Influence of Flour Type, Dough Acidity, Printing Temperature and Bran Pre-processing on Browning and 3D Printing Performance of Snacks

Abstract

3D printing is an emerging technology that offers the ability to produce tailor-made foods. This work addresses the physical properties of 3D-printed snacks enriched with wheat bran as a function of flour type (oat, barley), addition of acidity regulators (citric acid, sodium bicarbonate), printing temperature (20 °C, 30 °C, 40 °C), and bran pre-processing (high-intensity ultrasound, vacuum microwave and pulsed light). Polyphenol oxidase activity, total phenolic content, antioxidant activity of bran, the viscosity profile of the flour-bran blend, the precision of 3D printing and browning kinetics of the physical properties of the dough and of baked snacks were investigated. During 1 h required to print ten pieces, the dough became very distinctly darker. Adjusting the printing temperature to 20 °C and adding sodium bicarbonate resulted in a dough, which changed colour less, but still very distinctly. Bran pre-processing inactivated polyphenol oxidase activity by 77-92%, which stopped browning of the dough within 50 min without affecting the printing precision. The use of ultrasound, vacuum microwave and pulsed light could be extended to other food components to achieve a greater inactivation of undesirable enzymes. Preprocessing techniques resulted in minor differences in the baked snack, so their future choice depends mainly on the amount of water that can be added to the recipe.

Bioprocessing of Wheat and Amaranth Bran for the Reduction of Fructan Levels and Application in 3D-Printed Snacks

“…), considering the loss of water during baking (i.e., the baking loss). Baking loss was determined using the following formula [ 24 ]: Baking loss (%) = (m pd − m bs /m pd ) × 100 where m pd represents the weight of dough before baking and m bs the weight of baked snack.…”

“…According to our previous study [ 24 ], the dough was prepared in three steps but with slight modifications. First, rice proteins, salt, baking powder, and sunflower oil were mixed with a hand mixer (M350LBW, Gorenje, Slovenia) (3 min at low speed), and then the suspension of unprocessed or bioprocessed WB or AB was added (mixing for 1 min at low and 1 min at medium speed), followed by the addition of oat flour (mixing for 2 min at low speed).…”

“…All oscillatory measurements were performed using a parallel plate geometry of 25 mm diameter with a 1 mm gap with an MCR 92 rheometer (Anton Paar, Graz, Austria). The amplitude sweep test (with the shear rate of 0.01–100 s −1 at a constant frequency of 1 Hz) was performed to determine the linear viscoelastic region (LVER) and the shear strain (0.05%) for the frequency sweep test, which was then employed in the range of 1–30 Hz at 20 °C [ 24 ]. Before each test, the dough was placed under the parallel plate and, after putting the plate down, trimmed if necessary.…”

“…Healthy snacks are a rising popular food category, as consumers seek low-sugar and salt and high fibre snacks [ 23 ]. Three-dimensional (3D) extrusion-based printing represents a novel approach for producing nutritionally adapted and balanced cereal snacks [ 24 , 25 ]. It provides a possibility of using alternative ingredients, but it is necessary to understand their rheological properties, i.e., their ability to flow and support the given 3D structure [ 25 , 26 , 27 ], as well as the ability of the dough to resist deformation during post-processing [ 28 ].…”

“…It provides a possibility of using alternative ingredients, but it is necessary to understand their rheological properties, i.e., their ability to flow and support the given 3D structure [ 25 , 26 , 27 ], as well as the ability of the dough to resist deformation during post-processing [ 28 ]. In recent years, several studies reported success in the 3D printing of snacks [ 24 , 26 , 29 ]. To our knowledge, no study has investigated the impact of fructans removal techniques or fermentation in general on the 3D-printability of snacks.…”