Date Processing & Packaging Industry

11/10/2012

Air-drying and rehydration characteristics of date palm (Phoenixdactylifera L.) fruits

The influence of variety and drying temperature range of 50–80 °C on air-drying pattern of date palm fruits were investigated. Results indicated that drying took place in the falling rate period. Moreover, the effect of variety and rehydration temperature range of 15–45 °C, maintaining a fruit : water ratio of 1:25 w/w were also investigated. Moisture transfer during air-drying and rehydration were described by applying the Fick’s diffusion model, and the effective diffusivities and activation energies were calculated. Arrhenius relation with activation energy range of 35.17–44.02 and 30.29–40.29 kJ/mol expressed the effect of temperature on the diffusivities during air-drying and rehydration, respectively.

11/10/2012

Air-drying and rehydration characteristics of date palm (Phoenixdactylifera L.) fruits
The influence of variety and drying temperature range of 50–80 °C on air-drying pattern of date palm fruits were investigated. Results indicated that drying took place in the falling rate period. Moreover, the effect of variety and rehydration temperature range of 15–45 °C, maintaining a fruit : water ratio of 1:25 w/w were also investigated. Moisture transfer during air-drying and rehydration were described by applying the Fick’s diffusion model, and the effective diffusivities and activation energies were calculated. Arrhenius relation with activation energy range of 35.17–44.02 and 30.29–40.29 kJ/mol expressed the effect of temperature on the diffusivities during air-drying and rehydration, respectively.

11/10/2012

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Comparison of antioxidant activity, anthocyanins, carotenoids, and phenolics of three native fresh and sun-dried date (Phoenix dactylifera L.) varieties grown in Oman.
Al-Farsi M, Alasalvar C, Morris A, Baron M, Shahidi F.
Source
Plant Research Center, Ministry of Agriculture and Fisheries, Al-Khoud, Muscat, Oman.
Abstract
Fresh and sun-dried dates of three native varieties from Oman, namely, Fard, Khasab, and Khalas, were examined for their antioxidant activity and total contents of anthocyanins, carotenoids, and phenolics, as well as free and bound phenolic acids. All results are expressed as mean value +/- standard deviation (n = 3) on a fresh weight basis. Fresh date varieties were found to be a good source of antioxidants (11687-20604 micromol of Trolox equiv/g), total contents of anthocyanins (0.24-1.52 mg of cyanidin 3-glucoside equiv/100 g), carotenoids (1.31-3.03 mg/100 g), phenolics (134-280 mg of ferulic acid equiv/100 g), free phenolic acids (2.61-12.27 mg/100 g), and bound phenolic acids (6.84-30.25 mg/100 g). A significant (p < 0.05) amount of antioxidants and carotenoids was lost after sun-drying of dates, whereas the total content of phenolics and free and bound phenolic acids increased significantly (p < 0.05). Anthocyanins were detected only in fresh dates. Date varieties had different levels and patterns of phenolic acids. Four free phenolic acids (protocatechuic acid, vanillic acid, syringic acid, and ferulic acid) and nine bound phenolic acids (gallic acid, protocatechuic acid, p-hydroxybenzoic acid, vanillic acid, caffeic acid, syringic acid, p-coumaric acid, ferulic acid, and o-coumaric acid) were tentatively identified. Of the date varieties studied, Khalas, which is considered to be premium quality, had higher antioxidant activity, total carotenoids, and bound phenolic acids than other varieties. These results suggest that all date varieties serve as a good source of natural antioxidants and could potentially be considered as a functional food or functional food ingredient, although some of their antioxidant constituents are lost during sun-drying.
PMID: 16159191 [PubMed - indexed for MEDLINE]

11/10/2012

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Compositional and sensory characteristics of three native sun-dried date (Phoenix dactylifera L.) varieties grown in Oman.
Al-Farsi M, Alasalvar C, Morris A, Baron M, Shahidi F.
Source
Plant Research Center, Ministry of Agriculture and Fisheries, Al-Khoud, Muscat, Oman.
Abstract
Three native sun-dried date varieties grown in Oman, namely, Fard, Khasab, and Khalas, were examined for their proximate composition, sugars, dietary fiber, minerals, and organic acids as well as sensory characteristics. The study was conducted on sun-dried dates due to their higher consumption compared with fresh dates. All results are expressed as mean value +/- standard deveiation (n = 3) on a fresh weight basis except for sensory analysis. Date varieties were found to be low in fat and protein, but rich in sugars, dietary fiber, and minerals. They were found to be a good source of energy (278-301 kcal/100 g), due to the high sugar content. Total sugar content ranged from 56.1 to 62.2 g/100 g, being lowest in Khasab and highest in Khalas. Total dietary fiber content of dates varied from 6.26 to 8.44 g/100 g, of which 84-94% was insoluble fiber. Twelve minerals were studied in dates, among which the major minerals were potassium, calcium, magnesium, and phosphorus. Date varieties were also found to be an excellent source of selenium (ranging from 0.36 to 0.53 mg/100 g). Six organic acids were positively identified, among which malic acid predominated in all varieties. Differences (p < 0.05) in the contents of dietary fiber, organic acids, and certain minerals were observed among the three date varieties examined. Descriptive sensory analysis showed that among the nine sensory attributes studied, only the attributes color and desirability were rated as being of significantly (p < 0.01) higher intensity in Fard than in Khasab, whereas flesh firmness was lower (p < 0.01). Thus, these results suggest that although all three dates serve as a good source of vital nutrients, the Khalas variety, which is considered as premium quality, had significantly higher contents of sugar and selenium and a significantly higher energy value than the other varieties studied.
PMID: 16159190 [PubMed - indexed for MEDLINE]

11/10/2012

Health benefits of dates

Wonderfully delicious, dates are one of the most popular fruits packed with an impressive list of essential nutrients, vitamins, and minerals that are required for normal growth, development and overall well-being.

