Texture and colour of pasta containing mill fractions from hull-less barley genotypes with variable content of amylose and fibre

ABSTRACT Hull-less barley (HB) genotypes may have zero amylose (ZA), waxy, ‘normal’ amylose (N) and high amylose (HA) starch, and elevated levels of beta-glucans (BG) and arabinoxylans (AX). Accordingly, HB has potential to modify food texture and impart health benefits. We report the effects on spaghetti colour and texture of enriching durum wheat semolina with HB roller milling fractions. ZA, N, and HA starch genotypes were pearled to various degrees and roller milled. BG and AX partitioned among milling fractions, being lowest in flour and highest in a fibre-rich fraction (FRF). FRF BG and AX contents ranged up to 18% and 8.5%, respectively. Spaghetti was enriched with 20% and 40% HB flour, and separately with sufficient FRF to increase spaghetti BG by 2%. Colour of HB flour-enriched spaghetti improved (brighter, less red, more yellow) with pearling. Compared to 100% semolina spaghetti, colour remained inferior at the highest pearling level, but was acceptable. Texture was less firm regardless of starch type, due to gluten dilution. Colour of FRF-enriched spaghetti also was visually inferior to 100% semolina spaghetti, but ZA and HA FRF-enriched spaghetti colour was acceptable. Firmness of FRF-enriched spaghetti was equal to or better than 100% semolina spaghetti for all HB genotypes, confirming the potential of HB FRF as a functional pasta ingredient.