Improvement of antifungal compound production by L. plantarum in presence of quinoa

DALLAGNOL, A. M.; PESCUMA, M.; MOZZI, F; ROLLÁN, G; FONT, G

Egmond aan Zee

Simposio; 10th Symposium on Lactic Acid Bacteria; 2011

Federation of European Microbiological Societies (FEMS) and the Netherlands Society for Microbiology (NVvM)

Sourdough fermentations can naturally enhance bread shelf life due to the production of organic acids which are able to inhibit fungi growth. Lactobacillus plantarum CRL778, isolated from homemade sourdough, is able to produce phenyllactic acid (PLA) and hydroxyphenyllactic acid (OH-PLA), two antifungal compounds derived from phenylalanine and tyrosine catabolism, respectively. The PLA and OH-PLA are scarcely released during wheat sourdough fermentation. The aim of this work was to evaluate the PLA and OH-PLA production by L. plantarum CRL 778 in presence of quinoa flour to develop a bio-preservative starter culture. The wheat and quinoa doughs were started separately with L. plantarum CRL778 and the growth, proteolytic activity (SDS-PAGE and RP-HPLC) and PLA - OH-PLA release (RP-HPLC) were analyzed. The strain grew better in quinoa than in wheat flour showing also higher proteolytic activity after 24h. The SDS-PAGE analysis indicated that the quinoa protein bands were hydrolyzed between 41 and 100%, while only the 63 kDa wheat protein was degraded (25%) after 8 h.. Consistently with these results, more peptides from quinoa hydrolysis were found respect to wheat. L. plantarum CRL778 released 2-fold more PLA and OH-PLA in quinoa than in wheat flour, fact that could be correlated with the higher proteolytic activity on the former substrate. Consequently the addition of quinoa to wheat sourdough could be an interesting alternative to increase antifungal compounds concentration to enhance bread shelf life.