Evaluation of Chios mastic gum as antimicrobial agent and matrix forming material targeting probiotic cell encapsulation for functional fermented milk production

Chios mastic gum (Pistacia lentiscus var. chia) was evaluated as an encapsulating matrix-forming material for immobilization of the probiotic strain Lactobacillus casei ATCC393. In addition, was assessed the antimicrobial activity of resins' extracts against various clinical pathogens. The probiotic strain was to be successfully encapsulated within the mastic gum. Milk was fermented by the encapsulated biocatalyst and by free L. casei cells for comparison reasons. Chios mastic gum extracts showed antimicrobial effects against various microorganisms. In addition, a significant reduction of yeasts and fungi observed only in fermented milk produced by the encapsulated biocatalyst. On the contrast, probiotic cell counts were not affected by the presence of mastic gum and retained their high cell counts (> 10(9) CFU g(-1)) during 8 weeks of storage. GCMS/SPME analysis revealed an enhanced terpene profile accompanied with exceptional organoleptic characteristics. Finally, it is concluded that beneficial synergies between resins antimicrobial properties and bioactive components like probiotic bacteria supplied a novel safety- and health-promoting fermented milk.