Effect of a <i>Debaryomyces hansenii</i> and <i>Lactobacillus buchneri</i> Starter Culture on <i>Aspergillus westerdijkiae</i> Ochratoxin A Production and Growth during the Manufacture of Short Seasoned Dry-Cured Ham

• Main Authors: Lucilla Iacumin, Martina Arnoldi, Giuseppe Comi
• Format: Article
• Language: English
• Published: MDPI AG 2020-10-01
• Series: Microorganisms
• Subjects: <i>D. hansenii</i>; <i>L. buchneri</i>; <i>A. westerdijkiae</i>; biocontrol; ham
• Online Access: https://www.mdpi.com/2076-2607/8/10/1623

Recently, specific dry-cured hams have started to be produced in San Daniele and Parma areas. The ingredients are similar to protected denomination of origin (PDO) produced in San Daniele or Parma areas, and include pork leg, coming from pigs bred in the Italian peninsula, salt and spices. However, these specific new products cannot be marked as a PDO, either San Daniele or Parma dry cured ham, because they are seasoned for 6 months, and the mark PDO is given only to products seasoned over 13 months. Consequently, these products are called short-seasoned dry-cured ham (SSDCH) and are not branded PDO. During their seasoning period, particularly from the first drying until the end of the seasoning period, many molds, including <i>Eurotium</i> spp. and <i>Penicillium</i> spp., can grow on the surface and work together with other molds and tissue enzymes to produce a unique aroma. Both of these strains typically predominate over other molds. However, molds producing ochratoxins, such as <i>Aspergillus ochraceus</i> and <i>Penicillium nordicum</i>, can simultaneously grow and produce ochratoxin A (OTA). Consequently, these dry-cured hams may represent a potential health risk for consumers. Recently, <i>Aspergillus westerdijkiae</i> has been isolated from SSDCHs, which could represent a potential problem for consumers. Therefore, the aim of this study was to inhibit <i>A. westerdijkiae</i> using <i>Debaryomyces hansenii</i> or <i>Lactobacillus buchneri</i> or a mix of both microorganisms. Six <i>D. hansenii</i> and six <i>L. buchneri</i> strains were tested in vitro for their ability to inhibit <i>A. westerdijkiae</i>. The strains <i>D. hansenii</i> (DIAL)1 and <i>L. buchneri</i> (Lb)4 demonstrated the highest inhibitory activity and were selected for in situ tests. The strains were inoculated or co-inoculated on fresh pork legs for SSDCH production with OTA-producing <i>A. westerdijkiae</i> prior to the first drying and seasoning. At the end of seasoning (six months), OTA was not detected in the SSDCH treated with both microorganisms and their combination. Because both strains did not adversely affect the SSDCH odor or flavor, the combination of these strains are proposed for use as starters to inhibit OTA-producing <i>A. westerdijkiae</i>.