Effect of particle size of chia seeds on bioaccessibility of phenolic compounds during in vitro digestion

Chia seeds have a high content of polyunsaturated fatty acids (PUFAs), dietary fiber, and phenolic compounds considered to have health-promoting effects. Structural properties such as botanical integrity and particle size can affect the stability, extractability, and the availability of bioactive compounds for uptake in the gastrointestinal tract. The aim of the study was to compare the release and estimate the bioaccessibility of PUFAs and phenolic compounds during in vitro digestion of chia seeds with different particle size. The effects of temperature (23.0, 5.0, and -18.0 degrees C) and period of storage (0, 7, 14, 21, and 28 days) of milled chia seeds were also evaluated by comparing lipid autoxidation products, but significant differences were not detected. The extractability of phenolic compounds and PUFAs were higher in chia flour with smaller particle size than in samples with larger particle size and whole chia seeds. Nevertheless, chia seeds that were included in the study serve as a richer source of omega-3 and phenolic compounds than traditional cereal crops.