Food Technology
Fayza Hussein Alhasan; Mostafa Mazaheri Tehrani; Mehdi Varidi
Abstract
Preparing air-in-oil-in-water (A/O/W) double emulsion involves two key steps: oleofoam formation and dispersion of the oleofoam in an aqueous solution containing protein as an emulsifier and hydrocolloid as a thickening agent. This study aimed to investigate the effect of oleofoam level and varying concentrations ...
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Preparing air-in-oil-in-water (A/O/W) double emulsion involves two key steps: oleofoam formation and dispersion of the oleofoam in an aqueous solution containing protein as an emulsifier and hydrocolloid as a thickening agent. This study aimed to investigate the effect of oleofoam level and varying concentrations of protein-polysaccharide ratios on the thermal stability, encapsulation yield and rheological properties of A/O/W double emulsion. An oleofoam was obtained using a lipophilic emulsifier (distilled monoglyceride MG) and sunflower oil at 5°C with maximum stability. Two levels of oleofoam (20% and 25 wt %) were added to an aqueous solution containing different concentrations of sodium caseinate (SC) (5, 8, and 10 wt %) and kappa carrageenan (KC) (0.4 and 0.8 wt %). Results indicate that oleofoam level did not significantly affect air encapsulation efficiency and particle size, while protein-polysaccharide ratios could significantly impact all properties of A/O/W double emulsion. Increasing the concentration of sodium caseinate and kappa carrageenan improved thermal stability and encapsulation yield while simultaneously reducing particle size. All A/O/W emulsions exhibited shear thinning behavior among the range of shear rates studied, indicating significant potential for food applications.
Food Engineering
Fatemeh Yousefzadeh; Masoud Taghizadeh
Abstract
Introduction The consumption of milk and its products is considered as a main indicators of development of human societies. In order to promote the health of children and provide the sufficient amount of calcium and nutrients and make the consumption of these products attractive. Necessary measures ...
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Introduction The consumption of milk and its products is considered as a main indicators of development of human societies. In order to promote the health of children and provide the sufficient amount of calcium and nutrients and make the consumption of these products attractive. Necessary measures should be taken to increase milk consumption in society and increase the diversity of these products (Keshtkaran et al., 2013). Gelatin as one of the gelling agents used in dairy desserts is a hydrocolloid with unique functional properties and has been used in various industries for a long time (Karim & Bhat, 2008). Gelatin is extracted from the partial hydrolysis of skin collagen, white connective tissue, and animal bones. One of the problems with using gelatin in dairy desserts is the instability at ambient temperature. Therefore, it is necessary to evaluate the characteristics of other native hydrocolloids as an alternative. Tragacanth is a dried gum secreted from several plant species and Iran is the largest exporter in the world. Structurally, the material is regular, odorless and hard. It can be used in various food products. The simultaneous utilization of hydrocolloid mixtures is used to create a synergistic property and to improve these products. Starch originated from a variety of sources , including corn, rice, wheat, potatoes, cassava, bananas, and sorghum (Murphy, 2000) is used in the food industry. Among the sources of starch production, wheat is cultivated in large quantities in Iran. Materials and Methods In this study, pasteurized milk was purchased from Salamat Dairy Products Company, gelatin made in Pakistan, tragacanth gum and Gonabad wheat starch were purchased from Kian Shimi Company and sugar and vanilla were purchased from confectionery stores located in Mashhad. Ingredients for dessert production include 80% milk, 10% sugar, 0.1% vanilla, tragacanth gum at concentrations of 1.3%, 1%, and 0.7% and starch at concentrations of 3% , 2%, and 1% by weight (powder selection) according to the method of Tarrega et al. 2004 with a slight modification. A sample containing 1.5% gelatin was considered as a control sample. The mixture was heated to 90 ° C for 20 minutes, stirring at medium speed. The samples were then placed in special containers and cooled to ambient temperature. Prior to testing, the samples were refrigerated (4-5 ° C) for 24 hours. The samples were coded based on the concentration of gum and starch (: T% of tragacanth gum and: S% of wheat starch). Results and Discussion The flow behavior in all dairy dessert samples was similar to the control and was pseudoplastic type. The Power model was selected as the best model (R <98, RMSE> 1.6). As the concentrations of tragacanth gum and wheat starch increased, the parameters of hardness, consistency, adhesion and adhesion strength increased significantly, and the samples 0.7T2S, 0.7T3S and 1T, 1S had the same value in terms of all textural parameters. At constant concentration of starch, with increasing tragacanth gum from 0.7% to 1.3%, the rate of syneresis of samples decreased from 0.34% to 0.06% and at constant concentration of gum, with increasing concentration of wheat starch, Syneresis decreased significantly from 0.34 to 0.24%. Increasing the shelf life of the samples naturally led to an increase in syneresis. In the samples 0.7T3S, 1T3S, 1T2S, and 1.3T3S, the increase of syneresis occurred to a lesser extent.. According to the results of analysis of variance, the effect of gum on zeta potential was very significant (p <0.05). Increasing the concentration of hydrocolloids in most samples led to an increase in the amount of negative charge and zeta potential. In most samples, at a constant concentration of tragacanth gum, with increasing the concentration of wheat starch from 1% to 3%, the span decreased, while at a constant concentration of starch, the increase in tragacanth gum from 0.7% 0 to 1.3% led to increase the span. Among the dairy dessert samples, 5 dairy dessert samples include: 0.7T2S, 0.7T3S, 0.7T1S, 1T2S and 1.3T1S, were selected the best in terms of physical and rheological characteristics to the control sample. They were more similar, selected and used for sensory evaluation. The results of comparing the mean of the data showed that different concentrations of tragacanth gum and wheat starch had a significant effect on the sensory characteristics of the samples including: color, flavor, sweetness, adhesion, gum state and overall acceptance (P> 0.05) and increasing the concentration of tragacanth gum and wheat starch had no significant effect on other sensory properties (p> 0.05). Conclusion In general, due to the similarities of the physical, rheological and sensory properties of the treatment samples with the control, 1S1T sample was selected as the most suitable sample to replace the sample containing gelatin.
Homa Mahpour; Toktam Mostaghim; Shahla Shahriari
Abstract
Introduction: Dairy products fortification especially ice cream is one of the most important goals and priorities of today's humanbeing to produce health food products. Protein isolate is one of the compounds used to produce health products.The aim of this study was to produce ice cream with new features ...
