Page 27 - CSHS 2022 Book of Abstracts - 2022-08-22 web version

CSHS 2022 Conference

(FP.5) Antifungal potential of squalene and reuterin for the inhibition of phytopathogenic molds
in cold-stored strawberries
Yasmine Lamri , Ismail Fliss , Arturo Duarte Sierra
1,2
1,2
1*
1. Food Science Department, Food and Agriculture Faculty, Laval University, Quebec, QC; 2. Institute of Nutrition and
Functional Foods, Laval University, Quebec, QC
________________
Maintaining the microbiological and physical quality of strawberries during the post-harvest stage has been a real
challenge for years. The use of fungicides at post-harvest is the most efficient approach until now, with most of them
being of chemical origin, and therefore subject to strict regulations (i.e., maximum residue limit). The possibility of
replacing these chemical fungicides with natural based fungicides is relevant from a compliance standpoint. The
objective of this study is to validate the antifungal potential of reuterin and squalene, and to compare both with a
commercial fungicide (i.e. fludioxonil) by in vitro and in vivo tests on Botrytis cinerea, Colletotrichum acutatum,
Rhizopus stolonifer and Penicillium expansum. Minimum inhibitory concentrations (MIC) and fungicides were
determined. In addition, the effects on texture, color, total soluble solids, titratable acidity, weight loss and visual
quality of treated strawberries were analyzed after 10 d of storage at 4 °C/ 90-95 % RH. Squalene at 2000 mM was
not effective in vitro. Conversely, reuterin at 187.26 mM and fludioxonil at 5 mM displayed a fungicidal effect on all
four strains. Reuterin was also effective in vivo at 50 mM since a significant reduction (p=0.003) of spores was
observed at this concentration. The spore decline was 3 log CFU mL-1 on strawberries inoculated with both Botrytis
cinerea and Colletotrichum acutatum. Furthermore, the applied reuterin concentration did not affect any of the
quality parameters measured in the strawberries. These observations may pave the way for the use of reuterin as a
new post-harvest biofungicide.

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