engleski

EFFECT OF OIL CONTENT AND ENZYMATIC TREATMENT ON DOUGH RHEOLOGY AND PHYSICAL PROPERTIES OF 3D-PRINTED CEREAL SNACK

3D printing is a beneficial technology for using alternative raw materials such as food by-products and oil in cereal snacks. However, 3D-printing is a slow process where cereal-based snacks are susceptible to enzymatic browning and further deformation in post-processing. The aim of this work was to investigate the influence of oil amount (10-30% on a flour basis), xylanase level (17-57 U/g on a flour-bran basis) and treatment time (1-3 h) on dough rheology, 3D printing precision and snack quality (shrinkage, texture, colour). The snacks were based on oat flour, supplemented with wheat bran and pea protein, and contained glucose oxidase to prevent undesirable dough browning. Dough rheology was measured with oscillatory rheometer (MCR 92, Anton Paar) and ViscoQuick (Brabender). Shape shrinkage was determined with digital image analysis and snack colour and texture were assessed instrumentally with colourimeter or cutting test (respectively). Artificial neural networks identified the highest sensitivity of the snack formulation to the amount of oil and the lowest to the enzymatic treatment time. The optimum amount of oil in the snack was 20% (at flour and bran basis), resulting in a fat content of 16.5% in the final product. At lower amount of oil, the dough showed higher complex viscosity, yield point and flow point, whereby snacks were harder, darker, redder and yellower. Regardless of the treatment time, the addition of xylanase at the optimum level of 37 U/g resulted in a reduction of shrinkage during baking from 17% to 5%. Dough rheological properties, especially flow point and complex viscosity, but also yield point and breakdown viscosity, can be valuable predictors of snack quality such as printing precision, hardness and colour.

artificial neural networks, 3D shape shrinkage, 3D printability, hardness ; viscosity, xylanase

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