Potential probiotic and food protection role of wild yeasts isolated from pistachio fruits (Pistacia vera).

BACKGROUND The biotechnological potential of yeasts from nuts such as pistachio, not only for health applications but also for industry use, is scarcely studied. Interest in the probiotic capability of yeasts has increased in the past years as well as their utilisation as food or feed preservatives. Their capabilities as biocontrol against problematic (spoilage or toxigenic) microorganisms or as antioxidants have been revalued. As a result, both abilities would be desirable to develop a new potential probiotic microorganism which could be added to food or feed to improve their properties. RESULTS Molecular techniques allowed the identification of a total of 7 different species and 15 strains. A screening of the probiotic potential of these strains was carried out. It was found that 65% of the strains resisted the gastrointestinal conditions as well as presented a generation time of < 22h. Additionally, some strains showed better kinetic parameters than Saccharomyces boulardii (positive control). Complementary tests were done to determine their auto-aggregation capacity, cell surface hydrophobicity, behaviour in a sequential simulated digestion, biofilm formation capability and carbon source assimilation. Finally, 67% and 13% of the studied yeasts showed biocontrol and antioxidant activities, respectively. CONCLUSIONS Diutina rugosa 14 followed by Diutina rugosa 8 were the best wild yeast from Pistacia vera as potential probiotic and in carbon source utilisation. On the other hand, Hanseniaspora guilliermondii 6 and Aureobasidium proteae 5 could be used to improve food or feed product preservation because of their notable biocontrol and antioxidant capabilities. This article is protected by copyright. All rights reserved.