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Industrial Crops and Products 42 (2013) 567– 572

Contents lists available at SciVerse ScienceDirect

Industrial Crops and Products

journa l h o me page: www.elsev ier .com/ locate / indcrop

arotenoids, fat soluble vitamins and fatty acid profiles of 18 varieties of dateeed oil

osam M. Habib ∗, Hina Kamal, Wissam H. Ibrahim, Ayesha S. Al Dhaheriepartment of Nutrition and Health, Faculty of Food and Agriculture, United Arab Emirates University, P.O. Box 17555, Al Ain, United Arab Emirates

r t i c l e i n f o

rticle history:eceived 17 April 2012eceived in revised form 25 June 2012ccepted 25 June 2012

eywords:ate seedate seed oilatty acid profile

a b s t r a c t

The seed oil of 18 leading varieties of date fruits cultivated in the UAE (Khalas, Barhe, Lulu, Shikat alkahlas,Sokkery, Bomaan, Sagay, Shishi, Maghool, Sultana, Fard, Maktoomi, Naptit Saif, Jabri, Khodary, Dabbas,Raziz and Shabebe) were analyzed and compared for fat soluble vitamins, carotenoids and fatty acid pro-files. Results showed significant variations among the different varieties for their fatty acid, carotenoid,vitamin E, and vitamin K content. Results also revealed that the major fatty acid in date seed oil is oleicacid (49.50%), followed by myristic acid (14.52%) and linoleic acid (10.23%). Pentadecanoic, palmitic,heptadecanoic, stearic, arachidic, behenic, palmitoleic, cis10-heptadecenoic, cis11-eicosenic, linolenic,cis11,14-eicosadienoic, cis-11,14,17-eicosatrienoic were also found in date seed oil. �-Carotene was

at soluble vitaminsarotenoids

found to be the most occurring carotenoid in all of the 18 date seed oil varieties and ranged between1.18 mg and 2.68 mg/100 g. Moreover, the 18 date seed oils depicted considerable concentrations ofvitamin E (ranged between 1.01 mg and 1.86 mg/100 g �-tocopherol; 0.61 mg and 0.98 mg/100 g �-tocopheryl acetate; 0.40 mg and 0.70 mg/100 g �-tocopherol), and vitamin K1 (ranged between 0.10 mgand 0.19 mg/100 g). The results obtained indicate a strong potential for date seed oil to be used as a sourceof essential fatty acids in healthy edible oil, as well as in cosmetics and pharmaceutical applications.

© 2012 Elsevier B.V. All rights reserved.

. Introduction

The date (Phoenix dactylifera) has always played an importantole in the economy and social life of the people of arid and semiaridegions of the world. The United Arab Emirates (UAE) is consid-red to be one of the vital and known date producing countries.he world production of date fruits was about 6.64 million tons in007 (FAO, 2007), with Egypt, Iran, Kingdom of Saudi Arabia, UAEnd Pakistan being the main producing countries, with a produc-ion of 1.13 million ton, 1 million ton, 983.00 ton, 755.000 ton and57.000 ton respectively. The relative percentage weight of dateeeds to the date fruits ranges from 6.10% to 11.47% (Habib andbrahim, 2008). According to the above mentioned values we esti-

ated the annual world production of date seeds at about 697,000ons in 2007.

Date seeds are commonly considered as a waste product that isither discarded or used in animal feed. However, date seeds have

een shown to possess extractable high value added componentsHabib and Ibrahim, 2011). Date seeds, which are low cost agricul-ure by-products, are a good precursor for production of activated

∗ Corresponding author. Tel.: +971 3 7136578; fax: +971 3 7675336.E-mail address: hosamh@uaeu.ac.ae (H.M. Habib).

