B vitamin-producing lactic acid bacteria as biotechnology strategy for bio-fortification of quinoa sourdough

MONTES DE OCA, C.; CARRIZO, S.L.; ROLLAN, G.; LEBLANC, JEAN GUY

San Miguel de Tucuman

Simposio; V Simposio Internacional de Bacterias Lácticas.; 2016

CERELA

Vitamins are essential for life, but humans are unable to synthesize most of them, so they must be obtained from exogenous sources. Folates (B9) and riboflavin (B2) are important co-factors of numerous metabolic enzymes of the cell. These vitamins are present in a wide variety of foods; however, deficiencies in B9 and/or B2 are very frequent in many parts of the world. Many countries have developed different food fortification programs to offset nutritional deficiency. An attractive alternative for vitamin inclusion in foods is the use of selected lactic acid bacteria (LAB) that are able to synthesize these B vitamins to obtain bio-enriched fermented foods. Quinoa (Chenopodium quinoa) is a gluten free ancient Andean crop with high nutritional value. Previously, LAB were isolated from sourdough (SD) prepared with quinoa and amaranth flours, and selected for their ability to produce B2 and B9 in vitamin-free culture media. The aim of this study was to evaluate the production of B2 and B9 in situ in quinoa sourdough fermented with previously selected LAB. Eighteen strains belonging to the species Lactobacillus (L.) rhamnosus, L. sakei, L. plantarum and Leuconostoc (Leuc.) mesenteroides were evaluated. LAB culture was inoculated (107 CFU/g dough) in the dough (DY=160) and incubated for 24 h at 30°C. Dough performed in the same way without inoculum was used as control. The cell count and the pH were determined at the beginning and end of the fermentation. The extraction of B2 and B9 was performed using a trienzymatic method and the vitamins concentrations were determined using a microbiological method with L. rhamnosus ATCC 7469 and L. rhamnosus NCIMB 10463 as indicator strains, respectively. L. plantarum CRL 1964, 1973 and L. rhamnosus CRL1984 produced high levels of B9 (> 3 µg/g dough), the other strains produced this vitamin in a range between 1.37-2.97 µmg/g dough. L. plantarum CRL 1973, 1967, 2107 and Leuc. mesenteroides CRL 2131 produced high levels of B2 (> 6 µg/ g dough) while the other strains produced values between 2.81 and 5.83 µg/g dough. These B9 and B2 concentrations were higher than those observed in the control dough, 2.19 ± 0.02 and 3.98 ± 0.39 µg/g dough, respectively. The results obtained in this study demonstrate that autochthonous LAB isolated from the ancestral Andean grains, quinoa and amaranth produce significant levels of vitamin B2 and B9 in situ, making them potential starter cultures to obtain novel quinoa-based foods preparation with higher nutritional value.