The effect of sucrose on the extrusion of varied whole sorghum genotypes was studied using a single-screw system. The raw sorghum flours were characterized in terms of chemical composition and particle size. Specific mechanical energy (SME) was measured as a process parameter, as well as expansion properties, hydration, paste viscosity, instrumental color, and texture, along with total phenolic compounds (TPC) and total condensed tannins (TCT) in the puffed extrudates. In general, the addition of 10% sucrose reduced SME (p < .05), sectional expansion, hydration, and cold paste viscosity, indicating lower starch conversion and increased lightness (L*) and hardness (F_c). In contrast, BRS 501 showed opposite results for most of the variables measured, due to the suppression of the lubricant effect attributed to the high lipid in this genotype. Furthermore, the extrusion process at 0% sucrose released TPC values by 71.2% and 317.5% for low-tannin extrudates, while the addition of sucrose (10%) did not alter the TPC (p > .05) and had a protective effect on TCT retention in BRS 305 genotype extrudates.

Practical applications

The worldwide food intake of non-traditional whole grains such as sorghum has been restricted. Although it has been recently considered as an interesting an attractive gluten-free cereal due to its high and varied content of phytochemicals that provide health benefits and dietary fiber source. To take advantage of its potential, thermoplastic extrusion technology was used as a tool to develop textured sorghum expanded products with improved digestibility and retention of bioactive compounds. On the other hand, in order to improve its potential use as sweet snacks, the addition of sugar concentrations (10%) was added to improve its palatability, allowing to obtain expanded extrudates rich in fiber and bioactive compounds with improved taste compared to conventional extrudates, which would be of interest of the consumer and the food industries.