Delicious Dates

Delicious Dates
Available all year round
Delicious Dates
ADFCA-052-04-2012-01
Available all year round
Table of Contents
Dates in the UAE6
Ingredients of Dates9
Nutritional and Medical Benefits of Dates
10
Tannins and their Role during the Stages of Date Ripening
13
Role of Enzymes in Date Ripening
13
Different Stages of Dates14
Date Storage between originality of the past and
facilities of the Present20
General Guidelines for drying dates
22
Modern methods of date packaging and packing
24
Signs of Date Decay25
Food Safety Considerations and Potential Hazards
25
Controlling Hazards Related to Date Palm Tree Pollution
27
Programs of the Abu Dhabi Authority with Respect to
Date Safety safety of dates:
27
Program for Monitoring Pesticide Residues in Dates
28
Program For Detecting Metal Pollutants and Mycotoxins
28
Program for Examining the Microbiological Contamination of Dates29
References30
Dates in the UAE
The cultivation of date palm trees has spread
throughout the United Arab Emirates where the
country has made tremendous growth in the
cultivation of large numbers of this blessed tree and
has increased its production and manufacturing
of dates. The Ministry of Environment and Water
also developed a website dedicated to date palm
research, and has compiled documentation of the
types of dates that have come to be grown in the
Emirate of Abu Dhabi.
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Ingredients of Dates
Dates contain many substances, which are needed by the human body, including: glucose, fructose, sucrose,
starch; and minerals such as potassium, sulfur, phosphorus, iron, sodium, magnesium, and zinc. It also
contains vitamins A, B, C, and E; in addition to fats, and acids such as phosphoric acid, folic acid, formic acid,
cellulose, pectin, tannin, proteins.
Nutritional Value of some Types of Dates according to the Results of an Analysis conducted at the
laboratories of the Abu Dhabi Food Control Authority:
The nutritional components of dates were analyzed at the laboratories of the Abu Dhabi Food Control
Authority with respect to the following types: Birhi, Khalas, Jibri, Lulu, Kheneizi, Sekkeri and the following
results were reached:
•
The disaccharides, monosaccharides and total
saccharides based on wet weight:
Minerals
quantity
expressed as one
part per million
- Glucose content percentage 13.7 - 32.3% :
Potassium
5219 – 7672
- Glucose content percentage 12.8 - 30.7% :
Phosphorous
980 – 1336
- Maltose content percentage 0.7 - 1.8%
Calcium
333 – 819
Magnesium
460 – 711
- Sucrose content percentage 0.8 - 2.3%
- Reducing Sugar content percentage 27.6 - 61.6%
- Total Saccharides content percentage 30 - 61.6%
Zinc
2.65 – 12.36
Protein content
Copper
0.652 – 2.04
percentage 1 - 1.97%
Iron
5.69 – 17.79
•
Fat content percentage
0.01- 0.4%
Manganese
•
Fiber analysis 3.2 - 3.4%
•
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2.12 – 3.9
Nutritional and Medical Benefits of Dates
Dates have many benefits, such as:
• A general tonic which treats anemia and protects against nervous disorders because it contains a
high percentage of sugar and potassium.
• It also helps the womb to contract at delivery and in secreting the hormones that stimulate lactation for
breastfeeding women (such as the prolactin hormone), because it contains glycine and threonine.
• Dates reduce the risk of heart disease and clogged arteries. It is among the foods that help treat and
prevent increased blood cholesterol by reducing the absorption of cholesterol in the intestinal tract
because it contains soluble pectin.
• The date skin contains a high level of flavonoids, which act as antioxidants and as stimulus and catalyst
for the heart by strengthening the walls of the blood vessels, prevent capillary permeability and bleeding
and act as anti-fungi, anti-bacterial, anti-viral, and anti-cancer agent.
• It also contains cellulose fibers, which activate the bowel movement, and helps to treat chronic
constipation.
