Food Biotechnology
Maryam Moosavi; Mahboobeh Kashiri; Yahya Maghsoudlou; Morteza Khomeiri; Mehran Alami
Abstract
Introduction: Hydrogels are a three-dimensional network of polymeric matrices with the ability to absorb water through chemical or physical cross-linking. Recently, the development of bio-based hydrogel with the aim of reducing the use of fossil fuel is becoming interested. Wheat filter flour (WFF) is ...
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Introduction: Hydrogels are a three-dimensional network of polymeric matrices with the ability to absorb water through chemical or physical cross-linking. Recently, the development of bio-based hydrogel with the aim of reducing the use of fossil fuel is becoming interested. Wheat filter flour (WFF) is a by-product obtained from air-classification in the modern wheat milling industry. It contains a high level of non-endosperm materials with the ability of water absorption and bio-film making capacity. Nevertheless, hydrogel-based films usually display weak water resistance, flexibility problems, and gas barrier properties. Carvacrol as a phenolic component is used to improve the functional properties of film and reduce the growth of pathogenic and spoilage microorganisms. Materials and Methods: Hydrogel based films were prepared by casting technique. Six grams of WFF was added to 100 ml of distilled water, the pH of the solution was adjusted near to 10.7 with NaOH solution (1 N). The dispersion was heated up to 85°C, with gentle stirring at 250 rpm for 30 min.Glycerol (35 g/100g of dry polymer) was then added and stirred for another 15 min. Carvacrol, as an active agent incorporated at two concentrations (5 and 10% (g/100g of dry polymer)) and stirred for another 15 min at 40°C and dried in a forced-air oven at 35± 5°C for 24 h. Physical (density, water-solubility, moisture content), mechanical, barrier and antimicrobial properties of active hydrogel-based film were determined. Antimicrobial properties of active hydrogel-based were evaluated in the vapor phase by using the micro- atmosphere method and liquid medium (immersion in broth) as a food model system. Statistical analyses were performed on a completely randomized design with the analysis of variance procedure using SAS software. Results and Discussion: Increasing the carvacrol concentration in the film making solution led to decreasing the water solubility, moisture content, and hydrophobicity properties of WFF based films. The SEM observations confirmed a porous structure of the active hydrogel-based film. The highest water vapor permeability (1.32×10-10 gm-1s-1Pa-1) and the minimum water solubility (37.01± 0.63%) were observed in hydrogel film with 10% carvacrol. An increase in the concentration of carvacrol produced a greater growth inhibition zone for all microorganisms. The results in vapor phase showed that A.niger exhibited greater sensitivity to carvacrol than other studied bacteria. Hydrogel based films with 5% carvacrol in liquid food model system produced 1.16 and 1.34 log reduction against E. coli and L. monocytogenes, respectively. The greatest antibacterial activity was observed with films containing 10% carvacrol against L. monocytogenes (2.71 log reduction). This work suggested that the WFF hydrogel base film with 10% carvacrol can be used as an active packaging for improving the safety and shelf-life of food products.
Food Technology
Somayeh Ghandehari alavijeh; Mehran Alami; Yahya Maghsoudlou; Alireza Sadeghi Mahoonak
Abstract
Introduction: Porous starch granules are becoming of great interest such as non-toxic absorbents, owing to their great absorption capacity derived from the major specific surface area. Pores can protect sensitive elements as oils, minerals, vitamins, bioactive lipids, food pigments such as beta-carotene ...
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Introduction: Porous starch granules are becoming of great interest such as non-toxic absorbents, owing to their great absorption capacity derived from the major specific surface area. Pores can protect sensitive elements as oils, minerals, vitamins, bioactive lipids, food pigments such as beta-carotene and lycopene that are sensitive to light, oxidation or high temperature. Alpha-amylases from Bacillus and glucoamylases from Aspergillus niger have the strongest hydrolytic ability toward starch. Ultrasonic treatments have been reported to produce modified starch. In the last years, the effects of sonication on the starch microstructures and properties have been studied. It was shown that the C–C bonds of starch granules were destroyed, and hollows or pores were formed on the surface and inside the granules. Therefore, the main objective of this study was to identify a suitable starch (corn or wheat) to carry and protect iron ions. The enzyme having a fixed concentration of 0.1% within a fixed period of 36 hour, was added to the starch solutions in three different steps - after, simultaneously and before - the ultrasound processes. The power of the ultrasound was 350 watt for 10 minutes. Iron ions (Iron Ammonium Sulfate (II)) were added to the porous corn and wheat starches in concentrations of 40, 60 and 80 ppm. Materials and methods: The ability of water and oil adsorptions were measured in the produced corn and wheat porous starches. The microstructures of porous starches were revealed by using Scanning Electron microscopy (SEM). After adding iron ammonium sulfate (II) to the porous starches of corn and wheat, the amount of iron ions absorbed and the type of bonds formed between starch and iron ions were determined by inductively coupled plasma (ICP) and infrared spectroscopy (FTIR), respectively. Statistical analysis was performed by using SPSS software and the mean comparison test at 5% probability level and in the form of factorial test. Results & Discussion: The hydration capacity in processed wheat starch was lower than corn starch due to the differences in granular structure of wheat and corn starch. The hydration capacity in native wheat and corn starches was significantly (p < 0.05) lower than the processed forms. No significant difference (P>0.05) was observed between the three steps of adding enzyme (e after, simultaneously and before the ultrasound processes). According to the results, the oil adsorption capacity in the processed starches was more than that of the native forms. Scanning Electron Microscopy (SEM) shows that the native corn and wheat starch granules appeared without any clear of fissures, fractures and pores. The corn and wheat starches which were treated by the enzyme after (step 1), simultaneously (step 2) and before (step 3) the ultrasound change and lose their smooth surfaces and become uneven. The surface of corn granules in group 2 and 3 have less pores and porosities with more laminated. In simultaneously processes (phase 2) the ultrasound causes the enzyme to be inactivated. In phase 1, it can be concluded that the ultrasound helps the enzyme performance in creating the porosities and cavities. The wheat granules in step 1, 2 and 3 have a lot of damage on the surface and it is likely that the surface of the wheat granule is more resistant to enzyme penetration than the corn. The results of the ICP test show that processed corn starch has significantly (P <0.05) greater ability to absorb iron ions than processed wheat starch. Also, corn starch had a significant difference in iron uptake in the step 1 than steps 2 and 3 (P <0.05), but the data of the second and third steps did not differ significantly (P> 0.05). Hydroxyl groups of D-glucose units in starch granules bond with iron ions and FTIR spectrums give drop at 575 (cm-1) wavelengths. This study showed that enzymatic treatment and ultrasound led to the native corn starches convert to porous starches. The corn starch is more suitable than the wheat because the wheat is more resistant and the cavities were rarely formed. The corn porous starch is a suitable carrier for iron ions.
Mehran Alami; Bahareh Fathi
Abstract
Introduction: Millet is one of the cereals resistant to drought, pest and disease and has a short growing season. As the world's population grows and water resources decline, this agricultural product will increasingly become- important for human use in the future. Millet is gluten-free grain and can ...
