Effect of Surfactant Type on Microencapsulation of a Low-Trans Fat in a trehalose-Based Matrix

SOLEDAD ALVAREZ CERIMEDO; ANALÍA DEL VALLE DIAZ; ROBERTO J. CANDAL; MARÍA LIDIA HERRERA

´Quebéc City, Quebéc, Canadá

Congreso; 98th AOCS Annual Meeting and Expo; 2007

AOCS

A low trans fat blend with crystalline material formulated with 40 wt. % sunflower seed oil (SFO) in high melting fraction (HMF) of milk fat was encapsulated by freeze-drying emulsions. The matrix was a 20 wt. % trehalose aqueous solution. The selected emulsifiers were a mixed of 50 wt. % of the palmitic sucrose esters (SE) P-170 and P-1670, sodium caseinate (NaCas) or a 50 wt. % blend of SE and NaCas. The ability of formulation to encapsulate the selected fat system by freeze drying and to retain the core material with time was studied by storing the powders at different water activities. NaCas formulation was very efficient to encapsulate the fat phase. Retention value was 89.7 ± 0.1. SE and SE/NaCas formulations, however, were less efficient. Retention values were 64.9 ± 0.8 and 55.5 ± 1.0, respectively. NaCas formulation was also more efficient to retain core material during storage. Medium particle size was 0.56 ± 0.20 up to 2 months of storage both at aw 0.11 and 0.76. After that, powders collapsed and particles dramatically grew. For SE and SE/NaCas powders initial particle size was high since preparation. Medium sizes were 67.0 ± 1.0 and 69.2 ± 2.1, respectively. Core retention in NaCas powder was less affected by the presence of fat crystalline material than SE and SE/NaCas powders