Food Technology
Ali Hashemi; Jafar Milani; Ali Motamedzadegan; Sepide haghighat
Abstract
Introduction: Due to the low amount of prolamin, rice flour is the most suitable raw material for preparing food for patients with celiac disease. Particle size classification and thermal treatments are among the physical methods to improve the functional characteristics of gluten-free flours and as ...
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Introduction: Due to the low amount of prolamin, rice flour is the most suitable raw material for preparing food for patients with celiac disease. Particle size classification and thermal treatments are among the physical methods to improve the functional characteristics of gluten-free flours and as a result, improve the quality of the products obtained from them. Particle size can increase the quality of gluten-free products by affecting the physicochemical properties of flour during hydration. Dry heat treatment and moist heat treatment are common techniques for physical modification which, depending on the intensity of temperature and storage time, lead to the improvement of gluten-free products by modifying starch grains, aroma, and flavor, and reducing microbial load. Considering that the effect of rice flour particle size on the quality of gluten-free bread has not been studied so far, in the current research, by dividing rice flour into particles with sizes of 180, 150, and 125 microns and using moist and dry heat treatment, it is possible to Improving the functional characteristics of rice flour and improving the quality characteristics of gluten-free bread were investigated. Materials and Methods: The content of moisture, pH, ash, and protein of rice flour was measured using AACC standard method (2000) and the total amount of starch was measured by the alkaline extraction method and the amount of starch damage was measured by non-enzymatic rapid method. To classify the size of the particles, waxy rice flour was divided by a shaker sieve with different sizes of 180, 150, and 125 microns, then under the influence of dry heat treatment for 2 hours and moist heat treatment with humidity, 25% for 5 hours at a temperature of 110 degrees. Celsius was placed. To produce gluten-free bread, the formulation used by Haghighat‐Kharazi in 2020 was used with a slight change. Ingredients for gluten-free bread formulation for 100 grams of rice flour included 125 ml of water, 4.5 grams of sugar, 2 grams of salt, 6 grams of vegetable oil, 3 grams of yeast, and 2 grams of xanthan gum. Bread tests, which include weight loss, specific volume, oven spring, Crumb crust ratio Shape index, porosity, crust and Crumb color, and bread texture analysis were studied to evaluate the quality of bread. Finally, the factorial test was used to investigate the effects of particle size and heat treatment of rice flour, and Duncan's multiple range test was used to compare the means at the 5% probability level.Results and Discussions: The results showed that the effect of particle size on weight loss, specific volume, oven spring, Crumb to crust ratio, crust, and Crumb color parameters, and bread texture was not significant (p>0.05). Regarding the sample volume index, C80 and DHT120 significantly had the lowest volume index (p<0.05). The HMT80-treated sample significantly increased the weight loss, and the moist heat-treated samples significantly increased the specific volume and the core to shell Crumb (p<0.05). In this study, the sample treated with HMT 120 had the highest volume index. moist heat treatment and dry heat significantly led to a decrease in brightness and an increase in the yellowness of the crust and Crumb of the bread compared to the control sample, but there was no change in the amount of redness (p<0.05). Moist heat treatment samples had the lowest hardness and Chewiness in this research compared to the control sample and the dry heat treatment sample. In general, the sample obtained from 125-micron particles and moist heat treatment led to the improvement of gluten-free bread quality.
Food Technology
Hoda Ghorbanzadeh; Jafar Milani; Ali Motamedzadegan
Abstract
IntroductionWith the growth of the population and more demand for obtaining food and supplying the required food, the interest in the cultivation and consumption of edible mushrooms has increased. Since 1990, the world has focused on the mushroom production industry. In recent years, mushrooms have become ...
