SOURCE: THE NATIONAL

BY: DANIEL BARDSLEY

As any UAE resident knows, dates are one of the country’s favourite foods.

Supermarkets have a seemingly unlimited supply of a myriad types of the fruit, with more than 100 varieties grown in the Emirates alone.

The many varieties – among the most popular that are grown locally are sheesh, lulu and dabbas – offer sometimes subtle differences that are appreciated by enthusiasts.

And just as there are almost countless varieties, so the absolute numbers of dates grown locally is huge: the country has about 42 million date palms.

Indeed, according to reports citing the United Nations’ Food and Agriculture Organisation, in 2010, production in the Emirates peaked at an extraordinary 830,000 tonnes. Some tables have put the UAE as high as fourth in the world when it comes to total date production, and the country is certainly comfortably in the top 10 globally.

Most of the UAE’s dates are sold and eaten when they are in their later stages of ripening.

The science

In a 2001 study, researchers classified the ripening process into 16 stages, although more typically three main divisions are identified: bisr, rutab and tamar, names that are spelt a variety of ways.

These stages are associated with the dates transforming from yellowish-green to dark brown in colour, very visible alterations that are linked to underlying chemical changes.

The changes take place because, as the 2001 piece of research concluded, dates are a type of climacteric fruit, meaning that they continue to ripen even after they have been picked. Other climacteric fruits include figs, apricots, bananas, apples and kiwi fruit.

What characterises the ripening process is the softening of the fruit, which is caused by the activities of enzymes, including a key one called polygalacturonase that helps to break down the pectin in the cell walls.

Also closely associated with the ripening process of climacteric fruits is the production of the gas ethylene, which is made of two hydrogen and four carbon atoms and which in turn promotes ripening of fruit nearby. This is why fruit kept together in a container ripen faster: the ethylene promotes the chemical changes associated with ripening.

Non-climacteric fruits include oranges, cherries, watermelons and strawberries. These do not ripen after they have been picked, but instead simply start to deteriorate.

Dates are usually eaten in the late tamar stage, by which time the moisture content has fallen to between 10 and 30 per cent, or in the medium rutub stage, when the moisture content is higher, at about 30 to 35 per cent.

It is much less common for dates to be consumed in the early bisr stage, when they are about 50 per cent water and have a crunchy texture, with the polygalacturonase and other ripening enzymes having not yet started work in earnest to break down the cell walls.

But could this lack of interest in the UAE in eating unripe dates change?

A team of scientists in the department of agribusiness in the College of Food and Agriculture at UAE University in Al Ain set out to answer this question in a recently published paper. Entitled Market Acceptability of Dried Dates at the Unripe “Bisr” Stage in United Arab Emirates, the study was published in the Emirates Journal of Food and Agriculture.

The taste test

The researchers, Dr Berhanu Degefa, Dr Safdar Muhammad and Dr Eihab Fathelrahman, recruited more than 250 people, most of them UAE University students, but also including faculty, staff members and local residents. An extensive survey and focus-group analysis was carried out to find out what people thought of the unripe bisr dates.

Perhaps surprisingly, the overall verdict was a fairly positive one.

Just 5 per cent of respondents extremely disliked the taste of the bisr sample, while 13 per cent liked it extremely. Overall, 73 per cent of those taking part said they liked the taste to some degree, with just 20 per cent disliking the bisr dates to some degree.

The study found that 70 per cent of people would buy bisr dates if they were available commercially.

A complex statistical analysis was carried out on the results to better understand what factors make people more or less likely to enjoy these unripe dates. It was found that more-educated people were more likely to like them, as were those who had had previous experience of eating them.

The researchers noted that natural additives could be used to deal with some of the factors that put people off the bisr dates, notably their smell, although other factors such as colour, taste and flavour were also found to be important in determining whether people like bisr dates.

What now?

“The whole project was about value addition and market promotion,” said Dr Degefa, adding that the work offers the prospect of “diversification” in the dates sold in the UAE.

Dr Degefa described dates as being “one of the primary products of the culture of the Middle East and society here”, highlighting the potential importance of generating interest in new ways of eating them.

“It seems consumers are getting more awareness of the nutritional [value of] foods,” he said.

This is a key point associated with bisr dates. These crisp, unripe dates have a lower sugar content and contain more fibre than ripe dates, which means that they are likely to offer health benefits, an important consideration in a country with high levels of obesity.

“I think the next step is to promote it to businesses,” Dr Degefa said of the bisr dates.

“It’s quite significant if the product can be made available this way.”

So in the future we might be seeing more unripe dates for sale in supermarkets in the country, expanding the UAE market for dates and potentially improving health.

With Abu Dhabi set to host the Sixth International Date Palm Conference from March 19 to 21, the recent UAEU study will provide plenty of food for thought for the assembled delegates.