Efeito da micronização sobre a biotransformação do bagaço de oliva em modelo estático de fermentação colônica

Abstract

Olive cultivation, in recent years, has shown significant growth in Brazil, especially in the state of Rio Grande do Sul, which has favorable climatic conditions for this culture and which has increased the number of olive gr oves and the volume of oil produced. From the manufacture of olive oil, olive pomace is generated, a solid residue that requires previous treatment for proper disposal. Olive pomace is rich in polyphenols and dietary fiber, but due to its high lignin conte nt, it is not easily accessible for digestion and metabolism. An alternative to modify the fibrous matrix and increase its functionality is the use of physical methods such as micronization. Thus, the aim of this study was to evaluate the effects of micronization on the biotransformation of olive pomace using an in vitro colonic fermentation model with human feces, investigating the impact of this process on the nutritional characteristics of the residue. After in vitro digestion and fermentation simu lation, the biotransformation of phenolic compounds during fermentation was evaluated by HPLC MS MS. The crude olive pomace, that is, unfractionated (NF) was submitted to granulometric fractionation (F2NM) and presented a particle size of 143.0 ± 5.3 µm. T he fractionated and micronized olive pomace (F2MTL) presented a particle size of 22.4 ± 0.9 µm, allowing standardization of the particle size in the olive pomace. During fermentation a reduction in pH was observed in 8h for F2MTL, in 24h for F2NM and F2MT L and 48h compared to control without sample. At the initial fermentation time (0h), the F2MTL fraction presented the highest concentration of total phenolic compounds among the analyzed samples . Micronization favored the release of hydroxytyrosol in F2MTL compared to F2NM at 2h and 8h (p < 0.05). Tyrosol only increased to F2MTL in 2h. The amount of oleuropein was significant for F2MTL at 0h and was completely degraded up to 2h and the oleuropein aglycone in F2NM and F2MTL increased the release up to 2h of fermentation. The granulometric fractionation associated with micronization favored the release of phenolic compounds bound to the matrix, producing a greater amount of phenolic compounds during fermentation in relation to non micronized olive pomace . In v ivo assays are needed to confirm the bioavailability of phenolic compounds and the effect on the gut microbiota to further corroborate the beneficial effects of micronized olive pomace on human health.