Cold-Chain Integrity Logging for Agricultural DPPs — IoT Sensor Hashing

South Africa exports over 150 million cartons of citrus annually, making it one of the world's largest citrus exporters. Maintaining cold-chain integrity from the Eastern Cape packhouse to the Rotterdam cold store is critical for product quality and EU market access. Cold-chain integrity logging uses IoT sensors and SHA-256 hashing to create tamper-proof temperature records that satisfy EU Food Safety Regulation 178/2002 and PPECB certification requirements.

The Cold-Chain Integrity Architecture

A complete cold-chain integrity system for South African citrus exports consists of four components:

1. IoT temperature loggers — Wireless sensors placed in each pallet or container that record temperature every 15 minutes throughout the journey.
2. GPS location tracking — GPS coordinates recorded alongside temperature data, creating a location-stamped temperature log.
3. Data aggregation and hashing — Temperature and GPS data is aggregated into a JSON package and hashed using SHA-256 at the end of each leg of the journey.
4. DPP integration — The SHA-256 hash of the temperature log is included in the agricultural DPP passport, creating a tamper-proof cold-chain record.

PPECB Certification Integration

PPECB (Perishable Products Export Control Board) inspectors verify cold-chain compliance at South African packhouses and ports. PPECB issues a phytosanitary certificate for each consignment, confirming that the product meets the importing country's phytosanitary requirements. The PPECB certificate is included in the DPP passport as a SHA-256 hashed document.

EU Food Safety Regulation 178/2002 Requirements

EU Regulation 178/2002 requires food business operators to maintain traceability records that enable the identification of any person who has supplied a food product. For South African citrus exporters, this means:

• Recording the farm of origin (GPS coordinates)
• Recording the packhouse where the fruit was processed
• Recording the cold store where the fruit was held before export
• Recording the vessel and container number for sea freight
• Maintaining temperature logs for the entire journey

The National DPP Registry's Agriculture DPP minting process captures all of these data points and generates a single, SHA-256 hashed record that satisfies EU Regulation 178/2002 traceability requirements.