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 Ctype 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.

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Pinhão and corn starches are submitted to phosphating with sodium tripolyphosphate and their properties are evaluated by thermogravimetry, differential scanning calorimetry, viscoamylography, X‐ray powder diffractometry, field emission gun‐scanning electron microscopy analysis. The phosphating process is divided into three steps to analyse the behaviour of the sample on exposure to phosphate groups. After the modification, there is a decrease in the transition temperatures and gelatinisation enthalpy of both starches. During the three phases of phosphating, small differences are observed in the thermal stability of the modified samples, but a lower value is obtained for corn starch after the third stage. The decrease in pasting temperature is accompanied by an increase in the peak viscosity of the starch suspensions, however, higher values for setback and breakdown are also recorded. The degree of relative crystallinity of the phosphated starches increases, and from microscopy it is possible to observe the presence of crystals of sodium tripolyphosphate during phosphating process.

The effects of different doses of gamma radiation on the thermoanalytical, structural and pasting properties of black rice (Oryza sativa L.) flour were studied using thermogravimetry and derivative thermogravimetry (TG-DTG), differential scanning calorimetry, X-ray diffraction (XRD), field emission gun-scanning electron microscopy (FEG-SEM) and pasting properties (RVA) analysis. The thermogravimetric curves showed four mass losses. A small displacement was observed for the second loss, which occurred for the irradiated flours, compared to the control sample. The irradiated samples showed a slight decrease in the thermal parameters: initial temperature (T o), peak temperature (T p) and gelatinisation enthalpy (4H). All the black rice flours exhibited A-type crystallinity pattern, and the gamma radiation did not change the XRD patterns or the degree of crystallinity. The microimages obtained using FEG-SEM showed a composite of organic and heterogeneous material; after gamma radiation, some changes occurred, such as cracks, pores and smaller fragments. The pasting properties decreased significantly with irradiation. The decrease in setback and breakdown viscosity after irradiation suggested an indication that it may be possible to improve the quality of food based on black rice flours. Gamma radiation can be a useful tool to modify rice flours in order to suit various functionalities and to help meet the growing demands of the food industry.

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