School of Agricultural, Earth and Environmental Sciences

Managing Fruit Quality Focus of PhD Research

Managing Fruit Quality Focus of PhD Research

Research into techniques to improve the maintenance of citrus fruit and avocado pear quality from the time of harvesting to the final consumer resulted in Dr Khayelihle Ncama graduating with a PhD in Horticultural Science.

Ncama (26), who achieved the rare feat of completing his research in the space of two years, said being awarded his doctorate was a childhood dream come true.

Ncama, now a lecturer at North-West University, developed novel techniques for the application of radiation spectroscopy and organic coatings using extracts of grapefruit seed and moringa leaf to achieve improved assessment of fruit maturity and maintenance of fruit quality in postharvest storage.

He developed coatings that are organic, contain fungicidal effects and are efficient alternatives to the currently used waxes and chemicals that are gradually being banned in international fresh fruit markets.

Ncama explains that fresh fruits harvested before or after optimal horticultural maturity shrivel, lack ideal flavour and often go to waste, making it important to develop systems capable of indexing maturity without harvesting sample fruit, rather than collecting sample fruit to represent the entire orchard.

The models he developed exhibited 99% accuracy in assessing various maturity indices – usually laborious to analyse – in oranges, grapefruit and avocado. When applied, the system assures improved accuracy of indexing fruit parameters within seconds. Additionally, the models he developed can be applied at any stage in postharvest handling of citrus fruit and avocado pears, even to assess the nutritional value of the fruits in supermarkets.

‘Postharvest is a critical stage of food loss since there have been extensive investments during cultivation, and food wastage in postharvest storage is a serious threat to food security,’ said Ncama, who believes research in this field is important to curb food losses in developing countries.

He recommended that farmers, distributors, researchers and anyone involved in fruit quality maintenance consider the near-infrared radiation (NIR) spectrometer as an efficient, effortless and rapid instrument to use, if calibrated accurately.

He hopes his research results will form the basis for further studies of postharvest quality management and non-destructive analysis of fruit parameters. He has presented his research at two international conferences, published a book chapter as well as three journal papers on it.

Ncama’s work has potential in commercial application for the use of flavour and nutritional parameters, rather than fruit size, as a basis for determining purchase price.

The newly minted PhD graduate from the rural area of Ezinqoleni, who studied at UKZN from undergraduate level and received his master’s degree cum laude, dedicated this achievement to his mother who he thanked for her support throughout his academic career.

Ncama acknowledged the quality of supervision he received from supervisors Dr Lembe Magwaza, Dr Samson Tesfay and Dr Asanda Mditshwa, thanking them for their availability and encouraging him to think creatively about challenges he faced.

Having come from a disadvantaged background that made accessing further education a challenge, Ncama hopes he will serve as a positive example to other students in similar situations.

In addition to continuing with research in his current academic position, he hopes to contribute to the industry and develop patented organic coatings and models as well as develop further ideas to improve the quality of fruit and vegetables.

Words: Christine Cuénod

Photograph: Supplied and Gugu Mqadi