MINERAL PROFILE AND PRINCIPAL COMPONENT ANALYSIS OF RICE EXTRUDATES ENRICHED WITH GRAPE POMACE FLOUR

Brazil is a major grape producer, with a substantial portion of its production destined for winemaking. During processing, approximately 20% of the fruit weight is generated as grape pomace, consisting mainly of skins, seeds, and residual pulp. This material is rich in macro and micronutrients and has potential for use in human nutrition as a functional ingredient. This study evaluated the mineral profile of rice flour extrudates enriched with fermented grape pomace flour from Magna and Saperavi varieties. Extruded formulations containing 30-40% grape pomace flour and 10% calcium caseinate were produced using a twin-screw extruder. Extruded and control (100% rice flour) formulations were ground and sieved. For mineral analysis, mineralized using a heating block (HNO₃+H₂O₂) and essential elements (Ca, Cu, Fe, K, Mg, Mn, Na, P, and Zn) were quantified by ICP OES, in triplicate. Principal Component Analysis (PCA) was performed on a 15x9 data matrix, which contained 15 sample results for 9 minerals (135 assays). Loadings and score plots demonstrated that by-product incorporation significantly influenced the extrudates mineral composition, highlighting the influence of both grape varieties and the percentage of grape residue flour used in the formulations. Zinc was identified as one of the main variables responsible for sample discrimination, particularly due to its higher content in the control samples. Overall, the results demonstrate the potential of grape pomace flour as a sustainable ingredient for mineral-enriched extruded foods.

Acknowledgments: CNPq (173478/2023-9, 304152/2024-2, and J.R.L. grant), FAPESP (2022/11541-1), FINEP (1310/24 and 1050/24).