Flowability and extrusion behavior of black soldier fly (Hermetia illucens L.) prepupae protein powder for three-dimensional food printing applications

초록

Black soldier fly (Hermetia illucens L.) prepupae (BSFP) are a sustainable protein source, but the use of full-fat prepupal protein powder in extrusion-based three-dimensional food printing is limited by poor structure and flow control. This study developed black soldier fly prepupal protein-based pastes and evaluated the effects of tapioca starch concentration and thermal treatment on rheology, die swell, and printing stability. Pastes were formulated at 80% moisture content using 0.5% gellan gum, tapioca starch at 0%, 2.5%, or 5%, and corresponding BSFP powder contents of 24.87%, 21.98%, and 19.09%, respectively. Thermal treatment significantly strengthened the paste structure, increasing the initial storage modulus to 3,998.56, 6,248.78, and 8,891.23 Pa for 0%, 2.5%, and 5% starch, respectively. Steady shear analysis showed shear-thinning behavior, while model-estimated yield stress after heating increased from 363.577 to 636.062 Pa with starch addition. Large-amplitude oscillatory shear and Chebyshev coefficient analysis showed that starch increased nonlinear elastic resistance and strain stiffening. However, 5% starch caused the high die swell ratio of 1.96 and edge roughness of 0.074 mm. The 2.5% starch formulation showed the lowest edge roughness of 0.049 mm and thickness variation of 8.1%, producing the most stable printed structure. Overall, moderate starch addition improved printability by balancing flow, recovery, and shape retention. Copyright: © 2026 Author(s). This is an Open-Access article distributed under the terms of the Creative Commons Attribution License, permitting distribution, and reproduction in any medium, provided the original work is properly cited. https://creativecommons.org/licenses/by/4.0/

키워드