Evaluation the physical properties of Vicia Villosa seed and Study the effect of defatting and pH on the physicochemical and functional properties of its flour

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.  

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.  

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.