title: Lactic acid fermentation as a tool to enhance the antioxidant properties of Myrtus communis berries.
abstract: BACKGROUND
  Myrtle (Myrtus communis L.) is a medicinal and aromatic plant belonging to Myrtaceae family, which is largely diffused in the Mediterranean areas and mainly cultivated in Tunisia and Italy. To the best of our knowledge, no studies have already considered the use of the lactic acid fermentation to enhance the functional features of M. communis. This study aimed at using a selected lactic acid bacterium for increasing the antioxidant features of myrtle berries, with the perspective of producing a functional ingredient, dietary supplement or pharmaceutical preparation. The antioxidant activity was preliminarily evaluated through in vitro assays, further confirmed through ex vivo analysis on murine fibroblasts, and the profile of phenol compounds was characterized.
  
  
  RESULTS
  Myrtle berries homogenate, containing yeast extract (0.4%, wt/vol), was fermented with Lactobacillus plantarum C2, previously selected from plant matrix. Chemically acidified homogenate, without bacterial inoculum and incubated under the same conditions, was used as the control. Compared to the control, fermented myrtle homogenate exhibited a marked antioxidant activity in vitro. The radical scavenging activity towards DPPH increased by 30%, and the inhibition of linoleic acid peroxidation was twice. The increased antioxidant activity was confirmed using Balb 3 T3 mouse fibroblasts, after inducing oxidative stress, and determining cell viability and radical scavenging activity through MTT and DCFH-DA assays, respectively. The lactic acid fermentation allowed increased concentrations of total phenols, flavonoids and anthocyanins, which were 5-10 times higher than those found for the non-fermented and chemically acidified control. As shown by HPLC analysis, the main increases were found for gallic and ellagic acids, and flavonols (myricetin and quercetin). The release of these antioxidant compounds would be strictly related to the esterase activities of L. plantarum.
  
  
  CONCLUSIONS
  The lactic acid fermentation of myrtle berries is a suitable tool for novel applications as functional food dietary supplements or pharmaceutical preparations.
authors.affiliation: Dipartimento di Scienze del Suolo, della Pianta e degli Alimenti, University of Bari, Via G. Amendola 165/a, Bari, 70126, Italy. josancuriel@gmail.com.
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Curiel
authors.affiliation: Giuliani S.p.A., Milan, 20129, Italy. dpinto@giulianipharma.com.
authors.forename: Daniela
authors.initials: D
authors.lastname: Pinto
authors.affiliation: Giuliani S.p.A., Milan, 20129, Italy. bmarzani@giulianipharma.com.
authors.forename: Barbara
authors.initials: B
authors.lastname: Marzani
authors.affiliation: Dipartimento di Scienze del Suolo, della Pianta e degli Alimenti, University of Bari, Via G. Amendola 165/a, Bari, 70126, Italy. pasquale.filannino@uniba.it.
authors.forename: Pasquale
authors.initials: P
authors.lastname: Filannino
authors.affiliation: Dipartimento di Scienze ambientali agrarie e biotecnologie agro-alimentari, Università degli Studi di Sassari, Sassari, Italy. gafarris@uniss.it.
authors.forename: Giovanni Antonio
authors.initials: GA
authors.lastname: Farris
authors.affiliation: Dipartimento di Scienze del Suolo, della Pianta e degli Alimenti, University of Bari, Via G. Amendola 165/a, Bari, 70126, Italy. marco.gobbetti@uniba.it.
authors.forename: Marco
authors.initials: M
authors.lastname: Gobbetti
authors.affiliation: Dipartimento di Scienze del Suolo, della Pianta e degli Alimenti, University of Bari, Via G. Amendola 165/a, Bari, 70126, Italy. carlogiuseppe.rizzello@uniba.it.
authors.forename: Carlo Giuseppe
authors.initials: CG
authors.lastname: Rizzello
mesh_terms: D000818:Animals; D000975:Antioxidants; D005285:Fermentation; D005347:Fibroblasts / Q000378:metabolism*; D005638:Fruit / Q000737:chemistry*; D019344:Lactic Acid; D051379:Mice; D031651:Myrtus / Q000737:chemistry*; D017382:Reactive Oxygen Species
chemical_list: D000975:Antioxidants; D017382:Reactive Oxygen Species; D019344:Lactic Acid