926-6690/$ – see front matter © 2012 Elsevier B.V. All rights reserved.ttp://dx.doi.org/10.1016/j.indcrop.2012.06.039

carbon (Girgis and El-Hendawy, 2002; Banat et al., 2003). More-over, a commercial date seed product (date seed powder used asa coffee substitute) has been introduced recently to the market(Rahman et al., 2007). Recent studies conducted on the character-istics and chemical composition of date palm (Phoenix canariensis)seed oil grown in Tunisia suggest that the most important fattyacids were oleic, linoleic, lauric, palmitic, myrisic and stearic, whichtogether compose about 98.6% of the total fatty acids (Nehdi et al.,2010). Moreover, various reports suggested the presence of �-carotene, �-tocopherol, �-tocopherol, �-tocopherol, �-tocopherol,�-tocotrienol and �-tocotrienol in date seed oil (Besbes et al., 2004;Nehdi et al., 2010). To the best of our knowledge, however, no inves-tigations have been conducted on different varieties of date seedsoil. The present study attempted to shed light on the fatty acid pro-file, along with fat soluble vitamins and carotenoids present in the18 leading varieties of date seed oil from date fruits cultivated inthe UAE.

2. Materials and methods

2.1. Materials

Khalas, Barhe, Lulu, Shikat alkahlas, Sokkery, Bomaan, Sagay,Shishi, Maghool, Sultana, Fard, Maktoomi, Naptit saif, Jabri, Kodary,

568 H.M. Habib et al. / Industrial Crops and Products 42 (2013) 567– 572

Table 1Fat soluble vitamins content of date seed oil (mg/100 g date seed oil).a

Date seed variety �-Tocopherol �-Tocopherol �-Tocopheryl acetate Vitamin K1

Khalas 0.57 ± 0.037bc 1.05 ± 0.013b 0.87 ± 0.004ef 0.19 ± 0.001gBarhe 0.60 ± 0.004bcde 1.07 ± 0.005bc 0.91 ± 0.003fg 0.14 ± 0.021cdefLulu 0.62 ± 0.040cdef 1.23 ± 0.002hi 0.98 ± 0.005i 0.13 ± 0.019abcShikat alkahlas 0.65 ± 0.044defg 1.13 ± 0.010de 0.69 ± 0.018bc 0.16 ± 0.021defSokkery 0.63 ± 0.008cde 1.21 ± 0.003ghi 0.95 ± 0.005hi 0.10 ± 0.002aBomaan 0.62 ± 0.009cdef 1.06 ± 0.003b 0.83 ± 0.009e 0.10 ± 0.000aSagay 0.64 ± 0.008cdefg 1.30 ± 0.003j 0.83 ± 0.001e 0.10 ± 0.002aShishi 0.68 ± 0.023fg 1.25 ± 0.005i 0.85 ± 0.028e 0.12 ± 0.007abcMaghool 0.40 ± 0.019a 1.17 ± 0.002f 0.66 ± 0.008b 0.11 ± 0.002abcSultana 0.70 ± 0.013f 1.20 ± 0.001fgh 0.87 ± 0.027ef 0.12 ± 0.008abcFard 0.68 ± 0.018fg 1.04 ± 0.003b 0.93 ± 0.016gh 0.11 ± 0.001abMaktoomi 0.67 ± 0.036cfg 1.20 ± 0.006fg 0.86 ± 0.002ef 0.12 ± 0.002abcNaptit saif 0.62 ± 0.005bcdef 1.05 ± 0.006b 0.97 ± 0.004hi 0.13 ± 0.014bcdJabri 0.65 ± 0.0189defg 1.17 ± 0.019ef 0.76 ± 0.028d 0.17 ± 0.005fgKhodary 0.45 ± 0.015a 1.01 ± 0.003a 0.71 ± 0.019c 0.16 ± 0.008efDabbas 0.59 ± 0.009bcd 1.10 ± 0.002cd 0.96 ± 0.004hi 0.12 ± 0.002abcRaziz 0.55 ± 0.002b 1.18 ± 0.001f 0.61 ± 0.012a 0.12 ± 0.004abcShabebe 0.67 ± 0.038efg 1.86 ± 0.039k 0.97 ± 0.006hi 0.13 ± 0.006cdeCalculated average for all varieties 0.61 ± 0.080 1.18 ± 0.184 0.85 ± 0.113 0.13 ± 0.027

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a Different letters in a column denote significant differences, P < 0.05.

abbas, Raziz and Shabebe were the varieties investigated in thistudy. Among them Khalas, Barhe, Fard, Raziz and Bumaan are theost common varieties grown and utilized in the UAE. All the

8 varieties of date seeds were obtained at “tamr” stage from aell-known commercial date pack house in the UAE (Al Ain Dates

actory), and had been subjected to uniform harvest and post-arvest treatments (Barreveld, 1993).

