Study of the gastrointestinal resistance and controled release of a Lactobacillus paracasei strain microencapsulated by complex coacervation and ionic gelling (Póster)

SÁNCHEZ, G.; QUIBERONI, A.; ARÍNGOLI, E.; ANDRICH, O.; REINHEIMER, J.; SANTIAGO, L.

Tucumán, Argentina

Simposio; III Simposio Internacional de Bacterias Lácticas. Segundo Encuentro Red BAL Argentina; 2009

Centro de Referencia para Lactobacilos (CERELA), CONICET

Functional food formulation with probiotic incorporation has different problems such as their viability loss due to food environment, phage infection, and gastrointestinal pass effects. Either, coacervation between proteins and anionic polysaccharides and ionic gelling could become an important tool to design microcapsule shell resistant to stomach acid conditions and that release their activity under some stimulus action. In this sense, the objective of this work was to find the best condition to microencapsulate a Lactobacillus paracasei probiotic strain by complex coacervation and  ionic gelling between milk whey protein and sodium alginate. Encapsulation experiments were done following a factorial experimental design 2^2 with a replication. The factors were protein:polysaccharide ratio (Pr:Ps) (4:1 –8:1) and ionic strength (CaCl2 concentration: 10–50mM). The microencapsulation method was: i) mixing biopolymers in the experimental design levels; ii) addition of microorganisms ( m.o.); iii) reduction of pH with 0.5M HCl in order to achieve coacervation; iv) addition  of CaCl2  solution to achieve ionic gelling; v) freeze drying the coacervated phase. Microorganism  releasing assays in sodium phosphate buffer pH 7 during 4 h and also  tolerance assays to simulated gastric (pH 3), bilis (0,3% P/V)  and lysozyme (0,1 mg•ml-1) were done on each sample. Every counts of Lactobacillus paracasei were done in Agar MRS, incubated during 48 h at 37ºC. It was found that Pr:Ps ratio 4:1 promotes the releasing at pH 7 of the microencapsulated m.o., compared to 8:1 ratio. On the other hand,  the encapsulated microorganisms at Pr: Ps  ratio 8:1, with 10mM CaCl2 show higher resistance to the gastric-intestinal simulation assays than the Lactobacillus paracasei control culture without microencapsulation. This experimental design let us find the best conditions to microencapsulate a Lactobacillus paracasei probiotic strain, resistant to gastric-intestinal conditions with a high potential use in food product formulation.