Grapes and their derivatives – wine, sparkling wine and juice – are among the most loved and consumed drinks in the world. But how safe are they from the point of view of mycotoxin contamination?
The answer is an investigation conducted by the CVUA Sigmaringen, the German Chemical and Veterinary Investigation Office, which from 2019 to the end of 2025 analyzed 203 samples of wine, sparkling wine and grape juice to verify the presence of these toxins. We immediately specify that the researchers do not report the geographical origin of the samples, simply indicating that they are products available on the European market. We therefore do not know if Italian wines or juices were present in the test.
Mycotoxins: what they are and why they are worrying
Mycotoxins are toxic substances produced by different species of mold, secondary metabolites that can be harmful to humans and animals even at low concentrations.
The main problem lies in their stability, in fact they resist normal food processing processes and can therefore be found in finished products even when the grapes have been contaminated during cultivation, conservation or transformation.
When molds attack plants in the fields or foods during processing, under certain environmental conditions they produce these substances which enter the food chain as unwanted contaminants. In the case of grapes, if the fruit becomes infested, mycotoxins can be found in wine, sparkling wine and derived juices.
The results of the investigation
The data that emerged from the analysis of 109 samples of wine and sparkling wine and 94 samples of grape juice are significant: approximately 80% of the products contained detectable mycotoxins. Specifically, 81% of grape juices and almost 82% of alcoholic beverages had traces of contamination.
The most frequently detected toxins were those produced by fungi of the Alternaria genus, in particular tenuazonic acid (TEA) and alternariol (AOH). Many samples were contaminated with both toxins simultaneously. Other Alternaria toxins such as AME, Tentoxin and Altenuen have only been found in exceptional cases.
Alongside Alternaria toxins, the investigation also looked for ochratoxin A, a mycotoxin known for its renal toxicity and classified as possibly carcinogenic to humans based on effects observed on animals.
The good news is that ochratoxin A was found in less than 5% of the samples analyzed, and in all cases the levels were well below the maximum limits established by European legislation (EU Regulation 2023/915). These values were therefore not considered problematic for the health of consumers.
Alternaria toxins: the big question
The real crux of the matter concerns Alternaria toxins. Unlike ochratoxin A, there are still no maximum limits established by European law for these substances, mainly due to the lack of data on their toxicity for humans and animals and on their actual presence in foods.
The levels found in the investigation were nevertheless reassuring: AOH was always found at concentrations lower than 10 µg/kg, while TEA reached a maximum of around 140 µg/kg, with over 90% of the values lower than 25 µg/kg. These levels are predominantly lower than the guide values established for other foods, exceeding which would require an investigation into the causes.
Even in the absence of specific legal limits, the philosophy that guides European food safety is that of the ALARA (As Low As Reasonably Achievable) principle, which aims to maintain the presence of contaminants at the lowest level reasonably achievable.
The existing guide values for some specific foods – although not yet for grapes and their derivatives – serve precisely this purpose: when they are exceeded, an investigation is activated to identify and correct the factors that have led to high concentrations of toxins.
Towards European regulation
The importance of surveys such as that of the CVUA Sigmaringen lies precisely in the systematic collection of data. The German laboratory, which has included Alternaria toxins in its test methods, regularly submits results to the German federal government and the European Union.
This monitoring activity is fundamental to build a solid knowledge base that will allow, in the future, to develop specific legislation at European level and to implement adequate risk assessments to protect consumer health.
CVUA Sigmaringen has announced that it will continue the investigation by extending it to other products. In the meantime, consumers can rest relatively calm: despite being present, the mycotoxins in the wines and grape juices analyzed did not exceed the legal limits for regulated substances and remain at generally low levels even for toxins still under study.
