Biocontrol sheet: Membrane and method for the preservation of Agricultural produce
Postharvest table grapes are susceptible to fungal infection even when stored at the optimal temperature of −0.5°C. The most important pathogen of stored Table Grapes is grey mould, which is caused by Botrytis cinerea. Some countries fumigate their grapes with sulphur dioxide gas. However, if the grapes are going to be transported over long distances, this method is not practical.
Sulphur Dioxide (SO2) generating pads were developed to facilitate the transportation and postharvest storage of table grapes, for periods of up to four months. Sulphites released from SO2 are a major concern and there is ongoing research to find alternatives. The responsible use of SO2 is currently the only commercially viable method of storing and transporting of table grapes. In most western countries, sulphite residues must be <10 ppm. In some countries (notably Germany) the residues must be as low as <5 ppm. Certain grape cultivars are sensitive to SO2, resulting in SO2 bleaching, which is undesirable from a consumer point of view. SO2 pads are also sensitive to increases in temperature, which can result in elevated sulphite residues and bleaching.
To address this challenge, the Agricultural Research Council (ARC) in collaboration with the Council for Scientific and Industrial Research (CSIR) have developed and patented novel essential oil-based controlled release sheets that can replace SO2 gas. These sheets have a similar fungal control efficacy but without the negative effects associated with the use of SO2. The novel formulation is efficacious without blemishing the fruit or affecting its taste or aroma.