Date Palm – Health Benefits of Dates (Phoenix dactylifera)

Revisado por Equipe Editorial a 13 janeiro 2018

The date (Phoenix dactylifera) is the fruit of the date palm. It is a berry of golden yellow colour or reddish-brown when ripe. Its meat is soft, aromatic and sweet, with a stone inside it of elongate shape and with a longitudinal furrow. Dates are consumed fresh or dry and represent a basic food for the inhabitants of North Africa and Near East, who are the main producers. These fruits have a similar taste to honey and grow in clusters in the crown of the tree, around 25 m high. In North America they are related to sweet meals and in the Arab countries they are eaten stuffed, crystallized, distilled, in salads and with couscous.

In India they are used to prepare chutneys and curry. In the Sahara oases and other parts of North Africa they make date cakes intended for feeding the groups of travellers. In the Middle East they make the palm wine or toddy by means of fermenting the sweetened sap extracted from the crown of the date palm. Dried dates are kept in fresh and dry places for several months, even a year. The soft varieties are stored in the fridge for two weeks. The optimal relative moisture of this fruit is between 70-75%. They have a great nutritional value that lies on its easily assimilated sugar content and proteins, calcium, phosphorus, iron and vitamins of the B and A group. 

Types and Varieties of Dates 

The great range of date varieties can be classified in three groups depending on their maturation in the tree; they can be soft, semidry and dry. Fresh dates are harvested after a short period of maturation (5-6 months) in the tree. They must be kept in the fridge and they are widely cultivated in Israel from where most of the European imports come. Fresh dates are also imported from California. Among the semidry dates there is a very popular one known world-wide as ‘Deglet Noor’ or ‘ Date of the light’. Its skin is even and bright, and it is marketed in boxes in which the fruit is joined to the rachis. The date ‘Medjool’ has a wrinkled skin. The real dates of Tunisia and the black dates of Turkey are of superior quality, although the ones from Elche, in Spain, are also regarded as excellent dates. Other varieties with commercial importance are Zahidi, Halawi and Bardhi. Dry dates are harvested fully ripe when the sun has already dried them in the tree. They can be preserved in good conditions for long periods of time. It is a very hard fruit that is sometimes ground for processing flour. It is also softened by means of soaking it in water before its consumption. Among the most common varieties intended for production of dry fruit stand out the following, some of which have already been mentioned for the production of semidry dates. 

‘Medjoul’: Chief variety of Israel, large, tender and sweet.
‘Amary’: Large, reddish-brown date with a high content of fibre.
‘Deglet Nour’: Also called Moscatel date, it is as tender as exquisite.
‘Dayri: Dark brown skin. It tastes like sweets.
‘Halawi: Tender and sweet. It is one of the best varieties.
‘Zahidi: Not as sweet as other varieties.
‘Hadrawi’: Sweet and fleshy. It resembles the variety Halawi. 

The Plant 

The palm (Palmaceae) represents one of the most numerous families of tropical plants. The scientific name of the palm is Phoenix Dactylifera. There are almost 200 genus and more than 2,000 species of palms. The great majority is native to the deserted areas of Asia and America, except for some that come from Africa. These plants, mainly the date palm and the coconut palm, are of vital importance for the towns of the warm countries. The date palm (Phoenix dactilifiera) is the plant bearing dates. This dioecious tree usually measures 15 to 25 m high. It is provided with abundant and long palm branches, that does not bear fruit before until it is 5 or 6 years old. The yield is around 70 kg during 30 or 40 years. It can live for more than 2 centuries. The date palm has to be, as an Arab proverb says ‘ with the feet in the water and the head in the fire’. On the one side it needs the sun rays and on the other a humid soil, from which the roots extract water in a radius of 6 m. In these conditions it will bear an abundant output. These needs have turned it to be a characteristic tree of the desert. The fruit which is consumed fresh is not harvested until fully ripe, but the fruit intended for exporting as dry fruit is harvested before maturation. 

