Rheological behavior of soluble dietary fiber fractions isolated from artichoke residues

ROJAS, ANA M.; SANTO DOMINGO, CINTHIA; GERSCHENSON, LIA N.; ZUKOWSKI, ENZO; FISSORE, ELIANA N.

Vienna

Conferencia; E-CONFERENCE on Food Texture and Rheology; 2019

ISEKI Food Association

Globe artichoke (Cynara cardunculus var. scolymus) by-products (stems, outer bracts,leaves) constitute an 80% of the plant. Artichoke agroindustrial by-products can be appliedto the extraction of soluble dietary fibers. In this work, the rheological behavior of fractionsisolated from bracts and stems of artichoke was studied. Soluble dietary fiber fractionsisolated from stem (S) and bracts (B) by means of a heat treatment followed by processingwith sodium citrate buffer (S1, B1) or buffer/protease (S2, B2) or hemicellulase (S3, B3) orboth enzymes (S4, B4) were composed, mainly, by pectin (degree of methylation, DM 53%) and inulin. When dissolved in water (2.00% w/v) with Ca 2+ (40 mg/g pectin), fiberfractions were sensitive to calcium showing shear thinning flow, with initial yield stress inthe case of B2, B3 or S3. Citrate buffer extracted fractions showed the highest viscosities(B1, S1) whereas extraction with buffer and both enzymes (B4, S4) produced the leastviscous fiber fractions. Rest assays performed under dynamic conditions, revealed theformation of gel-like networks with varying lifetimes of the calcium junction zones.Networks formed by fibers were favored, in general, by higher pectin and inulin content,homogalacturonan proportion, and low DM. Leftovers of artichoke can be used to extractsoluble dietary fiber fractions that might be utilized as natural thickeners and gelling agentsin foods, pharmaceutical and cosmetics, helping to add value to raw materials and to closethe bioeconomy loop in relation to this plant.