Valorization of Avocado Leaf as a By-Product of the Avocado Fruit: Nutritional, Textural, and Sensory Properties of Gluten-Free Erişte (Turkish Noodles)

Abstract

This study investigated the potential use of avocado leaf powder (ALP), a food waste product with high phenolic content and antioxidant capacity, in producing gluten-free Erişte (GFE). For this purpose, GFE samples were formulated by replacing rice flour with different levels of ALP (5%, 10%, and 15%) and evaluated in terms of nutritional, physicochemical, textural, and sensory properties. Increasing the ALP content in the formulations led to gradual increases in ash (0.65%–1.33%), protein (11.35%–16.04%), fat (4.09%–4.16%), total dietary fiber (1.03%–7.13%), total phenolic content (46.74–90.63 mg GAE/100 g), antioxidant capacity (27.78–50.44 mg Trolox/100 g), mineral content, hardness, chewiness, and resistant starch (2.81%–6.26%). Conversely, cooking loss (10.53%–6.47%), adhesiveness, total starch content (74.59%–65.17%), and glycemic index (82.22%–65.85%) decreased with higher ALP incorporation. The cooking process increased L* in all samples while reducing a* and b* color parameters. According to sensory analysis results, GFE15 received the highest scores for color, aroma, hardness, and stickiness, whereas GFE10 had the highest overall acceptability score. Avocado leaves have been successfully applied as a functional ingredient in enriching gluten-free noodles, demonstrating their suitability for functional noodle production and high nutritional value.