Poster 25
A
c
i
dic a
n
d sa
lin
e s
tr
esses modify m
i
croflora composition of table
olives
p
roduced b
y
spo
n
taneous fermen
t
ation.
Caridi Andrea, De Bruno Alessandra, Piscopo Amalia, Zappia Angela and Poiana Marco
Department AGRARIA, Mediterranea University of Reggio Calabria, Reggio Calabria, Italy
acaridi@unirc.it
The main components of the table olive microflora are lactic acid bacteria (LAB) and yeasts. Their growth is affected byboth environmental and technological stresses. Among others, nutrient depletion (1),salt
concentration and low pHlevels (2) can induce a shift from homo- to hetero-fermentative metabolism of LAB(3). When LABgrow in ahigh salt medium, the structural properties ofthe cell wall change (4).Several LAB produce exopolysaccharides as a resistance mechanisms phenolic stress (5).On the other hand, under stressing conditions yeasts synthesize a number of bioactive antioxidant compounds (6,7). In order to improve the industrial production process, we tested the effect on the autochthonous LAB and yeasts ofacidic (by lactic acidaddition) and saline (by NaCI addition) stresses during table olive production. Our preliminary results and the relevant related literature arediscussed considering, above all, the industrial advantages and the consequences for starter selection.
l.Ruiz-Barba JL and Jlmenez-Dlaz R- JAppl Bacteriol 76, 350 -355, 1994 2.Bobillo, M and Marshall VM - J Appl Bacteriol 73, 67 -70, 1992 3.Panagou EZet 01.- Food Microbiol 25, 348-358, 2008
4.Piuri Met 01. -JAppl Microbiol 98, 84-95,2005
5.Manca de Nadra MC and Strasser de Saad AM - Int JFood Microbiol 27, 101 -106,1995
6.Cruz JM et 01.- Food Chem 67,147 -153, 1999
7.Martinez-Montanes F et 01.(20ll) Mol Microbiol 79, 1008-1023,2011
This research wos supported by POR CALABRIA FESR2007/2013 -1.1.1.2
NUOVE TECNOLOGIE PER LA VALORIZZAZIONE DELLA FILIERA DELLE CONSERVE: CONSERVO
