Methylcellulose-based films containing FOS and lactic acid bacteria for the formulation of a functional food

TAVERA-QUIROZ M J; ROMANO N; MOBILI P; BERTOLA N; GOMEZ-ZAVAGLIA A; PINOTTI A

Buenos aires

Conferencia; 6th International Conference on Science and Technology of Composite Materials COMAT 2015; 2015

The goal of this work was the development and characterization of methylcellulose (MC) based films containing fructo-oligosaccharides (FOS) and Lactobacillus plantarum CIDCA 83114. Additionally, film application as a functional coating for a baked apple snacks was evaluated.Different concentrations of FOS into MC films (0, 1, 3, 5% w/v) were assayed. Dynamic mechanical analysis (DMA) and stress-strain curves demonstrated that FOS incorporated into the MC films had a plasticizing effect. As well, the incorporation of microorganisms into the MC films had no effect on vitreous transition temperatures. A concentration of 3% w/v FOS was selected considering the films as matrices capable of maintaining viable microorganisms and adequate mechanical properties. Scanning electronic microscopy images showed a good incorporation of microorganisms without affecting the homogeneity of the films and FTIR spectroscopy showed structural changes in the bacteria-loaded films respect to the MC films without bacteria. Water sorption isotherms exhibited an impervious behavior at low aw but on exceeding 0.7 of aw the film started to dissolve and form syrup, causing a drastic drop of bacterial viability. Bacteria-loaded MC films containing FOS was used to functionalize an apple snack. The quality of the novel system was studied focusing on its microbiological and technological properties. The apple snacks coated with bacteria-loaded MC were evaluated for lactobacilli cultivability during 90 days of storage. The snack loaded showed a crunchy texture and good sensory attributes. Upon storage the bacterial load (1.94×108 ± 9.99×107 CFU/g) was still above the minimum necessary (106-107 CFU/g) to obtain the benefits of probiotic consumption.The results obtained support the use of MC films containing FOS as a good strategy to immobilize lactic acid bacteria. The formulated snacks resulted from a balance between technological, prebiotic and probiotic properties are of great significance for the development of functional foods