Field experiments were carried out in three consecutive grow-ng seasons (2007–2008, 2008–2009 and 2009–2010) at the Al Ainate factory, Al Ain, UAE (24◦13′09′′N; 55◦47′38′′E). The averagennual climatic characteristics of the field experimental locationere: annual average temperature 29 ◦C, annual average maxi-um temperature 36.5 ◦C, annual average minimum temperature

2.2 ◦C, annual average wind speed 13.7 km/h, total rain days5 days, total annual precipitation of rain 60.88 mm, with voidotal days with snow or tornado. The soil type was yellow-brownandy. The season (summer) of collecting tamr (fully ripe dates)s usually spread over a period of 2–3 months; that is, the indus-ry receives freshly harvested tamr batches over a 2-month to-month period. Samples (5 kg from each of the varieties ana-

yzed) were collected randomly from tamr batches at the end ofhe season, with no preference to size, color, appearance or firm-ess. Seeds from the three different seasons were mixed in equalroportions, soaked in water, washed to get rid of any adher-

ng date flesh, and then air-dried. Subsequently, date seeds ofach variety were separately ground to powder form in a heavyuty grinder (IKA M 20 Universal Mill; IKA werke GmbH Co. KG,taufen, Germany) and then stored at −80 ◦C for the chemical anal-sis.

HPLC-grade ethanol, chloroform, n-hexane and acetonitrile forhe preparation of mobile phases and also of standard solu-ions were obtained from Sigma–Aldrich (Taufkirchen, Germany).C–MS grade methanol and formic acid from Sigma–AldrichTaufkirchen, Germany) were used for UPLC analysis. External stan-ards for the quantification of fat soluble vitamins, i.e., vitamin1, �-tocopherol, �-tocopherol, and �-tocopheryl acetate wereought from Supelco (Bellefonte, PA, USA). Whereas, externaltandards for the quantification of carotenoids including lutein,ryptoxanthine, chinenone, lycopene, �-carotene, �-carotene and

-carotene were purchased from Sigma–Aldrich (Taufkirchen,ermany). External standards for identification and quantificationf fatty acid peaks were purchased from (Supelco, Bellefonte, PA,SA).

2.2. Methods

2.2.1. Fat contentLipid extraction was carried out with an SER 148 Solvent Extrac-

tor (Velp Scientifica, Milan, Italy) equipped with six Soxhlet posts.The extraction was carried over a 30 min period, with thimblesimmersed in boiling petroleum ether and 60 min of reflux wash-ing (Besbes et al., 2004). The solvents from seed oils were removedunder a stream of nitrogen and then stored in a freezer (−20 ◦C)until analyzed.

2.2.2. Fatty acid analysisThe extracted oil was converted to their methyl esters using the

standard boron trifluoride–methanol (BF3) method (Moss et al.,1974). The resultant mixture of fatty acid methyl esters (FAME)was injected into a Varian 3900 gas chromatograph equipped withflame ionization detector (FID), capillary column (50 m × 0.25 mm)WCOT Fused Silica (CP-Sil 88 for FAME) at column temperature of190 ◦C, while injector temperature was 270 ◦C and detector tem-perature was 300 ◦C. Separations were carried out with Hydrogencarrier gas. A small quantity of methyl ester solution (1 �L) wasintroduced into the column. The peaks were identified based on theretention times and quantified according to the peak areas of thestandard fatty acid methyl esters at 10 mg/mL. All determinationswere performed in triplicate and the mean values were reported(Nehdi et al., 2010).

2.2.3. Fat soluble vitamins analysisVitamin K1 and vitamin E (�-tocopherol, �-tocopherol, and

�-tocopheryl acetate) standards were first dissolved in n-hexane(1 mg/mL) then diluted with methanol to furnish a 50 �g/mLsolution. For the calibration, each of the standards prepared forvitamin K, �-tocopherol, �-tocopherol, and �-tocopheryl acetatewere diluted separately with methanol, in volumetric flasks, in theconcentration ranges of 0.1–20 �g/mL. Calibration was performedat six concentrations.

