Reduced sprouting (respro): novel and natural approaches for sustainable control of potato sprouting during storage

Respro will develop novel approaches to reduce/eliminate traces of toxic anti-sprouting molecules currently used in the potato value chain. Respro strategies are based on: 1) epigenetics, 3) assessment of a new non toxic sprouting inhibitor, 2) combination of pre- and post-harvest treatment.

Storage of potato tubers requires an optimal control of temperature and the use of chemicals to prevent tuber sprouting. Low temperature storage (<5°C) can effectively inhibit potato sprouting but is associated with a phenomenon referred to as cold-induced sweetening (CIS) due to the accumulation of reducing sugars. Accumulation of reducing sugars reacting with amino acids in the so-called Maillard reaction causes the undesirable brown to black pigmentation of fried potato products, as well as the production of the toxic and carcinogen acrylamide, during potato chip and French fry production. CIS is a persistent, costly problem for the potato processing industry. Therefore the potato value chain is extensively using isopropyl 3-chlorophenylcarbamate (CIPC or Chlorpropham), a sprouting inhibitor, to prevent potato sprouting at higher temperature (>8°C). The potential toxicity of CIPC traces recently found on potato peels and potato-based processed food has prompted the potato value chain to investigate alternative routes to control potato sprouting during storage. In the present project, we will take a multiprone approach to develop alternative routes for the control of potato sprouting and to limit/abolish the use of conventional sprouting inhibitor molecules. We propose the following approaches: WP1) Genetics: development of a potato improvement method to reduce the accumulation of reducing sugars in tubers stored at higher temperature (>8°C). Recent works in potato demonstrated that Maillard reaction in stored potato can be significantly reduced by altering either starch degradation pathway or asparagine biosynthesis. For example the silencing of a vacuolar invertase in potato allowed no increase in reducing sugar content after storage at 4°C for 180 days. Noticeably the potato chips processed from silencing lines showed a 15-fold reduction in acrylamide content and lessened Maillard reaction. We propose to use a novel approach to lower the expression of candidate genes in potato tubers by sequence-specific alteration of the epigenome. When successfully implemented, this method would allow a rapid improvement of the low CIS trait in all commercial potato cultivars and a significant reduction in the use of sprouting inhibitors. This novel technology will be developed on the standard varieties of the potato processing industry (eg. cultivars Bintje and Agria). The efficiency of those epigenic modifications in terms of after-cooking darkening control will be compared with the darkening of the few existing varieties dedicated to the crisps or French fries industry and storable at low temperature (eg. cultivar Verdi). WP2) Novel molecules: assessment of new non-toxic and natural molecules with sprouting inhibitor properties. Because of CIPC toxicity, the potato value chain strongly relies on the development and commercial release of new sprouting inhibitor molecules (i.e. mint oil, carvi oil, ethylene associated with 1-methylcyclopropene (1-MCP) and 1,4-dimethylnaphthalene (1,4 DMN)) with no or reduced toxicity. We intend to assess the efficacy of new non toxic molecules, specifically including BIO 024 from Agriphar whose preliminary assessment shows strong sprouting inhibitor activity. If the efficacy of the alternative molecules is not equivalent to CIPC, these tuber treatments could be supplemented with reduced doses of CIPC to meet the requirement of the potato value chain. We will also develop storage management techniques to optimize the use and efficacy of BIO 024 and other new sprouting inhibitors. WP3) Combination of foliar and tuber treatment products: test of combined pre-harvest and post-harvest tuber applications of respectively, maleic hydrazide (MH), BIO 024 and the most efficient alternative(s) to CIPC identified in WP2. Pre-harvest application of MH is instrumental to reduce potato sprouting, though not sufficient to block sprouting during prolonged storage periods (>3-4 month). Nevertheless, this product allows a higher flexibility in the management of potato storage. The entry of the harvested potato in the storage chambers starts in September and ends in November. During this period, it is difficult to maintain the storage temperature due to the repeated opening and closing of the storage chambers. Once the storage chambers are full, then the temperature can be controlled and treatment with sprouting inhibitor is initiated for storage of potato exceeding 3-4 months. WP4) Registration file and patents: Elaboration and submission of the registration file for BIO 024 as well as continuation of the patent application Either solo application of BIO 024 and other candidates defined in WP2 or in combination with MH should lead to a significant reduction in the application of CIPC in the potato value chain. Provided an efficacy equivalent to CIPC, the aforementioned treatments alone or in combination could evolve into the implementation of a CIPC-free treatment to control sprouting.
Project ID: 
9 894
Start date: 
Project Duration: 
Project costs: 
1 120 000.00€
Technological Area: 
Agricultural technology
Market Area: 
Food and Beverages

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