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Essential oils as antigerminants in potato storage

October 9, 2012 – One of the critical moments in the final quality of potatoes occurs during storage, where the risk of sprouting or rotting due to pathogenic agents, such as bacteria and fungi, can occur. In order to avoid this, agricultural engineer David Gómez Castillo carried out research for his PhD on the possibility of substituting chemical products, currently used to treat tubers, with essential oils of mint, caraway, coriander, eucalyptus and clove.

The chemical product Clorprofam (CIPC) is the most commonly used as a sprout suppressant on stored potatoes. Nevertheless, possible reductions in permitted dosages, market and consumer pressures seeking healthier and more environmentally-friendly products have made it necessary to find alternatives to these synthetic products.

David Gómez Castillo studied the effect of applying essential oils of mint, caraway, coriander, eucalyptus and clove with both table stock varieties (Agata and Monalisa) and processing varieties (Agria and Kennebec), and compared the results with potatoes that had been treated chemically.

The research analyzed two parameters: the commercial quality (germination, texture and colour of the tuber) and the culinary and technological quality (colour and texture of slices of the potato, dry material, total soluble solids, reductor sugars and sensorial analysis). Evaluations at 10, 25, 40, 55 and 70 days in storage were also undertaken to assess the antimicrobial effect of the essential oils.

“We found a high antigerminant capacity with treatment using the essential oil of coriander for industrial crops, and with the essential oil of mint for both industrial and table-stock crops,” said Gómez. “These showed great inhibitory potential on the principal phytopathogenic problems studied and all this makes a good alternative to CPIC use for storage of potatoes.”

The essential oil of eucalyptus also showed a high antigerminant capacity with table-stock potatoes and “could be another alternative for reducing post-harvest losses due to phytopathogenic problems, obtaining even better results if the treatment is accompanied by the essential oil of clove.”

The use of treatment with essential oils in the storage of potatoes “can provide added value in the application of antigerminant treatment, due to its efficacy in controlling the progress of important phytopathogens,” said Gómez.