While I was working at the 'Energy Centre' at CAST (the College of Arts, Science and Technology) in Jamaica I was involved in a very interesting R&D project to investigate the commercial drying of bananas using the sun.

Bananas are fragile and quality control at the exporting Jamaican ports is rigorous – one suspect banana on a bunch will condemn the bunch. This results in mountains of almost perfect bananas which have to be disposed of.

We were approached by an astute young man who surmised that, if dried and chopped, this scrap material could be used to replace the expensively-imported dried fruit in baking. We set up a research project and I designed a dryer to investigate the feasibility of solar-drying bananas commercially. We built a prototype and, using precise data-logging, determined the optimum airflow and speed the bananas travelled through the dryer – the results were very satisfactory. The bananas with blemishes would be chopped for the baking industry, but those without blemishes could open a new export market for whole dried bananas. There are significant advantages in shipping the fruit dry – it weighs just 20% of the whole fruit; it contains all the nutrients of the whole fruit, and it is very robust. With the EU’s pressure on the Windward Islands’ subsidised sales in the UK, producing an alternative market for the banana crop could rescue many farmers.

While we experimented with the drying process, we asked the biology department to investigate the bio-digestion of the banana peel to provide backup heat for the dryer. Initial results were disappointing until they found that it worked if they started the process with some animal manure.

Based on our findings, I designed the production dryer but, very sadly, this whole project ground to a rapid halt when the instigator died.