PECAN NUT FLOUR AS AN INGREDIENT IN NOODLES: IMPACT OF DRYING TEMPERATURE ON STRUCTURE AND QUALITY ATTRIBUTE

Pecan nut flour, rich in nutrients, is a promising ingredient for value-added foods; however, its incorporation may affect pasta drying behavior and product quality. This study evaluated the effect of hot-air drying temperature on the physicochemical, microstructural, and mechanical properties of pecan flour-enriched noodles. Noodles were produced by replacing 50% of the wheat flour fraction with pecan nut flour and dried under two conditions: D30 (30°C, 40 % RH) and D50 (50°C, 40 % RH). Moisture loss was monitored during drying, and final moisture content, water activity, microstructure, fracture properties, and cooking loss were determined. D30 exhibited a final moisture content of 11.6% and a water activity of 0.514, whereas D50 reached lower values (8.78% and 0.463, respectively), indicating a more intense dehydration process. Surface analysis revealed that D30 retained a more homogeneous and continuous structure, with a uniform distribution of pecan flour particles, whereas D50 displayed a rougher, more heterogeneous surface. These differences were confirmed by optical microscopy, which showed a more cohesive and compact matrix at 30°C, with no evidence of severe structural collapse, whereas samples D50 exhibited discontinuities, localized depressions, and reduced structural continuity associated with shrinkage phenomena and surface rigidification during drying. Mechanical properties reflected these microstructural changes. Noodles D30 showed significantly higher fracture stress values (0.569±0.043 MPa) than D50 (0.384±0.035 MPa), indicating greater mechanical resistance. In contrast, apparent strain did not differ significantly between treatments. Cooking loss was also lower in D30 (10.06±0.24%) than in D50 (11.58±0.03%), suggesting a greater ability to retain solids during cooking. These findings demonstrate that low-temperature drying is a suitable strategy for preserving the structural integrity of noodles containing high levels of pecan nut flour, supporting the valorization of this agro-industrial by-product in the development of nutritionally enriched pasta products thereby improving the technological quality of pecan flour-enriched noodles.