For saponification, 1 g of the sample was added into a 45 mL cen-trifugation tube, followed by the addition of 5 mL of the ethanol:ascorbic acid solution (1:1 ratio) and 2 mL of 50% (w/v) KOH solu-

tion. Tubes were vigorously vortex-mixed for 20 s and placed in awater bath at 80 ◦C for 20 min. After removing from the water bath,the contents of the tubes were cooled down, by placing the tubeson ice for 10 min. After that, 20 mL of petroleum ether and 15 mL of

ops and Products 42 (2013) 567– 572 569

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H.M. Habib et al. / Industrial Cr

old distilled water were added. In order to separate the emulsion,he tubes were centrifuged at 2000 × g for 15 min at room tem-erature. After centrifugation, the top organic layer was carefullyransferred to a clean Pyrex tube and evaporated, under a gentletream of nitrogen, on a warm plate at 40 ◦C. The fatty residue waseconstituted in 2 mL of methanol (Korchazhkina et al., 2006).

The fat soluble vitamins were analyzed using ACQUITY UPLC sys-em (Waters, Miliford, MA, USA) operated by Empower 2 software.he analytical UPLC system consisted of a Binary Solvent ManagerWaters E08UPB-133M), Sample Manger (Waters F08UPA-204M)nd a Tunable UV (TUV) detector (Waters E087UPH-918M) withhannel A (291 nm) and channel B (265 nm), resolution 1.2 nmnd a sampling rate of 1 points/s. ACQUITY UPLC BEH C18 column2.1 × 150 mm, 1.7 �m), was held at 25 ◦C. The system was run iso-ratically with 100% mobile phase (0.1% formic acid in acetonitrile),t a flow rate of 500 �L/min and pressure limits of 1000 psi (low)nd 14,500 psi (high). The injection volume and running time were0 �L and 10 min respectively (Escriva et al., 2002).

.2.4. Carotenoids analysisLutein, cryptoxanthine, chinenone, lycopene, �-carotene, �-

arotene and �-carotene standards were first dissolved in hexane1 mg/mL) then diluted with chloroform to furnish a 50 �g/mLolution. For the calibration, each of the standards prepared wereiluted separately with chloroform, in volumetric flasks, in the con-entration ranges of 0.5–25 �g/mL. Calibration was performed atix concentrations.

A sample (0.5 g) was mixed with 0.5 mL of 95% (v/v) ethanol,.1 mL of 0.2% (w/v) BHT in ethanol and 4 mL of hexane in a centrifu-ation tube. Tubes were mixed vigorously and then centrifuged at00 × g for 5 min at room temperature. After centrifugation, 3.5 mLf the top organic layer was carefully transferred to a clean Pyrexube and evaporated, under a gentle stream of nitrogen, on a warmlate at 40 ◦C. The lipid extract was reconstituted in 1 mL of chlo-oform and injected into an HPLC system.

Reversed Phase-High Performance Liquid Chromatography (RP-PLC) was performed on a 1525 Binary HPLC pump (Waters,iliford, MA, USA) separation module equipped with a 717

lus auto-sampler (Waters, Miliford, MA, USA) and 2487 Dual-bsorbance detector (Waters, Miliford, MA, USA) operated byreeze software. The sample (25 �L) was analyzed at 450 nm using

symmetry C18 column (5 �m, 4.6 mm × 150 mm). The system wasun in an isocratic condition with 100% mobile phase (80% ace-onitrile and 20% chloroform) with a flow rate of 0.8 ml/min for aunning time of 20 min (Miller et al., 1984).

.2.5. Statistical analysisAll analytical determinations were performed in triplicate. Sta-

istical analysis was performed using SPSS for windows (version 19;PSS Inc., Chicago, IL, USA). Data obtained was analyzed using anal-sis of variances to determine the significance (P < 0.05) of the mainffects followed by Tukey’s multiple comparison test for signifi-ance of differences. Values of different parameters are expresseds the mean ± standard deviation.