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Introduction: Millet is one of the cereals resistant to drought, pest and disease and has a short growing season. As the world's population grows and water resources decline, this agricultural product will increasingly become- important for human use in the future. Millet is gluten-free grain and can be used to produce special food for celiac patients. Due to the low quality of baking products made from gluten-free cereals, additives and physical treatment of flour can be used to improve the baking properties. Therefore, in the present study, heat-moisture treatment of millet grains was used as a method to modify the flour properties. Materials and Method: Proso millet (Panicum miliaceum L.) was dehulled using a stone mill and then moistened to 20, 25 or 30% of moisture by spraying sufficient distilled water, mixing and keeping in polyethylene bags at 4°C overnight. The moistened grains were poured into glass containers and heated in an oven at various temperatures (100 or 120 ° C) for 3 h. After heating, the samples were removed from the containers and dried at about 40°C until about 9% moisture content. The samples were then milled and passed from the screen with standard mesh 80. In this study, cakes were prepared from untreated and treated millet grain. The specific gravity of batter was measured by dividing the weight of a specific volume of batter to the weight of the similar volume of water. Batter viscosity was determined by Brookfield viscometer. Cake volume was measured by the rapeseed displacement method. Color of cake crumb and crust were determined by scanner and image J software. The oven method was used for measuring cake moisture. The hardness of cakes was evaluated by texture profile analyzer. For study of the microstructure of cakes, scanning electron microscope (Hitachi) was applied. In this study, the effects of two factors including moisture of heat-moisture treatment (at 3 different levels) and temperature of heating (at 2 different levels) on the batter and cakes properties were studied by a completely randomized design. Statistical analyses were done via analysis of variance (ANOVA) and Duncan’s multiple range tests for significance at p<0.05 using SAS 9.1 software. Results and discussion: The low specific gravity shows the better aeration of cake batter which can result in greater cake volume. Heat-moisture treatment of millet grains reduced the specific gravity of the cake batter so that the specific gravity of the untreated millet flour batter was the highest. The low batter viscosity reduces the cake volume because the batter cannot keep trapped air bubbles inside it and when the batter is placed in the oven, these bubbles move up to the surface of batter and they get out of the cake. However, a very viscous batter also cannot produce high volume cakes due to the limited expansion of the batter. Therefore, the optimum and appropriate viscosity of the batter is necessary for the production of large volume cakes. Heat-moisture treatment of millet grains significantly increased the viscosity of the batter (p<0.05) so that the lowest viscosity was in the control sample and the highest viscosity was in the treated sample at 30% moisture and 120°C. The samples treated at lower moisture and temperature had higher cake volume compared to the control sample, while the treated samples at higher moisture and temperature showed no improvement in volume. Millet flour treated at 30% moisture and 120°C significantly reduced cake volume (p<0.05) and this effect may be due to excessive viscosity of the batter which prevents the batter expansion in the oven. Increasing the treatment temperature and moisture significantly increased the darkness and redness of the cake color. However, at the baking day and during storage, there was no improvement in the texture and moisture content of the cake crumb after heat-moisture treatment of millet grains. The scanning electron micrographs of raw and treated millet cake showed that heat-moisture treatment of grains increased the uniform and fine cavities in the cake texture. Furthermore, in the cake prepared from treated millet, the gelatinized starch granules are found in the greater numbers.The development of gluten-free bakery products has a growing market worldwide. Therefore, food industry specialists are looking for the production and improvement of the quality of these products. Due to the increasing consumer demand for non-additive foods, there is a growing interest in the physical treatment of cereals as it changes the starch performance without the addition of external ingredients. In this regard, the results of the present study revealed the ability of heat-moisture treatment to modify the performance of millet flour for application in gluten-free product formulations by improving their qualitative properties. Application of heat-moisture treated millet increased cake batter viscosity and air penetration and reduced its specific gravity. Heat-moisture treatment of millet grain at low moisture and temperature improved cake volume. However, the treatment of millet grains did not improve texture and moisture content of the cake during storage. Study of microstructure of the cakes showed that the heat-moisture treatment of millet grain increased the uniform and fine air cells in the cake structure and also the starch granules were more gelatinized. According to the results of this study, heat-moisture treatment of millet grains at 25% moisture and 100 ° C improved quality parameters of batter and cake compared with control.
Rahil Rezaei; Morteza Khomeiri; Mahdi Kashani-Nejad; Mostafa Mazaheri Tehrani; Mehran Alami
Abstract
β-d- glucan as a soluble dietary fiber, has many desirable physical and physiological characteristic. In this research the effect of β-d- glucan and aging conditions (Time and Temperature) on some physicochemical and textural properties of frozen soy yogurt was investigated. Three variables ...
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β-d- glucan as a soluble dietary fiber, has many desirable physical and physiological characteristic. In this research the effect of β-d- glucan and aging conditions (Time and Temperature) on some physicochemical and textural properties of frozen soy yogurt was investigated. Three variables including concentration of oat β-d- glucan (0, 1 and 2%), aging time (2, 13 and 24 h) and aging temperature (2, 4 and 6°C) were studied. The results showed that the addition of β-d- glucan to frozen yogurt increased viscosity, overrun, hardness and fat destabilization but the melting resistance and L*value were decreased. In terms of aging conditions, it was revealed that increasing aging time could improve the quality of product whereas higher temperature had an undesirable effect on the quality of frozen soy yogurt. Longer aging time caused an increase in viscosity, hardness, fat destabilization and melting resistance. By increasing aging temperature, fat destabilization, overrun and viscosity were decreased and melting rate was increased. It was concluded that addition of β-d- glucan as a dietary fiber and prolonged aging time at low temperature could adjust textural properties of frozen soy yogurt and improve quality of this frozen dessert.
Mohammad Farhadi Chitgar; Mehran Alami; Yahya Maghsoudlou; Mohammad Reza Ataroudi
Abstract
Introduction: Gummy candies are included in many confectionery products, such as jellies, pastilles and etc. The texture of gummy candies is achieved by using various gelling agents, such as gelatin, starch and pectin. Color is the most important quality attribute of gummy candies because it is appreciated ...
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Introduction: Gummy candies are included in many confectionery products, such as jellies, pastilles and etc. The texture of gummy candies is achieved by using various gelling agents, such as gelatin, starch and pectin. Color is the most important quality attribute of gummy candies because it is appreciated for its intrinsic aesthetic value and also allows us to estimate food quality. Synthetic dyes have commonly been applied for food coloring purposes because of their stability against light, oxygen and heat. However, some of these synthetics have been related to toxic effects and it has been reported that their consumption affects children's behaviors. Therefore, synthetic dyes are being increasingly replaced by natural pigments. The principal groups of natural food colorants are anthocyanins, betacyanins, carotenoids, curcuminoids, and chlorophylls. Among these pigments, anthocyanins have gained growing interest because they are widely distributed pigments in nature and represent a wide range of color from red and orange to purple and blue. Berberis b .L (barberry) is the largest genus in the family Berberidaceae and contain about 450–500 species of deciduous or evergreen shrubs. Iran is the largest producer of barberry (B.vulgaris) in the world. Besides, other species in different parts of Iran, especially North Khorasan province, grow wildly. B.cratagina is one of the wild barberries which is known as black barberry among Iranian people. B. cratagina contains large amounts of anthocyanin that can be used as an alternative to synthetic colorants. However, its successful application mainly depends on the stabilization of its anthocyanins. Studies have been shown that some hydrocolloids especially pectin can enhance the stability of anthocyanins. So, the aim of this study was to evaluate the effect of different concentrations of high methyl esterified apple pectin on the degradation kinetics of monomeric anthocyanin and visual color parameters (L, a*, b* and TCD) of black barberry in a fruit pastille model system.