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Introduction: Dairy products fortification especially ice cream is one of the most important goals and priorities of today's humanbeing to produce health food products. Protein isolate is one of the compounds used to produce health products.The aim of this study was to produce ice cream with new features based on a functional material by partially replacing dry matter with wheat germ protein isolate. Materials and Methods: In present research wheat germ protein isolate with 1%, 3% and 5% was extracted and added to ice cream. In the first step, protein isolate was evaluated by tests of moisture content, fat percentage, acid insoluble ash, particle size and flour grain size. In the next step, protein isolate of wheat germ by 1, 3 and 5 percent was added to ice cream mix and its effects on rheological and texture properties, color, physico-chemical and sensory parameters of ice cream were evaluated. Results and discussion: The results showed that the moisture, fat and acid insoluble ash of protein isolate were 8.41±0.42, 11.34±0.44 and 3.57±0.23 respectively. The particle size and flour grain size was 282±0.01. Laboratory data showed that by increasing protein isolate replacement, the viscosity, melting resistance and volumizing index were reduced significantly. Whereas, texture, hardness and adhesion parameters, density, particle size and diameter, specific distribution and surface area, and yellowness and redness indices were significantly increased. All the laboratory results and sensory evaluation of the samples revealed that the ice cream sample with 1 percent of wheat germ protein isolate was a preferred and optimized sample.
Raheleh Mahjoub; Vahid Hakimzadeh; Esmaeil Atayesalehi; Jamshid Farmani
Abstract
Introduction: The solidification of edible oils via some techniques like hydrogenation is always accompanied by an increase in the amounts of saturated fatty acids (SFA) and trans fatty acids (TFA). Such fatty acids play a crucial role in cardiovascular diseases which put health of consumers at risk. ...
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Introduction: The solidification of edible oils via some techniques like hydrogenation is always accompanied by an increase in the amounts of saturated fatty acids (SFA) and trans fatty acids (TFA). Such fatty acids play a crucial role in cardiovascular diseases which put health of consumers at risk. Today, various techniques are applied to reduce the amounts of SFA and TFA in fatty-based products. These techniques are including the blending of some fats, esterification and recently oleogel system. In this study, some oleogel systems prepared by mixing monoacyleglycerol (MAG) and polyglycerol ester (PGE) and adding to a mixture of 20% palm stearin oil and 80% rapeseed oil to decrease saturation in shortening were studied. Materials & Methods: This research was conducted to investigate the structuring effect of mono-acilglycerol (MAG) and polyglycerol ester (PGE) to formulate some fatty-based product. For this purpose, various binary mixtures (VBM) of PGE:MAG were added to base oils ( 80% Canola Oil and 20% Palmestearin Oil ) at concentrations of 3, 6 and 9 (wt %) with ratios of 0:100, 20:80, 40:60, 60:40, 80:20, 100:0. Result and Discussion: The results showed that saturated fatty acid (SFA), slip melting point (SMP) and solid fat content (SFC) increased with an increase in the VBM of MAG. MAG did not affect peroxide value and the free fatty acids. Rancimat test presents contradictory results. The rheological analysis revealed that G", G', G* and tan δ of the base oil were increased to 105 Pa. With proper plasticity and low SFA, MAG-based fats can be applicable in the production of some fatty-based products like bakery margarine and all-purpose shortening.Due to the necessity of reduction in SFA content and TFA content in fatty-based products, researchers and producers have prompted to identify the applicable techniques for producing healthy fats. This study was set up in order to introduce the structured fats with low-SFA/TFA suitable in the formulation of shortenings and margarine.
Azam Sattari; Jafar Mohammadzadeh Milani; Zeynab Raftani Amiri; Ali Pakdin Parizi
Abstract
Introduction: Oat establishes a healthy basis for food products. It has gained relevance in human nutrition because it is one of the few cereals with a high content of soluble fiber namely β -glucan, and is a good source of proteins, vitamins, and minerals (Butt et al., 2008). β-glucan is one ...
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Introduction: Oat establishes a healthy basis for food products. It has gained relevance in human nutrition because it is one of the few cereals with a high content of soluble fiber namely β -glucan, and is a good source of proteins, vitamins, and minerals (Butt et al., 2008). β-glucan is one such polysaccharide that has received much attention from the past few years due to its several health beneficial properties, including the ability to remove free radicals in a way identical to antioxidants (Gardiner, 2000). β-glucan is an unbranched polysaccharide consisting of β-D-glucopyranose units linked through (1→4) and (1→3) glycosidic bonds in cereals and (1→6) glycosidic bonds in fungal sources (Ahmad et al., 2016). β-glucan from different sources vary in their molecular structure, chain conformation, solubility, number of β- (1→3)- or β-(1→6)-linkage, and thus different biological activities (Descroix et al., 2006). β-glucan is regarded as an important functional ingredient to lower serum cholesterol, promote weight management, reduce glycemic response, enhance immune system, besides having a prebiotic effect (Zhu et al., 2016; Shah et al., 2016). β–glucan from barley and oat at a 3 g/day dosage as recommended by FDA would reduce cardiovascular disease risk including a reduction in blood glucose and also has satiety effects. Therefore, in order to meet the demands of people related to diets that have a low glycemic index and antioxidant property, non-starch polysaccharides like β-glucan can be used as an ingredient in the products to develop new functional foods (Lee et al., 2016). Oat grain’s fat content is more than that of wheat and it is full of lipase, lipoxygenase, and other hydrolytic enzymes. Over time, enzymes lead to the hydrolysis of the fats present in the oat that make the rancidity taste. Due to the effect of enzyme activity on the stability of oat flakes, these enzymes need to be deactivated during oat processing. One of the methods for disabling enzymes is a hydrothermal process (Doehlert et al., 2010). In this study, the effect of the hydrothermal process using autoclave on the physical and rheological properties of oat β-glucans at different times and temperatures has been investigated. Materials and methods: In this study, beta-glucan was extracted from oats using the hot water extraction method. Hulled oat grains, it put into the autoclave for hydrothermal processing, at three different temperatures of 110, 120 and 130°Ϲ in two different times (10 and 20 minutes) intervals, to measure the effect of time and temperature on physicochemical and functional and rheological properties of β-glucan. After extraction, the physiochemical and functional properties of extracted β-glucan such as solubility, foaming, foaming stability and rheological properties were tested. In order to measure the moisture, ash and protein content, the standard methods (AOAC, 2005) were used. The fat content of the flour was measured by the standard AACC method 25-30. The starch was determined by polarimetry method. For solubility measurement, according to Betancur-Anoka (2003) method, after preparing 90 ml of 1% w / v solution from each sample β-glucan, it was divided into 3 equal parts. Then each of them was placed in a warm bath of 25, 50 and 75 °C for 30 minutes. After centrifuging for 15 minutes at about 8000 g, 10 ml of the upper clear solution was transferred to an oven at 125 °C to reach a constant weight. Finally, solubility percentage at different temperatures was calculated.The foaming capacity and foam stability were studied using the temelli method (1997). For this purpose, 2.5 g, β-glucans was dissolved in 100 mL distilled water. The resulting solution was mixed vigorously for 2 min using a hand held food mixer at high speed in a stainless steel bowl with straight sides and volumes were recorded before and after whipping. To determine foaming capacity, foams were slowly transferred to a 1000 mL graduated cylinder and the volume of foam that remained after staying at 25 ± 2°C for 2 h was expressed as a percentage of the initial foam volume (Temelli et al. 1997; Ashraf