Multiphasic and mixture lactic acid bacteria screening approach for the removal of antinutrients and off-flavors present in a pea, oat and potato blend.

The antinutrients and off-flavors present in plant-based foods are some of the major organoleptic and consumer acceptance drawbacks considered when developing plant-based fermented dairy alternatives (PBFDA). Here, we investigated a combination of genotypical and phenotypical consecutive screening methods to find out the optimal single- and combination of lactic acid bacteria (LAB) strains based on volatile off-flavors, phenolic acids, saponins, and trypsin inhibitor degradation through the fermentation of a pea, oat, and potato (POP) blend. Lactiplantibacillus plantarum strains were the most optimal for the partial/complete degradation of p-coumaric (>98 %) and ferulic acid (10-20 %) compounds in the POP blend. Leuconostoc pseudomesenteroides strains, and their PII-type proteinases were demonstrated to be effective degrading trypsin inhibitors. Also, specific Leuconostoc mesenteroides and L. plantarum strains achieved higher degradation rates of plant saponins such as avenacoside A (10-40 % degradation) and soyasaponin B (55-75 % degradation) present, correlated with their β-glucosidase activity (30-50 U/mL). Strict heterofermentative LABs such as Leuconostoc spp. strains were significantly better at removing hexanal, pentanal, benzaldehyde, and nonanal up to 85 % after 6 h. Finally, 384 combinations of 2 and 3 LAB selected strains (L. plantarum - L. mesenteroides - L. pseudomesenteroides) were tested at different strain-ratios, which demonstrated synergistic effects at degrading ferulic acid to more than 80 %, increasing acidification rates, and producing higher concentrations of diacetyl and acetoin (up to 3.28 and 28.13 µg/g sample) when L. pseudomesenteroides 1993 was included in the mix. This study demonstrated the potential of using unconventional plant-adapted LAB strains as starter cultures for the elimination of multiple unwanted compounds for the development of higher quality PBFDA without the use of conventional dairy-based LAB isolates. Finally, the screening approach could be used for microbial screening purposes throughout the development of starter cultures for plant-based yogurts, cheese, and other non-dairy fermented products.
Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: The authors declare the following authors have a relationship that may be considered as potential competing interests: Geoffrey Ras and Raquel Fernández Varela, as well as Denise Felix da Silva, are employees at Novonesis. The following authors, Claus Heiner Bang-Berthelsen, Egon Bech Hansen, Guillermo Eduardo Sedó Molina, Charlotte Jacobsen, Giovanni Barone, and Lene Duedal Olsen, have several ongoing collaboration projects with Novonesis but declare that they have no additional known competing personal relationships or financial interests that could influence the work in this paper.
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