Alessandria, Valentina

Cocolin, Luca

Dolci, Paola

Ferrocino, Ilario

Franciosa, Irene

Rantsiou, Kalliopi

English

Institutional Research Information System University of Turin

Salame Piemonte is an typical fermented sausages of Nord-West of Italy that is preserved by protected geographical indication (PGI).These kind of products constitute a significant part of the Mediterranean diet and have a long tradition originating from Europe. Theirmicrobiota is specific of the region or area where they are produced and it is essential in the better management of microbialresources to protect the sensory characteristics of the product (Aquilanti et al., 2007).With the aim of the selection of autochthonous starter cultures for this local fermented sausage, the ecology and microbial dynamicsduring the fermentation process of three different productions from the same factory were evaluated. The study of fermented sausageshas been carried out by culture-dependent and independent methods in addition to volatilome profile, chemicals and sensory analysis(Ferrocino et al., 2018; Greppi et al., 2015).References:Aquilanti L., Santarelli S., Silvestri G., Osimani A., Petruzzelli A., Clementi F. (2007).The microbial ecology of a typical Italian salami during its natural fermentation. Int. J.Food Microbiol. 120, 136–145.Ferrocino I., Bellio A., Giordano M., Macori G., Romano A., Rantsiou K., Decastelli L.,Cocolin L. (2018). Shotgun metagenomics and volatilome profile of the microbiota offermented sausages. Appl. Environ. Microbiol. 84 (3), e02120-17.Greppi A., Ferrocino I., La Storia A., Rantsiou K., Ercolini D., Cocolin L. (2015).Monitoring of the microbiota of fermented sausages by culture independent rRNA-basedapproaches. Int. J. Food Microbiol. 212, 67-75.Sampling: • 3 batch: February (Y), March (Z), May (X)• 6 sampling times: T0, T4, T8, T15, T30, T50Analysis:• Culture - dependent analysis: LAB (MRS), CNC (MSA), Fungi/Yeast (AMT)• Culture - independent analysis: V1–V4 region of the 16S rRNA (Illumina MiSeq)Fig.2: Relative abundance of the major taxonomic groups detected by means of 16Ssequencing. Only OTUs with an incidence above 0.2 % in at least two samples are shown• Lb. sakei was the most abundant OTU in all samplesafter 4 days until the end of fermentation, itsabundance was never lower than 50%.• Through principal coordinate analysis (PCoA) with aweighted UniFrac distance matrix, it was possible toshow that meat samples at time 0 separated well allsalami samples on the basis of the microbiota• Through Principal-component analysis (PCA), it waspossible to show that samples from batch Z groupedtogether and that they were well separated frombatch X and Y on the basis of their microbiota• Through predicted metagenomes, it was possible toshow that T0 of all three batch has a similarpathways correlations• With the aim of selection of new starter cultures,REP characterization for all isolated strains will beperform• Shotgun metagenomics and volatilome profile (withGC-MS analysis) will be perform to confirm themetabolic pathways and the microbial ecologyFig.3: Principal coordinates analysis of weighted UniFrac distances for 16SrRNA gene sequence data. Samples are color-coded by batch: blue (Y;February), green (Z; March), red (X; May)T0Fig.4: Principal-component analysis (PCA) based on the OTUs relativeabundance of the three different batch: blue (Y; February), green (Z; March),red (X; May)PC2 11.13 EXPL.VARPC1 68.13 EXPL.VART0T0T0Fig. 5: Boxplotsshowing the relativeabundance at speciesor genus level of theOTUs differentiallyabundant based onWilcoxon matchedpairs test (p≤0.05) inthree different batch:blue (Y; February),green (Z; March), red(X; May)aabababaabab b baaba abaabba aFig.1: a. pH and aw measurements of the fermentedsausages during maturation; b. Growth of LAB, CNC, yeastand fungi during the maturation process.aba aab bcdacbbc bc bcab bb b baaaa aaab ababaa bFig. 6: Heat plot showingSpearman’s correlationsbetween OTUs occurring at0.2% in at least 2 samples andpredicted metabolic pathways,filtered for KO gene samplepresence >10 in at least 10samples, related to aminoacid, lipid AND carbohydratemetabolism. Rows andcolumns are clustered by Wardlinkage hierarchical clustering.The intensity of the colorsrepresents the degree ofcorrelations between the OTUsand KO as measured by theSpearman’s correlations.• Blue = Z March• Green = Y February• Red = X MayMicrobiological characterization of Salame Piemonte IGPIrene Franciosa*, Ilario Ferrocino, Valentina Alessandria, Paola Dolci, Kalliopi Rantsiou, Luca CocolinDepartment of Agricultural, Forest and Food Sciences, University of Turin, Italy*email: irene.franciosa@unito.it 

Microbiological characterization of Salame Piemonte IGP

https://iris.unito.it/bitstream/2318/1676305/1/Franciosa_FoodMicro2018.pdf

Microbiological characterization of Salame Piemonte IGP

Abstract

Similar works

Full text

Available Versions

Institutional Research Information System University of Turin