Khan et al., 2016). β -Glucan gum solutions were prepared in duplicate in the desired concentration (1.0% of gum, w/w) using distilled water. The rheological properties of the samples were studied by an Anton Paar Physica Rheometer (Physica, MCR 301, Anton Paar GmbH, Germany), with a parallel plate geometry. Results and discussion: β-glucan obtained from hydrothermal process on oat flour at 120°C for 10 minutes had the highest solubility at 25°C and the lowest solubility at 50°C, and 130°C treatment for 10 minutes had the highest solubility at 75°C from hydrothermal process on oat flour at 120°C for 10 minutes had the highest solubility at 25°C, and the treatment of 110°C for 10 minutes and also the treatment of 120°C for 20 minutes had the highest solubility at 50°C and 75°C. The amount of foam in treatment at 130°C for 10 minutes were lower than other treatments and the treatment at 110°C for 10 minutes had the highest foaming stability. In the study of rheological properties, the effect of shear rate on viscosity showed by increasing the shear rate, viscosity decreased in all samples. β-glucan from hydrothermal process on oat flour at 120°C for 10 minutes, had the highest amount of viscosity. In the temperature sweep the parameters included G′ modulus and G″ modulus, the amount of G′ and G″ in β -glucan sample that extracted from hydrothermal process on oat flour were decreased in all samples. Also, G′ and G″ of extracted β-Glucan from hydrothermal process on oat flour at 120°C for 10 minutes was higher than other treatments. In the frequency sweep, at a lower frequency, the amount of G″ was more than G′, and both of them were increased by an increasing frequency and the amount of G′, G″ and η* at 120°C for 10 minutes was higher than other treatments in the frequency of 1 and 10 (Hz). The results showed that the hydrothermal process had a significant effect on the properties and functional properties of β -glucan. Extracted β -glucan sample at 120°C for 10 minutes had the highest solubility at 25°C, and the sample had the lowest solubility at 50°C. The sample treated at 120°C for 20 minutes had the highest solubility at 75°C. The foaming capacity of the sample at 130°C for 10 minutes was lower than other treatments and the treatment at 110°C for 10 minutes had the highest foaming stability. In the study of rheological properties, the effect of shear rate on viscosity decreased in all samples and the treatment of 120°C for 10 minutes had the highest amount of viscosity. In temperature sweep measurement, the amount of G′ and G″ were decreased in all samples and at 120°C for 10 minutes it had the highest amount of G′ and G″. In the frequency sweep, at a lower frequency, the amount of G″ was more than G′, and both of them were increased by an increasing frequency and the amount of G′, G″ and η* at 120°C for 10 minutes was higher than other treatments in the frequency of 1 and 10 (Hz).
Elnaz Shafie; Mohammad Goli
Abstract
Introduction: Milk dessert is a product that contains at least 50% the fresh cow milk or reconstituted milk, which is made with supplementary additives such as flavors, sweeteners, thickeners, and stabilizers, after undergoing heat treatment such as pasteurization or sterilization. Spirulina platensis ...
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Introduction: Milk dessert is a product that contains at least 50% the fresh cow milk or reconstituted milk, which is made with supplementary additives such as flavors, sweeteners, thickeners, and stabilizers, after undergoing heat treatment such as pasteurization or sterilization. Spirulina platensis is a multi-cellular microalgae and a green-blue filament that is a rich source of protein, essential amino acids, essential fatty acids, vitamins, minerals and pigments. Today, as a substitute for sucrose, non-caloric sweeteners are used, which in a small amount make too much sweetness, but they are not absorbed by the body. Of these, stevia with higher sweetness than sucrose (300 to 400 times), less calories and lower glycemia index, is a good herbal sweetener to replace sucrose. Materials and methods: Factor A contains the percentage of algae Spirulina platensis (alternative to milk powder) at 5 levels (0-2 % of the final formula), factor B contains the percentage of stevia replacement with sucrose at 5 levels (0-100), to achieve optimal pudding production formula were selected. Optimization of formula was performed based on the parameters of syneresis, viscosity, hardness and cohesiveness by Response Surface Method (central composite design, α=2 with 6 central points). The results were analyzed using SPSS 20 software and the comparison of the means was done by LSD at 5% level and the charts were drawn by Excel software. Results & Discussion SyneresisGenerally, due to the increase of molecular connections between the chains and the outflow of water from the structure is created. According to the results of Table 3, the independent effect of stevia replacement with sugar, the interaction effect of Spirulina platensis and stevia replacement, and the quadratic effect of each of the independent variables on the Syneresis factor were significant (P <0.05). The rate of syneresis of the samples at higher levels of stevia replacement was reduced by decreasing the percentage of Spirulina platensis replacement, and at lower levels of stevia replacement, with the decrease in the percentage of Spirulina platensis replacement, the amount of syneresis significantly increased. Water holding capacity is linked to the ability of proteins, fats, and dietary fiber to maintain water inside the product structure. Because Spirulina platensis has high levels of protein, dietary fiber and fat, its presence in the formulation of frozen desserts has a significant effect on reducing the product's syneresis. ViscosityAs shown in Table 3, the independent effect of Spirulina platensis replacement and stevia replacement, the interaction effect of Spirulina platensis and stevia replacement, the quadratic effect of Spirulina platensis and stevia replacement on the amount of viscosity was significant (P <0.05 ). The level of viscosity at lower levels of stevia replacement decreased with a decreasing percentage of Spirulina platensis replacement, and at the higher levels of stevia replacement, reducing Spirulina platensis replacement percentage was no significant effect on the viscosity (Fig. 2). In general, the presence of Spirulina platensis in the pudding formulation increased its viscosity, which could be due to the Spirulina platensis protein structure and intercellular interactions. Spirulina with high water absorption reduces water mobility. Also, the presence of fiber and hydroxyl compounds in the structure of this fine algae has a significant effect on the viscosity of the product. Hardness and cohesivenessReplacement of Spirulina platensis and Stevia in pudding formulations did not have a significant effect on the hardness and cohesiveness of texture. While the interaction effect of Spirulina platensis and Stevia replacement on the hardness and cohesiveness of the pudding samples was significant (P<0.001). The quadratic effect of Spirulina platensis and stevia replacement on the amount of hardness and cohesiveness of texture was significant (P <0.05). At lower levels of stevia replacement, by increasing the Spirulina platensis replacement percentage, the hardness of the samples first increased and then decreased, while at higher levels of stevia replacement, with increasing Spirulina platensis replacement percentage, the hardness of the samples first decreased and then increased. Large particles of Spirulina platensis can cause unconnectedness and network connectivity and ultimately create a more sophisticated structure. In fact, Spirulina platensis protein molecules, having a hydrophilic property, compete with other molecules to bind to water molecules, which results in a weaker and more unstable gel structure. On the other hand, tissue hardness is largely dependent on dry matter, the amount and type of protein in the sample. High levels of protein cause cross-linking in the gel network and, ultimately, a rigid and dense structure. But it should be noted that the amount of sample fat plays an important role in the product's texture. Since Spirulina platensis, in addition to protein, also has significant amounts of fat, the intervention of the fatty molecules of this small algae can be effective in forming a weaker gel network and producing soft texture in the product. Finally, optimal formula 1 (2 % Spirulina platensis and 95% Stevia replacement) and optimal formula 2 (0.1% Spirulina platensis and 50% Stevia replacement) were predicted.
