- R Jacobs and L Korsten
- Department of Microbiology and Plant Pathology University of Pretoria, Pretoria 0001, South Africa
- 2004
Penicillium species are among the most common fungal species affecting litchi fruit post-harvest. These species have the ability to colonise almost any surface from fruit to packhouse walls and air conditioning systems. The presence of these spores in storage and transport facilities therefore holds great potential for post-harvest spoilage of fruit and may result in significant economic losses to the exporting fruit industry. During this study, we aim to identify the prominent Penicillium spp. in the litchi export chain from South Africa to the European markets. We were able to identify at least fourteen different Penicillium spp. throughout the export chain. These species are P. aurantiogriseum, P. brevicompactum, P. chrysogenum, P. citreonigrum, P. citrinum, P. corylophilum, P. decumbens, P. expansum, P. fellutanum, P. glabrum, P . janthinellum, P. rugalosum, P. solitum and P. viridicatum. In comparison to previous studies, many of these species identified do not naturally infect and colonise litchi fruit. The wide diversity of species identified during the export chain is an indication of possible cross-contamination occurring within distribution centres.
Summary:
The study aimed to identify the prominent Penicillium species present throughout the litchi export chain from South Africa to distribution centres in the Netherlands and United Kingdom.
Fourteen different Penicillium species were identified on fruit and surfaces along the export pathway: P. aurantiogriseum, P. brevicompactum, P. chrysogenum, P. citreonigrum, P. citrinum, P. corylophilum, P. decumbens, P. expansum, P. fellutanum, P. glabrum, P. janthinellum, P. rugalosum, P. solitum, and P. viridicatum.
Many of these species do not naturally infect litchi fruit, suggesting significant cross-contamination occurs during transit and storage.
Sampling included random swabs, contact plates, and air samples from packhouses in South Africa and distribution centres in Europe, with isolates grown and identified through morphological and microscopic analysis.
Penicillium spp. were found in abundance on almost any surface, especially in wet or humid areas such as cold rooms and packhouses, which increases the risk of post-harvest spoilage and economic loss.
The highest diversity and number of Penicillium isolates were found in European distribution centres, particularly where multiple fruit types from different origins were stored.
Sanitation practices varied, with centres showing lower species diversity considered to have better hygiene protocols.
The study supported previous findings that soil contamination and facility cleaning methods greatly affect fungal presence in export environments.
Evidence suggests a need for improved sanitation and handling practices to minimize cross-contamination and spoilage risk in the litchi export industry.
Future work will focus on identifying sub-species variation and tracing cross-contamination trends within the international litchi supply chain.