Common Vetch (Vicia sativa) as a New Starch Source: Its Thermal, Rheological and Structural Properties After Acid Hydrolysis

Abstract

The common vetch plant is used mainly for animal nutrition. The seeds from this leguminous plant contain a relatively high quantity of starch. There are few studies regarding common vetch and this research was designed to evaluate the thermal, rheological and structural properties of the starch extracted from common vetch seeds, both native and after treatment with HCl at different concentrations (0.1 mol L−1 and 0.3 mol L−1) and temperatures (25 °C and 50 °C). The curves obtained from differential scanning calorimetry showed an increase in the peak and conclusion temperatures after the acid modification. The thermogravimetric curves of the native and acid-modified samples presented three characteristic mass losses, with higher thermal stability after acid modification. The viscoamilographic analysis showed an increase in the final and peak viscosities for the common vetch starch after the treatment, which was probably due to the hydrolysis of the protein that was present in the sample. The micro-images obtained by field emission gun-scanning electron microscopy showed that the granular structure of the starch was not affected after acid treatment. The diffractometry analysis showed the same C-type pattern for all the samples. The common vetch starch presented interesting properties that could lead to different uses in industry and aggregate more value for this product.