yazdi; Mehdi Nasiri mahalati
Abstract
The objective of this study was evaluating the effectiveness of encapsulated nisin in liposoms in contrast to free nisin in control of Listeria monocytogenes ATCC 19117 in Feta cheese during its ripening. The size of the nano-encapsules with nisin was around 103-150 nm and of the nano-encapsules without ...
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The objective of this study was evaluating the effectiveness of encapsulated nisin in liposoms in contrast to free nisin in control of Listeria monocytogenes ATCC 19117 in Feta cheese during its ripening. The size of the nano-encapsules with nisin was around 103-150 nm and of the nano-encapsules without nisin was of approximately 101-143 nm. Addition of 500IU/g nisin to cheese resulted into 0.57, 4 and 3.7 log reduction in viable cells, respectively in free nisin, nano-encapsulated nisin (formulation 1) and nano-encapsulated nisin (formulation 2) at the end of four weeks ripening. In addition, changes in pH during this period of time was also affected by the form of addition of nisin, it was significantly different from liposomal nisin formulations(p
Research Article
Safie Khalilian; Fakhri Shahidi; Mohammad Elahi; Mohebbat Mohebbi; Majid Sarmad; Mansoureh Roshan Nejad
Abstract
In this study the effect of different levels of xanthan and pectin on water activity and sensory properties of fruit pastille formulation based on Cantaloupe puree has been studied. The effects of xanthan (0, 0.1, 0.2, 0.3 %) and pectin (0.2, 0.3, 0.4, 0.5 %) were analyzed in a completely randomized ...
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In this study the effect of different levels of xanthan and pectin on water activity and sensory properties of fruit pastille formulation based on Cantaloupe puree has been studied. The effects of xanthan (0, 0.1, 0.2, 0.3 %) and pectin (0.2, 0.3, 0.4, 0.5 %) were analyzed in a completely randomized design with factorial experiment. Results of ANOVA revealed that different levels of xanthan, pectin and interaction effects between pectin and xanthan had significant influence on water activity of cantaloupe pastilles (p≤0.05). The effects of pectin and xanthan were evaluated on sensory attributes by using multivariate variance analysis (MANOVA). Generally, only pectin level significantly changed (Hotelling Trace = p≤0.05) the sensory attributes. Pectin showed significant influence (p≤0.05) on color intensity, flavor color and appearance acceptance of pastilles. Xanthan had significant effect (p≤0.05) on color intensity and surface adhesivness. Pectin-xanthan interactions also showed significant influence (p≤0.05) on color intensity and stiffness of pastilles. Results of PCA determined that texture and flavor properties were more important than appearance attributes on total acceptance of cantaloupe pastille.
Keywords: Fruit pastille, Cantaloupe, Sensory properties, Water activity, Principal Component Analysis
Research Article
Masoud Najaf Najafi; Rassoul Kadkhodaee
Abstract
Limonene is one of the widely used natural flavorings in the food industry. This compound has high volatility and sensitivity to oxidation and hence a significant portion of it is lost during processing and storage of foods. This work was, therefore, aimed at microencapsulating D-limonene by using freeze ...
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Limonene is one of the widely used natural flavorings in the food industry. This compound has high volatility and sensitivity to oxidation and hence a significant portion of it is lost during processing and storage of foods. This work was, therefore, aimed at microencapsulating D-limonene by using freeze drying. To this end, oil-in-water emulsions composing of 10% limonene (wall material basis) in an aqueous solution of 2, 5 and 10% sodium caseinate or modified starch (capsul) was prepared by ultrasound. The influence of the type and concentration of wall material on the properties of freeze-dried microcapsules such as percent of oil retention, surface oil content, encapsulation efficiency, moisture content and release rate of oil was evaluated. Comparison of microcapsules characteristics revealed that those made up with 10% modified starch could retain more limonene than those containing sodium caseinate or lower concentrations of modified starch with longer half-life over 6 weeks of storage at 25 °C.
Keywords: Microencapsulation, Sodium caseinate, Modified starch, Limonene, Freeze drying
Research Article
Hassan Rashidi; Mostafa Mazaheri Tehrani; Seyed Mohammad Ali Razavi; Mohsen Ghods rohani
Abstract
There is overwhelming scientific evidence that saturation fat consumption increases the risk of both coronary and cancer disease. As a result, fat reduction in UF-Feta cheese (≈ 45% fat in dry matter content) is favorable but unfortunately has some negative effects on the quality of cheese. In this ...
