An idea that could eventually help reduce the plastic footprint of the pomegranate industry and may curb food losses throughout its value chain. That’s what a recently graduated PhD student in Horticultural Science at Stellenbosch University (SU) in South Africa, Dr. Tatenda Kawhena, came up with when he developed an edible coating that extends the storage and shelf life of this plant. Mediterranean fruit.
Dr. Tatenda Kawhena
The coating includes ingredients such as gum arabic, corn starch, lemongrass essential oil, glycerol, and an emulsifier. Gum arabic, a natural gum, consists of the hardened sap of two species of acacia trees, Senegalia senegal and Vachellia seyal, which are not indigenous to South Africa.
Through laboratory studies, Dr. Kawhena showed proof of concept that soaking ‘Wonderful’ pomegranates in the solution he developed works well to extend storage and shelf life of the fruit. In addition, the fruits last even longer when they are first dipped in the coating solution and then packed in plastic bags and standard open cardboard boxes.
Left: treated pomegranates Right: untreated pomegranates
The next step would be to test it within the context of a packing house. There has been a rapid increase in pomegranate production in South Africa to meet global demand. However, the pomegranate fruit is very susceptible to postharvest losses and waste, which limits the growth of the local industry.
“You have to be very careful so that the pomegranates last as long as possible and are not wasted once collected. They are easily damaged throughout the postharvest logistics chain. Therefore, the development and application of new science-based technologies to reduce pomegranate postharvest losses is a priority. Currently, as part of efforts to make exported pomegranates last longer, about ten fruits are packed together in a plastic bag, and then in cardboard boxes… Within a fruit season, all of that it adds up a lot of plastic, which is often only used once,” explains Dr. Kawhena.
His PhD studies were funded by the South African Pomegranate Growers Association (POMESA) and the DSI-NRF South African Research Chairs Initiative (SARChI) in Postharvest Technology at SU. Her studies were supervised by Professor Umezuruike Linus Opara, the South African Research Chair (SARChI) in Postharvest Technology, a Distinguished Professor in the UB Department of Horticultural Sciences and a world leader in pomegranate postharvest care ad Prof. Olaniyi Fawole of the University of Johannesburg.
Path to a PhD
Dr. Kawhena hails from Marondera in Zimbabwe and enrolled in 2009. Some of their results have already been published in peer-reviewed scientific journals.
Dr. Kawhena is now pursuing a career in the South African horticultural sector, as a Project Manager for a Paarl-based company that focuses on the independent evaluation of new fruit cultivars and rootstocks.
For more information:
Dr. Tatenda Kawhena
Faculty of Agricultural Sciences, Stellenbosch University
Telephone +27 79 142 9373
Email: [email protected]
www.agric.sun.ac.za
