Effect of oil content and enzymatic treatment on dough rheology and physical properties of 3D-printed cereal snack

Abstract

Interest in healthier snacks is on the rise. 3D printing of healthier snacks enables the use of alternative ingredients such as grain by-products, but also presents challenges such as dough darkening and post-process deformations. This work aimed to investigate the influence of the amount of oil (10–30% on flour basis), xylanase activity (17–57 U/g on flour-bran basis) and resting time (1–3 h) of the dough on rheology of dough with added glucose oxidase, its 3D printing precision and snack quality (shrinkage, texture, colour). Response surface methodology, partial least squares and artificial neural networks (ANN) were compared for modelling the dough rheology and snack quality. ANN identified the highest sensitivity of the snack formulation to the amount of oil and the lowest to the resting time. Optimal amount of oil was 20%; at lower amounts, dough had higher complex viscosity, yield point and flow point, whereby snacks were harder, darker, redder and yellower. At the optimum xylanase amount of 37 U/g, shrinkage during baking was minimized (5.4%) as the structure scanned by electron microscopy was more complex and compact. ANN showed that rheological properties of the dough can be valuable predictors of shrinkage and colour of 3D-printed snacks, facilitating product development.