Natural antimicrobial agents as replacement for SO2 in table grapes
Botrytis cinerea causes pre- and post-harvest losses of table grapes. Therefore, inhibiting its growth during storage and transportation is an important aspect in assuring the quality of table grapes at the selling point. To inhibit Botrytis growth, table grapes are stored and transported at low temperatures. Sulphur dioxide (SO2) is used as the main additional post-harvest control of pathogen infection. However, SO2 is under pressure from the legislative authorities and will possibly be removed from the 'Generally Regarded As Safe' (GRAS) list. EC-PACK is developing an environment friendly alternative for the use of SO2.
BotrytisIn the production and distribution chain, grapes are often subjected to long storage periods and long distance transportation. Such situations offer an excellent opportunity for the growth of moulds.
Decay caused by Botrytis cinerea, a born-mould in grapes, is the most important post-harvest disease during storage and transportation of table grapes.
SO2 application
Application of SO2 takes
place through fumigation shortly after harvest and through the application
of SO2 generating pads within the grape package.
According to the FDA, SO2
should not be applied on fresh fruits. This treatment is not only bad for
the health, the consumer moreover does
not view it as a ‘natural’ way to
preserve food.
Natural antimicrobial agents
Natural antimicrobial agents are
bioactive compounds derived from biological sources. In some cases, they
are ‘generally regarded as safe’ (GRAS-status); other natural
antimicrobials have, for example, an FDA approval.
EC-Pack has been working on the use of
natural antimicrobial agents to inhibit the growth of Botrytis in grapes. Successful results have been achieved with components of the
flavour or scent of the product.
Inhibition of Botrytis on grapes
Several product-own components have
been tested for their antimicrobial action on biological grapes in
combination with modified atmosphere (MA). Statistical analysis has shown
that treating the grapes with these natural compounds results in a
significant lower percentage of rotten grapes (spoiled by Botrytis).
These product-own antimicrobial agents, are potential candidates for replacing the SO2
treatment.
Hurdle technology aims to use an effective combination of different food preservation techniques (temperature, pH, water activity, MA, etc) to achieve mild preservation. The replacement of SO2 with natural compounds will be applied within this hurdle concept.
