Date, the fruit of the date palm, is considered an ideal food that provides a wide range of essential nutrients with many potential health benefits.
It is a delicious fruit with a sweet taste and a fleshy mouth feel. The main constituent of dates are carbohydrates (mainly sucrose, glucose, and fructose), which make up about 70 per cent of the fruit.
These sugars are easily digested and can immediately be transported to the blood after consumption and quickly metabolised to release energy for various activities of the human body cells.
The fruits are also a good source of dietary fibre and contain significant amounts of calcium, iron, potassium and selenium.
They also contain a number of phytochemicals such as carotenoids, phenolics, flavonoids and anthocyanins, which possess antioxidant properties.
Dates are considered a staple food in the Arab regions. They are produced largely in the hot deserts of South West Asia and North Africa, and are marketed worldwide as a high-value fruit crop.
Date fruits can be distinguished from most of other fruits by the fact that they achieve their botanical maturity at various distinct levels.
They usually undergo four stages of development known by their Arabic names as follows: Kimri (green, unripe), Khalal (full-size, crunchy), Rutab (ripe, soft) and Tamar (ripe, dried).
These stages of maturity are usually described by changes in nutrient composition, size, colour, texture, taste and flavour.
At the kimri stage, there is a rapid increase in sugar content, size and weight. The moisture content at this stage is 85 per cent.
At the end of this stage, the fruit turns yellow or red depending on the variety. In the khalal stage, weight gain is slow, the sucrose starts to be converted to glucose and fructose, the moisture content goes down, and tannins begin to precipitate.
The tips of the fruit start ripening by turning brown as they enter the rutab stage that is characterised by a decrease in weight due to moisture loss, the conversion of sucrose into invert sugar (a mixture of glucose and fructose obtained by the hydrolysis of sucrose) and browning of the skin as well as softening of the tissues.
The moisture content decreases to about 35 per cent and the dates at this stage are sold as fresh fruit. When the dates are left to ripen further on the palm or sun dried, they develop into the tamar (dried) stage.
Besides the ripening stage, other factors that affect the nutrient composition of dates are cultivar used, soil conditions as well as agronomic practices.
Dates are mainly consumed as fresh (30 to 40 per cent) or in the dried form (60 to 70 per cent) as rutab (semi ripe) and tamar (fully ripe) stages.
They are usually taken with beverages like coffee, milk or yoghurt. In the processed form, they are consumed as a blended paste, syrup, in shakes, smoothies, pickles, jams, jellies, and are used in many bakery or confectionery products together with chocolate, coconut, honey or vinegar.
Sun drying is the common method of drying dates. This takes about seven to 10 days depending on the day’s temperature that varies from 30 to 50 degrees Celsius.
The consumption of dates is seasonal. It reaches its peak in the holy month of Ramadan where dates are needed to break the fast, and the consumption declines after this month.
There is reported religious significance of date palms and fruit. In Judaism, dates are regarded as one of the seven holy foods.
Date palm leaves are used as a “lulav” (a closed frond of date palm tree) in the Jewish holiday of “Sukkot” the Feast of Booths.
There are many references about date palm and its fruit in the Bible. Date palm leaves are also used during Palm Sunday in Christian religion.
Islam gives the highest priority to dates. The nutritional significance and health benefits of dates are mentioned in the The Koran.
Date fruit can play a major role in human nutrition because of its wide range of nutrients and antioxidant compounds.
Research is required to explore the use of the fruit’s functional components in the development of various value-added food products and supplements.
Production of the various date products for the local market is equally a good business venture. This will significantly increase the market and consumption of these nutritious fruits.
Ms Ndungi is based at the Department of Human Nutrition, Egerton University.