Hydrogels based on ozonated cassava starch: Effect of ozone processing and gelatinization conditions on enhancing 3D-printing applications

Ozone is an interesting alternative for modifying starch, as it is considered an emerging and environmentally friendly technology. New applications for food ingredients are receiving attention, such as 3D printing. Consequently, the impact of emerging technologies on new applications must be understood. In this work, cassava starch was modified by ozone to evaluate its printability. Increasing ozonation time produced a starch with higher carbonyl and carboxyl contents, lower pH and molecular size, and gels with different behaviors (stronger and weaker than the native ones, as a function of processing time). The hydrogels obtained were evaluated in relation to pasting and gel properties, including their printability. The effects of starch concentration, gelatinization temperature and storage period were also evaluated. Starch ozonated for 30 min showed the lowest peak apparent viscosity at all the temperatures and starch concentrations evaluated, and provided the strongest gel. Gels produced by native starches and starches ozonated for 30 min showed good printability when the gelatinization temperature used was 65 degrees C, but up to this temperature, only starch ozonated for 30 min produced gels with good printability. This work highlights that, by using the ozone process to modify starch and varying the process conditions, it is possible to obtain hydrogels with enhanced pasting properties, gel texture, and printability, thereby expanding the potential of starch applications. (C) 2019 Elsevier B.V. All rights reserved.