title: Impact of microbial cultures on proteolysis and release of bioactive peptides in fermented milk.
abstract: This study aimed at evaluating co-cultures of selected microorganisms for their proteolytic activity and capability to produce fermented milk enriched with ACE-inhibitory (ACEI) peptides. Selected yeasts (Torulaspora delbruekii KL66A, Galactomyces geotrichum KL20B, Pichia kudriavzevii KL84A and Kluyveromyces marxianus KL26A) and lactic acid bacteria strains (Lactobacillus plantarum LAT03, Lb. plantarum KLAT01 and the not virulent Enterococcus faecalis KE06) were screened as single cultures for their capacity of releasing ACEI peptides without producing bitter taste. Three strains cultures (yeast, Lb. plantarum and E. faecalis) were performed to evaluate the combined impact on microbial growth, lactic acid production, citric acid consumption, proteolysis, ACEI activity, and bitter taste after 36 h of fermentation at 28 °C. While G. geotrichum KL20B showed a strong stimulating effect on Lb. plantarum strains and the production of peptides with ACEI activity, the presence of T. delbruekii KL26A in the cultures was deleterious both to ACEI activity and product taste. The most effective combination was P. kudriavzevii KL84A, Lb. plantarum LAT3, E. faecalis KL06, which showed the highest ACEI activity (IC50 = 30.63 ± 1.11 μg ml(-1)) and gave no bitter taste for 7 days at 6 °C. Our results highlight the importance of choosing the strains combination carefully, to obtain a high yield of ACEI activity without bitter taste.
authors.affiliation: Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Via C.R. Lerici 1, 64023 Mosciano Sant'Angelo, TE, Italy.
authors.forename: Clemencia
authors.initials: C
authors.lastname: Chaves-López
authors.affiliation: Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Via C.R. Lerici 1, 64023 Mosciano Sant'Angelo, TE, Italy.
authors.forename: Annalisa
authors.initials: A
authors.lastname: Serio
authors.affiliation: Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Via C.R. Lerici 1, 64023 Mosciano Sant'Angelo, TE, Italy. Electronic address: apaparella@unite.it.
authors.forename: Antonello
authors.initials: A
authors.lastname: Paparella
authors.affiliation: Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Via C.R. Lerici 1, 64023 Mosciano Sant'Angelo, TE, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Martuscelli
authors.affiliation: Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Via C.R. Lerici 1, 64023 Mosciano Sant'Angelo, TE, Italy.
authors.forename: Aldo
authors.initials: A
authors.lastname: Corsetti
authors.affiliation: Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Via C.R. Lerici 1, 64023 Mosciano Sant'Angelo, TE, Italy.
authors.forename: Rosanna
authors.initials: R
authors.lastname: Tofalo
authors.affiliation: Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Via C.R. Lerici 1, 64023 Mosciano Sant'Angelo, TE, Italy.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Suzzi
mesh_terms: D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000378:metabolism*; D001419:Bacteria / Q000254:growth & development / Q000378:metabolism*; D005285:Fermentation; D006801:Humans; D008892:Milk / Q000737:chemistry / Q000382:microbiology*; D059748:Proteolysis; D013649:Taste; D015003:Yeasts / Q000254:growth & development / Q000378:metabolism*
chemical_list: D023181:Antimicrobial Cationic Peptides
keywords: Angiotensin converting enzyme; Bitter taste; Co-colture starter; Fermented milk; Kumis