Narjes Badfar; Seyed Ali Jafarpour; Mehdi Abdollahi
Abstract
Introduction: There is an expanding market for surimi in the world, and much interest in surimi throughout the seafood and food industry by the rapid growth in popularity of surimi-based products. This interest justifies an investigation into the applicability of freshwater fish species such as Silver ...
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Introduction: There is an expanding market for surimi in the world, and much interest in surimi throughout the seafood and food industry by the rapid growth in popularity of surimi-based products. This interest justifies an investigation into the applicability of freshwater fish species such as Silver carp, as an alternative fish resource, for surimi and surimi based products. Rheology concerns the flow and deformation of substances and, in particular, to their behavior in the transient area between solids and fluids. Moreover, rheology attempts to define a relationship between the stress acting on a given material and the resulting deformation and/or flow that takes place. Rheological properties are determined by measuring force and deformation as a function of time. Rheological evaluation is a useful technique for gathering information on the textural characteristics of surimi and kamaboko. It describes the surimi dynamic characteristics in the form of storage modulus (G′), loss modulus (G″), and phase angle (δ). Materials and methods: Whole Silver carp fish were gutted and the head removed, Fillets were minced by a meat mincer with a mesh size of 3 mm, then mince washed one, two and three times at ratio of 1:3 and 1:2 (mince: water) and dewatered. The mince was turned into surimi in a food processor operated for 2 min. salt (2%) was sprinkled over the mince. Ice water was also sprinkled over the mince to adjust the moisture content of the paste to 80 mL/ 100 g.Dynamic tests using a rheometer (MCR-301, Anton Paar- Germany) were carried out on the surimi gel after setting. The region of linear viscoelasticity of the surimi paste was determined by both stress and frequency sweep tests. The thermorheological behavior of Silver carp surimi was evaluated using a temperature sweep test and reported using sol-gel transition thermographs. The stress of 100 Pa was considered as the stress and the frequency of 1 Hz was considered as the frequency in the frequency sweep test, then Temperature sweep test involved heating the surimi samples from 10 to 90°C. Also Crip-recovery test was performed on the surimi in 300 seconds. Results & discussion: Rheological tests: Frequency sweep, Stress sweep and Temperature sweep graphs were relatively similar and in all samples affected by H2O2 and the control sample, the lowest value of G' was recorded between 50 and 52°C. Then, with increasing temperature from 52 to 62°C, the curve G' increased and the curve was stable at temperatures up to 80°C. Changes in the G' graphs can be attributed to the process of forming the gel by heating. Changes in the G" graph showed a similar trend with G’. In the creep-recovery test, the lowest and most strain were belonged to the control and sample 5 (1% H2O2, 1: 2, twice washing). Studying the figure of Creep-recovery test showed the samples affected by H2O2 had more resistance against applied stress in compression with control sample which expressed the effect of H2O2 on creating more and effective covalence cross-linking resulting more stable and constant gel network. During Surimi's heating, there are several reactions that involve various mechanisms, such as protein gelation. About Surimi, the observed macroscopic changes are related to the effect of temperature on proteins. The presence of H2O2 during the washing process did not have a significant negative effect on rheological properties of Surimi.
Nafiseh Ravatab; Simin Asadollahi; Mohammad Reza Eshaghi
Abstract
Introduction: Chocolate is a complete and correct process of mixing one or more primary ingredients with the cocoa beans. These raw materials include the edible sweeteners or sugar, dry milk powder, edible essential oil and flavors as well as plant kernels. Despite high levels of fat and sugar, chocolate, ...
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Introduction: Chocolate is a complete and correct process of mixing one or more primary ingredients with the cocoa beans. These raw materials include the edible sweeteners or sugar, dry milk powder, edible essential oil and flavors as well as plant kernels. Despite high levels of fat and sugar, chocolate, has a significant contribution to human nutrition through the supply of antioxidants and polyphenols. It also has the beneficial minerals, especially potassium, magnesium, copper and iron. Milk chocolate is a complex rheological system that includes the solid phase (cocoa powder, sugar powder and no-fat dry milk powder) released in the continuous phase of cocoa butter. As mentioned, the chocolate contains three essential ingredients in foods, namely, protein, carbohydrate and fat, along with essential minerals that considering its physicochemical properties, the property of functionality can be activated in it by adding certain materials. The first member of omega-3 family is the alpha-linolenic acid that is not produced in the human body, hence it is called essential fatty acid and plays a very important role in many physiological responses of the human body and is considered as a necessity in the diet. The plant resources are healthier, cheaper, and more accessible. The highest amount of fatty acids, α-linolenic acid (short omega-3 chain), was found in plants. Among the plants, flaxseed has the highest fatty acid content (about 50%). Considering the above-mentioned cases, the possibility of producing the functional milk chocolate containing omega-3 fatty acid by this plant resource was investigated.
