Mycoflora and Mycotoxicological Quality of Four Freshly Harvested Paddy Rice Cultivars and Relation with Harvest to Industry Reception Timing

Abstract

Grain quality and safety of four freshly harvested paddy rice (Oryza sativa L.) cultivars (Epagri 109, SCS 114 Andosan, Tio Taka 113 and Epagri 115 CL) grown under irrigation system in the north of Santa Catarina State, Brazil were studied. The quality parameters evaluated were mycoflora, mycotoxins (aflatoxins, ochratoxin A and zearalenone), water distribution (moisture content and water activity) apart from environmental conditions (relative humidity and temperature) and the relation between harvest and the industry reception timing. All cultivars presented an average waiting time of 8.6 h (ranged from 0.3 to 24.9 h), a total fungi load of 8.6×104 cfu/mL (ranged from 1.8×103 to 9.4×105 cfu/mL) with a rather high humidity condition of 19.0% moisture content (varied from 14.9% to 24.5%) and 0.92 water activity (varied from 0.78 to 0.99) under the average environmental conditions of 87.3% relative humidity (varied from 80.0% to 96.8%) and 25.4 °C (varied from 22.5 to 27.5 °C), respectively. The conditions to which the samples were submitted allowed fungal growth, but no mycotoxins were detected. Regarding the rice cultivars fungal genera isolated, Aspergillus and Penicillium were the most often isolated among all the cultivars and variation on fungi distribution among them was not observed. Moreover, it was not found a correlation of the grain loading & unloading time with the humidity conditions and the total fungi load. Furthermore, all results and the importance of monitoring the rice mycotoxicological quality and safety were discussed.