The starches were isolated by alkaline extraction from white and red sorghum, predominant cultivars in the Sahara of Algeria. Morphological, thermal properties and amylose content of isolated starches were examined. T...The starches were isolated by alkaline extraction from white and red sorghum, predominant cultivars in the Sahara of Algeria. Morphological, thermal properties and amylose content of isolated starches were examined. The starches of two sorghum landraces of white and pigmented kernels growing in hyper arid environmental conditions showed significant differences in granule size, amylose content and thermal behavior which ultimately affect the physicochemical and functional properties. When observed using environmental scanning electron microscopy （ESEM）. The starch granules showed polyhedral shape. Some of them showed pinholes. The granular size ranged between 6.325-39.905 μm and 7.096-44.774 μm, respectively for white and red sorghum starches. The granule size distribution was unimodal. The amylose content in white sorghum starch （27.1%） was higher than that in red sorghum （24.8%）. Differential scanning calorimetry （DSC） analysis revealed that sorghum starches present higher temperatures at the peak （70.60℃ and 72.28℃ for white and red sorghum starches, respectively） and lower gelatinization enthalpies （9.087 J/g and 8.270 J/g for white and red sorghum starches, respectively） than other cereal starches. The determination of these properties is relevant to the comprehension of starch and starch-based foods digestibility in order to direct them towards the specific applications in food and nonfood sectors.展开更多
文摘The starches were isolated by alkaline extraction from white and red sorghum, predominant cultivars in the Sahara of Algeria. Morphological, thermal properties and amylose content of isolated starches were examined. The starches of two sorghum landraces of white and pigmented kernels growing in hyper arid environmental conditions showed significant differences in granule size, amylose content and thermal behavior which ultimately affect the physicochemical and functional properties. When observed using environmental scanning electron microscopy （ESEM）. The starch granules showed polyhedral shape. Some of them showed pinholes. The granular size ranged between 6.325-39.905 μm and 7.096-44.774 μm, respectively for white and red sorghum starches. The granule size distribution was unimodal. The amylose content in white sorghum starch （27.1%） was higher than that in red sorghum （24.8%）. Differential scanning calorimetry （DSC） analysis revealed that sorghum starches present higher temperatures at the peak （70.60℃ and 72.28℃ for white and red sorghum starches, respectively） and lower gelatinization enthalpies （9.087 J/g and 8.270 J/g for white and red sorghum starches, respectively） than other cereal starches. The determination of these properties is relevant to the comprehension of starch and starch-based foods digestibility in order to direct them towards the specific applications in food and nonfood sectors.