• It is also rich in many compounds that enhance the immune system, such as
“beta glucan 1-3 D”, which activates the body's immune system and has the
ability to unite with, or enclose materials alien to the body.
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Tannins and their role during the Date Ripening
Process
• Tannins, which are in the class of "polyphenols," account for 3% of the components of the fruit of
palm trees.
• Throughout the stages of ripening, tannins become insoluble and they associate with proteins,
leading to improving the taste of dates and ridding them of their acidic taste.
• Tannins play a role in transforming the color of the fruit to brown, along with the transformation
caused by enzymatic activity.
Role of Enzymes in the Date Ripening Process
The following enzymes play a major role in the fruit ripening process and bring about physiological
changes during the fruit ripening stages:
• The invertase enzyme converts the disaccharides “sucrose” the monosaccharide “glucose and
fructose” which affects the taste of fruits, as fructose is sweeter.
• Polygalacturonase and pectinesterase enzymes work to transform the pectin materials to soluble
pectin, which helps to soften the tissue of the fruit.
• The cellulase enzyme breaks down cellulose, which increases soluble materials and glucose and
reduces the proportion of the fibers.
• The “polyphenol oxidase” enzyme causes vital chemical changes in natural phenolic materials such as
tannins, and is an important enzyme in that it changes the dates' color to brown.
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Stages of the Date Palm Tree
• The Hibabo stage.
• The Khlal (full-size) stage.
• The Bisr stage.
• The Rutab (ripe, soft) stage.
• The Tamr (ripe, sun dried) stage.
The Hibabo Phase.
The Hibabo stage starts right after pollination and it lasts for
five weeks during which the fruit is small and spherical then
another stage starts, namely the kimri stage during which the
fruit becomes oval and green, but bitter.
The Al-kimri Stage
During this phase, the fruit grows rapidly in size and becomes
less bitter as the percentage of sucrose increases. This phase
witnesses the greatest increase in fruit acidity and water
content (which reaches 85%); the fruit also assumes its final.
shape when its would-be color starts to appear.
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The Unripe or Bisr Stage
During this phase, the fruit reaches its final size and takes on the color and shape representative of its
type, which makes it easy to identify the different types. The ratio of water decreases from 85% to 50%;
the fruit becomes hard but crispy; and the taste improves as the tannin starts to sediment, causing the
fruit to lose its acidic taste and become sweet.
This process occurs rapidly in some types of dates, which makes such types edible during this phase as the
color of the front part of the fruit turns brown. Care must be taken when harvesting the fruits to prevent
damage. Some types such as the Birhi and Kheneizi can be marketed during the Bisr phase.
The Rutab (Ripe) Phase
• The Rutab phase is charcterized by a decrease in weight, and the disaccharide “sucrose” is transformed
into the monosaccharides “glucose and fructose” according to the fruit type.
• The outer skin of the fruit becomes brown and the texture become soft.
• When the ratio of water is in the order of 30 to 45%, the fruits can be marketed during this phase as
fresh fruits which require caution to protect them from being damaged.
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The Tamr (Dry) Stage
When fruits are left to ripen while in the trees, they naturally progress
from the rutab stage to the the tamr phase charcterized by the brown or
“amber” color, and they retain about 24%-25% of water.
After the fruits are harvested, they are dried in the sun to retain about
10%-20% of water. to increase their endurance while maintaining their
attractive LOOK.
Texture ranges from soft to firm.
During this phase, dates are not exposed to microbic decay and can be
stored at room temperature but should be protected against pollution
by insects
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Date storage between the originality of the
past and facilities of the present
but continues causing the fruit to ripen and take on an an undesirable color.
The freezer's temperature should be at its lowest one day at least before storing the rutab, and freezing
should take place at the lowest temperature possible.
