Nano technology to enhance fruit preservation | Sunday Observer

Nano technology to enhance fruit preservation

15 January, 2017

Post-harvest loss of fresh fruits and vegetables could be as high as 40 to 50 percent at present, and the use of plastic crates and cushioning material to pack perishable commodities during transportation would help reduce such losses, says Additional Director, Research and Development at the Industrial Technology Institute (ITI), Dr. Shanthi Wilson.

Dr. Wilson, a post-harvest specialist, said researchers at ITI are developing eco-friendly, bio degradable cushioning material by processing agricultural waste material from banana plantations as part of their project for ‘Enhancing the preservation of fruits using nano technology’.

The specific crops the ITI project is working on are mango, papaya and banana. Research experiments are in progress for the commercialization of an edible bio wax for extending storage and the shelf life of fruits such as mango and papaya.

Dr. Wilson says that such losses can be reduced by the adoption of proper post-harvest technology and handling procedures such as tools for harvesting fruits (The Department of Agriculture has developed some tools for harvesting mangoes, rambutan and papaya), the use of maturity indices such as those developed at the Industrial Technology Institute and the Institute of Post Harvest Technology for mango, banana, pineapple, tomato, green chilli, passion fruit and papaya.

“Pre-harvest treatment to induce uniform flowering in fruit crops such as pineapple, and mango are also available along with procedures for management of fertilizer application and pruning systems to improve yields and facilitate harvest operations by enabling uniform development of the crop and spray treatments that delay maturity and extend the harvest season of the crop,” she said.

“Maturity indices indicate the stage of development of the fruit or vegetable (egg, ripeness, colour and size) and enable the farmer to harvest the fruit at the most advantageous time for selling his produce at the best price.

It also allows for transportation to distant markets without produce getting over-ripe or damaged,” said Dr. Wilson. Other post harvest technologies that should be used, include tagging of fruits at the time of flowering to know the age of fruits and help with harvesting according to market destinations and needs, safe methods to control pests and disease, such as bagging fruits against insect and pest attack and the use of pheromone traps against fruit flies etc., and the use of edible waxes for maintaining the quality and freshness of produce.

Dr. Wilson said that it was necessary to investigate the means by which the use of plastic crates can be made affordable for the transport of perishable commodities.

Dr. Wilson pointed out that ethylene absorbents could be used to prevent premature ripening and that the technology to use the natural ripening agent ethylene which is liberated by plants during ripening and senescence should be promoted as a safe way to induce ripening.

This procedure is practiced in many countries. The use of carbide is not permitted for use on food items in Sri Lanka and should not be used as a ripening agent as it carries impurities such as arsenic and phosphine. She also said that dipping and spraying of fruits with chemical ripening agents are harmful to human health.

An important technology used to reduce damage and deterioration of food is low temperature storage. Though it is used extensively in developed countries, it is not extensively used in Sri Lanka due to high costs.

The introduction of affordable and environment-friendly solar powered refrigeration technology for storage of produce will help retain the good appearance and the inherent nutrient value of these commodities, while providing quality produce to consumers.

“The application of compounds, generally regarded as safe, could be used to prevent losses due to insects and pests in the field as well as during storage.

The field treatment of fruit and vegetable crops with permitted chemicals at recommended doses as per the Registrar of Pesticides of the Department of Agriculture should cease at least three weeks before the crop is harvested,” she said.

“While some loss is inevitable, in developed countries losses are usually maintained at below 10% of the harvested produce. Unfortunately, in Sri Lanka post-harvest losses are often between 20–50% and not all farmers have access to information on good agricultural practices at pre and post-harvest level,” Dr. Wilson said.

The Department of Agriculture needs to revive the excellent extension service that it once had and be supported by officers stationed at the Vidatha Centres established by the Ministry of Science Technology and Research to take technology to farmers, she said.

“The present losses can be reduced if collective farming and organized production is encouraged. It is hoped that policy makers will not only develop a policy framework for this purpose, but ensure that it is implemented with all stakeholders engaged in the effort,” Dr. Wilson said.

Sri Lanka as a developing nation needs to conserve its limited resources and cannot afford the loss of up to half of the fresh produce that is grown in the country.

Dr. Wilson said that steps taken to prevent post-harvest loss will make a significant contribution to national food security, making more produce available to consumers.