. Results and discussion

.1. Fat soluble vitamins

Vitamin K1, �-tocopheryl acetate, �-tocopherol and �-ocopherol of the 18 date seed oil varieties were analyzed, and theesults obtained illustrate that in date seed oil, �-tocopherol was

he highest, followed by �-tocopheryl acetate, �-tocopherol, anditamin K1 (Table 1). The results showed significant (P < 0.05) dif-erences among several of the 18 date seed varieties for both dateeed and date seed oil. Ta

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570 H.M. Habib et al. / Industrial Crops and Products 42 (2013) 567– 572

Table 3Saturated fatty acid content of date seed oil (g/100 g date seed oil).a

Date seed variety C14:0 C15:0 C16:0 C17:0 C18:0 C20:0 C22:0

Khalas 13.72 ± 0.02f 0.04 ± 0.00a 12.52 ± 0.02i 0.11 ± 0.00g 3.48 ± 0.01m 0.44 ± 0.00j NDBarhe 14.02 ± 0.01g 0.25 ± 0.01g 11.72 ± 0.01d 0.03 ± 0.00a 3.05 ± 0.00f 0.31 ± 0.00d 0.01 ± 0.00bLulu 14.72 ± 0.01i 0.17 ± 0.01e 11.41 ± 0.02b 0.17 ± 0.01i 2.80 ± 0.00d 0.31 ± 0.00d 0.02 ± 0.00cShikat alkahlas 13.33 ± 0.01d 0.37 ± 0.01h 11.91 ± 0.01e 0.03 ± 0.00a 3.34 ± 0.00k 0.40 ± 0.00i 0.03 ± 0.00dSokkery 15.33 ± 0.01k 0.67 ± 0.01d 12.95 ± 0.06k 0.17 ± 0.00i 3.31 ± 0.01j 0.33 ± 0.00e 0.03 ± 0.00dBomaan 13.73 ± 0.02f 1.22 ± 0.01l 13.32 ± 0.01l 0.14 ± 0.00h 3.83 ± 0.00o 0.39 ± 0.00h NDSagay 13.24 ± 0.02c 0.27 ± 0.02g 12.13 ± 0.02g 0.04 ± 0.00b 3.08 ± 0.01g 0.29 ± 0.00c NDShishi 14.23 ± 0.02h 0.63 ± 0.01i 12.92 ± 0.01k 0.03 ± 0.00a 3.42 ± 0.00m 0.29 ± 0.00a 0.17 ± 0.00fMaghool 14.73 ± 0.01i 0.73 ± 0.01j 12.01 ± 0.01f 0.08 ± 0.00 cd 3.52 ± 0.00n 0.31 ± 0.00d NDSultana 10.43 ± 0.01a 1.07 ± 0.01k 14.20 ± 0.01m 0.11 ± 0.00g 6.05 ± 0.00q 0.59 ± 0.00k 0.01 ± 0.00bFard 13.54 ± 0.02e 0.17 ± 0.01e 12.12 ± 0.02g 0.11 ± 0.00g 3.88 ± 0.01p 0.38 ± 0.00g 0.01 ± 0.00bMaktoomi 12.73 ± 0.01b 0.10 ± 0.00bc 11.31 ± 0.01a 0.09 ± 0.00e 2.70 ± 0.00b 0.29 ± 0.00c NDNaptit saif 14.70 ± 0.05i 0.10 ± 0.00bc 12.41 ± 0.01h 0.07 ± 0.00c 3.15 ± 0.00h 0.27 ± 0.00b NDJabri 14.92 ± 0.01j 0.13 ± 0.00d 12.52 ± 0.01i 0.09 ± 0.00e 3.42 ± 0.00m 0.37 ± 0.00f NDKhodary 17.92 ± 0.01m 0.22 ± 0.00f 13.34 ± 0.03l 0.08 ± 0.00d 2.78 ± 0.01c 0.29 ± 0.00c NDDabbas 18.23 ± 0.01n 0.10 ± 0.00bc 12.41 ± 0.01h 0.08 ± 0.00d 2.87 ± 0.00e 0.33 ± 0.00e NDRaziz 14.72 ± 0.01i 0.08 ± 0.01b 11.51 ± 0.01c 0.10 ± 0.00f 2.52 ± 0.00a 0.29 ± 0.01c NDShabebe 17.14 ± 0.02l 0.12 ± 0.00 cd 12.72 ± 0.01j 0.10 ± 0.00f 3.28 ± 0.01i 0.28 ± 0.01b 0.06 ± 0.00e

.41 ±

arKl0hhSplw�aras1o

flK

TM

Calculated average for all varieties 14.52 ± 1.82 0.36 ± 0.34 12

a Different letters in a column denote significant differences, P < 0.05.

