18E-6

D. J. PIMENTEL-GONZÁLEZ, Dept. de Biotecnología, Univ. Autónoma Metropolitana-Iztapalapa, San Rafael Atlixco # 186, Mexico City, 09340, Mexico, Y. I. Granados-Hernández, R. G. Campos-Montiel, Biotecnología Agroalimentaria, Univ. Autónoma del Estado de Hidalgo, Rancho Universitario s/n, Tulancingo, 43612, Mexico, F. Cruz-Sosa, Dept. de Biotecnología, Univ. Autónoma Metropolitana, Iztapalapa, Mexico, and E. J. Vernon-Carter, IPH, Univ. Autónoma Metropolitana Iztapalapa, Mexico.

Lactobacillus rhamnosus is a lactic acid microorganism that contributes to improved gut function. It is convenient for obtaining an enhanced performance of this microorganism to protect it against environmental factors and to achieve its delivery in the gut at controlled rates. The aim of this work was to obtain a kinetically stable W₁/O/W₂ multiple emulsion containing L. rhamnosus in the inner aqueous phase (W₁) evaluating the influence of the concentration and type emulsifiers, ratio W₁ to inner W₁/O emulsion and of W₁/O to W₁/O/W₂ on the droplet coalescence. L. rhamnosus was cultured in a compound medium made up by 50% w/w milk whey. Inner W₁/O emulsion was made by adding different disperse phase fractions (0.1, 0.2, 0.3, 0.4) of L. rhamnosus medium (W₁) a mineral oil phase containing different concentrations (0.5, 1, 2, 4, 8, 10, 16, 30%) of Span 80 as emulsifier. Afterwards, different disperse fractions (0.1, 0.2, 0.3, 0.4) of W₁/O were added to different aqueous concentrations of gum arabic (6, 8, 10 %) to obtain the W₁/O/W₂ multiple emulsions. The volumetric and Sauter mean and droplet size distribution of the inner and multiple emulsions were determined by laser diffraction and image analysis. W₁/O/W₂ multiple emulsions were sheared at 100 1/s for 15 min in a concentric cylinder rheometer. Results indicate that the emulsions that showed higher stability against shear (showing more uniform inner and multiple droplet size and distribution over time) were those made up with 8% Span 80, a W₁ disperse fraction of 0.3, Arabic gum concentration of 10% and W₁/O disperse fraction of 0.2. These results provide the basis for delivering L. rhamnosus to the gut in a vehicle that may contribute to prolong the functionality of this probiotic by dosifying its release in controllable and persistent way.

Session 18E, Nutraceutical & Functional Foods: General I
2:00 PM - 5:30 PM, Sunday PM Room Hall I-2

2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana