{"hq_id":"hq-p-fod-000124","name":"Fermented Plant Protein — Koji and Tempeh (Mycotoxin Risk, Biogenic Amines, Acrylamide Trace from Processing)","category":{"primary":"food_safety","secondary":"fermented_protein","tags":["koji","tempeh","Aspergillus oryzae","Rhizopus oligosporus","fermentation","mycotoxin","aflatoxin","biogenic amine","histamine","tyramine","acrylamide","fermented","soy","grain"]},"product_tier":"FOD","overall_risk_level":"low","description":"Koji (Aspergillus oryzae-fermented grain) and tempeh (Rhizopus oligosporus-fermented soybean) represent traditional fermented protein sources with millennia of safe use in Asian cuisines, now experiencing rapid growth in Western markets as both ingredients and standalone protein sources. The safety profile of these products depends critically on strain purity and fermentation control. A. oryzae is classified as GRAS by FDA and is taxonomically close to A. flavus (the primary aflatoxin producer), but domesticated koji strains have lost functional aflatoxin biosynthetic gene clusters through millennia of selective cultivation. However, contamination with wild-type Aspergillus during home fermentation or inadequately controlled commercial production can introduce aflatoxin-producing strains. Tempeh fermentation with R. oligosporus is generally safe, but improper temperature control (>35C) can allow growth of contaminating Bacillus cereus or Burkholderia gladioli, which have caused fatal foodborne outbreaks in Indonesia (bongkrekic acid from B. gladioli — a potent mitochondrial toxin). Biogenic amine accumulation (histamine, tyramine, putrescine) increases with fermentation duration and can trigger pseudo-allergic reactions in sensitive individuals. Thermal processing of fermented soy products generates trace acrylamide through asparagine-sugar Maillard reactions.","synthesis":{"derived_risk_level":"severe","synthesis_confidence":0.757,"synthesis_method":"compound_composition","context_used":"human_child","context_source":"product_users","exposure_modifier":1,"vulnerability_escalated":true,"escalation_reason":"Child exposure group","compounds_resolved":1,"compounds_total":1,"synthesis_date":"2026-05-09","synthesis_version":"1.2.0","methodology_note":"exposure_modifier and adjusted_magnitude are computed from ALETHEIA-calibrated heuristics (route × duration × frequency multipliers, clamped to [0.5, 1.4]). Multipliers are directionally informed by EPA Exposure Factors Handbook (2011) and CalEPA OEHHA but are not regulatory consensus. See /api/methodology for full disclosure."},"hazard_summary":{"sensitive_populations":"home fermenters without training (contamination risk), individuals on MAO inhibitor medications (tyramine interaction), histamine-intolerant individuals, immunocompromised consumers","overall_risk":"low","primary_concerns":["Home fermentation contamination: wild Aspergillus (aflatoxin) or Burkholderia gladioli (bongkrekic acid — potentially lethal)","Biogenic amines (histamine, tyramine) accumulate with extended fermentation duration","Trace acrylamide from thermal processing of fermented soy products","Tempeh bongkrek (coconut-based) historically linked to fatal food poisoning outbreaks"],"exposure_routes":"Ingestion (sole route — consumption of fermented plant protein products)."},"exposure":{"routes":["ingestion"],"contact_types":["ingestion_direct"],"users":["adult","child"],"duration":"chronic","frequency":"weekly","scenarios":["Consumer eating commercially produced tempeh and koji — well-controlled fermentation, minimal risk","Home fermenter producing tempeh without temperature control — Bacillus cereus or Burkholderia gladioli contamination risk","Individual sensitive to biogenic amines consuming aged koji or long-fermented tempeh — histamine/tyramine reaction","Consumer of imported fermented soy products from unregulated production facilities"],"notes":"Aspergillus oryzae