Material and Methods: The fruit pastille prepared according to Demars & Zeigler (2001) recipe. Six g gelatin was mixed with pectin (the amount of pectin was varied between 0.5, 1, 1.5 and 2 g) and 20 g water in a beaker. The mixture was heated and deairated in a water bath. Additionally, 30 g of sucrose, 25 g of glucose syrup (80°Brix) and 10 g of water were combined, the mixture was heated at 115°C(2 min), resulting in a total soluble solids content of 80°Brix and added to the gelatin solution. Subsequently, after cooling to 80°C the Berberis juice (10 g ) was added to the mixture Finally, the gel solution was poured into a plastic molds, stored at 4°C for 24h and dried at 25°C until aw=0.6. For shelf life experiments, samples were stored under dark (20±0.5°C) condition for a period of 30days. Samples were drawn at regular intervals of 6 days to quantify total anthocyanin and for color analyses. Total anthocyanin content of samples was determined by the pH differential method and color analysis was performed using computer vision. Linear regression analysis was applied using Slide write software version7.0 to obtain the kinetics parameters. All experiments were repeated at least three times and results were expressed as mean ± SD. Significant differences (α=0.05) of physicochemical properties and kinetic parameters throughout storage were determined using the Duncan's test for differences between independent samples. Data evaluation was performed using the SPSS software version16
Result and Discussion: There was a significant difference (P
Hadi Bagheri; Mahdi Kashani-Nejad; Mehran Alami; Aman Mohammad Ziaiifar
Abstract
Introduction: Roasting is one of the processing steps involved in the nut industry to improve the flavor, color, texture and overall acceptability of the product. Ppeanut is a fruit or pod of the order Leguminosae and contains 47–50% oil, 25–30% protein and is an essential source of minerals and ...
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Introduction: Roasting is one of the processing steps involved in the nut industry to improve the flavor, color, texture and overall acceptability of the product. Ppeanut is a fruit or pod of the order Leguminosae and contains 47–50% oil, 25–30% protein and is an essential source of minerals and vitamins; thus it makes a substantial contribution to human nutrition. Peanuts are readily acceptable as a cheap protein source and popular snack item that can be eaten alone or combined with other foods. Recently, peanuts have gained much attention as functional food and roasted peanuts is one of the most popular snack foods, in which roasting is a key step in the process and directly impacts the quality (crispness, taste, and flavor) and shelf-life of the final product. Understanding of the roasting process is of interest because roasting is a critical processing step not only for peanuts, but many other food products such as coffee, cocoa, grains and other tree nuts. Roasting is a process to develop color, flavor and textural characteristics of product through chemical reactions, therefore proper roasting is critical to flavor and texture development as well as nutritional content of the final product.
Materials and methods: In this study, dried Goli peanuts were supplied from a local market in Minodasht, Iran in 2015 and stored at 4°C until processing. The average moisture content of peanut kernels was measured as 5.1 % (d.b.). Kernels were sorted manually to get the uniform sizes for roasting. 100 g peanut kernels were soaked in 500 ml of 25% salt solution for 30 min. After soaking, the salt solution was drained using a strainer and the excess water was removed by a cloth filter. After soaking, the moisture content of soaked peanut kernels increased to 8.27 % (d.b.). For roasting, three temperatures (140, 160 and 180°C) and three times (10, 20 and 30 min) and constant air velocity (1 m/s) were applied. Roasting was performed in a hot air roaster equipped with a controller to adjust the roasting temperature. After roasting, the whole kernels were allowed to cool at room temperature (23 ± 2°C). Roasting process was performed in 3 replications. Instrumental texture measurements (Uniaxial compression test) were carried out at room temperature using a TA-XT Plus Texture Analyzer using cylinder probe (diameter 25 mm) on peanut halves. The textural parameters of peanut halves were expressed as fracture force (initial peak or first fracture force (N)), hardness (highest peak compression force (N)), initial tangent modulus or apparent modulus of elasticity that shows sample rigidity in the linear part of the force-deformation curve (N/m) and compressive energy or area under the curve for the compression that is the work (N×m) required to attain deformation, indicative of internal strength of bonds within product. Sensory attributes including colour, texture, flavor, odour, total acceptance and final acceptance were assessed according to a five-grade hedonic scale (5 points – the best, 1 point – the worst). A completely randomized factorial design was used to evaluate the results and analysis of variance (ANOVA) was carried out to compare the mean values. All significant differences were reported at P ≤ 0.05 levels. Minitab statistical software (Minitab Release 16, Minitab Inc., USA) was used for all statistical analyses in the present research. However, MSTATC (Version 2.10, Michigan State University) was used to determine significant differences.
Results & discussion: Roasting is one of the most important steps in peanuts processing that leads to the development of the desired aroma, taste, texture and color of the final product. The results showed that increasing the roasting temperature and time decreased the fracture force (75.19–45.92 N), instrumental hardness (81.74–48.90 N), apparent modulus of elasticity (7.508-5.446 N/s), compressive energy (469.0–199.1 N.s) and improved the sensory characteristics of peanut kernels. During roasting process, moisture content of peanut kernels decreased and they became more crumble and fragile which causes to break easier and moisture reduction helps to create a desirable crisp texture. The results of the consumer test showed that the roasted peanut kernels have good acceptability for color (4.50), texture (4.15), flavor (3.89), odor (4.05), total acceptance and final acceptance (3.97) on roasting temperature and time (160°C and 30 min). The results obtained for VIP coefficients (standard coefficients) in PLS regression for fracture force, instrumental hardness; apparent modulus of elasticity and compressive energy variables indicated that apparent modulus of elasticity could be able to predict the individual sensory attribute of peanut kernels except color. PLS results showed that apparent modulus of elasticity could successfully predict quality sensory characteristics of peanut kernels. Thus, instrumental apparent modulus of elasticity could be replaced with sensory analysis for evaluation the quality of peanut kernels.
Mohammad Farhadi Chitgar; Mehran Alami; Elnaz Milani; Yahya Maghsoudlou
Abstract
Introduction: Barberry (Berberis vulgaris) from the distant past has been used as one of the main medicinal plants in Iran and many other countries. Currently, it has been known for pharmaceutical active compounds such as berberine, which has wide application in pharmaceutical industry. Barberry fruits ...
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Introduction: Barberry (Berberis vulgaris) from the distant past has been used as one of the main medicinal plants in Iran and many other countries. Currently, it has been known for pharmaceutical active compounds such as berberine, which has wide application in pharmaceutical industry. Barberry fruits are used in preparing sauces, jellies, candies, marmalades and especially fruit juices. Also, the fruit contains health promoting compounds such as polyphenols and anthocyanins. Anthocyanins are bioactive compounds present in many fruits, vegetables and their products. They are responsible for the wide array of colors present in flowers, petals, leaves, fruits and vegetables and are a sub-group within the flavanoids characterized by a C6-C3-C6 skeleton. A substantial property of anthocyanin is their antioxidant activity, which plays an important role in prevention of neuronal and cardiovascular illnesses, cancer and diabetes, among others. Therefore, preservation of these compounds during processing of barberry juice is very important. Conventional thermal pasteurization is the common preservation technique used for fruit juice processing. Although this method inactivates microorganisms and enzymes causing spoilage and extends the shelf life of juices, but also it causes degradation of anthocyanins and loss of the nutritional quality of these products. Moreover, the increasing demand for natural and fresh fruit juice resulted in the development of various non-thermal technologies, such as radiation processing, osmotic dehydration, pulse electric field, sonication and high pressure. Power ultrasound has shown important advances in food processing and has a potential to meet the FDA requirement of a 5 log reduction in pertinent microorganisms found in fruit juice. Physical (cavitation, micromechanical shocks and mechanical effects) and chemical (formation of free radicals) mechanisms are responsible for the biocidal effect of sonication. Other advantages of this technology include low cost, reduced processing time and environmentally friendly technique. However, ultrasound by itself is not very effective for microbial inactivation and the use of other technologies during sonication such as temperature (thermo-sonication) and pressure (mano-sonication) has shown efficient results in inactivation of microorganisms. Thermosonication has been reported as an alternative to thermal pasteurization for processing of fruit juices such as strawberry juice, blackberry juice and orange juice. According to the negative effect of thermal processing on color and anthocyanins of barberry juice this study aimed to evaluate the effect of thermo-sonication as an emerging technology in two intensities 18.32 and 27.62 W/cm2 at 45°C for 5 and 10 minutes on the quality of barberry juice.