Fresh dates compose of soft, easily digestible flesh and simple sugars like fructose and dextrose. When eaten, they replenish energy and revitalize the body instantly. For these qualities, they are being used to break the fast during Ramadan month since ancient times.

The fruit is rich in dietary fiber, which prevents LDL cholesterol absorption in the gut. Additionally, the fiber works as a bulk laxative. It, thus, helps to protect the colon mucous membrane by decreasing exposure time and as well as binding to cancer-causing chemicals in the colon.

They contain health benefiting flavonoid polyphenolic antioxidants known as tannins. Tannins are known to possess anti-infective, anti-inflammatory, and anti-hemorrhagic (prevent easy bleeding tendencies) properties.

They are moderate sources of vitamin-A (contains 149 IU per 100 g), which is known to have antioxidant properties and essential for vision. Additionally, it is also required maintaining healthy mucus membranes and skin. Consumption of natural fruits rich in vitamin A is known to help to protect from lung and oral cavity cancers.

They compose antioxidant flavonoids such as ß-carotene, lutein, and zea-xanthin. These antioxidants found to have the ability to protect cells and other structures in the body from harmful effects of oxygen-free radicals. Thus, eating dates found to offer some protection from colon, prostate, breast, endometrial, lung, and pancreatic cancers.
Zea-xanthin is an important dietary carotenoid that selectively absorbed into the retinal macula lutea, where it thought to provide antioxidant and protective light-filtering functions. It thus offers protection against age-related macular degeneration, especially in elderly populations.

Dates are an excellent source of iron, contains 0.90 mg/100 g of fruits (about 11% of RDI). Iron, being a component of hemoglobin inside the red blood cells, determines the oxygen-carrying capacity of the blood.

Further, they are very good in potassium. 100 g contains 696 mg or 16% of daily-recommended levels of this electrolyte. Potassium is an important component of cell and body fluids that help controlling heart rate and blood pressure. They, thus, offers protection against stroke and coronary heart diseases.

They are also rich in minerals like calcium, manganese, copper, and magnesium. Calcium is an important mineral that is an essential constituent of bone and teeth, and required by the body for muscle contraction, blood clotting, and nerve impulse conduction. Manganese is used by the body as a co-factor for the antioxidant enzyme, superoxide dismutase. Copper is required for the production of red blood cells. Magnesium is essential for bone growth.

Further, the fruit has adequate levels of B-complex group of vitamins as well as vitamin K. It contains very good amounts of pyridoxine (vitamin B-6), niacin, pantothenic acid, and riboflavin. These vitamins are acting as cofactors help body metabolize carbohydrates, protein, and fats. Vitamin K is essential for many coagulant factors in the blood as well as in bone metabolism.

10/10/2012

This article provides information on the nutritional and functional constituents of dates (Phoenix dactylifera L.) and their seeds from over 80 references. Date flesh is found to be low in fat and protein but rich in sugars, mainly fructose and glucose. It is a high source of energy, as 100 g of flesh can provide an average of 314 kcal. Ten minerals were reported, the major being selenium, copper, potassium, and magnesium. The consumption of 100 g of dates can provide over 15% of the recommended daily allowance from these minerals. Vitamins B-complex and C are the major vitamins in dates. High in dietary fiber (8.0 g/100 g), insoluble dietary fiber was the major fraction of dietary fiber in dates. Dates are a good source of antioxidants, mainly carotenoids and phenolics. Date seeds contain higher protein (5.1 g/100 g) and fat (9.0 g/100 g) as compared to the flesh. It is also high in dietary fiber (73.1 g/100 g), phenolics (3942 mg/100 g) and antioxidants (80400 micromol/100 g). This detailed information on nutritional and health promoting components of dates and their seeds will enhance our knowledge and appreciation for the use of dates in our daily diet and their seeds as a functional food ingredient.

10/10/2012

The date (
Phoenix dactylifera
L.), a high-energy fruit, is regarded as a popular food commodityfor thousands of years in Iran, the persian Gulf peninsula and its neighboring region. The aim of present study is to characterize the biochemical and nutritional values of constituents of the Egyptian datefruits. Date palm fruits contain a variety of B-complex vitamins B1, B2, Nicotinic acid and vitamin A.the date palm extracts contains 13.80 % moisture and 86.50 % total solid. Ash and Crud fibers contentswere 2.13 and 5.20 respectively. Protein, carbohydrates and lipids contents were 3.00%, 73.00% and 2.90% respectively. The low level of lipids content 2.90% compared with its content of sugars means that,the date palm is save to heart and blood patients because its containing a very low level of fatty acidsand cholesterol. HPLC analysis of sugars content showed that, the carbohydrate content consists of a largeamount of glucose, fructose and sucrose, The protein pattern on SDS-PAGE showed that, most of proteinsin the date palm are a high molecular weight proteins between 80 and 135 KD and contained a minimumlevels of the LMW proteins less than 55 KD. Date Palm contained high concentration of Aspartic acid,Proline, Glycine, Histidine, Valine, Leucine and Arginine, but low concentration of Threonine, Serine,Methionine, Isoleucine, Tyrosine, Phenylalanine and Lysine and very low concentration of Alanine. Thedate palm fruits provide unique functional and nutritional values. Numerous health benefits beyond itsnutritional value have been associated with consuming date palm fruits to enrich nutrition values of different kinds of food.

10/10/2012

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