Effect of glycerol and Ca+2 addition on physicochemical properties of edible carrageenan/porphyran-based films obtained from the red alga, Pyropia columbina

RAUL CIAN; PABLO SALGADO; SILVINA DRAGO; ADRIANA N MAURI

JOURNAL OF APPLIED PHYCOLOGY

SPRINGER

Lugar: Berlin; Año: 2015 vol. 27 p. 1699 - 1708

0921-8971

Our aim was to study the effect of glycerol and Ca+2 addition on physicochemical properties of phycocolloid(carrageenans/porphyrans)-based films obtained fromPyropia columbina aqueous fraction. Films were formed bycasting from aqueous dispersions of phycocolloid-enrichedfraction (P) with different levels of glycerol (0, 12.5, and25 g (100 g)−1 dry solid) and the optional addition of Ca+2(16 g (100 g)−1 dry solid), yielding six formulations accordingto a multi-factorial design (P, PG1, PG2, PCa, PCaG1, andPCaG2). All films were homogeneous, flexible, and slightlygreenish. Moisture content, water solubility, and water vaporpermeability of films were significantly increased by addingglycerol to the formulation (11, 12, and 6 %). Increasingglycerol content in formulations (12.5 to 25 g (100 g)−1 drysolid) allows obtaining more stretchable but less resistantfilms (with less tensile strength and elastic modulus) thanthose produced without plasticizer (P). Ca+2 addition maskedglycerol effect in some properties (water solubility and watervapor permeability), but in others, the effect of Ca+2 wasadded to the plasticizer glycerol effect (mechanical properties).Ca+2 could stabilize the three-dimensional structure of Pphycocolloids by interactions between sulfate groups, promote water retention, and open film structure. Use of theseadditives yielded films from P. columbina with a wide rangeof mechanical properties, thus extending the scope of thesematerials.