Background: The winemaking process includes two key steps performed carried out by microorganisms, i.e. alcoholic fermentation (AF) and malolactic fermentation (MLF). The AF primarily produce the is essential; conversion of grape must sugars from grape must are converted into ethanol. This fermentation is carried out by yeast, mainly by Saccharomyces cerevisiae strains: However, that, however,, this is not the only yeast involved in the process. In fact,A few specificseveral non-Saccharomyces species, such as Hanseniaspora uvarum, have been proved to positively modify the wine chemical composition, contributing to the sensory characteristics of wines. On the other side, MLF is carried out by lactic bacteria (LAB), mainlyprincipally by Oenococcus oeni and Lactobacillus plantarum strains. While Although the possible interactions of enological significance between S. cerevisiae and O. oeni strains have been extensively studied, little is known about possible interactions between non-Saccharomyces and O. oeni strains. Objective: In the light of the rising request for autochthonous starters tailored for given 'terroir', the objective of this work was to select identify the best inoculation time of autochthonous of Oenococcus oeni or Lactobacillus plantarum strains in combination with two autochthonous S. cerevisiae strains and one H. uvarum strain, all isolated from Apulian wines. Methods: Both, yeasts S. cerevisiae and non-Saccharomyces, were co-inoculated in red must, and L. plantarum or O. oeni strains were co-inoculated or sequentially inoculated during AF, when ethanol content was 2%, 4%, 6%, 8%, 10% or 12% (v/v). Ethanol formation, L-malic acid consumption and bacterial cell viability were monitored during the vinifications. Conclusions: The co-inoculation of H. uvarum with S. cerevisiae did not affect the AF. In all cases AF was finished completed in about 4 days. Ethanol concentration at the moment of bacterial inoculation was a crucial factor for the developing success of MLF. The co-inoculation with S. cerevisiae and H. uvarum was the best strategy for maintaining the highest LAB populations concentration, in order to successfully and therefore for carryicarryng out the MLF in red must. Bacterial cell viability and L-malic consumption after AF were strain-dependent. This research was supported by the Apulian Region Project cod. QCBRAJ6 "Biotecnologie degli alimenti per l'innovazione e la competitività delle principali filiere regionali: estensione della conservabilità e aspetti funzionali - BIOTECA", and by the Apulian Region Project "Sviluppo di approcci microbiologici innovativi per il miglioramento della qualità di vini tipici regionali (NEWine)". Vittorio Capozzi was supported by 'Fondo di Sviluppo e Coesione 2007-2013--APQ Ricerca Regione Puglia "Programma regionale a sostegno della specializzazione intelligente e della sostenibilità sociale ed ambientale--FutureInResearch".
INVESTIGATION OF THE INOCULATION TIME OF APULIAN AUTOCHTHONOUS OENOCOCCUS OENI AND LACTOBACILLUS PLANTARUM STRAINS IN IN MULTI-STARTER WINE FERMENTATIONS
F Grieco;
2017
Abstract
Background: The winemaking process includes two key steps performed carried out by microorganisms, i.e. alcoholic fermentation (AF) and malolactic fermentation (MLF). The AF primarily produce the is essential; conversion of grape must sugars from grape must are converted into ethanol. This fermentation is carried out by yeast, mainly by Saccharomyces cerevisiae strains: However, that, however,, this is not the only yeast involved in the process. In fact,A few specificseveral non-Saccharomyces species, such as Hanseniaspora uvarum, have been proved to positively modify the wine chemical composition, contributing to the sensory characteristics of wines. On the other side, MLF is carried out by lactic bacteria (LAB), mainlyprincipally by Oenococcus oeni and Lactobacillus plantarum strains. While Although the possible interactions of enological significance between S. cerevisiae and O. oeni strains have been extensively studied, little is known about possible interactions between non-Saccharomyces and O. oeni strains. Objective: In the light of the rising request for autochthonous starters tailored for given 'terroir', the objective of this work was to select identify the best inoculation time of autochthonous of Oenococcus oeni or Lactobacillus plantarum strains in combination with two autochthonous S. cerevisiae strains and one H. uvarum strain, all isolated from Apulian wines. Methods: Both, yeasts S. cerevisiae and non-Saccharomyces, were co-inoculated in red must, and L. plantarum or O. oeni strains were co-inoculated or sequentially inoculated during AF, when ethanol content was 2%, 4%, 6%, 8%, 10% or 12% (v/v). Ethanol formation, L-malic acid consumption and bacterial cell viability were monitored during the vinifications. Conclusions: The co-inoculation of H. uvarum with S. cerevisiae did not affect the AF. In all cases AF was finished completed in about 4 days. Ethanol concentration at the moment of bacterial inoculation was a crucial factor for the developing success of MLF. The co-inoculation with S. cerevisiae and H. uvarum was the best strategy for maintaining the highest LAB populations concentration, in order to successfully and therefore for carryicarryng out the MLF in red must. Bacterial cell viability and L-malic consumption after AF were strain-dependent. This research was supported by the Apulian Region Project cod. QCBRAJ6 "Biotecnologie degli alimenti per l'innovazione e la competitività delle principali filiere regionali: estensione della conservabilità e aspetti funzionali - BIOTECA", and by the Apulian Region Project "Sviluppo di approcci microbiologici innovativi per il miglioramento della qualità di vini tipici regionali (NEWine)". Vittorio Capozzi was supported by 'Fondo di Sviluppo e Coesione 2007-2013--APQ Ricerca Regione Puglia "Programma regionale a sostegno della specializzazione intelligente e della sostenibilità sociale ed ambientale--FutureInResearch".I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