Origin and Production 

The date palm is native to Mesopotamia, the earth strip between the Tigris and the Euphrates. The Babylonians ennobled its culture, and 50,000 years ago it spread all over the Afro-Asian dry climate countries, from Morocco to Pakistan. The Spanish missionaries introduced it in America, where it is still cultivated nowadays, mainly in California, Arizona, Texas and Mexico. Among the last countries introducing this crop are South Africa, Australia, Greece, Sicily and the south of Europe, being these last three places the only ones in of Europe where the date is grown. The chief countries producing and exporting dates are Iraq, Saudi Arabia, Algeria, Pakistan and Morocco. The most recent sources obtained from the FAO date from 2000 and they indicate that 5,237,941 t of dates were produced in the world; the distribution by continents is as follows:

Continent    Tons 
  Africa    1,860,280 
  Asia    3,345,908 
  Europe    8,000 
  North and Central America    23,450 
  Oceania    Without yield 
  South America    303 
  Total    5,237,941 

Source: FAOSTAT Database Results (2000)

As it is shown, the main producer is Asia with 3,345,908 t of the world-wide total production in 2000, followed by Africa, with 1,860,240 t. The 8,000 t of European production are totally supplied by Spain. The main producers of dates are:

  Country    Tons 
  Iran    930,000 
  Egypt    890,340 
  Saudi Arabia    650,000 
  Pakistan    579,880 
  Iraq    540,000 
  Algeria    430,000 
  United Arab Emirates    318,000 
  Sudan    175,500 
  Oman    135,000 
  Libya    132,000 

Source: FAOSTAT Database Results (2000)

The main producing country is Iran (930,000 t), followed by Egypt and Saudi Arabia, as chief producers in 2000.

458,902 tons of dates are imported in the world according to FAO data from 1999. The main import countries are, in the first place, the United Arab Emirates, followed by India and Pakistan. The ten first world-wide importers are shown in the following table:

  Country    Tons 
  United Arab Emirates    180,000 
  India    46,000 
  Pakistan    23,016 
  France    20,872 
  Bangladesh    19,218 
  Sri Lanka    14,557 
  Malaysia    13,831 
  United Kingdom    13,577 
  Yemen    13,116 
  Indonesia    10,951 

Source: FAOSTAT Database Results (1999)

Spain imported in 1999 five thousand and thirty five tons of dates.

the world-wide imports in 1999 amounted to 267,508 thousand dollars. The United Arab Emirates was the country with greater capital investment intended for importing, followed by France and the United Kingdom. The table below includes the ten first countries with greater investment destined to imports.

  Country    Thousand dollars 
  United Arab Emirates    47,000 
  France    38,035 
  United Kingdom    21,202 
  Italy    15,078 
  Germany    11,709 
  Spain    10,938 
  Malaysia    10,867 
  India    10,000 
  Bangladesh    8,904 
  China    8,575 

Source: FAOSTAT Database Results (1999)

Spain occupies the sixth place with 10,938 thousand dollars in imports.

467,200 tons of dates are exported world-wide according to 1999 data from the FAO. The main exporting countries are, in the first place, the United Arab Emirates, Iran and Pakistan. The ten first world-wide exporters are shown in the following table:

  Country    Tons 
  United Arab Emirates    189,189 
  Iran    101,094 
  Pakistan    48,612 
  Iraq    30,000 
  Saudi Arabia    24,852 
  Tunisia    23,099 
  Algeria    10,000 
  France    8,329 
  Oman    6,000 
  Egypt    3,588 

Source: FAOSTAT Database Results (1999)

Spain exported in 1999 two hundred and sixty eight tons of dates.

The world-wide exports in 1999 amounted to 248,963 thousand dollars. The country with greater economical investment in exports was the United Arab Emirates, followed by Tunisia and Pakistan. The table below includes the ten first countries with greater capital investment in exports.

