From waste to value: Enhancing vegetable leather quality using guar and xanthan gums in carrot pomace and tomato pulp systems

This study investigated the effects of guar and xanthan gums on the physicochemical, bioactive, structural, color, textural, and sensory properties of carrot pomace and tomato pulp leathers dried at 60°C. κ-Carrageenan failed to produce continuous leathers in either matrix, whereas guar and xanthan gums supported successful leather formation. Xanthan gum generally improved structural integrity, color retention, bioactive compound preservation, texture, and sensory acceptance, although its effects were matrix-and concentration-dependent. In carrot leather, 1% xanthan gum provided the most favorable overall sensory performance and enhanced carotenoid and phenolic retention, whereas 2% xanthan gum produced the highest overall sensory acceptance and lycopene retention in tomato leather. Guar gum showed advantages for certain properties, including water absorption and browning control. SEM analysis confirmed hydrocolloid-induced modifications in pore structure, while correlation analysis demonstrated relationships among bioactive compounds, acidity, browning, and dry matter. These results support converting vegetable processing residues into low-moisture, nutrient-rich products, thereby supporting waste valorization and sustainable food innovation.