Abstract

AGUIRRE-EZKAURIATZA, E. J.; RAMIREZ-MEDRANO, A.; AGUILAR-YANEZ, J. M.  and  ALVAREZ, M. M.. Production of freeze dried protein and Lactobacillus casei probiotic biomass from goat milk whey. Rev. Mex. Ing. Quím [online]. 2009, vol.8, n.1, pp.67-76. ISSN 1665-2738.

In this communication, we document the technical feasibility of elaboration of two added value products from goat whey: (a) freeze-dried protein and (b) freeze-dried probiotic biomass of Lactobacillus casei. Results from goat milk whey ultrafiltration experiments are presented, from which high protein/lactose ratio protein is recovered. In its lyophilized form, this protein presents superior solubility characteristics with respect to analogous commercial products. The ultrafiltration permeate was utilized as growth culture medium for the probiotic microorganism L. casei. Results from batch and fed-batch fermentation experiments are reported. The growth kinetics of L. casei in de-proteinized goat milk whey is analyzed. From batch experiments, a kinetic characterization is conducted. A strong inhibition of biomass growth by lactic acid production is observed. Fed-batch strategies resulted in higher average productivities, lower residual substrate concentrations, and higher product viable counts than batch strategies.

Keywords : Lactobacillus casei; fed-batch; bioreactors; goat milk; whey; probiotic.