Performance of Thermoplastic Extrusion, Germination, Fermentation, and Hydrolysis Techniques on Phenolic Compounds in Cereals and Pseudocereals

Abstract

Bioactive compounds, such as phenolic compounds, are phytochemicals found in significant amounts in cereals and pseudocereals and are usually evaluated by spectrophotometric (UV-VIS), HPLC, and LC-MS techniques. However, their bioavailability in grains is quite limited. This restriction on bioavailability and bioaccessibility occurs because they are in conjugated polymeric forms. Additionally, they can be linked through chemical esterification and etherification to macro components. Techniques such as thermoplastic extrusion, germination, fermentation, and hydrolysis have been widely studied to release phenolic compounds in favor of their bioavailability and bioaccessibility, minimizing the loss of these thermosensitive components during processing. The increased availability of phenolic compounds increases the antioxidant capacity and favor their documented health promoting.

Keywords: antioxidant capacity; enzymes; extrusion; grains; microorganism; sprouting.

Figure 1

Chemical structure of main phenolic acids found in cereals and pseudocereals.

Figure 2

Chemical structure of main flavonoids found in cereals and pseudocereals.

Figure 3

Chemical structure of main non-flavonoids found in cereals and pseudocereals.

Figure 4

Conventional techniques for fermentation processes.