15E-25 |
Incoporation of bifidobacterium spp by hydrodynamic mechanism in a porous fruit matrix |
G. Maguiña1, G. A. Briceño1, M. S. TAPIA2, C. Rodríguez2, V. Roa1, and J. Welti-Chanes3. (1) Química y Procesos Biológicos, Universidad Simón Bolívar, Valle de Sartenejas, Baruta, Edo. Miranda, Caracas, 89000, Venezuela, (2) Instituto de Ciencia y Tecnología de Alimentos, Facultad de Ciencias, Universidad Central de Venezuela, Aparatado 47097, Caracas, 1041, Venezuela, (3) Ingeniería Química y Alimentos, Universidad de las Américas-Puebla, Santa Catarina Martir, Cholula, Puebla, 72820, Mexico In a vacuum impregnation process, the hydrodynamic mechanism (HDM) can be used to facilitate incorporation of microorganisms like Bifidobacterium spp into the porous spaces of fruit tissues, thus obtaining probiotic-containing fruit pieces. Granny Smith apple as model of a porous vegetable matrix was impregnated with a solution of Bifidobacterium spp. Microbial concentration in the impregnated samples was determined by culturing the microorganism in Miller-Pricket tubes with Reinforced Clostridium Agar and an overlay of Arroyo, Martin and Cotton Agar. Four different vacuum pressure pulses were used. Applied vacuum had a significant effect on X values as well as on incorporation of Bifidobacterium spp. In all cases though, the organism was incorporated at levels higher than 107 cells/g. Evaluation of its concentration in the apple pieces during storage a 4 for 12 days revealed that viable populations decreased only by a log cycle after the sixth day, and remained in that level until the end of storage. Visualization of the organism into the fruit tissues was followed by scanning electron microscopy (SEM). Apple seems to be a good vehicle for this probiotic organism as shown by sensory evaluation and viability of the culture at 4 ºC, at levels higher than 106. The use of simple equations based on mass balances that utilize volumetric fraction X instead of effective porosity and a measure of liquid adherence to address final mass and composition of the fruit pieces, predicted satisfactorily the weigth of impregnated fruit pieces and Bifidobacterium spp concentration.
Session 15E, Nutraceuticals & Functional Foods I
|