Cheaper Chocolate — Chromatography Investigates

When is chocolate not chocolate? Well, in the future the answer could be ‘when it’s made of jackfruit seeds’. Researchers have recently published a paper in the Journal of Agricultural and Food Chemistry (JAFC) describing how the seeds of the jackfruit could potentially be used as a low-cost substitute for cocoa beans. Interested? Read on.

Jackfruit — the largest fruit

Jackfruit is a species that belongs in the same family as the fig or breadfruit. It is thought that it originated on the Indian subcontinent, but is now found in South and South-eastern Asia. The fruit of the tree is the largest tree-borne fruit known — weighing up to 35kg and almost a metre in length, you may need a bigger fruit bowl.

The flesh of the fruit is starchy, but a good source of fibre with the flavour said to be a combination of apple, banana, mango and pineapple. It is used in many Southeast Asian dishes including curry in Bangladesh, where the flesh is eaten on its own. The seeds are often dried and used in curries — and it is the seeds that might get chocolate lovers interested in this largest of fruits.

Cocoa cannot meet demand

Farmers produce millions of tons of cocoa every year — almost four million tons. But unfortunately, the forecast is for our sweet tooth’s to get sweeter and that demand will be around 4.5 million tons in the next few years. So, food scientists are searching for something that can be used as a substitute to cocoa and keep us all happy.

One candidate, as the paper in JAFC — Optimization of Postharvest Conditions To Produce Chocolate Aroma from Jackfruit Seeds — suggests are the seeds produced in the fruit of the jackfruit tree. In Brazil — where the researchers are based — the seeds of the jackfruit are considered waste. So, in the home of the largest cocoa producer in the Americas, the team set about seeing if they could make a chocolate substitute from the seeds.

It’s chocolate — but not as we know it

The researchers made the seeds into a flour by acidifying or fermenting them before they were dried. They made 27 different flours by roasting the flours at different temperatures for different lengths of time like the methods used to produce the chocolate aromas associated with cocoa beans.

The team then isolated and identified the aromas of the flour using gas chromatography – mass spectrometry. Gas chromatography is one of the key techniques in the separation of components with the type of silica used key to the success of the method. The impact of different silica types is discussed in the article, Spheres-on-sphere (SOS) Silica a Real Support for Separation of Large Biomolecules.

The researchers could identify several components that contributed to the chocolate aroma they produced and volunteers were able to grade the different flours on their chocolate smell. The conclusion is that jackfruit seeds can act as a substitute for cocoa.