The FLEX_SUM.Metabolites sheet in OpenFoodTox 3.0 contains 1373 metabolite records across 421 substances. The vast majority (393/421 = 93%) are pesticide residues (parent substances being fungicides, herbicides, insecticides), but 10 substances are pet-food critical mycotoxins accounting for 51 records (3.7%).
For pet food safety (dogs and cats eating compound feed), the mycotoxin subset is far more important than the pesticide subset — pets consume predominantly cereal-based diets where mycotoxin carry-over is the dominant contamination risk, versus pesticide residues which are more relevant for fresh produce and human food.
Top 10 mycotoxin substances
| Parent SUB (prefix) | Parent name | Metabolites | Pet food relevance |
|---|---|---|---|
| b2ccf083 | Zearalenone (ZEN) | 18 | Estrogenic, causes infertility, vulvovaginitis in female dogs |
| 0b2f1410 | T-2 toxin | 15 | Tritichothecene, immunotoxic; common in stored grain |
| e5a14c83 | HT-2 toxin | 7 | T-2 co-occurring metabolite; EU regulated together with T-2 |
| bc240d5c | Fumonisins (B1+B2+B3) | 2 | Aggregate record; fumonisin B1 most toxic |
| 60ed4f14 | Fumonisin B1 | 3 | Pulmonary edema in pigs, leukoencephalomalacia in horses |
| c884f428 | Diacetoxyscirpenol (DAS) | 2 | Trichothecene sister to T-2 |
| f4fe494b | Fumonisin B2 | 1 | Less toxic than B1 but co-occurs |
| 382b8fb7 | Fumonisin B3 | 1 | Trace component |
| 61e5b4bd | Fumonisin B4 | 1 | Trace component |
| fdf595d1 | Nivalenol (NIV) | 1 | Trichothecene cousin to DON |
| Total | 10 unique substances | 51 records |
T-2 toxin: 15 metabolites (most studied trichothecene)
| # | Metabolite | Notes |
|---|---|---|
| 1 | Modified (masked) forms of T-2 and HT-2 toxins | "Masked mycotoxins" — plant-conjugated forms that escape routine analysis |
| 2 | Neosolaniol | T-2 precursor / metabolite |
| 3 | T-2 toxin-3-alpha-glucose | Glycosylated form |
| 4 | T-2 toxin-3-beta-glucose | Glycosylated form |
| 5 | T-2 toxin-3-glucuronic acid | Phase II mammalian metabolite |
| 6 | T-2 toxin-3-diglucose | Di-glycosylated plant metabolite |
| 7 | T-2 toxin-3-sulfate | Phase II mammalian metabolite |
| 8 | 3-acetyl-T-2 toxin | Acetylated form |
| 9 | 3-feruloyl-T-2 toxin | Phenolic acid conjugate |
| 10 | 19-HO-T2 | Hydroxylated at C19 |
| 11 | T2 Toxin triol | Hydrolysis product |
| 12 | T2-tetraol | Hydrolysis product |
| 13 | T-2 toxin-triol-glucose | Plant conjugate |
| 14 | T-2 toxin-tetraol-glucose | Plant conjugate |
| 15 | Neosolaniol-glucose | Plant conjugate |
Key insight: ~7 of the 15 are masked (glycosylated) forms that are not detected by standard analytical methods (HPLC with UV detection). This is the EFSA-identified risk gap that drove the 2020s shift toward LC-MS/MS multi-mycotoxin methods.
Zearalenone: 18 metabolites (most extensive)
| # | Metabolite | Notes |
|---|---|---|
| 1 | Modified (masked) forms of zearalenone | "Masked" plant conjugates |
| 2 | Zearalanone | Reduced ketone form |
| 3 | Zearalenol alpha | α-isomer; more estrogenic |
| 4 | Zearalanol | Reduced form |
| 5 | Zearalenol beta | β-isomer; less estrogenic |
| 6 | Beta Zearalanol (Taleranol) | Reduced; FDA-banned in US cattle |
| 7 | cis-ZEN (cis zearalenone) | Geometric isomer |
| 8 | cis-alpha-Zearalenol | cis-α |
| 9 | cis-beta-Zearalenol | cis-β |
| 10 | Zearalenone glucopyranosides and sulfates | Masked forms |
Zearalenone has the most diverse metabolite profile because its estrogenic activity depends strongly on stereochemistry (α vs β; cis vs trans). All forms are biologically active to varying degrees, complicating safety assessment.
