Ochratoxin A Control in Meat Derivatives: Intraspecific Biocompetition betweenPenicillium nordicumStrains

Abstract

APenicillium nordicumstrain previously assessed for its atoxigenicity was tested against a toxigenic strain of the same species on salami, in order to assess its effectiveness as a biocontrol agent for OTA containment. Sixtysalamiwere inoculated with different combinations ofP. nordicumOTA−/OTA+ suspensions and ripened under controlled thermohygrometric conditions. After 7, 18, 29, and 40 days, both fungal counts and chemical analyses were carried out on casings. OTA was never found insalamiused as a control, while it was occasionally detected in traces (0.08–0.76 μg/kg) insalamiinoculated with the atoxigenicP. nordicumstrain. It was otherwise detected at levels varying from 2.84 to 15.85 μg/kg in coinoculated salami and from 48.66 to 177.79 μg/kg insalamiinoculated with the toxigenicP. nordicumstrain. OTA levels detected when coinoculation occurred were 91.1%, 85.8%, and 94.2% lower than those found in samples inoculated with the toxigenic strain, respectively, after 18, 29, and 40 ripening days. Biocontrol approach using intraspecific competition proved very effective in reducing both settlement of toxigenic strains and OTA contamination and could be therefore considered an interesting strategy to avoid OTA contamination in moulded meats, if used in association with fungal commercial starters.

Ochratoxin A in Slaughtered Pigs and Pork Products

“…P. nordicum is a psychrotrophic fungi and widely distributed contaminant in various meat products [70][71][72][73][74]. It is considered an important OTA producer in dry-cured ham and dry-cured fermented sausage [24,28,70,[75][76][77][78]. The ability of P. nalgiovense, P. chrysogenum, P. olsonii, P. solitum and P. salamii to produce OTA in dry meat products has been reported in previous studies [50,79].…”

“…The occurrence of OTA in contaminated meat products may also be due to the growth of OTA-producing fungi in these products [26][27][28][29][30]94]. Surveys in ham-manufacturing plants revealed that OTA toxigenic strains of Aspergilli and Penicillia were present in the ripening rooms [98,189].…”

“…The contamination of pork meat/edible offal with OTA is mainly derived from the consumption of OTA-contaminated feed by the pigs [24,25]. Additionally, the presence of OTA in pork meat products (ham muscle, cured meats, salami or dry-cured ham) could be derived from the direct growth of OTA-producing fungi, such as Penicillium nordicum and Penicillium verrucosum [26][27][28][29][30], or from the addition of OTA-contaminated materials such as contaminated spices [31,32].…”

Molecular and HPLC-based approaches for detection of aflatoxin B1 and ochratoxin A released from toxigenic Aspergillus species in processed meat

“…Until now, both European and American regulations didn’t set an international legal limit of ochratoxin A in meat and meat products. Only Italy set the legal limit of ochratoxin A as 1 μg/kg meat [ 56 , 57 ].…”

Insights into existing and future fungal and mycotoxin contamination of cured meats

“…PgAFP-producing P. chrysogenum RP42C was also demonstrated to preserve ham from OTA occurrence, for up to 9 months, with respect to other mixtures of selected autochthonous non-toxigenic moulds [8]. An almost atoxigenic P. nordicum strain [84], was also shown to reduce OTA accumulation by 90% on salami when co-inoculated with a toxigenic P. nordicum strain. However, it should also be noted that commercial meat starter cultures of bacterial origin and autochthonous yeasts exert varying responses, sometimes stimulating growth and OTA production by A. westerdijkiae and P. nordicum in different meat-based media [85].…”