Bioaccessibility of Phenolic Compounds and Polyunsaturated Fatty Acids in Whole and Ground Chia Seeds and Sprouts

This study investigated the effect of grinding and germination on phenolic compounds, fatty acids, and antioxidant capacity of chia seeds after in vitro gastrointestinal digestion. After digestion, the samples ground chia (GC) and ground chia sprouts (GCS) showed the highest values of total phenolic compounds, antioxidant capacity, and fatty acids when compared to the respective whole samples, whole chia (WC), and whole chia sprout (WCS). The total phenolic compounds reached 7.00 mg GAE/g (GC) and 8.76 mg GAE/g (GCS), compared to 4.40 mg GAE/g (WC) and 2.57 mg GAE/g (WCS). In the evaluation of antioxidant capacity, GC and GCS showed higher values in the FRAP (40.38 and 38.62 µmol FS/g), ABTS (79.98 and 74.99 µmol TE/g), and DPPH assays (63.36 and 51.51% AA), compared to WC and WCS (FRAP: 2.85 and 11.53 µmol FS/g; ABTS: 57.40 and 47.98 µmol TE/g; DPPH: 39.27 and 42.11% AA, respectively). In addition, rosmarinic acid was detected only in the ground samples (seeds or sprouts), while rosmarinic acid 3-O-glycoside and caffeic acid were detected only in the ground seeds after digestion. Regarding the lipid content, values of 6.33 g/100 g for GC and 5.36 g/100 g for GCS were obtained, while WC and WCS showed only 0.19 g/100 g. On the other hand, omega-3 was identified in all samples, although its amount decreased in the sprouts. It is concluded that under the evaluated conditions, grinding was a more determining factor than germination in improving the bioaccessibility of phenolic compounds and fatty acids in chia seeds.