Binding of nutritional interest molecules to high pressure partially gelatinized starch granules (oligoelements and natural antioxidant substances)

ALINE TEIXEIRA; LORENA DELADINO; MIRIAM MARTINO; INMACULADA ALVAREZ; ANTONIO MOLINA-GARCÍA

Conferencia; Food Structure and Functionality Conference ? 15 years later; 2013

Starch granules can be fully gelatinized by physical processes. These include thermal treatments but also other alternative processes, such as high hydrostatic pressure. Pressures over 600 MPa are often required (depending on the starch type and origin) for complete gelatinization. When lower pressure levels are applied (300-400 MPa), a partially gelatinized product is obtained, which retains some of the granular characteristics and independence which are lost in fully gelatinized systems (as can be appreciated by low temperature scanning electron microscopy observations), while differential scanning calorimetry allows to calculate the gelatinization degree achieved. These granules present an open network of amylose and amylopectin protruding chains which are prone to interact with a number of potentially useful ligands. This is the case of oligoelements and natural antioxidant substances. It has been considered that partially gelatinized starch could constitute a good vehiculization media for delivering the required molecules along with foods, as supplements or health-promoting additives. The ability of corn starch treated by hydrostatic pressure at 400 MPa to bind oligoelements (zinc and magnesium salts) and natural antioxidants (yerba mate -Ilex paraguarensis- extracts) were tested and the promising results for the use of these modified polysaccharide will be shown. Results of metal binding to high-pressure modified starch monitored by atomic absorption and EDS microimage are presented. Meanwhile, the union of mate extract compounds with antioxidant activity was followed by HPLC-MS and it is also reported here.