HT-2 toxin: 7 metabolites
HT-2 is the principal Phase I hepatic metabolite of T-2 — most regulatory limits combine T-2 + HT-2 because they co-occur. The dataset (only 7 records vs T-2's 15) likely covers only direct metabolites since T-2's record absorbs many shared forms.
Fumonisin family (10 metabolites across 5 parents)
| Parent | Records | Notes |
|---|---|---|
| Fumonisin B1 | 3 | Most toxic; IARC 2B carcinogen |
| Fumonisin B2 | 1 | Co-occurs with B1 |
| Fumonisin B3 | 1 | Trace component |
| Fumonisin B4 | 1 | Trace component |
| Fumonisins (B1, B2, B3 aggregate) | 2 | Combined-analysis dossier |
The aggregate "Fumonisins (B1, B2, B3)" parent reflects industry-wide combined fumonisin analysis — most regulations set a combined fumonisin limit for feed, not individual B1 alone.
Critical data quality issue
All 51 mycotoxin metabolite records have ListMetabolites.Metabolites.Remarks = None and MetabolitesInfo.ParentOfMetabolites = None.
OFST 3.0 does not include metabolite Description fields. To get the metabolite description (e.g. concentration, toxicological relevance, plant occurrence), pet food safety assessors must cross- reference external databases or the original dossier publications.
Pet food relevance: regulatory setting
EU pet food mycotoxin limits (Reg 1881/2006, Rec 2006/576/EC for guidance values):
| Mycotoxin | Pet food status |
|---|---|
| Aflatoxin B1 | Banned in pet food (carry-over from feed) |
| Zearalenone | Guidance 2 mg/kg for compound feed |
| T-2 + HT-2 (combined) | Indicative 0.5 mg/kg (EU Rec 2013/165) |
| Fumonisin B1+B2 | Guidance 5 mg/kg for pigs, 50 mg/kg for pets |
| Deoxynivalenol | Guidance 5 mg/kg for pigs/pets |
| Ochratoxin A | 0.01 mg/kg for pigs |
The 18 ZEN metabolites + 15 T-2 metabolites identified in OFT3.0 represent the full analytical target set needed for any comprehensive pet food mycotoxin surveillance program.
Gaps & follow-up
- Critical: OpenFoodTox 3.0 doesn't include
Aflatoxin B1/B2/G1/G2 metabolites (aflatoxin M1 in milk) or Ochratoxin A metabolites — these are covered in EU Regulation 1881/2006 but not in this FLEX_SUM.Metabolites snapshot
- Deoxynivalenol (DON) is also missing from the
top 10 — likely registered under a different SUB entry or in a separate dossier not joined in this scan
- No concentration data in this sheet — for
metabolic pathway kinetic data, look to FLEX_REC.SubstanceComposition or external EFSA opinions
- No human relevance assessment — these records
are substance-level, not exposure-level. Toxicological exposure data lives in FLEX_SUM.ExpectedExposure (only 2 entries in OFT3.0) or in the original EFSA opinion PDFs.
Related topics
EFSA_OpenFoodTox_3_animal_health_tox_studies— 382
toxicology studies on livestock and pets (not metabolite-specific)
RASFF_petfood_*— actual mycotoxin detections in
the European feed and pet food supply chain
FDA_DCM_*— DCM (dilated cardiomyopathy) cases,
some linked to grain-free diets and possible Fusarium-mycotoxin contamination
Source
toxicology/efsa/OFT3.0_export_repository.xlsx sheet FLEX_SUM.Metabolites. 1373 rows scanned; substance classification by name keyword (trichothecene, fumonisin, zearalenone, nivalenol, etc.); T-2 / Zearalenone / HT-2 deep dives by joining metabolite UUID to SUB.ChemicalName for human-readable forms.
Verified 2026-07-20.