Characterization of Lactic Acid Bacteria in Pecorino di Farindola Cheese and Manufacturing with a Lacticaseibacillus paracasei Autochthonous Culture

Giuseppe Aprea,Ilaria Del Matto,Daniela D’Angelantonio,Arianna Boni,Diana Neri,Francesco Pomilio,Giacomo Migliorati,Alessandra Alessiani,Lorena Sacchini,Silvia Scattolini,Franca Rossi,Elisabetta Di Giannatale,Anna Franca Sperandii,Patrizia Tucci,Gabriella Centorotola

doi:10.3390/app11177897

Abstract

This study focused on the characterization of lactic acid bacteria (LAB) in a renowned traditional Italian cheese, Pecorino di Farindola, in order to select an autochthonous culture and investigate its potential for the improvement of safety and functional properties. Two hundred and six LAB isolated throughout production and maturation from nine cheese lots of three farms were identified by 16S rRNA gene sequencing and tested for the presence of genes encoding virulence factors, vancomycin resistance (for enterococci), biogenic amines (BAs) and bacteriocin production for antimicrobial activity; and for the capacity to survive in the gastrointestinal tract (GIT) based on tolerance to low pH and bile salts and adhesion to CaCo-2 cells. A Lacticaseibacillus paracasei isolate was used in cheese making and determined a decline of spiked Listeria monocytogenes and Escherichia coli O157 faster than in the control cheese. The autochthonous bacterial groups were numerically unaffected, apart from lactobacilli that were recovered in higher numbers in cheese with the addition of the L. paracasei strain. Based on repetitive extragenic palyndrome (Rep) polymerase chain reaction (PCR) profiles, the added strain possibly dominated until day 88 in the cheese. Results encourage further trials with autochthonous cultures in order to efficiently inhibit hazardous bacteria and to enrich a functional microbiota in Pecorino di Farindola and similar cheeses.

Highlights

Traditional cheeses are a food category with economical relevance for defined geographical areas and are appreciated by consumers for their peculiar organoleptic features and genuineness [1]
Pecorino di Farindola cheese is an example of dairy product from this category, and it is included in the list of the Italian traditional cheeses held by the Italian Ministry of Agriculture [3]
NCTC 13386 and ATCC 367, Limosilactobacillus fermentum ATCC 55884, Listeria monocytogenes ATCC7644 and European Union (EU)-RL 12M0B098, Escherichia coli O157 VTEC ISS, ATCC 25952 and European Union Reference Laboratory for Listeria monocytogenes (EURL) C07, Salmonella Typhimurium ATCC 14028 and Staphylococcus aureus ATCC 33862 were used as positive control strains in specific polymerase chain reaction (PCR) reactions, antimicrobial production tests and cheese making trial

Summary

Introduction

Traditional cheeses are a food category with economical relevance for defined geographical areas and are appreciated by consumers for their peculiar organoleptic features and genuineness [1] Most of these products in Italy are obtained from raw milk, added or not with natural whey cultures, following the European Union (EU) guidelines in order to ensure safety [2]. Pecorino di Farindola cheese is an example of dairy product from this category, and it is included in the list of the Italian traditional cheeses held by the Italian Ministry of Agriculture [3] It is prepared, curiously only by women, from raw and non-refrigerated ewe’s milk in nine towns of a mountainous district of the Abruzzo region. The product has an ageing time from three to five months [4]

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Conclusion