Isolation and characterization of microorganisms and volatiles associated with Moroccan saffron during different processing treatments

Saffron may be spoiled by a variety of microorganisms during cultivation, harvesting, and post harvesting. As
saffron can be dried and stored in different ways, this preliminary study explored the natural microbiota present
in Moroccan saffron when subjected to different drying techniques. An analysis of the carotenoid-derived volatiles
present in the saffron was also carried out. The culturable microbiota of the saffron samples dried using
different methods, namely in the shade (also called natural), in the sun, or in the oven, were studied using
classical and molecular approaches. The effect of the drying methods on head-space chemical volatiles was also
determined. Eighty-two isolates grown in the different culture media were chosen from the colonies, and genotype
analysis grouped the microorganisms into 58 clusters, revealing a wide diversity. Out of the 82 isolates, 75
belonged to the Bacillaceae family. The other isolates were distributed within the Dietziaceae, Paenibacillaceae
and Carnobacteriaceae families. The dominant species was Bacillus simplex, which was detected in all samples,
regardless of the drying method used. Lysinibacillus macroides was dominant in the sun-dried saffron. No pathogens
were isolated, but an isolate belonging to Dietzia maris, a potential human pathogenic species, was
detected. The biodiversity indexes were linked to the drying method and generally decreased as the intensity of
the treatment increased. The results of this preliminary work show that the different drying methods strongly
influenced the microbiota and affect the saffron volatile profile. Further analysis will be needed to determine
possible effects of selected microbiota on saffron volatiles.