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IntroductionWith the growth of the population and more demand for obtaining food and supplying the required food, the interest in the cultivation and consumption of edible mushrooms has increased. Since 1990, the world has focused on the mushroom production industry. In recent years, mushrooms have become one of the most important food and medicinal sources. One of the largest species of edible mushroom is button mushroom (Agaricus bisporus), which has high nutritional and medicinal value. Button mushroom has high nutritional value due to the presence of things such as fiber, carbohydrates, protein, amino acids, minerals, vitamins, etc., and it also has antioxidant, anti-cancer, and anti-diabetic properties. This food has shown good health properties for humans. The quality of button mushrooms is determined by their color, texture, and taste. Color is the first characteristic that is perceived by consumers. Browning is one of the main reasons for the loss of mushroom quality, which reduces the commercial value of mushrooms. One of the most used methods today is the use of edible coatings for perishable foods, these coatings almost prevent the penetration of oxygen, depending on the type of coating used, and reduce the loss of moisture during storage. Chitosan has functional characteristics such as antimicrobial and antioxidant properties, and as an edible film, it can be considered a very good carrier to be combined with antioxidant and antimicrobial agents.Materials and methodsTo make chitosan solutions, first, each type of chitosan (70% deacetylated, 80% deacetylated, 90% deacetylated, and 100% deacetylated) was weighed in amounts of 0.5g, 1g, and 2g. then it was dissolved in 100 ml of 0.5% acetic acid solution and stirred for 12 hours at a speed of 1000 rpm at room temperature to dissolve uniformly. After 12 hours, each sample It was centrifuged for 15 minutes at 6000 rpm at 25 °C to separate the undissolved material. Mushrooms were prepared freshly harvested, washed with water, and then excess moisture was removed. After sorting and screening in terms of size and approximate weight, the mushrooms were added to 0.5%, 1%, and 2% chitosan solutions without being sliced and were immersed in the solution for one minute. The control sample was immersed in 0.5% acetic acid solution for one minute. After that, the mushrooms were air-dried at room temperature for one hour, and at the end, their excess moisture was removed with a tissue. The mushrooms were placed in 18*14 size polyethylene zip-top bags and stored in a refrigerator at 4°C. The effects of chitosan coating on weight loss, mushroom color and browning index, enzyme activity, texture, and total phenolic compounds were studied.Results and discussionThe results indicated that in maintaining the amount of total phenol, controlling the peroxidase enzyme activity, the degree of firmness of the mushroom during storage and the amount of gumminess, the best treatment was chitosan with a deacetylation degree of 70%, while in controlling the weight loss, the activity of poly Phenol oxidase and sensory test, chitosan treatment with 100% and 90% deacetylation degree had better results, and in terms of browning index and texture, chitosan treatment with 80% deacetylation degree showed better performance. This study showed that the use of chitosan coating can be effective in maintaining the characteristics of edible mushrooms.ConclusionsThe spoilage of edible mushrooms happens in a short time, and the storage of mushrooms has become one of the most important things in mushroom production. Coating edible mushrooms is one of the suitable methods to increase the shelf life of edible mushrooms. In this research, chitosan with four degrees of deacetylation and three different concentrations was used as a coating for edible mushrooms. The results indicated that coating the mushroom with chitosan could delay the occurrence of spoilage and change its color or texture.
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).
Masoumeh Pourseyed; Ali Motamedzadegan; Jafar Mohammadzadeh Milani
Abstract
Introduction: Converting milk into milk powder increases its shelf life up to almost 1 year, without substantial loss of quality, even at ambient temperatures. Dairy powder is frequently used because of convenience in applications for transportation, handling, processing, and ease of product formulations. ...
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Introduction: Converting milk into milk powder increases its shelf life up to almost 1 year, without substantial loss of quality, even at ambient temperatures. Dairy powder is frequently used because of convenience in applications for transportation, handling, processing, and ease of product formulations. Functional properties of milk powder are important due to its wide range of applications, especially in bakery products requiring desirable texture and moisture content. These functional properties include emulsification, foaming, water absorption, viscosity, gelation, and heat stability. Fresh milk and milk products such as condensed or dried milk which have not been exposed to sufficient heat treatment are not suitable for good quality bakery products as properly heated milk, mainly due to the destruction of proteolytic enzymes by heat, denaturation and coagulation of the proteins, changes in the colloidal properties of the salt and alterations in the oxidation-reduction systems. Kirk (1971) has outlined a list of functional contributions provided by skim milk powder (SMP) in various bakery food products, such as increased absorption, buffering value, lactose color reaction, tenderizing effect, improved body and resilience of crumb. This is in agreement with the results showed by Pyler who added SMP to bread and cake affected. Pyler noted the advantages of lactose in food systems. Lactose mostly affect relative sweetness, browning reaction, protein stabilizing properties, alteration of crystallization patterns, flavor accentuation, selective fermentation, and has nutritional value.
Materials and methods: Yazdi cake was produced using baking wheat flour (from Golha factory), sugar (sucrose), hydrogenated vegetable shortening, baking powder, and baking soda. Eggs were bought the day before baking and refrigerated at 4°C. The dough was prepared in ratio of 30 % oil, 46 % sugar, 50 % water, 11.7 % eggs, 4 % baking powder and 1 % baking soda rather than flour. For improvements of flavor and taste, an equal value of vanilla was added to the whole dough formulations. Skim milk powder containing 1.5 % fat, 3-4 % moisture has bought from Pegah factory. 25 and 50 percent of skim milk powder was also added to the dough. Dough was prepared based on the method of double mixture steps and was baked at 180°C in oven for 30 min. Samples were vacuumed and kept at ambient temperature for further experiments
Result and discussion: The differences in specific volume and consistency of the dough values were found to be significant (p>0.01). According to Baeva studies, there is an inverse relationship between specific gravity and the entry air bubbles in the dough, so the sample with 50% had the lowest specific volume. The consistency of the dough increased significantly by increasing in SMP content (P