  Country    Thousand dollars 
  United Arab Emirates    57,973 
  Tunisia    41,175 
  Pakistan    23,166 
  Iran    22,797 
  Saudi Arabia    19,073 
  France    18,842 
  Algeria    14,000 
  Israel    6,714 
  Iraq    5,000 
  China    3,657 

Source: FAOSTAT Database Results (1999)

Spain invested 700 thousand dollars in date export. 

Availability 

Until recent time dates were known only as dry fruit that was sold in the market in winter. But during the 60’s took place the first attempts to introduce fresh produce into the market. At present, both soft as dried dates are found in the markets all over the year. It is recommended to choose those with uniform coloration and external appearance and to verify that they are not excessively dry or fermented. They are marketed with or without stone. The following table is an example of the dates of availability in the United Kingdom market, the origin and the weight of the packages.

Origin    Availability in the United Kingdom markets    Weight of the packages 
  ALGERIA    October-March    30 x 227 g 
  EGYPT    August-November    4 kg 
  IRAN    August-February    24 x250 g 
  IRAQ    September-December    30 x250 g 
  ISRAEL    All the year round    5 kg 
  MEXICO    September-November    30 x 227 g 
  MOROCCO    October March    Various 
  THE UNITED STATES    October-December    30 x227 g 
  TUNISIA    October-January    Various 
  PAKISTAN    July-September    4 kg 

Source: Fresh Produce Desk Book (2001) 

Packaging
Dates, both dry and fresh, are packed in bulk in cardboard boxes or in more or less large plastic containers; almost all of them come from Israel. 

Regulation
The DDF-08, ECE/UNO standard refers to the marketing and control of the commercial quality of dates. The ECE/UNO standards are used as a reference but they are not compulsory. The indexes of quality for dates, according to the University of California, Davis, are: the type or variety of the fruit, colour, texture, cleanness, and the absence of defects (like burns, damages caused by insects, the migration of the fruit’s sugar to the skin of the surface, and fermentation) and the deterioration caused by pathogens. 

Sweetness: The degree of sweetness is due to the sugar content, that in some varieties is quit scarce and extremely predominant in others. The total amount of sugar represents 50% in fresh dates and 75% in dry dates. 

Quality Criteria 

Postharvest Atmosphere Management 

The optimal temperature for storage during 6 or 12 months is 0ºC, depending on the variety (semidry dates like ‘Deglet Noor’ and Halawi, have a longer period of life than other fresh dates like ‘Medjool’ and ‘ Bardhi’). At -18ºC (0ºF) the period of storage extends. The freezing point is –15.7ºC (3.7ºF). The optimal relative moisture oscillates around 70-75%. Cooling is the technique used to preserve soft dates varieties for two weeks. In order to avoid dehydration, dry dates must be stored in cool and dry places, protected from the sun and air. Under these conditions the period of storage lasts for several months and even a year. The fresh produce consumed at present are put under preservation processes immediately after the harvest, ultra-frozen and later on defrosted just before they are put into sale. Dates which have undergone this treatment are barely damaged because they contain very little fluid and a lot of sugar (up to 70% of the total is inverted sugar). Ripe dates are hardly influenced by ethylene but they can really absorb the aroma of some other produce. Dates must not be stored next to garlic, onions and potatoes. Storage under controlled atmosphere with nitrogen (excluding oxygen) diminishes rottings of the dates and prevents the infections caused by insects. 

Postharvest
The same environmental conditions for conservation are recommended for the transport and distribution stages. These are: temperature around 0ºC for preservation between 6 and 12 months and relative moisture between 70 and 75%. 

Postharvest Problems
After the harvesting some problems may arise caused by rotting, the fruit turning sour, the sugar crystallization on the surface and damages caused by pathogens. 

Rotting
Dates undergo enzymatic and non-enzymatic processes that increase with humidity and high temperatures. The enzymatic processes can be inhibited by means of low concentrations of oxygen. It can be that the enzymatic processes release fluids that favour the proliferation of pathogens. 