safety: GRAS (FDA), QPS (EFSA). Aflatoxin gene cluster: present but non-functional in domesticated A. oryzae strains (loss of functional aflR regulator). Risk scenario: wild Aspergillus contamination during home/artisanal fermentation. Tempeh outbreaks: Indonesia has documented >100 bongkrekic acid fatalities from contaminated tempeh bongkrek (coconut residue tempeh) — Burkholderia gladioli produces bongkrekic acid at >25C, lethal dose ~1 mg for adults. Standard soybean tempeh: lower risk than coconut-based tempeh. Biogenic amines: histamine (>100 mg/kg triggers symptoms in sensitive individuals), tyramine (MAO inhibitor interaction risk), putrescine. Acrylamide: asparagine + reducing sugars at >120C; detectable in fried/roasted tempeh at 10-80 ppb."},"consumer_guidance":{"usage_warning":"Purchase commercially produced koji and tempeh from reputable manufacturers with controlled fermentation conditions. If fermenting at home, use verified starter cultures from reputable suppliers, maintain strict temperature control (30-32C for tempeh), and discard any batches showing unexpected colors (green, black, or yellow mold indicating contamination). Individuals on MAO inhibitor medications should limit fermented food consumption due to tyramine content. Do not consume tempeh that smells off or has slimy texture.","safer_alternatives":["Commercially produced tempeh with verified starter cultures and batch testing","Pasteurized miso (lower biogenic amine content than raw/aged varieties)","Fresh tofu (non-fermented soy protein, no biogenic amine concern)","Natto from verified production (Bacillus subtilis — well-characterized safety)"]},"regulatory":{"applicable_regulations":[{"jurisdiction":"USA","regulation":"FDA GRAS Status for Aspergillus oryzae and Fermented Soy Products","citation":"21 CFR 184.1985 (A. oryzae enzyme preparations GRAS); FDA GRAS for traditional fermented soy foods","requirements":"A. oryzae fermentation products have GRAS status for food enzyme production. Tempeh and koji sold as food fall under general FSMA requirements. No specific fermentation safety standards for artisanal/home production. Indonesia BPOM regulates tempeh production with mandatory aflatoxin and microbiological testing.","compliance_status":null,"effective_date":null,"enforcing_agency":"FDA CFSAN","penalties":null,"source_ref":null}],"certifications":[],"labeling":{"required_disclosures":[],"prop65_warning":{"required":null,"chemicals":[],"endpoint":null,"notes":null},"ghs_labeling":{"required":null,"signal_word":null,"pictograms":[],"hazard_statements":[],"notes":null},"hidden_ingredients":{"trade_secret_protected":null,"categories_hidden":[],"estimated_count":null,"known_concerns":null,"notes":null},"notes":null},"recalls":[],"regulatory_gap":null,"notes":null},"lifecycle":{"recyclable":true,"disposal_guidance":"Dispose of expired fermented products in compost or regular trash. Discard any product showing signs of unwanted mold growth.","hazardous_waste":false,"expected_lifespan":"5-7 days refrigerated for fresh tempeh; koji rice 6 months dried"},"formulation":{"form":"varies","key_ingredients":[],"certifications":[]},"materials":{"common":[],"concerning":[],"preferred":[]},"compound_composition":[{"hq_id":"hq-c-org-000013","compound_name":null,"role":"processing_byproduct","typical_concentration":"trace acrylamide from Maillard reaction during thermal processing of fermented soy; typically <50 ppb in finished tempeh/koji products"}],"identifiers":{"common_names":["fermented plant protein — koji and tempeh (mycotoxin risk, biogenic amines, acrylamide trace from processing)"],"aliases":[],"manufacturer":null,"brands":[]},"brand_examples":[],"brand_examples_disclaimer":null,"sources":[{"type":"expert_curation","name":"ALETHEIA Safety Database","date":"2026-03-26"}],"meta":{"schema_version":"4.0.0","last_updated":"2026-03-26","timestamp":"2026-05-13T22:22:04.794Z"}}