Material and methods: Barberry (B. vulgaris) ripe fresh fruits were collected from gardens of Qaen. Fruits were crushed into pieces in an electric blender. The mixture was then filtered through a nylon filter and kept in dark condition at 4°C before subjecting to thermosonication. Barberry juice was sonicated at 200W capacity batch sonication system (Sonopuls HD 3200 BANDELIN, Germany) and a constant frequency of 20 kHz with a 13mm probe. Barberry juice samples of 60 mL were placed in a 100 mL double wall cylindrical vessel pyrex glass through which water at 4±1°C and a flow rate of 0.5 L/min was circulated to attain a constant temperature in the juice sample during sonication. The samples were sonicated at 70 and 100% amplitudes levels for 10 and 15 min at 45°C with pulse durations of 15s on and 5s off (US70-5, US70-10, US100-5 and US100-10). After the sonication treatment, juice samples were kept in sterilized bottles and were stored at 4°C until further analysis. Total anthocyanin content of barberry juice was determined by the pH differential method and the color of juice samples was determined using a Chroma Meter (Color Flux, USA). The color values were expressed as L* (lightness), a* (redness/greenness) and b* (yellowness/blueness). The total phenolic content and antioxidant activity was determined by modified Folin–Ciocalteu method and DPPH radical scavenging activity. The counting of microorganisms was made using standard techniques (AOAC 1984), and included total plate counts and yeasts and molds. All experiments were carried out in at least three replicates and the results were expressed as mean ± SD. The significant differences between mean values of juice samples were determined by analysis of variance (one way-ANOVA) using Dunkan’s test at a significance level of P< 0.05. Data evaluation was performed using the SPSS software version16.
Results and discussion: The result showed that the processing in all treatments completely inactivated the microbial population. The reduction of total plate counts and yeast and mold counts after processing was equal to 3.68±0.1 and 3.34±0.48, respectively. Thermo-sonication, especially in low intensity (32/18 w/cm2) had little effect on total anthocyanin compounds of barberry juice. The losses in total anthocyanin content of juice samples were 0.03%, 1.14%, 1.56% and 10.79% in TS-70-5, TS-70-10, TS-100-5 and TS-100-10, respectively. Hydroxyl radicals produced by cavitation can be involved in the degradation of anthocyanins by opening of rings and formation of chalcone. Thermosonication had significant effect on color parameters of barberry juice. All the color values (L*, a*, b* and C*) of barberry juice treated with thermosonication treatment were decreased as compared to control. The color loss of barberry juice samples decreased with increasing the amplitude and time of thermosonication. Extreme physical conditions which occur within the bubbles during cavitational collapse at micro-scale reaction may be responsible for the degradation of color in fruit juices. A significant increase (p˂0.05) in both total phenolic content and antioxidant activity of samples treated at TS-70-5 and TS-70-10 was observed. However, higher amplitude significantly decreased the total phenolic content and antioxidant activity of barberry juice. It has been shown the enhancement of total phenolic content in juices after sonication might be attributed to the facilitation the release of bound phenolic present in the suspended particles. Since there is a correlation between total phenolic content and antioxidant activity, the extraction of bound polyphenols due to cavitation can be presumed the increase in antioxidant activity. The result of this study showed that thermo-sonication could be used as an alternative to thermal treatment.
Ali Mehraban Shendi; Mehran Alami; Shabnam Mokhtari
Abstract
Introduction: Cakes are usually formulated including wheat flour, sugar, egg and some liquids such as milk, water and oil. The textural properties of gluten in dough such as tensile, expansion and tolerance capability during mixing are major factors in baking industry. In fact, the structural protein ...
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Introduction: Cakes are usually formulated including wheat flour, sugar, egg and some liquids such as milk, water and oil. The textural properties of gluten in dough such as tensile, expansion and tolerance capability during mixing are major factors in baking industry. In fact, the structural protein to produce bread, cakes, muffins and biscuits is called gluten and the absence of gluten due to production of bakery products caused delicate texture, poor color, low size and porosity. The use of gluten-free flours such as corn, potatoes and rice, millet, Cassava, maize and sorghum in this category is inevitable. Therefore, the use of gluten alternatives such as hydrocolloids, enzymes and proteins, are essential in providing this products. MTG is transferase enzyme that can be made connection between glutamine and lysine. Result of this reaction improve nutritional and functional properties of the proteins. Covalent links generated by MTG has unique effects on gelation capacity, thermal stability and water holding capacities of products. Albumin and globulin do not have any effect on shaping of dough, but MTG connects the albumin and globulin to each other and then they become sedimented. This has beneficial effect on product quality. MTG has repairing ability on damaged wheat grains with binding protein. In this study, we try to contribute production of gluten-free sponge cake with guar gum, millet and rice flour, and MTG.
Materials and methods: TAROM rice flour purchase from local market and keep refrigerated until use it. Polyethylene bags with dimensions 15*25cm and thickness 40 microns were used. Guar gum (MEYPROTM GUAR, E412), vanilla (RHOVANILLA of RODYA company) and soy protein isolate (SPI) was prepared from China. Because of hygroscopic property of MTG, it was purchased in packages of 100 g, and stored at -15 ° C for further tests. For this purpose (0% millet-100% rice, 50%millet -50% rice, 100% millet-0%rice), guar gum (1, 2%) and MTG (0.25, 0.5%) were added. In order to increase the amino acid lysine as a substrate for the enzyme, soy protein isolate (SPI) was added to MTG containing samples. After baking (170 °C, 20 min) and cooling, each of the samples packed in polyethylene bags to evaluate characteristics. Moisture content Base on standard AACC, 2000, measured. For Size Measuring, a piece of cake weighed and placed into the container with the specific volume (Vt), The remaining space of container was filled with canola crops (Vs) and then volume of cakes calculated (Vt-Vs). For Evaluation of brain porous, cake was cubed in size 2*2 cm and Scanned by the scanner with a resolution of 1200 pixels (model: HP Scanjet G3010). Statistical analyze base on factorial design were prepared in triplicate. Duncan test at 5% level (P
Elham Nourmohammadi; Alireza Sadeghi Mahoonak; Mohammad Ghorbani; Mehran Alami; Masoumeh Sadeghi
Abstract
Introduction: Proteins are vital substances for health since they provide nitrogen, amino acids and the energy required for normal body performance. However, the applications of proteins are limited due to their certain properties, such as their low solubility. The enzymatic hydrolysis of proteins is ...