Materials and Methods: The treatments included control, L10, L20, L30 and L40 with the amounts of 0, 10, 20, 30 and 40% of flaxseed powder replacing butter, cocoa powder, dry milk and sugar. The experiments conducted included the study of physicochemical (sugar, fat, acidity, moisture content, peroxide, ash, particle size, texture and omega-3 levels) and sensory properties. In order to analyze the data of the research, a factorial experiment was used in a completely randomized design and the mean comparison was conducted by Duncan's multiple range test at the probability level of α =5%.
Results & discussion:The results obtained by studying the effect of adding flaxseed powder on the physicochemical properties, color, texture and sensory properties of functional milk chocolate showed that the addition of this material does not have a negative effect on the chemical properties of any treatment. The biggest concern was the oxidation of the oil in the flaxseed powder, which was solved with keeping conditions at 4 ° C and in none of the treatments the amount of peroxide did not increase more than the standard of chocolate (2%). On the other hand, the moisture content of the chocolate remained at the standard level due to the proper packaging and dry storage. Chocolate produced had a bitter taste in L30 and L40 treatments, despite having a good amount of sugar and dry milk powder, due to the relatively bitter taste of flaxseed oil and powder, but this bitterness was not so bad and unpleasant in L10 treatment. Chocolate acidity was not changed undesirably by adding flaxseed powder and replacing some of its oil with cocoa butter. Since the particle size of the flaxseed powder was more than that of cocoa powder and sugar, it reduced the volumetric surface, and fewer chemical bonds was formed between the hydrophilic and hydrophobic surfaces, resulting in less storage time of product at room temperature. Of course, this problem was less significant in L10 treatment, but in L30 and L40 treatments an inappropriate texture were found. The amount of omega-3 residues was zero in L10 and L20 treatments and was not detected by chromatography device, which indicated an inadequate ratio of antioxidant and flaxseed powder. However, since the maximum allowed antioxidants were used in chocolate, more amount of flaxseed should be used, so that as L30 and L40 treatment this fatty acid remains in the chocolate and does not oxidize. Also, by increasing the amount of flaxseed powder in treatments, viscosity also increased, due to the large size of particles and the lack of adequate bonding between hydrophilic and hydrophobic parts. Of course, this indicator was so high in L40 treatment that a problem was even created in molding. The texture analysis behavior of the chocolate indicated that the chocolate texture was loose in L40 treatment so that it lacked the value of production. The texture of this treatment was so loose that it became doughy at ambient temperature. In terms of sensory properties, a significant difference was found between the treatments and the control sample, indicating a decrease in the quality of chocolate produced. Overall, L40 treatment score was low due to so weak and doughy texture, inappropriate and bitter taste, the relatively dark color and the presence of many large pieces of flaxseed powder on chocolate. Therefore, its production does not seem logical, despite the proper amount of omega-3. L30 treatment had more desirable condition, but here, the texture was relatively loose too due to the presence of coarser flaxseeds. Of course, covering the bitter taste of flaxseed with sugar and dry milk powder and vanilla improved the opinion of the experts and increased their scores. It is noteworthy that the appearance and color of the product had better quality than L40 treatment. Regarding L10 and L20 treatments, although the scores of experts were better and they had better texture, color and flavor than two L30 and L40 treatments, but they did not have justifiable production due to the lack of remaining omega-3 in them that was the main purpose of this study. Totally, considering all properties, L30 treatment was introduced as the best treatment.
Ali Motamedzadegan; Elahe Omidbakhsh Amiri; Mahboubeh Jamshidi; Tandis Khosravi rad
Abstract
Introduction: In industrial operations, a product is submitted to a range of shear rates. The knowledge of the changes in rheology with temperature, frequency and shear rate is needed to design the equipment of operations. The lemon juice is used extensively in the food industry. Information about rheological ...
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Introduction: In industrial operations, a product is submitted to a range of shear rates. The knowledge of the changes in rheology with temperature, frequency and shear rate is needed to design the equipment of operations. The lemon juice is used extensively in the food industry. Information about rheological and physicochemical properties is important for scale up and optimization of processes such as transport and storage of concentrated lemon in commercial applications. The aim of this study was toevaluate the rheological and physicochemical properties of the concentrated lemon produced using vacuum evaporator.
Materials and Methods: Lemon juice was concentrated to 25, 35, 45, 55 and 65 Brix by a rotary evaporator under vacuum at 65°C. The content of soluble solids in terms of brix using refractometer, pH, acidity in terms of citric acid, color in terms of a* , b* and L*, flow behavior and viscoelasticity as function of strain, frequency and temperature using rheometer were investigated. Mean comparison carried out using the least significant difference.
Results&Discussion: As brix increased, pH reduced and acidity increased. An increase in the concentration resulted in a decrease in L* and b* parameters and an increase in a* parameter. Enzymatic browning in this study could be ignored due to the sensitivity of enzymes to temperatures above 50°C. Millard's non-enzymatic browning (formation of hydroxyl methyl furfural and its polymerization) and the degradation of pigments might be a major contributor to color variation, although a decrease in moisture content and an increase in soluble solids are other reasons for darkening of color. Based on coefficient of determination (R2) and root mean square error (RMSE), we could state that the Newtonian and Bingham models had the best fit with laboratory data of the stress-strain obtained for the control sample with the 7Brix, and the samples with 25 and 35 Brix. Newtonian and Bingham viscosity increased as brix increased (p
Maryam Farahmand; Mohammad Taghi Golmakani; Asgar Farahnaki; Gholam Reza Mesbahi
Abstract
Introduction: The pomegranate (Punica granatum L.) belongs to the family Punicaceae, which is planted around the world in different microclimatic areas. The pomegranate production has grown uninterruptedly, which is presumably due to the increasing consumer awareness of the benefits attributed to pomegranate ...
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Introduction: The pomegranate (Punica granatum L.) belongs to the family Punicaceae, which is planted around the world in different microclimatic areas. The pomegranate production has grown uninterruptedly, which is presumably due to the increasing consumer awareness of the benefits attributed to pomegranate and its polyphenols. Pomegranate fruit has valuable compounds with functional and medicinal effects like antioxidant, anticancer, and anti-atherosclerotic effects. Storage of juice concentrate can have a dramatic impact on physicochemical quality. The bioactive compounds and antioxidant activity in fruit juice products are influenced by many external factors like different storage temperatures. Knowledge of the rheological behaviour of juice products is essential for product development, design and evaluation of process equipment like pumps and piping. Pomegranate concentrate is so susceptible to the condition of storage, which results in a reduction in consumer acceptability and quality losses. Accordingly, the industrial concentrate stores frozen (-20 °C) which has a lot of costs to the producer. The objectives of this study were to evaluate the degradation visual color, the rheological characteristics of pomegranate juice concentrates, the stability of phytochemicals, the antioxidant activity, and the haze formation of reconstituted pomegranate juice concentrate during storage at different temperatures to determine the best storage conditions to reduce the quality losses and solving the problem about high cost of storage.
