ANTIOXIDANT POTENTIAL AND BIOACCESSIBILITY OF SELECTED PHYTOCHEMICALS AND MINERALS DURING IN VITRO GASTROINTESTINAL DIGESTION OF BRAZILIAN PALM KERNELS

Brazilian palm kernels are promising sources of antioxidant compounds and mineral elements, although total concentrations do not necessarily reflect the fractions available for absorption. This study evaluated changes in antioxidant potential and the bioaccessibility of selected phytochemicals and minerals in licuri (Syagrus coronata), jerivá (Syagrus romanzoffiana) and babassu (Attalea speciosa) kernels during simulated gastrointestinal digestion. Oral, gastric and intestinal phases followed the INFOGEST protocol with adaptations. Antioxidant potential was assessed by DPPH and ABTS assays and expressed as percentage inhibition; selected phytochemicals and minerals were quantified by HPLC-DAD and ICP-OES, respectively, in mg/100 g. Bioaccessibility was calculated as the ratio between the content in the soluble intestinal fraction and that in the undigested sample. All analyses were performed in triplicate. For each fruit, digestive phases were analyzed by analysis of variance (ANOVA), followed by Tukey’s multiple comparison test (p < 0.05). In licuri, chlorogenic acid showed the highest bioaccessibility (87.62%), decreasing from 0.315 ± 0.002 mg/100 g in the undigested sample to 0.276 ± 0.003 mg/100 g in the intestinal fraction. In jerivá, catechin showed the highest bioaccessibility (95.61%), decreasing from 0.228 ± 0.007 to 0.218 ± 0.008 mg/100 g. In babassu, trigonelline, a pyridine alkaloid, showed the highest apparent bioaccessibility (89.54%), decreasing from 508.237 ± 0.027 to 455.083 ± 0.019 mg/100 g. DPPH radical scavenging increased during the gastric phase to 22.64 ± 2.13% in licuri, 22.07 ± 2.85% in jerivá and 28.05 ± 1.70% in babassu. In the intestinal phase, DPPH responses decreased, whereas ABTS radical scavenging increased to 79.49 ± 1.23% in licuri, 87.24 ± 0.94% in jerivá and 76.43 ± 1.74% in babassu. This contrasting pattern indicates that digestion altered antioxidant solubility and reactivity. The high intestinal ABTS response, an assay applicable to compounds spanning a broad polarity range, was consistent with the persistence or release of bioactive compounds in the soluble fraction, although other digestion products may also have contributed. Mineral bioaccessibility exhibited matrix-specific patterns. In licuri, potassium (K, 57.10%), manganese (Mn, 36.40%), calcium (Ca, 35.45%) and phosphorus (P, 31.03%) were noteworthy. In jerivá, the highlighted minerals were zinc (Zn, 99.14%), phosphorus (P, 90.81%), potassium (K, 87.79%) and magnesium (Mg, 70.30%), whereas in babassu, potassium (K, 59.26%), boron (B, 37.93%), phosphorus (P, 26.19%) and magnesium (Mg, 21.99%) were highlighted. Among these elements, K contributes to electrolyte balance and neuromuscular function, Ca and P are important for bone health, P and Mg participate in energy metabolism and Zn and Mn serve as cofactors in enzymatic processes, including antioxidant defense. Therefore, gastrointestinal digestion modified the release and potential availability of constituents in each kernel, demonstrating that total composition alone is insufficient to estimate their nutritional and functional potential. The authors thank CAPES and CNPq for financial support.