Alternative technologies for the production of popped sorghum: a comparative study.

Sorghum is the fifth most harvested crop worldwide, being the popped sorghum as one of the most common snacks in India and some Asian regions. Therefore, this study evaluated how the processing method influences the microstructure, volumetric and textural properties of popped sorghum microstructure, volumetric and textural properties. White sorghum "Paloma" variety (11% moisture) was assessed, which was popped using three processing methods: microwave, pan-frying, and hot salt-frying using three temperature levels. Volumetric and yield characteristics were evaluated for the popped kernels, as their microstructure and texture profile. The popped sorghum obtained through the hot salt-frying method had a microstructure composed of polygonal cells. Also, it showed the best volumetric characteristics (volume), good expansion index, and high process yield. Finally, the hot salt-frying method showed better textural features associated with the attributes of a satisfactory product for consumers.

Amylose-lipid complex formation from extruded maize starch mixed with fatty acids.

Functional modifications of starch, such as paste properties, retrogradation, water absorption indexes, solubility, and swelling capacity, are induced by the amylose-lipid complex. This research comprehends the study of functional properties of extruded maize starch mixed with fatty acids (stearic acid, oleic acid, and maize oil) and the formation of amylose-lipid complexes. Maize starch with lipids (5 or 10 %), moisture (35 %) was extruded (single screw). Starch granule was modified by extrusion, to a lesser extent at 10 % of lipids, especially stearic acid, which covers starch granule surface. Viscosity decreased meaningfully with stearic acid addition. DSC showed both starch gelatinization enthalpy and amylose-lipid complex enthalpy for stearic or oleic acid, but it was just the first enthalpy for maize oil. X-ray diffraction showed orthorhombic crystals with or without the presence of lipids. Our results indicated that stearic acid yielded the highest amount of amylose-lipid complexes.

Impact of cooking and nixtamalization on the bioaccessibility and antioxidant capacity of phenolic compounds from two sorghum varieties.

Sorghum (Sorghum bicolor L. Moench) has been sparsely used as human food due to certain anti-nutritional factors such as tannins that reduce its digestibility, although the grain is an important source of bioactive compounds such as phenolic compounds (PCs). This study aimed to assess the impact of cooking and alkaline cooking (nixtamalization) on the bioaccessibility and antioxidant capacity of PCs of two sorghum varieties (white/red). Nixtamalization was the most effective procedure for the reduction of tannins (74.3%). Gallic acid proved to be the most bioaccessible PC (6359 µg/g). The total phenolics and condensed tannins correlated with the antioxidant capacity (ABTS/DPPH; R2: 0.30-0.43, p < 0.05). These results confirm the potential of thermal procedures to significantly modify the bioaccessibility of sorghum compounds, enhancing their concentrations and reducing anti-nutritional factors (tannins) while improving their antioxidant capacity.