Dates are characterized by a long validity period of their validity and they can be stored at room
temperature. In the past, traditional storage methods were used, such as:
• Storage a Jassa (a plastered room), which is a simple structure consisting of four walls and a ceiling
about two meters high, and whose walls are covered from inside with plaster and whose floor is
covered with clean palm branches. Dates are stored in it until it is filled. Due to the weight and
softness of the stacked dates and the high ambient temperature, sap flows through the floor through
a special slot, a sap called molasses.
• Storage by drying: Sufficient quantities of dried dates that meet the sufficient for a year are stored.
General guidelines for chilling Balah (Unripe):
• The balah phase can be stored in the refrigerator temperature.
• Chilling is an important and successful factor in extending the period of storing balah to several
weeks, taking into account the use of appropriate containers to reduce the formation of moisture
(which causes decay and mold) or loss of moisture (which causes the fruit to dry out) on the part of
balah, by using containers impermeable to water vapor. In this way, some types can be stored for
three months.
• The storage period can also be extended to 26 weeks through emptying air from containers and
using carbon dioxide.
The modern methods of Storage include:
Maintaining fruits at the bisr stage by controlling the activity of various enzymes
through increasing or decreasing it to control the lifetime of the various types of fruits.
Enzymes are sensitive to changes in heat. The enzyme’s activity stops completely when temperature is raised
to the degree that leads to change in its chemical composition. The Invertase enzyme loses 50% of its activity
at 50° and 90% of its activity at 65° for 10 minutes. On the contrary, cooling can reduce the enzyme’s activity
to varying degrees.
In addition, some temperatures such as 30°-40° stimulate the activity of enzymes, and moisture plays
a major role in affecting the activity of the enzyme and in protecting the fruits from becoming
contaminated with fungi and yeasts. Therefore, the storing dates by chilling or freezing reduces the
activity of enzymes and extends the duration of the storage period. The properties of enzymes were
used to hasten the ripening of date palm fruits according to the request and the type to be ripened.
Using chilling and freezing in date storage :
Chilling and freezing techniques are used, the latter being one of the best storage methods for many food
products, as freezing maintains the high quality of the product. Freezing is one of the easiest and cleanest
methods, killing or stopping most of the microorganisms that cause decay and stopping or slowing down
biological processes and oxidation significantly. However, enzymatic activity does not stop completely,
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General Guidelines for freezing Rutab (Ripe):
The freezing process is relatively expensive, so rutab fruits should be of the best quality and in perfect
condition while in the khlal phase, whether sweet or rutab. The rutab to be used in the freezing process.
should preferably be processed immediately after harvest to get the highest quality possible. If it is not
possible to do so, the fruits should be transported and stored in a cool place away from sunlight until
they are frozen at the earliest possible opportunity. Before the freezing process, small and deformed
fruits as well as impurities should be excluded, and fruits should be removed of dust and dirt by spraying
(not soaking) them with cold water.
Specifications of the freezer:
When buying the freezer, a number of factors should be taken into account including the the capacity
of the freezer, which depends on the quantity of products expected to be stored, as well as the capacity
of freezing to the lowest temperature possible (there are many freezers available on the local market,
with varying freezing capabilities), from -6° to -12°. However, the most common type of independent
freezers reaches -18°. It is also advised to cook the dates (by immersion in hot water or steam) to reduce
enzymatic activity before the freezing process.
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General Guidelines for Drying Tamr
• The purpose of the drying process is to reduce the moisture content of the dates, which in turn decreases the growth of microorganisms (bacteria, fungi, and yeast), whose growth depends on the
effectiveness of water activity for their growth, composition and ability to absorb water. In general,
fungi grow in less water activity than bacteria, which in turn grows in water activity less than the
bacteria. Therefore, fungi are the microorganisms that cause most decay in dates.
• Drying dates until they have 20% or less moisture content and storing them in suitable relative moisture greatly reduces the likelihood of their being contaminated with yeast and fungi, and extends
the storage period to a year at 25 degrees.
• To prevent decay resulting from infestations of pests, dates should be fumigated with carbon dioxide
for two days and their containers should be tightly sealed. They can also be vacuum-stored or heated
to the temperature of 50-55° for 2-4 hours then then cooled to 0, or frozen at -18 degrees for two
days, and stored at 5 degrees.