The different forms of vitamin E, �-tocopherol, �-tocopherolnd �-tocopheryl acetate, found in the 18 date seed oil varietiesanged between 1.01 mg/100 g and 1.86 mg/100 g for �-tocopherol;hodary had the lowest level, while Shabebe had the highest

evel. Furthermore, for �-tocopheryl acetate, it ranged between.61 mg/100 g and 0.98 mg/100 g; Raziz had the lowest, while Luluad the highest, whereas, for �-tocopherol, Sultana (0.70 mg/100 g)ad the highest, while Maghool (0.40 mg/100 g) had the lowest.imilarly, according to Besbes et al. (2004), �-tocopherol was theredominant component in both varieties of date seed oil ana-

yzed, however, Nehdi et al. (2010), determined a different trendith �-tocopherol being the predominant component followed by-tocopherol and lastly �-tocopherol. Vitamin E is an essentialntioxidant which protects polyunsaturated fatty acids from freeadical damage, thus contributing to the stability of the oil (Yongnd Salimon, 2006). Moreover, vitamin E deficiency affects nervousystem development in children and hemolysis in humans (Sokol,996). People with low vitamin E intake may be at increased riskf atherosclerosis (Rimm et al., 1993).

Date seed oil content for vitamin K1 was different among dif-erent varieties (Table 1), with Bomaan (0.10 mg/100 g) being theowest, while Khalas (0.19 mg/100 g) being the highest. Vitamin

plays an essential role in blood clotting, and recent evidence is

able 4onounsaturated fatty acid content of date seed oil (g/100 g date seed oil).a

Date seed variety C16:1

Khalas 0.13 ± 0.01b

Barhe 0.13 ± 0.02b

Lulu 0.13 ± 0.00b

Shikat alkahlas 0.15 ± 0.00c

Sokkery 0.13 ± 0.01b

Bomaan 0.16 ± 0.00c

Sagay 0.12 ± 0.00ab

Shishi 0.13 ± 0.00c

Maghool 0.13 ± 0.00ab

Sultana 0.16 ± 0.00c

Fard 0.16 ± 0.00c

Maktoomi 0.15 ± 0.00c

Naptit saif 0.15 ± 0.00c

Jabri 0.15 ± 0.01c

Khodary 1.14 ± 0.01e

Dabbas 0.15 ± 0.00c

Raziz 0.11 ± 0.00a

Shabebe 0.19 ± 0.00d

Calculated average for all varieties 0.20 ± 0.23

a Different letters in a column denote significant differences, P < 0.05.

0.74 0.09 ± 0.04 3.36 ± 0.75 0.34 ± 0.08 0.02 ± 0.04

increasingly demonstrating the importance of the vitamin for bonehealth (Suttie, 2006).

3.2. Carotenoids composition

A recent study on the crude P. canariensis seed oil showed thatthe oil exhibited a strong absorbance in the 418–470 nm rangeindicating the presence of an important quantity of carotenoids(5.51 mg/100 g of oil) which is responsible for the yellow color ofthe P. canariensis seed oil (Nehdi et al., 2010). The present investiga-tion is a step further in this direction, where the carotenoid profilesof date seed oil were analyzed, the results of which are illustratedin Table 2. Lutein, cryptoxanthine, echinenone, �-carotene and �-carotene were found in all of the 18 date seeds varieties, whereaslycopene was not detected in Sokkery, Shishi, Maghool, Dabbas andRaziz, together with �-carotene, which was also not detected in 10of the varieties, namely, Shikat alkahlas, Sokkery, Sagay, Maghool,Sultana, Fard, Khodary, Dabbas, Raziz and Shabebe.

