Determination of Coconut Viroid Contamination in Unprocessed Coconut Export Products

News source: Philippine Council for Agriculture,
Forestry and Natural Resources
Research and Development
For further information, see Rodriguez, M.J.B. and I.P. Estioko. Determination of CCCVd contamination in unprocessed coconut export products. Albay: Philipine Coconut Authority, 2001., 2003-02-01

Viroid Disease of Coconut

`CADANG-CADANG', a serious viroid disease of coconut, is prevalent in some parts of the Philippines, particularly in the Bicol region. The disease has been causing major problems in the international trade of coconut products. Specifically, the pathogen coconut cadang-cadang viroid (CCCVd) was found to be present in different parts of coconuts at varied concentration levels. Researchers studied the possible CCCVd contamination of some coconut export products.

Improved Mha Test

An improved molecular hybridization assay (MHA) was used to detect CCCVd. In the samples studied, the viroid was not detected in the meat and water of young and mature coconuts from diseased palms. This means that products derived from coconut endosperm, such as, desiccated coconut, coconut in powder or sliced form, `makapuno', `nata de coco', vinegar, and wine are free of CCVD. The viroid, however, was present in the husk (pericarp).

Viroid Survives in Husks, but Not in Meat or Water of Coconuts from Diseased Trees

The study confirmed that by-products from mature coconut husks like coco peat and coir fiber may be considered free of CCCVd as the husks are composed of dead tissues and the viroid could not survive additional exposure to processing conditions.

The study revealed that CCCVd could be inactivated or degraded by incubation at 100oC for 45 minutes; autoclaving at 118oC for 15-30 minutes; and treating with enzyme RNAse, alkali solution (e.g. 10% KOH), and at least 11% formalin.

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