Food Technology
Behdad Shokrollahi; Mohammad Ali Hesarinejad; Zahra Zamani; Negin Yousofi; Anna Abdolshahi; Ashkan Jebelli
Abstract
Introduction: Due to increasing the demand for new sources of protein and the lack of animal protein sources, using and replacing of plant proteins is widely considered. The purpose of this study was to identify the potential of Vicia villosa flour as a native and novel source of protein. In this research, ...
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Introduction: Due to increasing the demand for new sources of protein and the lack of animal protein sources, using and replacing of plant proteins is widely considered. The purpose of this study was to identify the potential of Vicia villosa flour as a native and novel source of protein. In this research, the physical properties of vicia villosa seed and chemical composition (protein, fat, ash, and carbohydrate and moisture contents) and color parameters of its full fat flour were determined and compared with defatted flour as well as the effect of defatting and pH on the functional properties of full fat and defatted vicia villosa flour were investigated. Materials and methods: Vicia Villosa seed was obtained from the local market in Chaharmahal and Bakhtiari province and was cleaned, skinned and, milled. Half of the full fat flour was defatted. The obtained flours were then refrigerated at 4°C for further analysis. Physical properties of the seed including size, dimension, mass, true and bulk density as well as porosity were measured using standard methods and calibrated equipments. Chemical composition of both the seed and skinned seed’s flour (moisture content, fat, protein and ash) were determined using standard methods (AACC, 2003). The carbohydrate content of the samples was determined by subtraction of the sum of other compositional substances from 100. Color properties, protein solubility, water soluble index, water and oil absorption capacity, least gelation concentration, foaming capacity and emulsifying capacity and emulsion stability and foaming stability were also measured for the full fat and defatted Vicia Villosa flours. Results and discussion: The results obtained from the measurement of physical properties for the Vicia Villosa seed showed that length, width, and thickness of the seeds were 5.4 mm, 5.37 mm, and 5.38 mm respectively. The surface area of seeds was found to be 90.98 mm2. True density, bulk density, and porosity of samples were found to be 1286.3 mm3, 788.8 mm3, and 38.67%, respectively. The amount of protein for full fat and defatted Vicia Villosa flour was 28.3% and 31.02%, respectively. L* was measured for the obtained flours and the highest L* was belonged to defatted Vicia Villosa flour, probably due to the removal of the seed shells in the solvent removal stage. Defatting of flour would result in brighter and increase in protein content of flour. The test on protein solubility showed the high dependency of this parameter to pH of the flour proving the U form dependency in the pH range of 2-12. At an isoelectric point of 4.5, the minimum solubility of existing proteins was shown. Water and oil absorption capacity of Full fat were 1.33± 0.4 and 0.85± 0.07 and Defatted Vicia Villosa flour,were 1.94± 0.2 and 1.19± 0.1 respectively (grams of water or oil per grams of the sample). Furthermore, at pH= 4.5, the emulsion and foaming capacity decrease due to its proximity to the isoelectric point. It is noteworthy that in isoelectric pH, the highest foaming stability and the lowest emulsion stability were observed. In addition, the results showed that pH and defatting conditions have a significant effect on functional properties that can be created by changing these parameters, flours, and products with various characteristics. The results showed that changes in pH and defatting process affected the solubility, water and fat absorption, least gelation concentration, foaming capacity and emulsion capacity of flour, so that by defatting and changing pH, functional properties improved significantly.
Masoud Taghizadeh; Hesam Akhoondzadeh; Zahra Zamani
Abstract
Introduction: Grains are important food sources for human diet because of high protein content. There are different kinds of grains used as food worldwide. Today herbal proteins play an important role as food sources in societies. Herbal protein sources are actually strategic points for improving national ...