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Introduction: Proteins are vital substances for health since they provide nitrogen, amino acids and the energy required for normal body performance. However, the applications of proteins are limited due to their certain properties, such as their low solubility. The enzymatic hydrolysis of proteins is an extensively used approach to produce bioactive peptides and promote the chemical, functional and nutritional properties of proteins. These compounds have interesting biological properties such as anti-oxidative, anti-hypertensive, anti-bacterial, anti-cancer and anti-thrombotic activities. Lipid peroxidation is one of the main reasons behind the deterioration of foodstuffs during processing and storage. In this case, the addition of anti-oxidative compounds is considered as an effective way to improve the shelf-life of lipid containing foods. Due to carcinogenic effect of synthetic anti-oxidative compounds, extensive efforts have been done to find natural anti-oxidative compounds with plant origin during recent years. Pumpkin (Cucurbitapepo) seeds are rich of proteins, unsaturated fatty acids, phytosterols and essential minerals like Zn, K, Ca, Mg, Fe, Cu and P. Oil content of pumpkin seeds is about 40-60%, and mostly consisted of oleic, palmitic and stearic acids. On the other hand, its protein content is about 45-46%, and this amount will reach to 55-56% after defatting. To date, pumpkin seeds have been mainly used for pumpkin oil production. After the oil extraction, a protein-rich by-product (pumpkin oil cake) remains, which is often used for animal feeding. In this study, the enzymatic hydrolysis of pumpkin oil cake protein isolate by a food-grade protease named trypsin was attempted and the optimum treatment was selected based on the DPPH radical scavenging and ferrous ion chelating activities Materials and Methods: In this study, the optimization of the hydrolysis of pumpkin (Cucurbitapepo) oil cake protein was investigated using response surface methodology (RSM) and central composite design (CCD) in order to achieve the maximum DPPH radicals scavenging and metal ion chelating activities. For this purpose, trypsin concentrations of 1-2% and hydrolysis temperatures and times of 35-45 ċ and 2-5 hours were examinedas independent variables. Preparations of pumpkin oil cake protein isolate (POCPI) Defatted pumpkin oil cake was dispersed in distilled water (1:10 w/v). The pH was adjusted to 10 with 1N NaOH, mixed for 1 hour at room temperature and centrifuged at 5000g for 20 minutes (Combi514R, South Korea). The supernatant was collected, pH was adjusted to 5 with 1N HCl and centrifugation was performed at the same condition. Supernatant was discarded and precipitate was collected as pumpkin oil cake protein isolate. Enzymatic hydrolysis Pumpkin oil cake protein isolate was dispersed in tris-HCl at pH= 8 for trypsin enzymatic treatment (5% w/v). After that, trypsin was added at 1%, 1.5% and 2% and hydrolysis was carried out for 2, 3.5 and 5h at 200 rpm in shaker incubator (8480-VS, South Korea). Hydrolysis temperatures were 35, 40 and 45˚C. At the end of hydrolysis, the enzyme was inactivated for 15 minutes at 85˚C; dispersion was centrifuged at 4000g for 30 minutes, the supernatant was collected and freeze dried. DPPH radical scavenging activity An aliquot of 1000 microliterpumpkin oil cake proteinhydrolysate was mixed with 1000 microliter of 0.1mM DPPH solution prepared in 96% ethanol. The mixture was allowed to stand for 60 minutes in the dark and the absorbance was read at 517 nm. The blank was prepared with the same manner except that 1000 microliter water was used instead of 1000 microliter pumpkin oil cake proteinhydrolysate. Ferrous ion chelating activity Pumpkin oil cake protein hydrolysate(4.7 ml) was mixed with 0.1 ml 2mM FeCl2 and 0.2 ml 5 mM ferrozine and was kept at room temperature for 20 min. The absorbance was read at 562 nm and the blank sample was prepared with the same manner except that 4.7 ml distilled water was used instead of sample. Results & Discussions: The results of this study, showed that the optimum conditions to reach the maximum DPPH radicals scavenging and metal ion chelating activities were 35 ċ, 5h, 1.1% enzyme concentration and 45 ċ, 2.05h and 2% enzyme concentration that showed DPPH radicals scavenging and metal ion chelating activities of 76.28% and 49.61% respectively. These results were to large extent similar to those suggested by Design Expert software (75.89% and 50.84%). The R2 was 0.9184% and 0.9761% for DPPH radicals scavenging and metal ion chelating activities respectively. Moreover the adjusted R2 was estimated to be 0.1333 and 0.1827 for DPPH radicals scavenging and metal ion chelating activities respectively, which suggested the suitability and fitness of proposed model for the considered responses. Conclusions: Based on the results, pumpkin oil cake protein hydrolysate demonstrated appropriate anti-oxidative and metal ion chelating abilities. The results of this study indicated that pumpkin oil cake protein hydrolysate had the ability to be used as an effective and natural anti-oxidative compound in lipid containing foods.
Abbas Abedfar; Alireza Sadeghi; Mahdi Kashani-Nejad; Morteza Khomeiri; Mehran Alami
Abstract
Introduction: Sourdough is a very complex biological system and an important modern fermentation method of cereal flours and water. Sourdough fermentation is based on lactic acid and alcoholic fermentation depending on the composition of micro flora and fermentation conditions. Commercial sourdough processes ...
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Introduction: Sourdough is a very complex biological system and an important modern fermentation method of cereal flours and water. Sourdough fermentation is based on lactic acid and alcoholic fermentation depending on the composition of micro flora and fermentation conditions. Commercial sourdough processes do not rely on fortuitous flora but on the use of specific starter cultures. There has also been much progress in the development of tools that allow for the selection of key sourdough microorganisms for particular activities such as those concerned with enzymatic, antimicrobial, nutritional and additive replacement aspects. Most of the beneficial properties attributed to sourdough are determined by the acidification activity of dominant Lactobacillus starters. Sourdough fermentation can improve texture and palatability of whole grain fiber-rich, stabilize or increase levels of various bioactive compounds, retard starch retro-gradation and improve mineral bioavailability. The acidification of the sourdough and the partial acidification of the bread dough will impact on structure-forming components like gluten, starch and arabinoxylans. The swelling of gluten in acid is a well-known effect and mild acid hydrolysis of starch in sourdough systems has also been hypothesized for delay bread staling. The objectives of this research were to apply the dominant Lactobacillus starter isolated from traditional sourdough for cup bread production with whole wheat flour and delay it's staling. Materials and methods: In this study, following isolation of dominant Lactobacillus starter from traditional sourdough produced with whole wheat flour, the starter was identified by specific PCR. The single colonies obtained from streak plate of the sourdough culture, were subjected to species specific PCR. Afterwards, the mentioned starter was used for sourdough preparation. For this purpose, the effect of flour components (extraction rate, moisture, protein, ash and falling number), fermentation times (8, 16, 24 h) and sugar contents (0.5, 1, 1.5%) on starter activity were evaluated. pH and total titratable acidity (TTA) of sourdough treatments were measured. After processing of cup breads with sourdough treatments, the staling of these breads were also examined 2, 48 and 96 h after baking, based on crumb firmness (texture analysis) and amount of porosity (Image j method). Finally for statistical analysis a completely randomized design with factorial arrangement and 3 replications was used. To study the relationship between bread hardness and porosity with fermentation conditions, multiple linear regression was used and regression models were exhibited. Results and Discussion: By sequencing of the PCR products (obtained from sourdough culture), dominant Lactobacillus starter was identified as Lactobacillus plantarum. The TTA profile for the sourdoughs was also quite similar (starters interestingly continue to produce acid) and by increasing of TTA, the pH values were decreased. The acid production depends on factors such as fermentation temperature, time and dough yield. In general, a higher temperature, a higher water content of sourdough and the utilization of whole meal flour enhances the production of acids in wheat sourdoughs. The effect of sourdough on softness improvement was partly due to a higher porosity. Among the bread samples, 96 h after baking, lowest crumb firmness was observed in sample produced with sourdough with 24 h fermentation and 0.5%. sugar content. The maximum amount of crumb firmness was observed in sample produced with sourdough after 8 h fermentation and 1.5% sugar content. Furthermore, the maximum amount of porosity was obtained after 24 h sourdough fermentation and 1.5% sugar content, while the lowest amount was obtained after 8 h sourdough fermentation and 0.5% sugar content. After evaluation the results of texture analysis and porosity tests, significant correlation coefficients were established between porosity and softness, and it is reported that volume improvement is the main reason for a better shelf life in sourdough breads. The relationship between factors affecting on sourdough fermentation including fermentation time, sugar content and flour components, were also exhibited as regression models for examination texture characteristics of sourdough breads based on those viscoelastic behavior. By increasing the fermentation time in all of the sourdoughs, crumb hardness was decreased. Acids strongly influence the mixing behavior of doughs. Doughs with lower pH values require a slightly shorter mixing time and have less stability than normal doughs. Fundamental rheological evaluation of acid effect on gluten systems model indicated that both softness and elasticity of gluten were increased. Further to the direct impact of low pH on dough characteristics, secondary effects of acidification and fermentation time including changes in the activity of cereal or bacterial enzymes associated. Wheat flour proteases have optimal activity around pH=4. In addition, proteolytic enzymes with acidic pH optima in vital wheat gluten have been detected. Process requirements for optimum quality were strain-specific and different for textural improvement which should be taken in to account in designing future sourdough baking processes. According to results of this research, the influence of sourdough on bread softness during storage was depended on fermentation conditions and significant effect of sourdough process conditions on bread staling was clarified in comparison to control sample.