Materials and methods: The concentrated pomegranate (Punica granatum (L.) cv. Rabab) juice used in this study supplied from Narni (Green farm, Neyriz, Iran) factory. The pomegranate juice concentrate was poured into falcons for measuring physicochemical attributes, and micro tubes for determination of antioxidant activities. Then the samples were divided into four parts and stored equally in four different temperatures (-20, 4, 20, and 35 °C). The control samples were stored at -80 °C as fresh sample for the storage period (140 days). Folin-Ciocalteu reagent and 2,2-diphenyl-1-picrylhydrazyl radical (DPPHº) were supplied from Sigma-Aldrich Company (St. Louis, MO, USA). All other chemicals were of analytical grade and purchased from Merck Company (Darmstadt, Germany). The total soluble solid (TSS) was determined with a digital refractometer (Carl Zeiss, Germany). Total insoluble solid was measured by centrifugation at (5,000 × g) according to the IFFJP method 60, using a high speed centrifuge (Ibarz et al., 2011). The haze formation of reconstituted juice was determined by “settling” in a glass tube for 3 hour at room temperature. Color measurements of the juice samples were carried out using a HunterLab (CHROMA METER CR-400/410, KONICA MINOLTA, Japan) after dilution. The rheological characteristics of the pomegranate juice concentrate stored in different temperatures were studied by using a computer controlled rotational viscometer. Sample compartment was monitored at a constant temperature (25°C) using a water bath/circulator, while TSS was 65 °Brix. The viscosity measurements, was carried out According to the methods described by Cárdenas et al., (1997), using a Brookfield cone and plate viscometer (DVII pro Brook field, USA) between the shear rate of 0.5–200 (1/s). Total phenolic content of samples was measured according to the Folin-Ciocalteu colorimetric method (Sun et al., 2007). Total flavonoid content in juices was determined via a spectrophotometer according to the method of Chang et al. (2002). Radical scavenging activities of the samples were measured by using DPPHº as described by Mazidi et al., (2012). The ferrous ion reducing antioxidant power (FRAP) of the samples was measured calorimetrically according to the method by Fawole and Opara (2013). All analyses were performed by the Statistical Analysis System (SAS) software V 9.1 (SAS Institute, Inc., Cary, NC, USA). By using the analysis of variance (ANOVA), the differences among means were determined for significance at P< 0.05.
Results and discussion: The industrial pomegranate juice concentrate stored at (-20, 4, 20, and 35 °C) for 20 weeks, and some physicochemical properties like the second turbidity, CIE Lab color parameters, the rheological properties, the bioactive component (total phenolic and flavonoid contents), and antioxidant properties (FRAP and DPPH) investigated in order to determine the best condition of storage. The second turbidity was obvious among the samples stored at 35 °C in the last fourth weeks. Although there were no significant differences among L* value of the samples stored at -20, 4, and 20 °C, a* and b* value of the samples stored at -20 and 4 °C had the same reduction trend for 14 weeks. Even though the control samples had shear thinning behavior, the samples showed a dilatant behaviour after storage. Antioxidant activities measured via DPPH and FRAP sowed reduction with increasing time and temperature. Flavonoid content increased by increasing time and temperature. In conclusion, storage at 4 °C for 14 weeks was the best storage condition to keep the quality and reduce the costs.
Mersad Ghorbannejad Shahroudi; Abdollah Golmohammadi; Davood Kalantari
Abstract
Introduction: Mechanical damages in agricultural products cause wastes directly and indirectly. Bruise damage due to quasi static load is one of the most important reasons of fresh fruit quality loss. Agricultural crops undertake many mechanical loads and physical damages during different stages of harvesting ...
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Introduction: Mechanical damages in agricultural products cause wastes directly and indirectly. Bruise damage due to quasi static load is one of the most important reasons of fresh fruit quality loss. Agricultural crops undertake many mechanical loads and physical damages during different stages of harvesting and post-harvest such as handling, transport, storage and processing. In many cases imported loads cause mechanical damages and cellular wall rupture and this rupture leads to perturbation of natural cellular interchanges. This object is one of the important problems of modelling and experimental studies in Biosystems engineering sciences. Tomato is one of the most important horticultural products and a widely produced products in the world. Larg amounts of tomato products are destroyed during the different stages of harvesting, transport and packaging. To study the viscoelastic behavior of agricultural crops, rheology science is used which is the science of biological materials deformation and flow ability under affection of loads at different times. For prediction and classification of materials behavior under different conditions of stress and strain, different rheological models are used. These models include different combinations of metallic body (spring) and Newtonian liquid body (dashpot) that illustrate complex behavior of agricultural products. Determining of factors that affect deformation value of tomato, lead to reduction of product waste.
Materials and methods: In this study, the effect of some important parameters such as static loading at three levels (2, 6 and 10 N), storage temperature at two levels (4 and 25 ˚C), loading at two directions for two cultivars (Supper-Beta and Petoerly-CH), were studied on deformation value. Samples were handy harvested at approximate ripeness level (reddish pink) from greenhouse and transported to the Lab. Some physical properties (mass, volume, major and minor diameters, height, sphericity coefficient, surface area) were measured. Samples were subjected to compressive loading using university made apparatus. The Experiments were performed in a fifteen-day period, at two different conditions, ones at temperature 4 ˚C and the other at environmental temperature 25 ˚C, using factorial test in form of completely randomized design. The first test was performed under constant load of 6 N in two directions of fruit axials (Z and Y directions), The second test was performed in three levels 2 and 10 N in direction of calyx face. By indicator, deformation value of tomatoes at 2, 4, 7, 10, and 15 days after loading was investigated. The third test was performed under constant loads of 15 N and deformation values of samples were recorded every 10 mins during a 60-minute period.
