Abstract
How gastrointestinal digestion reshapes the chemical composition of tiger nut and influences its subsequent utilization by fructophilic lactic acid bacteria (FLAB) remains poorly understood. To address this gap, tiger nut was first subjected to simulated gastrointestinal (GI) digestion and subsequently fermented with metabolically specialized FLAB strains with potential probiotic properties. Changes in carbohydrates, organic acids, free amino acids, phenolic compounds, peptides, antinutritional factors, antioxidant activity, and intestinal-cell responses were experimentally evaluated, whereas selected ADME properties, blood–brain barrier permeability, molecular-target interactions, and peptide bioactivities were assessed computationally. Simulated digestion markedly modified the amino acid, peptide, and phenolic profiles. Subsequent incubation with FLAB resulted in strain-associated changes in microbial growth, acidification, organic acids, amino acids, phenolic compounds, peptides, antioxidant activity, and antinutritional factors. Among the fermented matrices, PL34_DT showed high microbial growth and chemical antioxidant activity and was enriched in selected compounds including GABA, gallic acid, gallocatechin, and resveratrol. Several phenolics and peptides showed computationally predicted neuroactive properties, including blood–brain barrier permeability and affinity for neurotransmitter and immunomodulatory targets. PL34_DT was therefore selected for focused intestinal-cell experiments, where it maintained monolayer integrity under the tested conditions and reduced t-BOOH-induced intracellular ROS in Caco-2 cells. Overall, digestion-guided FLAB fermentation reshaped the biochemical composition of tiger nut, while the physiological relevance of the computationally predicted activities requires further experimental validation.