Soheil Amiri; Morteza Khomeiri; Mehran Alami
Abstract
Introduction: Mayonnaise is typical oil in water emulsion prepared from vegetable oil, egg yolk, vinegar, sugar, salt, mustard and a variety of food additives. Among its ingredients, egg yolk is most critical in term of stability of the mayonnaise. Nevertheless, one main problem with egg yolk is its ...
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Introduction: Mayonnaise is typical oil in water emulsion prepared from vegetable oil, egg yolk, vinegar, sugar, salt, mustard and a variety of food additives. Among its ingredients, egg yolk is most critical in term of stability of the mayonnaise. Nevertheless, one main problem with egg yolk is its high cholesterol content; therefore different attempts have been carried out to develop low cholesterol sauces with similar characteristics to the real mayonnaise. Employing another emulsifier in addition to egg yolk, or completely replace this important ingredient, provides several advantages, including a decrease in cholesterol content. Therefore, several protein products such as whey and soy protein have been evaluated as emulsifying agents in oil / water emulsions. On the other hand, to achieve mayonnaise with appropriate emulsion properties and high stability, several investigations have been conducted mostly using proteins with various emulsifiers and gums such as xanthan and guar gums. According to the studies identified, whey powder and Tragacanth gum have considerable emulsification and consistency properties. Therefore, the goal of this research was to investigate of the effect of gum tragacanth and whey powder as an emulsifying agent in mayonnaise. Material and methods:Raw materials characterizationRaw materials wereused in this research in order to production of mayonnaise included vegetable oil (alia GolestanCompany), water, egg, vinegar (varda company), spices, gum tragacanth (herbal local market in gorgan city) and whey powder (Pegah dairy company).pH measurement and stability testpH was determined using AOAC standard method (AOAC 2005) at 25 °C. The samples were assessed for the stability test after 24 h storage at 35 °C. Mayonnaise stability was determined after centrifugation (10 min, 2,500 rpm), and was expressed as the volume of separated phase to the total emulsion volume.Color measurementMayonnaise samples were measured for color in the L*, a*, b* system using a Lovibond Colorimeter (Lovibond CAMSystem500).Sensory analysisAfter 1 day storage Sensory characteristics including appearance, color, odor, texture, taste, and overall acceptability were evaluated by 14 semi-trained panel on 5-point hedonic scale (1 0 the least or the lowest; 5 0 the most or the highest).Viscosity measurementViscosity measurements were performed after 24 h storage using a Brookfield viscometer Model RVDV-II(Engineering Lab Inc., Stoughton, Mass., U.S.A) with a spindle no.7 at 25°C.Texture analysisMayonnaise samples were stored in refrigerator for 24 h until texture analysis. The measurements were carried out using a Brookfield texture analyzer (Brookfield LFRA texture analyzer model number 4500 texture prolite) equipped with a 38 mm diameter cylindrical probe at 25 °C.Statistical analysisIn this study, to evaluate the effect of gum Tragacanth and whey powder on physicochemical and sensory characteristics of low cholesterol mayonnaise, statistical design was used by statistical software minitab (16) which eventually combining multiple of 10 mixed were obtained and also to draw the charts and calculation software Excel 2010 and minitab (16) were used. For this purpose, to show the relationship of each of the dependent variables in the regression model with independent variables, their mixed contour diagram was drawn by the mentioned software from the appropriate equations and also to model data, the coefficient of determination of R2 model was determined.Results and Discussions: The results of physicochemical, rheological and sensory tests of low cholesterol mayonnaise have been illustrated in table 1. In terms of stability, viscosity and textural properties, samples containing whey powder and gum tragacantwere appropriate as an egg substitute. Except M5, M8 and M10 samples, other samples were stable, completely. On the other hand, the maximum and minimum viscosity was observed in M6 and M5, respectively. The highest preference belonged to M9.Table 1 – Experimental results for viscosity, hardness, adhesiveness, cohesiveness, stability and total acceptability for each sample.sample Viscosity(cp) Hardness(g) Adhessivness(mj) Cohesiveness Stability (%) L* acceptabilityM1 8460 213 6.6 0.66 100 81.2 4.28M2 8615 215.6 6.7 0.65 100 77.6 4M3 9390 223.2 7.4 0.63 100 77.3 4.14M4 10910 268.5 9 0.63 100 77.6 3.71M5 4315 100.6 4.9 0.76 54.3 70.2 4.14M6 13998 301.5 18.2 0.63 100 78.4 4.28M7 9925 240 7.7 0.65 100 77.3 4.28M8 5580 125 5.3 0.69 58.5 74.1 4.28M9 9700 226.5 7.6 0.66 100 70.2 4.57M10 5505 111 5.2 0.71 78.7 65.1 4.28The numbers were obtained from 3 replications.Considering optimization of low cholesterol mayonnaise formulation and study of its properties, it was revealed that 2.17 g egg, 5.28 g whey powder and 2.74 g tragacanth was an appropriate mixture in order to substitute egg in mayonnaise and making of low cholesterol product.
Vida Mardani Ghahfarokhi; Mehran Alami; Saeedeh Arabshahi- Delouee; Alireza Sadeghi Mahoonak
Abstract
In this study, phenolic compounds of evening primrose leaves (Oenothera biennis) were extracted with aceton 70%, ethanol 70% and methanol 70%. Total phenolic content of aceton extract was significantly higher than the ethanolic and methanolic extracts. Extracts were tested for their antimicrobial activity ...
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In this study, phenolic compounds of evening primrose leaves (Oenothera biennis) were extracted with aceton 70%, ethanol 70% and methanol 70%. Total phenolic content of aceton extract was significantly higher than the ethanolic and methanolic extracts. Extracts were tested for their antimicrobial activity against Lactobacillis plantarum and Saccharomyces cerevisiae, using micro broth dilution method. All extracts showed good antimicrobial activity against tested microorganisms. Aceton extract had the most efficient antimicrobial activity. Lactobacillis plantarum was found to be more sensitive to aceton extract than Saccharomyces cerevisiae. The MBC values of aceton extract for Lactobacillis plantarum and Saccharomyces cerevisiae was 0.5 and 1 (μg/ml), respectively. The antimicrobial activity of aceton extract (0.25, 0.5 and 1 μg/ml) was also evaluated in apple juice inoculated using Lactobacillis plantarum and Saccharomyces cerevisiae during 35 days storage at ambinent temprature. Concerning microbial data in apple juice, the extract was able to control Lactobacillis plantarum and Saccharomyces cerevisiae growth. Aceton extract also showed higher inactivation effect on Lactobacillis plantarum in apple juice. Phenolic compounds did not change during 35 days of storage. No change in organoleptic quality of apple juice treated with aceton extract (0.25 μg/ml) was observed, according to sensory evaluation.
