Mechanisms underlying the effect of commercial starter cultures and a native yeast on ochratoxin A production in meat products

Abstract

Processed meat products are of worldwide importance, but they are highly prone to fungal and ochratoxin A (OTA) contamination. In previous studies, several Lactic Acid Bacteria (LAB) and yeasts have been tested as biocontrol agents against P. nordicum growth and OTA production in meat products, with promising results. However, A. westerdijkiae has been poorly studied for this matrix.The aim of this work was to evaluate in vitro the mechanisms underlying the effects of a commercial starter culture and of a meat-native Candida zeylanoides strain on the growth and OTA production of P. nordicum and A. westerdijkiae, by co-culture in ham and sausage-based media under different conditions.In ham medium, C. zeylanoides live cells, cell broth and diffused compounds significantly inhibited OTA production by P. nordicum, but live cells of the starter culture significantly increased it. For A. westerdijkiae strong and significant stimulation was observed by direct contact in both media.In conclusion, ochratoxigenic fungi do not all respond to antagonistic microorganisms in the same way. This study sheds some light on the mechanisms behind the different effects of microorganisms.

Selection and Evaluation of Staphylococcus xylosus as a Biocontrol Agent against Toxigenic Moulds in a Dry-Cured Ham Model System

“…Moreover, some stressful conditions seem to stimulate secondary metabolism with the consequent increase of mycotoxin production [10,55]. In fact, fungal secondary metabolism is strongly stimulated by sub-optimal conditions like nutrient depletion or metabolites produced by other organisms [56]. Nevertheless, this phenomenon only occurs in P. nordicum Pn856 at 25 • C at the lowest concentration tested of S. xylosus Sx8, but not at any other temperatures, nor for other P. nordicum strains, when an outstanding reduction in OTA amount was recorded.…”

A Review of Ochratoxin A Occurrence, Condition for the Formation and Determination Methods

“…Number of studies finding report indicate that Ochratoxin A was existed in several processed and unprocessed food stuffs, species and different alcoholic beverage. For instance, in cereal, milk, meat and species [12][13][14][15] in alcoholic beverage such as beer and wine [16,17]. Likewise, some dried fruit and coffee was infected by Ochratoxin A in [17,18].…”

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

“…Nevertheless, in some cases, the use of short seasoning times can cause high moisture levels on the surface of the hams, which has detrimental effects, such as the growth of ochratoxin A (OTA)-producing molds. Several authors demonstrated the presence of OTA in meat products, due to the ability to grow on the surface of meat products of numerous fungi ( Penicillium verrucosum, P. nordicum, Aspergillus ochraceus, and A. westerdijkiae ) during seasoning and storage producing OTA [ 1 , 13 , 17 , 18 ]. Recently, small-scale or artisanal lots of SSDCH or meat products were contaminated with A. westerdijkiae [ 16 , 19 , 20 ].…”

“…10-93 09/06/1999). Consequently, it is essential to advance in efficient strategies to eliminate the risk [ 18 ]. For food detoxification purposes, chemical, physical, and biological approaches have been used [ 25 , 26 ], but they resulted in a failure to remove OTA due to its high stability [ 27 ].…”

“…The most realistic and interesting method is the use of bioprotective cultures, which is based on the antagonistic activity of autochthonous yeast and LAB species against molds [ 26 ]. Several studies [ 1 , 16 , 18 , 28 , 29 , 30 , 31 , 32 ] have evaluated the ability of autochthonous yeast to protect meat products against mold growth. In particular, D. hansenii and Candida famata were identified as the primary yeasts present in meat products from the early stage of seasoning to the end, when it becomes the predominant strain [ 3 , 33 , 34 , 35 , 36 ].…”