• At the level of commercial manufacture, and according to the Montreal Protocol, it was recommended to stop using methyl bromide in fighting pests, because of its direct impact on the ozone layer,
and the Alternative methods involve the use of phosphine or using physical methods, such as heating and cooling, ozone gas, or irradiation.
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Signs of date decay
• The Decay is caused by microbiological contamination, including:
Modern methods of date packaging and packing
-
Alcoholic fermentation caused by yeast activity.
• In the past, the processes of packaging and storing dates were done in a lot of farms in primitive ways, and
dates were often consumed by the farm owners and rarely marketed, and rarely marketed. If marketed, they
did not fetch lucrative prices. Later, clear progress was achieved by the United Arab Emirates in packing
and packaging dates in specialized factories using civilized methods. Many date factories were founded,
leading to an improvement in the quality of fruits traded in markets and contributing to the use of storage
during the storage and marketing periods.
-
Acidity caused by the activity of the lactobacillus bacteria.
-
Blackening caused by the Aspergillus niger fungus.
Packaging and Packing
• The Rutab dates should be packaged in tightly sealed containers to avoid the so-called “freezer burns”
which result from the loss of moisture, which causes the presence of brown or pale spots on the surface
of fruits and affects the quality of the product. Therefore, it's not advisable to use cardboard (carton)
containers unless they are coated with anti moisture transfer covers; and plastic (PVC) packages can be
used instead, because they are tightly sealed and cheaper. Metal containers can also be used because
their surfaces conduct heat quickly during freezing. Special packaging exists for freezing.
• There are many standards stipulated for packages, including: being impermeable to water vapor,
moisture, or odors, having no taste or smell, being suitable for food products, being durable, resisting
breakage due to freezing, being easy to use, seal, and write on, being designed to withstand tamping,
and being cost-effective.
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• Defects caused by pests.
-
Remains of pests.
-
Disruption of fruit tissues.
-
Change in the outer surface of the fruits.
Considerations of Food Safety Considerations
and Potential Hazards
Risks are divided into three categories:
• Risks arising from hazardous microbiology activity (microbiological risk).
-Salmonella
-
Escherichia coli.
• Physical hazards:
-
Foreign objects in date products such as sharp metal fragments in date paste.
• Chemical hazards
-
Pesticide residues.
-
Mycotoxins resulting from fungal infection.
-
Toxic metal pollution and environmental pollutants.
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Controlling the hazards of of
Pollution to Date Palm Trees
• The Abu Dhabi Food Control Authority, in cooperation with the concerned authorities in the United Arab
Emirates, conduct field surveys and use their outputs in making recommendations on the development of
specifications to ensure taking all the necessary precautions and controls to prevent the pollution of dates and
their products by microbes and their toxins, as well in controlling monitoring the use of pesticides.
• Decisions were made to require date factories to commit to implementing the Hazard Analysis & Critical Control Point
system (HACCP)
• The Abu Dhabi Food Control Authority encourages farmers to adopt good agricultural practices GAP.
• Transportation and storage requirements were developed:
• The Authority seeks to increase the knowledge of consumers through awareness programs to enable them to
contribute to controlling food quality and safety including dates.
Programs of the Abu Dhabi Authority with respect
to the safety of dates:
• The Abu Dhabi Food Control Authority plays an important role through monitoring factories to ensure that they
implement date quality control systems.
• The Authority conducts inspections on a regular basis during which samples are taken of the stages of the different
production lines periodically (every three months) from factories that market and export local dates and their
products inside and outside the UAE for the purpose of ensuring their quality and to ensure that they are free from any
pollutants and healthy for the consumer. The inspections also aim to monitor factories’ implementation of the food
safety terms issued by the Abu Dhabi Food Control Authority during the manufacturing process and and to follow up
their commitment to implement the Hazard Analysis & Critical Control Point system (HACCP).