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There is overwhelming scientific evidence that saturation fat consumption increases the risk of both coronary and cancer disease. As a result, fat reduction in UF-Feta cheese (≈ 45% fat in dry matter content) is favorable but unfortunately has some negative effects on the quality of cheese. In this research, the effect of different levels of retentate fat (0, 2, 6, 10, 14 and 18%) and CaCl2 (0 and 0.02%) on sensory (texture, taste, odor, total acceptance) and mechanical texture (texture profile analysis and penetration parameters) characteristics of UF-Feta cheese made from retentate powder was studied. The completely randomized design with two factors was used for production and data analyzing. The results of sensory test showed that cheese sample containing 10% fat retentate and 0.02% CaCl2 had highest texture score with significant difference. Therefore, the panelists were preferred taste and odor of full-fat samples and the maximum total acceptance was belonged to cheese sample made from 14% fat retentate. In texture profile analysis, fat reduction was resulted in significant decrease in gumminess, chewiness, adhesiveness, springiness and compression work but cohesiveness of samples didn’t have any significant differences. In penetration test, hardness, apparent modulus of elasticity, adhesiveness force, adhesiveness and penetration force were decreased with fat reduction. As a result, addition of 0.02% CaCl2 to retentate was increased generally the texture profile analysis and penetration parameters.
Keywords: CaCl2, Cheese, Fat reduction, Feta, Texture
Research Article
Sara Hoseinpoor; Behnaz Layegh; Asgar Farahnaki; Gholam Reza Mesbahi; Mahsa Majzoobi; Nazanin Darabzadeh
Abstract
Pectin is used as a gelling, texturizing and emulsifying agent in many foods. Sugar beet pulp is a good source of pectin, however due to its low molecular weight and poor gelling characteristic its uses in food industry are limited. In this research, pectin extracted from sugar beet pulp was cross-linked ...
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Pectin is used as a gelling, texturizing and emulsifying agent in many foods. Sugar beet pulp is a good source of pectin, however due to its low molecular weight and poor gelling characteristic its uses in food industry are limited. In this research, pectin extracted from sugar beet pulp was cross-linked by phosphorus oxycholride at pH 11 to improve it functional properties. Rheological tests carried out revealed that modified pectin had a higher viscosity and greater intrinsic viscosity and molecular weight than native pectin confirming the cross-linking of pectin polymers. Ketchup sauces formulated using modified and native pectins were compared with the control sample without pectin. The results showed that the sample containing modified pectin had a higher consistency and a lower syneresis value compared to the native pectin.
Keywords: Pectin, Sugar beet pulp, Cross-linking, Viscosity, Functional properties
Research Article
Masoumeh Bahreini; Mohammad Bagher Habibi Najafi; Mohammad Reza Bassami; Morteza Abbaszadegan; Ahmad Reza Bahrami; Hamidreza Ejtehadi
Abstract
The number of vegetable processing plants has been increased during recent years in Iran as many other countries. On the other hand, fresh vegetable products are susceptible to microbial contamination after harvest, processing, handling, packing and distribution. The aim of this study was to determine ...
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The number of vegetable processing plants has been increased during recent years in Iran as many other countries. On the other hand, fresh vegetable products are susceptible to microbial contamination after harvest, processing, handling, packing and distribution. The aim of this study was to determine and evaluate the level of microbial load of vegetables during different cleaning steps in a fresh-cut vegetable processing plant and to identify the critical points in the process lines and operating areas. Samples were taken from the plant before and after washing, disinfection, cutter, drying and packaging and kept in ice pack and delivered to the laboratory. The samples were analyzed for mesophilic aerobic count, yeasts and moulds, lactic acid bacteria, total coliforms, Enterobacteriaceae, E. coli and Staphylococcus aureous as well as for the presence of Salmonella, according to the standard guideline. The amounts of total aerobic bacteria, Enterobacteriaceae, E. coli, yeasts and moulds on surfaces and air were also determined. Results showed that bacteria as well as yeasts and moulds levels were decreased after washing and disinfectation up to 1 and 1.5 log10, respectively, but after that, the microbial load was increased due to secondary contamination. During all steps, salmonella was not detected, but E. coli detected in some of the steps and S. aureous was detected at all steps. The highest levels of total aerobic bacteria, Enterobacteriaceae, E. coli, yeasts and moulds were detected on the equipments (cutters, peeling, centrifuge machines, etc.). Different Hygienic areas should be separated enough to allow maintenance of good hygiene in cleaner areas in primary washing steps. Despite this, the results showed that there is a vital need to improve cleaning and hygienic practices in vegetable processing plants. Several practical recommendations were given for cleaning, design of production lines, training of employees and surface hygiene.
