Chili (Capsicum annum L.) of family Solanaceae is both a vegetable and a spice crop of significant economic value in Pakistan. Chili is an important ingredient in day to day curries, pickles and chatnies. It is very remunerative and brings good returns to the farmers. Chilies are produced seasonally but consumed throughout the year. The pods are marketed both in green and red form. There exists a great scope for its export. The pungency in chilies is due to an alkaloid capsaicin which has high medicinal value. The stem end of the pod has most of the glands that produce the capsaicin.
The world production of chili crop sums up to around 7 million tons, which is cultivated on approximately 1.5 million hectares of land. The world production of chilies has been increasing and there has been a significant rise in the production level since the late 1990s. It has reached around 7 million tons per year now from the figure of 2.5 million tons in the last decade. India, the largest producer of chilies in the world, accounts for 11 lakh tons of annual production followed by China (around 4 lakh tons) and Mexico and Pakistan (around 3 and 2 lakh tons, respectively).
Aflatoxins are the most potent carcinogens of mycotoxins and are the most commonly found toxin in chilli spice. Aflatoxins are only produced by some strains of Aspergillus flavus and Aspergillus parasiticus moulds if they encounter appropriate environments. The most potent aflatoxins are B1, B2, G1 and G2 all of which have been found in chilli spice. In addition occasionally ochratoxin A, produced by Aspergillus ochraceus or Aspergillus carbonarius may occur in chillies. Aflatoxins are chemically very stable. Therefore, if contamination has occurred, it is not possible to destroy them by processing or cooking.
The infection occurs on stored fruits and the contamination with aflatoxin deteriorates the quality and make the produce unfit for consumption, thereby restricting the export trade. The incidence of A. flavus contamination on chilli fruits was recorded up to 29.3% in Pakistan. Aflatoxin contamination and pesticide residues are the twin problems faced by Pakistani chillies in the global market trade. It is essential to formulate proper strategies for management of aflatoxin contamination in chilli, if these possible measures are taken to avoid this toxic effects on human health.
• Select right varieties
• Avoid drought stress before harvest and post harvest handling during the rains.
• Dry at high temperatures of 60 °C for the first 6 hours; reduce heat to 45 °C for final drying.
• Ensure short time between harvesting and drying.
• Remove diseased and injured fruits.
• Cut fruits before drying into small pieces
• Dry to moisture content of ca. 8 per cent.
• Pack quickly into air tight bags; avoid absorption of moisture
• Store under cool and dark conditions
• Grind to powder only shortly before shipment.
• Pack quickly into air tight bags.
Often a technical solution is relatively easy to find, but implementation is the problem. To avoid aflatoxin contamination you can shorten the pre-drying handling time; improve the drying method, storage after drying and the hygienic aspects and expedite the marketing way of the product to the customer and so on. But most important is that everyone who is involved with the product focuses his thinking on the important details of the process and promotes a greater awareness of its necessity. So it should highly recommendations for chilli grower to adopt these methods and safe fruit for future development of horticulture industry for export.
The authors are associated with the Institute of Horticultural Sciences, University of Agricultural Faisalabad, Pakistan.