Physicochemical properties of sorghum and technological aptitude for popping. Nutritional changes after popping

• 28 hybrids of red sorghum (RS) and white (WS) were characterized.
• Physicochemical properties were related with technological aptitude for popping.
• Nutritional changes after popping were evaluated.
• Available lysine, phytic acid, polyphenols and antioxidant capacity were reduced.
• Whole flour precooked by popping is an important source of antioxidants.

The aims were to characterize 28 hybrids of red (RS) and white (WS) sorghum by physicochemical analysis, relate them with their technological aptitude for popping, and asses nutritional changes after popping in selected samples. Through principal component analysis it was observed that the higher the grain hardness, the higher apparent volume of popped product was, and performance was higher for WS. An indicator of the ability of sorghum hybrids to pop was developed. Comparing precooked samples with their native flours, no significant difference for protein and fat content was observed, but ash, dietary fiber, and minerals were reduced by popping. Protein digestibility increased but available lysine decreased (WS:1.3 and RS:1.2 times). Phytic acid, polyphenols and antioxidant capacity were reduced (WS: 1.3 and RS: 1.5; WS: 1.3 and RS: 1.8; WS: 1.3 and RS: 1.7 times, respectively), but whole flour precooked by popping can be considered an important source of antioxidants. Popped sorghum is an interesting alternative as food itself, or as ingredient for making other foods such as cereal bars.