Elahe Eshraghi; Mahdi Kashani-Nejad; Yahya Maghsoudlou; Shahram Beiraghi-Toosi; Mehran Alami
Abstract
The aim of this research was to use Osmosis-Ultrasound Compound pre-treatment and studying the time of drying and the potentiality to rehydration in dried samples of kiwi fruit (Hayvard variety). The samples were drained in three timed phases, 10, 20 and 30 minutes in room temperature in 30, 50 and 70 ...
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The aim of this research was to use Osmosis-Ultrasound Compound pre-treatment and studying the time of drying and the potentiality to rehydration in dried samples of kiwi fruit (Hayvard variety). The samples were drained in three timed phases, 10, 20 and 30 minutes in room temperature in 30, 50 and 70 BX in Ultrasound bath osmosis solutions. The results of drying time showed that by decreasing the concentration of kiwi fruits samples from 8 to 6 mm and increasing the concentration of osmosis solution and ultrasound time, the time of gaining 20% moisture decreased for each treatment. The studies showed that the minimum time for getting 20% moisture in 6 and 8 mm kiwi fruits in pre-treated samples with 70 BX and 30 minutes ultrasound time is 263 and 313 minutes respectively. The results of rehydration in pre-treated compound samples showed that by increasing the concentration of osmosis solution, as well as the time for Ultrasound waving and increasing the kiwi fruits samples concentration from 6 to 8 mm, the rehydration decreased compared to control sample. The results of perceptive assessment in general acceptance of dried kiwi fruit showed that using pre-treated compound sample was more acceptable than the control sample.
Vida Mardani Ghahfarokhi; Mehran Alami; Saeedeh Arabshahi- Delouee; Rasul Khoda Bakhshi; Maryam Ghaderi
Abstract
Evening primrose (Oenothera biennis) is a biennial flowering plant increasingly cultivated for medicinal use of γ-linolenic acid rich oil of its seeds. In this study, total phenolic and flavonoids content, antioxidant and antimicrobial activity of aceton, ethanolic and metanolic extracts of evening ...
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Evening primrose (Oenothera biennis) is a biennial flowering plant increasingly cultivated for medicinal use of γ-linolenic acid rich oil of its seeds. In this study, total phenolic and flavonoids content, antioxidant and antimicrobial activity of aceton, ethanolic and metanolic extracts of evening primrose flowers were evaluated. Aceton extract had the highest extraction yield, total phenol and flavonoids content. Extracts were also tested for their antioxidant activity using scavenging activity of 2,2- diphenyl-1-picrylhydrazyl and reducing power of Fe+3 in comparision with BHT. BHT was the highest in DPPH radical scavenging and reducing power followed by aceton, ethanolic and methanolic extracts. The extracts also showed good antibacterial activity against all of tested microorganism and the tested gram-negative bacteria was more resistant to inhibitory effect of extracts. Among different bacteria tested, Salmonella. typhimurium was found to be the most resistant to aceton and ethanolic extracts. The MBC values, with respect to aceton and ethanolic extracts for Salmonella. typhimurium were 10 and 20 (μg/ml), respectively
Rahil Rezaei; Morteza Khomeiri; Mehran Alami; Mahdi Kashani-Nejad
Abstract
In this study, effects of Guar and Arabic gum on the viability of two common probiotic, Lactobacillus acidophilus and Bifidobacterium lactis, in frozen yogurt during 60 days were investigated. Results of survival evaluation of probiotics showed that although during storage time bacteria counts decreased ...
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In this study, effects of Guar and Arabic gum on the viability of two common probiotic, Lactobacillus acidophilus and Bifidobacterium lactis, in frozen yogurt during 60 days were investigated. Results of survival evaluation of probiotics showed that although during storage time bacteria counts decreased significantly, this product could maintain 107 cfu/gr of probiotic at the end of storage. Maximum death rate of lactobacillus acidophilus was observed in control sample. Best viability of this microorganism was seen in samples containing 0.2% guar gum and 0.1% Arabic gum that these two treatments had no significant difference. The highest loss of bifidobacterium lactis belonged to sample containing 0.3% guar and lowest was seen in samples containing 0.1% Guar and 0.1% Arabic gum.
Soheil Amiri; Mehran Alami; Amir Daraei Garmekhani
Abstract
Mayonnaise is a popular product which is consumed in large amounts. However, many consumers consider it as a unhealthy product as it contains high amounts of oil. Therefore, production of low fat mayonnaise with a quality close to that of traditional one might respond to consumer demand. In the present ...
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Mayonnaise is a popular product which is consumed in large amounts. However, many consumers consider it as a unhealthy product as it contains high amounts of oil. Therefore, production of low fat mayonnaise with a quality close to that of traditional one might respond to consumer demand. In the present study, gum tragacanth was used as a fat replacer for the preparation of low fat (LF) mayonnaise. Mayonnaise samples were analyzed in terms of their rheological, textural and sensory properties. Fat was partially substituted by gum tragacanth at levels of 20%, 30%, 40% and 50%, and the samples were referred as TRF20%, TRF30%, TRF40% and TRF50%, respectively. The full fat (FF) mayonnaise (75% oil) without gum tragacanth was used as a control. Results indicated that all LF mayonnaise samples had significantly lower energy content than control, but they had higher moisture content than their FF counterpart. In terms of textural properties, the highest value for firmness and adhesiveness was observed in TRF20%. There were no significant differences between the FF and TRF50%. In terms of rheological properties, all of mayonnaise samples exhibited thixotropic shear thinning behavior. In sensory evaluation, in terms of total acceptability, the highest score belonged to TRF20%, but there was not observed significantly difference in other samples. This study showed that gum tragacanth has high potential to use as a fat replacer in mayonnaise.
Elahe Eshraghi; Yahya Maghsoudlou; Mahdi Kashani-Nejad; Shahram Beiraghi-Toosi; Mehran Alami
Abstract
The aim of this research was to use ultrasound pre-treatment and studying the time of drying and rehydration in dried samples of kiwifruit (Hayvard variety). The samples were dehydrated for different lengths of time, 10, 20 and 30 minutes at room temperature in distilled water in Ultrasound bath (45 ...
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The aim of this research was to use ultrasound pre-treatment and studying the time of drying and rehydration in dried samples of kiwifruit (Hayvard variety). The samples were dehydrated for different lengths of time, 10, 20 and 30 minutes at room temperature in distilled water in Ultrasound bath (45 kHz). The results of drying time showed that by decreasing the thickness of samples from 8 to 6 mm and increasing the ultrasound time, the time required reducing the moisture content down to 20% for each treatment. It was also found that the minimum time for bringing the moisture down to 20% in 6 and 8 mm kiwi fruits in pre-treated samples with 30 minutes sonication time was 299 and 404 minutes, respectively. The results of rehydration in samples showed that by increasing the time of sonication and decreasing the kiwifruits samples thickness from 8 to 6 mm, the rehydration increased compared to control sample. The results of organoleptic valuations about to totality acception of dried kiwifruit product showed that using pre-treated ultrasound sample was more acceptable than the control sample.
Keywords: Rehydration, Drying, Kiwifruit, Ultrasound
Seyedeh Mahsa Dadpour; Morteza Khomeiri; Hamidreza Sadeghi Pour; Shiva Rofigari Haghighat; Mehran Alami
Abstract
Fermentation is an important process for black tea production. During this process, by exposure of substrate to enzymes and the underlying oxidation reactions, quality determining factors of tea is produced. It is known that the exogenous application of cell-wall degrading enzymes leads to the increased ...