Sourness
The fermentation that makes dates turn sour takes place in fruit with 25% of moisture content. 

Sugar crystallization
Sugar crystallization on the fruit’s skin and flesh occurs in some varieties of dates. It does not usually influence the taste but it affects the texture and appearance of the fruit. It is recommended to maintain low temperatures of storage in order to avoid this disorder. This type of crystallization usually takes place in varieties in which the glucose and fructose are the chief sugar elements. 

Damages caused by pathogens
Most of the damages caused by microbes are due to yeasts (most of them important), mould and bacteria. The yeast species Zygosaccharomyces are quite tolerant to high sugar contents than other found in dates. Dates infected by yeast give off an alcoholic smell (similar to fermentation). The bacterium Acetobacter is capable to turn alcohol into acetic acid (vinegar). Fungi (Aspergillus, Alternaria and Penicillum spp) may develop in dates with high levels of moisture, specially when they undergo humid or rainy periods. 

Healthy Effects

Date, Phoenix dactylifera / Fam.: Palmae
 Note: Composition for 100 g. of fresh product
           Values in ( min. – max. ) format.
Energy: 124.00-124.00 kcal
Fats: 0.10-0.10 g
Fibres: 1.80-1.80 gMineralsCalcium: 24.00-24.00 mg
Zinc: 0.20-0.20 mg
Chlorine: 210.00-210.00 mg
Phosporus: 28.00-28.00 mg
Iron: 0.30-0.30 mg
Magnesium: 24.00-24.00 mg
Manganese: 0.20-0.20 mg
Potasium: 410.00-410.00 mg
Selenium: 1.00-1.00. µg
Sodium: 7.00-7.00 mg
Proteins: 1.50-1.50 g
Carbohidrates: 31.30-31.30 gLiposoluble VitaminsA Retinol: 0.00-0.00 µg
A Carotenoids: 18.00-18.00 µgHydrosoluble Vitamins

B1 or Thiamine: 0.060-0.060 mg
B2 or Riboflavine: 0.070-0.070 mg
B3 or Niacine: 0.70-0.70 mg
B5 or Pantothenic Acid: 0.21-0.21 mg
B6 or Piridoxine: 0.12-0.12 mg
B9 or Folic Acid: 25.00-25.00 µg
C or Ascorbic Acid: 14.00-14.00 mg

Health Benefits of Dates
The date has an excellent concentration of iron. A hundred grams of dates provide with approximately 25 and 100% of the recommended daily consumption of 10 mg/day for men and between 15 and 70% for women in approximately 15 mg/day. The lack of iron is common all over the world, bringing about anaemia due to a diminution of the haemoglobin production. Dates have also a good concentration of folate, a vitamin of the B group closely related to health during pregnancy. Approximately 100 g of dates provide 20-35% of the recommended daily consumption of folate (0.2 mg/day). The lack of folate may cause anaemia. The reserves of folate in the body are related to the prevention of cardiovascular diseases. 

Popular Tradition
Many of the healing properties of dates were already known and used in the Old times. Nowadays these properties have been proved: most of them are due to the wealth of cellulose and fructose in this fruit. Dates whet the appetite, and are useful to treat intestinal and stomach disorders related to the lack of appetite. They are also recommended to treat hepatic disorders and anaemia, as well as constipation, since they act as smooth laxatives. Thanks to their high nutritious and energetic value they are good tonics. However, they are contraindicated in case of diabetes, obesity and gastric diseases along with hyperclorhydria. Due to their high content of sugar, an habitual consumption of dates may favour the appearance of dental decay and problems in gums. The presence of tyramine may cause migraine in sensible people. Dates have also the interesting property to soften dry cough and to fight the respiratory channel colds. 

Nutrition and Eating
Dates mean an important nutritional contribution in the diet of the Arabs of the desert. Their main nutritional contribution are glucids. The cellulose (fibre) occupies an important place too, but the percentage of proteins and lipids is scarce.