Keywords: Ready to eat vegetables, Microbial evaluation, Microbial quality, Minimal processing, Hygienic level
Research Article
Elham Nourmohammadi; Seyed Hadi Peighambardoust; Javad Hesari; Sodeif Azadmard Damirchi; Seyed Abbas Rafat
Abstract
In this study the possibility of sucrose substitution with different concentrations of sorbitol in formulation of reduced calorie sponge cake was studied. Physical properties of cake batter such as viscosity, specific gravity and cake characteristics such as volume, apparent density, solid density, porosity, ...
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In this study the possibility of sucrose substitution with different concentrations of sorbitol in formulation of reduced calorie sponge cake was studied. Physical properties of cake batter such as viscosity, specific gravity and cake characteristics such as volume, apparent density, solid density, porosity, symmetry and uniformity, moisture and water activity, crust and crumb color and textural firmness were evaluated. 100% sorbitol substituted samples showed lower specific gravity than that of control. Sample containing mixture of sorbitol- sucrose- oligofructose was as viscose as control, while other samples had more viscosity than control. Cakes prepared with sorbitol- sucrose- oligofructose had more volume and porosity and less apparent density than those of control, but other treatments showed significant decrease in volume and porosity and significant increase in apparent density. All treatments had better uniformity compared to that of control, while sorbitol- sucrose- oligofructose and sorbitol- oligofructose treatments showed similar symmetry with control samples. Cakes containing 100% sorbitol resulted in a significant decrease in the crust color. Sorbitol- sucrose- oligofructose treatment gave crumb color similar to that of control. However, other treatments had darker crumb color than that of control. 100% sorbitol substituted fresh (Day 1) sample had harder texture than that of 100% sucrose fresh sample. In 7th and 14th days of evaluation, samples prepared with all concentrations of sorbitol showed softer texture than control. Treatments prepared with sorbitol- sucrose- oligofructose had the same water activity to the control ones.
Keywords: Sorbitol, Oligofructose, Sucrose, Sponge cake
Short Article
Nazanin Darabzadeh; Sahar Sadat Mousavi Nasab; Mahmoud Aminlari; Roghaieh Ramezani
Abstract
In recent years soybean derived foods (such as soymilk) have received considerable attention due to their high nutritional value and functional properties. The purpose of this study was to investigate the changes in protein solubility and electrophoretic behavior of soymilk stored at refrigerator and ...
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In recent years soybean derived foods (such as soymilk) have received considerable attention due to their high nutritional value and functional properties. The purpose of this study was to investigate the changes in protein solubility and electrophoretic behavior of soymilk stored at refrigerator and freezer conditions. A 12% total solid content soymilk was produced and stored at 4 and -18ºC. At different time intervals samples were removed an analyzed for protein solubility and SDS-PAGE. A gradual decrease in solubility of proteins stored at -18ºC with time was observed such that after 3 weeks solubility was dropped from 75% to 45% (30% decrease) and remained at 41% thereafter up to 6 weeks. These changes appeared to follow a first order kinetics with a rate constant (k) of 0.014(day)-1 and half life (t1/2) of 62 days. Similar pattern was seen in the refrigerated sample except that the decrease in solubility occurred slowly and at final stage, solubility decreased by 17%. At this temperature the decrease in protein solubility followed a zero order kinetics with k of 0.625 (day)-1 and t1/2 of 144 days These results indicate that long term refrigeration and freezing of soymilk must be avoided.Keywords: Soymilk, solubility, SDS-PAGE
