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

Abstract

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 Eurotium spp. and Penicillium 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 Aspergillus ochraceus and Penicillium nordicum, can simultaneously grow and produce ochratoxin A (OTA). Consequently, these dry-cured hams may represent a potential health risk for consumers. Recently, Aspergillus westerdijkiae has been isolated from SSDCHs, which could represent a potential problem for consumers. Therefore, the aim of this study was to inhibit A. westerdijkiae using Debaryomyces hansenii or Lactobacillus buchneri or a mix of both microorganisms. Six D. hansenii and six L. buchneri strains were tested in vitro for their ability to inhibit A. westerdijkiae. The strains D. hansenii (DIAL)1 and L. buchneri (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 A. westerdijkiae 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 A. westerdijkiae.

Debaryomyces hansenii Is a Real Tool to Improve a Diversity of Characteristics in Sausages and Dry-Meat Products

“…Additionally, a decrease in OTA production and accumulation in food due to the presence of D. hansenii has been reported [ 90 , 91 , 95 , 100 ]. Very recently, the effect of D. hansenii on A. westerdijkiae ochratoxin A production and growth has been also described [ 101 ], however, it is important to mention that when a starter culture containing bacteria plus D. hansenii was co-inoculated with A. westerdijkiae or P. nordicum in meat-based media, OTA production was stimulated indicating possible unforeseen safety problems [ 102 ]. These findings are an important wake-up call regarding the need for specific studies in each case and, in fact, very recently new information indicating that D. hansenii reduced the OTA levels produced by P. nordicum in dry-meat products has been provided [ 99 ].…”

Ochratoxin A in Slaughtered Pigs and Pork Products

“…[80]. The occurrence of A. westerdijkiae has already been described in various meat products in many countries worldwide [30,[81][82][83], and its growth was associated with the presence of the OTA toxin in dry-cured meat products [84][85][86]. A. ochraceus was detected in OTA-contaminated sausages [75] or dry cured ham [27,76].…”

Ochratoxin A in Dry-Cured Ham: OTA-Producing Fungi, Prevalence, Detection Methods, and Biocontrol Strategies—A Review

“…The biopreservation ability of different LAB strains on coffee, fruits, and vegetables has been demonstrated [ 72 , 73 , 74 ]. Only Iacumin et al [ 75 ] reported Lactobacillus buchneri and D. hansenii as potential biological preservatives that could be used to inhibit OTA production by A. westerdijkiae in dry-cured hams. Nevertheless, there is a lack of studies on antifungal LAB against OTA in dry-cured hams.…”

“…To our knowledge, only short-seasoned dry-cured hams have been evaluated for the effect of D. hansenii and L. buchneri as biological agents on the sensorial acceptability of ham. The results showed no sensorial differences between the biocontrol treatment group and the control group [ 75 ]. Iacumin et al [ 78 ] explored the inhibitory activity of yeast on OTA production during speck production, and performed a sensory analysis.…”