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Introduction: Grains are important food sources for human diet because of high protein content. There are different kinds of grains used as food worldwide. Today herbal proteins play an important role as food sources in societies. Herbal protein sources are actually strategic points for improving national dietary all over the world. (Mashayekh et al, 2008). Food experts are becoming more open to Quinoa, because of high protein content, (Dallagnol et al., 2013). FAO compares Quinoa grain with concentered milk powder considering high nutritional facts, and called grains as multi vitamin (FAO, quinoa, 2011). According to scientific reports quinoa grain can be replaced with rice in national dietary (Ferreira et al, 2015. Oelk et al., 1992). Quinoa originally cultivated in South America (barazil, Chile, Peru etc.) and known as semi-cereals (Schoenlechner&Berghofe2010).Furthermore, Quinoa flour is a highly nutritional alternative to feed animals as well as in the production of foods which are suitable for patients with celiac disease and gluten-sensitive patient worldwide. (Dallagnol et al, 2013). From the technological point of view, functional properties hold an important position, Water and oil absorption capacity, protein solubility, gelatinization capacity, foam ability and foam stability are the most important functional properties. (Kaur and Singh, 2007. Ameri shahrabi, 1390). Functional properties are affected by different parameters such as protein network structure, lipid, carbohydrate, temperature and pH, respectively. (Alukoand Yada, 1995). This study proposed to investigate the physicochemical properties of Quinoa flour of three different varieties and monitor the effect of pH on their functional characteristics Materials and methods: three different variety of Quinoa grain, originated and cultivated in Peru, were used for experiments, varieties were black (BLACK COLLANA), white (SALCEDO INIA) and red (PASANKALLA), respectively. Grains were grind by 75 degree in mesh and refrigerated during storage. Carbohydrate, fat, ash, moisture content and protein were measured by AACC, (2003) methods. Functional properties were also measured using scientific methods, Owusu-Apenten, (2002), Kaur and Singh (2007) and customized Adebowale et al, (2005) method which used to measure protein solubility, Water and oil absorption capacity, foam ability and foam stability, respectively. Emulsion capacity and emulsion stability were measured using majzoobi et al, (2012) method. Results and discussion: chemical properties are important in both technological and nutritional aspects, chemical characteristics were observed and reported for three studied varieties. Protein solubility known as the first criteria in protein functional properties (Asadpour et al., 2010), this parameter is influenced by pH and the least value were observed in pH=4.5 (protein isoelectric point). Water and oil absorption capacity is one of the most important characteristics in flours (Kinsella, 1979), this parameter is a physical phenomenon which is known as oil or water confined in non-polar protein chains that is dependent on protein spatial shape. (Kinsella, 1979؛ Kaur and Singh, 2007؛ Trayunham et al., 2007) responses led to 1.285, 1.475 and 1.295 for white, red and black varieties, respectively. Foam ability and foamstability, actually known as volume increase caused by fast stirring and usually results in convenient rheological properties in products texture like ice cream and bread.this parameter refers to the ability of protein to make stable foam aginst mechanical and Gravitational stresses and measured in a 90 min. period of time (Oladela & Aina,2007) (Kinsella,1979). Least responses in this case were observed in pH=4.5 which is an isoelectric range of pH for protein chains. Results were corresponded by responses of El Nasri and El Tinay (2007), Lawal) 2004(, Taghizadeh et al, (2017) and Asadpour et al (2010) about other semi-cereal grains. Last metered parameter was emulsifying ability and emulsion stability, emulsifying in protein structure is an equilibrium between hydrophilic and hydrophobic parts of protein and affected by alkaline range of pH (Ragab et al., 2003( this parameter is influenced by protein solubility which is in the least measures in isoelectric point (Feizi et al., 2013). Results had shown that foam stability would decrease during time passes. This may be due to the coupling of dispersed phase particles (oil droplets) over time. Concerning the effect of pH on emulsion stability, the results showed that the stability values at alkaline pH were higher than that of acidic pH, so that this stability at pH = 9 was significantly different from other pHs. Among the three varieties of quinoa, the amount of protein in the black variety (16.81%) was higher than the other varieties, which could be further investigated as a potential protein source. In addition, results indicate functional properties are influenced by pH, which means out of iso electric point, protein solubility increase and other fictional properties were improve followed.