Results and conclusions: The Results showed at temperature 25 ˚C, with increasing load from 2 up to 10 N, deformation value of the product would be increased about 65%. Increase of deformation value indicates the effect of loading time for products such as tomatoes. This phenomenon can be a result of bulk density ratio reduction of product during the storage, because biochemical reactions are effective in fruit ripening, activating the destructive enzymes of cellular wall during the storage, softening and color changes. Maintaining fruits in direction of calyx face leads to lower deformation in comparison with 90 degrees proportion to calyx. This phenomenon is because of tomato tissue, its tissue in direction of calyx is harder and stiffer of normal direction, because of being flower. By reducing temperature from 25 to 4 ˚C, at constant load of 6N, deformation was decreased about 40%. With decreasing temperature, viscosity of biologic products would be increased and cellular walls get brittle and tissue stiffness increase. Therefore, it seems logical that deformation value of product at lower temperature decreases. Super-Beta cultivar had more durability in comparison with Petoerly-CH against compressive static loads. Under constant loading conditions, General Kelvin rheological model was considered suitable to estimate the strain versus time.
Vahid Mosayebi; Farideh Tabatabaei Yazdi; Zahra Emam-Djomeh
Abstract
Introduction: Pectin is a complex heteropolysaccharide presented naturally in the middle lamella and primary cell walls of plant tissues. Pectin is mostly composed of a linear backbone of α-(1, 4) linked D-galacturonic acid residues which are partially esterified with methyl alcohol or acetic acid at ...
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Introduction: Pectin is a complex heteropolysaccharide presented naturally in the middle lamella and primary cell walls of plant tissues. Pectin is mostly composed of a linear backbone of α-(1, 4) linked D-galacturonic acid residues which are partially esterified with methyl alcohol or acetic acid at the carboxylic acid. Pectin is widely used as a gelling agent in food systems such as jams and jellies, fruit juices, confectionaries, bakery fillings and as a stabilizer in acidified milk drinks. Black mulberry (Morus nigra.L), originating from Iran, is a juicy fruit with dark red color and slightly acidic flavor. Black mulberry has gained an important position in fruit markets and food industry due to its distinctive flavor and phytonutrients in recent years. Black mulberries can be consumed as fresh or processed into several products such as juice, marmalades, liquors, natural dyes or even be used as frozen fruit in ice cream production. However, due to short harvesting season and susceptibility to spoilage, black mulberries are mostly processed into juice besides its fresh consumption. Press cake residue or pomace is the main by-product which is generated in large amounts from the commercial juice extraction processes from berry fruits which contain several bioactive compounds and valuable ingredients including antioxidants, phenolics, pigments, pectin and so on. These berry pomaces are considered suitable for pectin recovery although their pectin content is somewhat lower in comparison to rich known sources of pectin. Recently, ultrasound assisted extraction technique, as a novel method of extraction, has gained remarkable attention due to its some advantageous effects including shorter extraction time, reduced solvent and energy consumption and higher yield and better quality of extracted compounds as compared to conventional acid extraction method. Therefore, the present work was aimed to evaluate and optimize the ultrasound assisted extraction parameters (time of extraction, ultrasound power and liquid/solid ratio) to maximize the extraction yield, degree of esterification and galacuronic acid content of pectin from black mulberry pomace using three level three factor face centered central composite design.
Materials and methods: Fresh and fully ripe black mulberry fruits were purchased from a local fruit market in Karaj (Iran) and subsequently pressed to separate pomace from juice. The obtained pomace was then vaccuum dried (until 7.8±1% moisture content), ground to obtain a homogenous powder, sieved, filled into polyethylene containers, and stored at refrigerator. Pectin extraction from this powdered pomace was carried out using an ultrasonic bath at operating frequency of 35 kHz under different parameters including extraction time (20-60 min), ultrasonic intensity (40-100%) and liquid-solid ratio (15:1 to 30:1 mL/g). The initial pH value of the solution was adjusted to 2.0 by adding 1.0 N HCl solution. At the end of extraction, extracts were quickly cooled, centrifuged, filtered using Buchner funnel, concentrated by 5 fold, coagulated with 96% ethanol (ER=1.5) and left for 8 hours in room temperature. The precipitated pectin was separated by Buchner funnel, rinsed twice with 96% ethanol, dried under vacuum (45°C) and finally powdered. The degree of esterification of pectin was determined by titrimetric method according to Bochek et al. (2001). The galacturonic acid content was quantified by the colorimetric method with m-hydroxydiphenyl reagent using a spectrophotometer at 520 nm. The intrinsic viscosity [ƞ] of pectin was determined using a capillary tube viscometer and accordingly the viscosity average molecular weight [Mv] was calculated from the Anger-Berth equation. Finally, the frequency sweep test was performed using a controlled stress rheometer to determine the values of storage modulus (G′) and loss modulus (G″). The experimental design and statistical analysis were performed using response surface methodology (RSM).
Results and discussion: According to the obtained results, the extraction yield, degree of esterification and galacturonic acid content of pectin varied in the range of 4.73-7.68%, 42.42-58.33 and 18.70-31.45%, respectively. The extraction yield of pectin was linearly affected by the extraction conditions and its value significantly increased with increasing all the studied independent variables (p
Hojjat Karazhiyan; Ehsan Hoseini Bay; Habibollah Mirzaee
Abstract
Introduction: Liquorice (Glycyrrhiza glabra) of the family Leguminosae is a 30±60 cm tall shrub having blue or violet flowers. Its roots are 15±20 cm long and have a cylindrical rod shape of 0.5±2.5 cm in diameter. Liquorice root contains a variety of compounds, the most prominent ...
