Real-Time CO2 Production Monitoring in Stored Oats as an Indicator of Type A Trichothecenes and Ochratoxin A Contamination Under Simulated Environmental Conditions.

Abstract

Grain industries are interested in an integrated approach to in-silo grain quality and safety management using carbon dioxide (CO₂) measurement with temperature and moisture monitoring. Our study investigates if CO₂ production could predict mycotoxin production (T-2 toxin, HT-2 toxin, its glucoside, and ochratoxin A (OTA)) and identify storage conditions exceeding legislative limits in stored oats for the first time. The influence of water activity (a_w) levels (0.70-0.95 a_w), temperature (15 and 20 °C), and storage duration on (a) Fusarium populations, (b) CO₂ respiration rates (RRs), and (c) mycotoxin concentrations in stored oats was examined. One hundred and twenty samples were analysed for multiple mycotoxins by LC-MS/MS. Substantial differences were found in the RRs of oats at ≥0.90 a_w at both temperatures. A moderate positive correlation between CO₂ and mycotoxins was noticed and mycotoxins exceeded their limits at ≥0.90 a_w (22% moisture content) when RR ≥ 25 µg CO₂ kg^-1 h^-1. This knowledge forms the basis for developing decision support systems for improving oats' storage management.