Functional and structural effects of hydrocolloids on Ca(II)-alginate beads containing bioactive compounds extracted from beetroot

SANTAGAPITA, PATRICIO R.; SANTAGAPITA, PATRICIO R.; PERULLINI, MERCEDES; PERULLINI, MERCEDES; AGUIRRE CALVO, TATIANA ROCIO; AGUIRRE CALVO, TATIANA ROCIO

LEBENSMITTEL-WISSENSCHAFT UND-TECHNOLOGIE-FOOD SCIENCE AND TECHNOLOGY

ELSEVIER SCIENCE BV

Año: 2019 vol. 111 p. 520 - 526

0023-6438

In the present research, valuable bioactives such as betacyanin and polyphenols of beetroot leaf and stem (a food waste)were extracted and encapsulated in Ca(II)-alginate beads, using sucrose, arabic and guar gums, and low and high methoxyl pectins as excipients. A complete SAXS evaluation from the molecular to the supramolecular changes (1?100 nm)produced by excipients and extracts on the microstructure of the hydrogel network was performed. Thus, combining structural-functional information allows for the design of Ca(II)-alginate systems based not only on functional aspects. Here we demonstrate that the presence of hydrocolloids affected the alginate dimers size and density, the rods size and compactness as well as their interconnectivity. Nevertheless, these modifications can be overlied by the presence of an extract, which leads to alginate coordination prior to gelation, strongly affecting the resulting microstructure. Among the used hydrocolloids, only guar gum achieves the two proposed criteria: increasing functional properties and generating stable microstructural modulations.