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Introduction: Liquorice (Glycyrrhiza glabra) of the family Leguminosae is a 30±60 cm tall shrub having blue or violet flowers. Its roots are 15±20 cm long and have a cylindrical rod shape of 0.5±2.5 cm in diameter. Liquorice root contains a variety of compounds, the most prominent of which is the water soluble triterpenoid glycoside glycyrrhizin that constitutes about 16 %. It is responsible for the characteristic sweet taste of liquorice (50 times sweeter than sucrose). The root also contains various sugars (to 18%), flavonoids, saponoids, sterols, starches, amino acids, gums, and essential oil. The water extract of liquorice root has found wide uses in medicine, pharmacology and food industry because of its physical and functional properties.In the food industry, its distinctive flavour makes it a popular sweetening/flavouring agent. It is also used as an emulsifier to create foam in drinks and beverages. Liquorice root extract is commonly consumed and marketed in liquid, concentrated, dry and powdered forms.Knowledge of the flow (rheological) behavior of the concentrates is useful in quality control, sensory evaluation and engineering applications that are related to the proper design and operation of unit operations, as well as for the understanding of the pertinent transport processes in the operations.The purpose of this investigation was to characterize the rheological behavior of liquorice extract concentrates and study the effect of temperature and soluble solids on the viscosity.Materials and methods: Extraction was made at 50°C and water to liquorice root mass ratio of 4:1. The mixture was shaken continuously for 100 min, centrifuged for 10 min and then filtered to obtain a clarified extract, which was concentrated to 50°Brix in a laboratory rotary vacuum evaporator.The rheological behavior of licorice extract has been studied at temperature range 10-70 0C and 5-50 % soluble solids using Brookfield viscometer. Results and discussion: The obtained results showed that all the samples exhibited Newtonian behavior at all the studied temperatures and concentrations. The flow index decreased slightly with sample concentration. Several workers observed Newtonian behavior of clarified and depectinated juices.The shear stress versus shear rate data obtained were well fitted to Newton's model. An increase in temperature decreased the viscosity and this inverse relationship has been likened to the incidence of a freer molecule to molecule interaction at elevated temperatures. Since viscosity is an indication of the resistance to flow such a freer interaction is expected to minimize the resistance. It was observed that, irrespective of the temperature a decrease in soluble solids content decreased the viscosity. It is due to dilution which increases the separation between the particles, thus decreases interaction between the particles.In contrast, the opposite effect was observed when soluble solids content became higher. Arrhenius type equation was found to be suitable in describing the relationship with correlation coefficient values between 0.94 and 0.99. The activation energy increased with the soluble solids content; therefore, temperature had a greater effect on samples with higher soluble solids content. The data obtained in this study can be used in designing equipment for handling of concentrated liquorice root extract at the temperature range studied.
Ommolbanin Godarzi; Mostafa Mazaheri Tehrani; Hashem Pourazerang
Abstract
In recent years, water or sugar syrup, flavoring agents such as fruit juice or fruit juice concentrates and stabilizers have been added to the acidified dairy beverage composition. Nowadays, the popularity of low fat and defatted fruit yoghurt drinks are mainly growing. The purpose of this study was ...
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In recent years, water or sugar syrup, flavoring agents such as fruit juice or fruit juice concentrates and stabilizers have been added to the acidified dairy beverage composition. Nowadays, the popularity of low fat and defatted fruit yoghurt drinks are mainly growing. The purpose of this study was to diversify the acidified dairy products by determining the sensory, rheological and stability attributes of these kinds of dairy products with considering added elements and hydrocolloids as variables and then optimizing the formulation of fermented beverage, being directly flavored with the fruit concentrates. Moreover, mutual effects of total solid materials, concentrate, sweetener and stabilizer were inspected using Minitab software and response surface methodology. In this regard, consistency, viscosity, pH and acidity, sensory characteristics and yeast and mold counts were assessed. Surveys indicated that contrary to flow behavior index, the stability and straightness index increased with adding stabilizer and decreasing water content. According to sensory evaluation, white samples got lower score in comparison with black cherry ones. Furthermore, adding high amount of hydrocolloids negatively affected the total acceptance. Not only yeast but also mold was grown on the optimal sample after 28 day storage at refrigerator temperature. Generally speaking, it can be concluded that highly viscose and extremely sweet products as well as samples with high amount of stabilizer were rejected by panelists whereas the ones with high amount of concentrate were accepted. According to mentioned properties, the optimum amounts of ingredients are as follow: 13% total solid materials, 9.5% concentrate, 6.2% sweetener and 0.78% stabilizer. This sample with 2.3% of serum scored 7.93 in mouth feel, 8.25 in texture, 7.68 in acidic and 7.84 in fruit flavor, 7.89 in color, 7.78 in sweetness and 7.93 in total acceptance and also had 84.36% of total satisfaction.
Arezu Salmanpour; Babak Ghanbarzadeh; Mahood Sowti Khiabani; Seyed Hossein Jalali
Abstract
In this research, the effects of three variables, whey protein concentrate, WPC (0.7- 2.8%), sodium Ceinate, SC (0.7-208%) as a substitute for egg and carboxymethyl cellulose, CMC (0.66-0.234 % w/w) as thickening agent on sensory (taste and texture) and rheological (Complex viscosity, η* , Storage modulus, ...
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In this research, the effects of three variables, whey protein concentrate, WPC (0.7- 2.8%), sodium Ceinate, SC (0.7-208%) as a substitute for egg and carboxymethyl cellulose, CMC (0.66-0.234 % w/w) as thickening agent on sensory (taste and texture) and rheological (Complex viscosity, η* , Storage modulus, G´ and Loss modulus, G˝ ) properties of salad dressing were investigated. The central composite experimental design (CCD) was used and the data were analyzed using response surface methodology (RSM). The results of analysis of variance (ANOVA) showed that P values of all models were significant and lack of fit P values was no significant at the level of 95%. Therefore, the adequacy of models was acceptable. The results showed that the optimum level of hydrocolloids for producing salad dressing with highest rheological properties were 2.27% WPC, 2.27% SC and 0.2341% CMC. The sensory evaluation of six treatments with improved physicochemical properties and stability of salad dressing (data not shown) and control sample (prepared with eggs) was carried out. The results suggest that there is no significant difference in the overall acceptability between control samples and samples prepared with the alternatives. So milk proteins can be used as a suitable substitute for egg in the salad dressing.
Fatemeh Raiesi; Mohammad Hojjatoleslami; Seyed Hadi Razavi; Mahdi Bahman; Mohammad Ali Shariaty
Abstract
In this study, three varieties of rice including Tarom, Anbarbo and Hashemi were selected and their heavy metals Content were analyzed. Subcritical water was used to provide rice bran extract at temperatures 100 and 120 ° C. In order to provide grape juice treatments, we used 5, 10, 15 and 20 % of extract ...
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In this study, three varieties of rice including Tarom, Anbarbo and Hashemi were selected and their heavy metals Content were analyzed. Subcritical water was used to provide rice bran extract at temperatures 100 and 120 ° C. In order to provide grape juice treatments, we used 5, 10, 15 and 20 % of extract in the formulation of red grape drink. samples which had packed and pasteurized, kept in the refrigerator for three months, then Rheological measurements were carried out by using Brookfield rheometer at 5°C .Physical and chemical characteristic evaluated by using SPSS software and one-way ANOVA and Duncan test >P) 0.05). Increasing temperature results in increasing rice bran extraction in subcritical water extraction method. Investigation of rheological properties showed that increasing in amount of rice bran extract cause to decrease consistency coefficient and increase flow index. Consistency coefficient of treatments during storage indicated that consistency coefficients were increased for all treatment
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.
