Mechanistic insights into performance limitations of fruit- and vegetable-based materials for 3D food printing and functional regulation of hydrocolloids.
Fruit- and vegetable-derived matrices provide nutrients, bioactive compounds, color, and flavor, but their heterogeneous composition often leads to unstable extrusion and poor shape retention. Previous reviews have generally treated these materials as a single group or summarized formulation strategies without relating matrix form to the mechanisms of print failure. Here, printable materials are organized into pulp-, juice-, and powder-based systems, and the main limitations of each system are traced from tissue disruption, particle and fiber organization, water distribution, acidity, and rehydration to rheological response, network formation, syneresis, and shape fidelity. The roles of xanthan gum, guar gum, pectin, alginate, κ-carrageenan, and carboxymethyl cellulose are then compared in terms of shear-thinning behavior, water immobilization, ionic or thermal gelation, and structural reinforcement. Emphasis is placed on matching hydrocolloid function and composite structuring strategies to the dominant defects of each matrix. By linking composition and multiscale structure with rheology and printing performance, this review offers a mechanistic basis for formulation design and the development of personalized, dysphagia-adapted, and more sustainable fruit- and vegetable-based printed foods.