Molecular identification of lactic acid bacteria from quinoa and amaranth grains from Northwestern Argentina

BELFIORE, C.; FONTANA, P.; SAAVEDRA, L.; HEBERT, E.M.; FONTANA, C.; BASSI, D.; RUIZ RODRIGUEZ, L.; KORHONEN, J.; VIGNOLO, G.; VON WRIGHT, A.

Estambul

Simposio; 23rd International ICFMH Symposium. Food Micro 2012; 2012

Quinoa (Chenopodium quinoa), and Amaranto (Amaranthus caudatus) are dicotyledonous plants, considering as pseudo-cereals and originating from the area between Southern Colombia to Northwest Argentina and Northern Chile, preferentially growing from 2500 mts above sea level. These crops resistant to cold, drought, high and poor soils, provided to the Andean population the necessary nutrients for physical and mental development representing the centerpieces of Andean diet. Hence, the Mayans and Incas civilizations considered sacred amaranth and quinoa grains. The FAO declared that "the quinoa has the balance of protein and nutrients closer to the ideal food for humans." Recently, the gluten-free characteristic of these pseudocereals have attracted attention as food worldwide. In this study, the dominant lactic acid bacteria (LAB) species present in these seeds from Northwestern Argentina (Quebrada de Humahuaca region) were identified by molecular methods. Inca Pirce, Chilena, Real Hornillo, Puno, Roja Pandela, Nerino Pesto and Cica Hornillo (quinoa varieties), and Kiguicha (amaranth) grains were analyzed. LAB counts after pre-enrichment (30 ºC, 24 h) in MRS added with cicloheximide were in the range of 106-107 cfu/g. A total of 265 isolates from quinoa and amaranth samples were analyzed by RAPD to asses the microbial diversity among LAB isolates. A considerable polymorphism among the strains isolated was observed being detected 58 different RAPD profiles. The taxonomic identities were achieves by means of species-specific PCR and 16S RNA ribosomal sequences. The main LAB species found were Enterococcus faecium, Enterococcus mundtii, Enterococcus hirae, Leuconostoc mesenteroides, Leuconostoc lactic, Lactobacillus curvatus, Lactobacillus casei/paracasei and Lactobacillus reuteri. Same potential technologic properties among identified strains were exanimate. All strains except one were able to fermented raffinose and 30 strains were slime-producing. The production of antimicrobial compounds was also exanimate; six strains from quinoa seed were able to inhibit Listeria monocytogenes while 17 out of 58 were able to inhibit Penicillium revealing important antifungical activity. Examination of these indigenous foods may provide information on unknown microbial genetic reservoirs which can be exploited as new functional starter cultures to improve nutritional and functional quality of traditional Andean foods.