• The Authority examines samples of the dates traded in Abu Dhabi in its laboratories within its activity of
inspection and survey campaigns and it monitors date exports.
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Program for Monitoring Pesticide Residues
Residues in Dates
• There are many pests that infect different types of palms, and the many pesticides used to fight these
pests, constitute pollutants in dates.
• Out of its concern for the safety of dates and their products used by the consumers, the laboratories
of the Abu Dhabi Food Control Authority developed a method for detecting pesticide residues in
dates through which most of the pesticides used in the palm pest control program can be detected.
• An annual surveying program has been developed for the detection of pesticide residues during
the various stages of the date ripening process during which the focus will be on local products and
some types imported from neighboring countries.
Program for Examining the Microbiological
Contamination of Dates
• Microorganisms which pollute dates can be detected during routine analyses for the
detection of bacteria, yeasts and molds. Through these surveys, the Abu Dhabi Food
Control Authority reduced the percentage of yeast and mold contamination of dates from
24% in 2006 to 16-19% in 2009.
• The surveys, which lasted for the period from January- August 2006, covered a number
of types of dates and various date pastes, for a total of 231 samples of the following local
types of dates: Lulu, Al-Naghal, Khalas with all its types, Shishi, Khidri, Rashidi, Safawi, Sifri,
Saji, Sekkeri, Mabroum, Abuamaan, Barhi, Nabtat Saif, Omm El-Dehn, Maktomi, Dabbas,
Arziz, Fard, Jibri, Kheneizi, Khadrawi, Nawat Al-Barkh, Berni, Nemishi, Sultana, Zamli, Sayr,
Birdy and Maknouz.
Program For Detecting Metal Pollutants and
Mycotoxins
The laboratories of the Abu Dhabi Food Control Authority detect mycotoxins (aflatoxins) in
dates on a regular basis. During the period since March 2009, surveys have examined 162
samples of dates. These included the following types: Dabbas, Lulu, Kheneizi, Nagal, Abuamaan,
Shishi, Khilas, Arziz, Fard, Sifri , Khidri, Sekkeri, Saji, Rashidi, Sayr, Nabtat Saif, Jibri, Dabbas,
Sultana, Barhi, Khadrawi, Maktomi, Nemishi, Mabroum, Safawi Daqlet Nour, Zamli, and Omm
El-Dehn. All of them were found to be in conformity with the UAE standard specifications and no basic
heavy metal contaminants such as arsenic or lead were detected.
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References
1.http://www.moew.gov.ae/Ar/InformationCenter/Pages/PalmTree.aspx
2.http://www.uae.gov.ae/uaeagricent/palmtree/typeofpalm-pic.stm#4
3. ABDULLA) H. ABBOUDI AND A.K. THOMPSON- MINISTRY OF AGRICULTUREAND
FISHERIESDUBAI, UAE
4. Elhadi M. Yahia - Facultad de Qumica, Universidad Autَnoma de Querétaro Querétaro, Qro.,
México- http://www.ba.ars.usda.gov/hb66/059date.pdf
5. Kader, A.A. and Hussein, Awad. 2009. Harvesting and postharvest handling of dates. ICARDA,
Aleppo, Syria. iv + 15 pp.
6. Hassan Abdel-Rahman Shanana: “Date Palm Trees and Date Production in the UAE-Harvesting
Dates and Taking Care of them.”
7. Dr./ Khaled Bin Naser Al-Redaiman/ Head of the Department of Plant Production and
Prevention, Faculty of Agriculture and Veterinary Medicine, AL-Qusaim University, KSA.
8. Dr./Abdulla Bin Mohamed Al-Hamdan/Assistant Professor of Food Processing Engineering,
Department of Agricultural Engineering, Faculty of Agriculture, King Saud University.
9. Results of Surveys and Analyses conducted by the Abu Dhabi Food Control Authority
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Abu Dhabi
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