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Fermentation is an important process for black tea production. During this process, by exposure of substrate to enzymes and the underlying oxidation reactions, quality determining factors of tea is produced. It is known that the exogenous application of cell-wall degrading enzymes leads to the increased production of these compounds through enhancement of enzyme-substrate interactions. Pectinases in an important enzyme in this regard which is produced by microorganisms like genera of Aspergillus. In the present study, pectin lyase was isolated and partially purified through three- phase partitioning method from Aspergillus niger. The enzyme was purified by 16.65- fold from Aspergillus niger. The yield of purification was 52%. To assay the effects of purified enzymes on some qualitative characteristics of tea, Crude and purified enzyme were sprayed in the fermentation stage of tea. Molecular weight, optimum pH and optimum temperature of enzyme were 12KDa, 8 and 40°C, respectively. Results showed the effect of crude enzyme preparation on qualitative characteristics of tea is more than purified enzyme.
Keywords: Pectin lyase enzyme, Aspergillus niger, Three phase partitioning, Black tea
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
Asra Talei; Alireza Sadeghi Mahoonak; Mohammad Ghorbani; Seyed Mahdi Jafari; Mehran Alami
Abstract
Tomato seeds are the main component of tomato pulp and considered as an excellent source of edible oils, protein, and essential amino acids. Tomato seeds can be used as an important source of protein for human nutrition. The purpose of present study was to evaluate the effect of heat treatment on functional ...
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Tomato seeds are the main component of tomato pulp and considered as an excellent source of edible oils, protein, and essential amino acids. Tomato seeds can be used as an important source of protein for human nutrition. The purpose of present study was to evaluate the effect of heat treatment on functional properties of tomato seed flour. The functional properties studied included water absorption capacity, oil absorption capacity, emulsification, foaming capacity and solubility. Isoelectric point of sample was around pH 4, while the highest solubility was observed around pH 12. The lowest value for all functional properties was observed at isoelectric point, which can be due decreased protein solubility at this point. Emulsion and foam properties of tomato seeds were desirable and therefore it can be used in some food formulation. Tomato seeds had some essential amino acid like phenylalanine, glutamic acid, aspartic acid, lysine and tryptophan.
Keywords: Tomato seed, Chemical properties, Functional properties, Amino acids profile
Morteza Khomeiri; Mahdi Kashani-Nejad; Mehran Alami
Abstract
Gums are the most important stabilizers that are used in ice cream and other frozen dairy dessert industries. In this study, effect of different levels of guar gum (0, 0.1, 0.2 and 0.3%) and Arabic gum (0, 0.1, 0.3 and 0.5%) on rheological behavior of frozen yogurt was investigated. The rheological behavior ...
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Gums are the most important stabilizers that are used in ice cream and other frozen dairy dessert industries. In this study, effect of different levels of guar gum (0, 0.1, 0.2 and 0.3%) and Arabic gum (0, 0.1, 0.3 and 0.5%) on rheological behavior of frozen yogurt was investigated. The rheological behavior of samples showed that all samples exhibit shear thinning behavior and power law model found to be the best model to predict flow behavior of samples. Sensory evaluation also showed that addition of gums could improve total acceptance of samples compare to control.
Keywords: Guar gum, Arabic gum, Frozen yogurt, Rheology
Alireza Sadeghi Mahoonak; Mehran Alami; Mohammad Ghorbani; Mohammad Hossain Azizi
Abstract
The acorn is an edible nut of oak trees (Quercus spp.) that had been used for human nutrition for a long time. Besides nutritious components, acorn contains considerable amounts of phenolic substances. At present study, two different varieties of Iranian oak acorns, namely, Q. branti var. persica (Qb) ...
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The acorn is an edible nut of oak trees (Quercus spp.) that had been used for human nutrition for a long time. Besides nutritious components, acorn contains considerable amounts of phenolic substances. At present study, two different varieties of Iranian oak acorns, namely, Q. branti var. persica (Qb) and Qcastaneifolia var. castaneifolia (Qc) were used. The total polyphenol content measured in two varieties were 9.11 and 4.33 (gr TAE/ 100 gr d.b), respectively. The effects of various processing methods such as soaking in water (at 25 and 50°C), acetic acid and sodium hydroxide (0.1, 0.5 and 1M) and sodium chloride (1, 5 and 10%) for 6, 12, 18 and 24 hours on the polyphenol removal from acorns were investigated. Repeated measures analysis of variance (ANOVA) was applied (P
Soheil Amiri; Mehran Alami; Seyed Mahdi Jafari; Alireza Sadeghi Mahoonak
Abstract
In the present study, physicochemical, rheological and textural properties of beta-glucan (BG) extracted from four Iranian hull-less barley lines (EHDS4, EHDS18, ALELI, CAM-B) were investigated. Two different methods namely, hot water (HW) and acidic (A) were used for extraction of beta-glucan. Results ...
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In the present study, physicochemical, rheological and textural properties of beta-glucan (BG) extracted from four Iranian hull-less barley lines (EHDS4, EHDS18, ALELI, CAM-B) were investigated. Two different methods namely, hot water (HW) and acidic (A) were used for extraction of beta-glucan. Results showed that the highest amount of beta-glucan belonged to EHDS4.The purity of HW extracted beta glucan was more than that of acidic method. Results of color measurements showed that HW extracted beta glucan was lighter than that of acidic method. while beta-glucan concentrated extracted by acidic method showed higher than redness values. HW extracted beta glucan was also superior to that of acidic extracted beta-glucan in terms of foaming ability, viscosity, and water binding capacity. Results of rheological studies showed that HW extracted beta- glucan had higher flow behavior index and higher consistency coefficient in compare to acidic extracted beta-glucan. It was also found that the power law model was more suitable to predict the flow behavior of beta-glucan solution. Texture analysis of beta- glucan concentrates showed that HW extracted beta-glucan had superior hardness, gumminess, and adhesiveness than that of acidic extracted beta-glucan. From the results, it was found that the beta- glucan extracted by HW method is more suitable to be used in food formulation and functional food production.
Keywords: beta-glucan, hull-less barley, physicochemical properties, rheological properties, textural properties
Seyed Mahdi Jafari; Morteza Khomeiri; Mehran Alami
Abstract
The aim of this study was to extract phenolic compounds from olive leaves of Cronaiky, Roghani and Mishen varieties by maceration and Microwave-assisted extraction (MAE) methods. Our result revealed that effect of extraction method and variety was statistically significant (p
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The aim of this study was to extract phenolic compounds from olive leaves of Cronaiky, Roghani and Mishen varieties by maceration and Microwave-assisted extraction (MAE) methods. Our result revealed that effect of extraction method and variety was statistically significant (p
Soheil Amiri; Mehran Alami; Rahil Rezaei
Abstract
In the present research work, influence of fleawort (Plantago ovate L.) seed hydrocolloid at three concentration level (0.1, 0.15 and 0.2%) was investigated on physicochemical, textural and sensory characteristics of low fat yoghurt. The treated yoghurt samples were compared with a positive (3% fat) ...
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In the present research work, influence of fleawort (Plantago ovate L.) seed hydrocolloid at three concentration level (0.1, 0.15 and 0.2%) was investigated on physicochemical, textural and sensory characteristics of low fat yoghurt. The treated yoghurt samples were compared with a positive (3% fat) and negative (0.2%) control sample after 1, 7 and 15 days of storage. Fleawort seed hydrocolloid did not change the pH and titrable acidity of samples, significantly (p
