QC Deep-dive: Preventing Salmonella in cashews — the most critical step in the supply chain

• Cashews are eaten raw (or lightly roasted) — unlike meat (cooked ≥75°C which kills pathogens)
• Survives dry environments — Salmonella persists for months in dry cashew kernel
• Low infectious dose — as few as 10–1,000 CFU can cause infection (very low threshold)
• Public health risk: causes diarrhea, fever, dehydration; particularly dangerous for children, elderly, and the immunocompromised

• 2012 — Sunland Inc: largest US peanut/nut recall; Salmonella Bredeney; >250 reported illnesses
• 2014 — Trader Joe's Tiny Triangle Organic Cashews: multi-state recall
• 2015-2020 — multiple Costco/BJ's recalls covering cashew + nut mixes
• Pattern: most driven by post-roast contamination (not raw) or kill-step validation failure

Salmonella has over 2,500 serotypes. Those documented in cashew recalls include:

• Salmonella Typhimurium
• Salmonella Bredeney
• Salmonella Enteritidis
• Salmonella Newport

Source: contamination from raw material (bird/rodent waste on farms), equipment cross-contamination, or post-processing handling.

Per FDA 21 CFR 117 (FSMA Preventive Controls), every ready-to-eat cashew must have a validated kill step — verified to achieve at least 5-log reduction (100,000×) of Salmonella.

Common kill-step methods:

1. Steam pasteurization: controlled pressure + temperature (common for raw cashew processors)
2. Dry roasting: 150-175°C for 15-25 minutes — validated
3. Oil roasting: 170-180°C for 5-10 minutes
4. PPO (Propylene Oxide) fumigation: used in some US facilities; uncommon in Asia because EU does not permit it

Inbound (raw cashew arrival)

• ☐ Environmental swab test at incoming storage (container floor, pallets)
• ☐ Random 250 g sample per lot for preliminary Salmonella test (qPCR method)
• ☐ Log lot with traceability code

Processing (partner factory)

• ☐ Validated kill step documented — temperature + time log
• ☐ Equipment sanitation schedule: daily hot-water rinse, weekly deep clean
• ☐ Zone separation: raw zone ≠ ready-to-eat zone (physical barrier, separate PPE)
• ☐ Airflow: positive pressure in the RTE zone

Outbound (pre-shipping)

• ☐ Lot-level Salmonella test — ISO 6579 method, accredited lab
• ☐ Certificate of Analysis attached (standard: n/c = negative per 25 g sample, 5 samples per lot)
• ☐ Time-temperature log during shipping (if buyer requires refrigerated transport)

You (the buyer) should ask every supplier these six questions:

• ☐ Q1: What is your validated kill step? (request a copy of the validation study)
• ☐ Q2: What test method do you use? (ISO 6579 is the standard — enriched PCR is also acceptable)
• ☐ Q3: Test frequency? (per lot is the minimum; random-batch testing is a red flag)
• ☐ Q4: Name of accredited lab + ISO 17025 certificate?
• ☐ Q5: Post-roast Salmonella testing (not only raw)?
• ☐ Q6: Environmental monitoring programme (EMP)?

If the supplier cannot answer all six → change supplier.

Rare, but if Salmonella is detected:

1. Hold the lot — do not ship
2. Investigate the source: raw material, equipment, personnel
3. Corrective action: re-sanitize, re-validate the kill step
4. Re-test after the corrective action
5. Dispose if remediation is not possible; re-process (additional kill step) if feasible
6. Document in the CAPA (Corrective and Preventive Action) log

Hotanuts has never had a positive-Salmonella shipment — but we maintain a CAPA protocol ready to deploy.