Nucleation behavior of blended high-melting fractions of milk fat as affected by emulsifiers

CERDEIRA, M;PASTORE, V; VERA, L.V; MARTINI, S.;CANDAL,RJ.; HERRERA, M.L.

EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY

WILEY-V C H VERLAG GMBH

Año: 2005 vol. 107 p. 877 - 885

1438-7697

The effect of highly hydrophobic emulsifiers, the palmitic sucrose ester P-170 (hydrophilic/lipophilic balance (HLB) = 1.0), the stearic sucrose ester S-170 (HLB = 1.0), thepolyglycerol ester decaglycerol decastearate DAS 7S (HLB = 3.7) and the polyglycerolester decaglycerol dodecabehenate DDB 750 (HLB = 2.6), on the nucleation of a highmelting point milk fat fraction (HMF) and its blends with sunflower oil (SFO) was investigatedby polarized laser light turbidimetry, X-ray diffractometry and polarized lightmicroscopy (PLM). Addition of polyglycerol esters accelerated nucleation, givingshorter induction times for the same supercooling. On the contrary, sucrose esters inhibitednucleation since induction times were elongated in all conditions selected.Addition of emulsifiers modified the polymorphic behavior in the blends with SFO. Theb? form was promoted especially with the addition of S-170. DAS 7S and DDB 750promoted crystallization. PLM images showed many small crystals that did not appearin HMF images. Addition of P-170 and S-170 delayed nucleation and inhibited crystalgrowth. Crystals were notoriously smaller than the ones that appeared in HMF images.The Fisher?Turnbull model was used to calculate activation free energies of nucleation.In all cases, sucrose esters elevated the energy barrier for nucleation. Polyglycerolesters, however, if they had an effect on the energy barrier, lowered the values.