The composition of the total natural carotenoid pigments in

date seed oil was highest in Naptit Saif (3.53 mg/100 g date seedoil), whereas it was the lowest in Dabbas (1.46 mg/100 g date seedoil. The difference in concentrations among the 18 date see vari-eties can be attributed to differences between cultivars, degree

C17:1 C18:1 C20:1

0.07 ± 0.00c 55.10 ± 0.01q 043 ± 0.00i0.08 ± 0.00d 48.01 ± 0.01j 0.49 ± 0.00j0.05 ± 0.00a 45.60 ± 0.00f 0.38 ± 0.00e0.07 ± 0.00c 44.90 ± 0.00e 0.53 ± 0.00k0.07 ± 0.00c 44.60 ± 0.00c 0.56 ± 0.00l0.07 ± 0.00c 46.90 ± 0.01h 0.35 ± 0.00c0.06 ± 0.00b 42.31 ± 0.01b 0.35 ± 0.01c0.07 ± 0.00c 46.20 ± 0.00g 0.36 ± 0.00c0.06 ± 0.00b 47.30 ± 0.00i 0.34 ± 0.00b0.06 ± 0.00b 41.40 ± 0.01a 0.37 ± 0.00d0.07 ± 0.00c 48.00 ± 0.00j 0.42 ± 0.00h0.07 ± 0.00c 44.40 ± 0.00d 0.37 ± 0.00d0.07 ± 0.00c 51.40 ± 0.00o 0.37 ± 0.00d0.06 ± 0.00b 48.20 ± 0.00l 0.39 ± 0.00f0.07 ± 0.00c 50.30 ± 0.00n 0.41 ± 0.00g0.07 ± 0.00c 48.10 ± 0.00k 0.42 ± 0.00h0.09 ± 0.00e 52.30 ± 0.00p 0.41 ± 0.00g0.10 ± 0.00f 49.50 ± 0.00m 0.33 ± 0.00a0.07 ± 0.01 47.47 ± 3.38 0.40 ± 0.06

H.M. Habib et al. / Industrial Crops and Products 42 (2013) 567– 572 571

Table 5Polyunsaturated fatty acid profile of date seed oil (g/100 g date seed oil).a

Date seed variety C18:2 C18:2t C18:2 conj C18:3 C18:3t C20:3

Khalas 8.88 ± 1.73abc ND 0.02 ± 0.00abc 0.09 ± 0.00e 0.05 ± 0.00ab 0.10 ± 0.00dBarhe 10.30 ± 0.00efgh ND 0.09 ± 0.00cd 0.11 ± 0.00g 0.23 ± 0.00c NDLulu 9.45 ± 0.00bcdef ND ND 0.05 ± 0.00d 0.02 ± 0.00a 0.01 ± 0.00bShikat alkahlas 9.67 ± 0.00cdefg ND 0.11 ± 0.00d 0.17 ± 0.00j 0.11 ± 0.00b NDSokkery 10.20 ± 0.00defg ND 0.01 ± 0.00ab 0.14 ± 0.00h 0.07 ± 0.00ab NDBomaan 7.90 ± 0.00a 0.01 ± 0.00b 0.09 ± 0.00cd ND 1.13 ± 0.00e 0.02 ± 0.00cSagay 13.90 ± 0.01k ND ND 0.18 ± 0.00k 0.22 ± 0.00c NDShishi 10.70 ± 0.00ghi ND 0.24 ± 0.00e 0.21 ± 0.00l 0.08 ± 0.10ab NDMaghool 11.50 ± 0.00hi ND 0.01 ± 0.00ab 0.04 ± 0.00c 0.02 ± 0.00a NDSultana 10.30 ± 0.01efgh ND ND 0.03 ± 0.00b 0.34 ± 0.00d 0.01 ± 0.00bFard 9.06 ± 0.00abcde ND 0.08 ± 0.10bcd 0.04 ± 0.00c 0.05 ± 0.00ab 0.01 ± 0.00bMaktoomi 10.05 ± 0.00cdefg ND 0.02 ± 0.00abc 0.03 ± 0.00b 0.05 ± 0.00ab NDNaptit saif 11.70 ± 0.00ij ND ND 0.17 ± 0.00j 0.10 ± 0.00b NDJabri 12.80 ± 0.00jk ND ND 0.40 ± 0.00m 0.09 ± 0.01ab NDKhodary 8.33 ± 0.00ab ND ND 0.10 ± 0.00f 0.11 ± 0.00b NDDabbas 9.02 ± 0.00abcd ND ND 0.14 ± 0.01h 0.06 ± 0.00ab NDRaziz 10.40 ± 0.00fgh ND ND 0.09 ± 0.00e 0.08 ± 0.00ab 0.01 ± 0.00bShabebe 9.93 ± 0.00cdefg ND ND 0.15 ± 0.00i 0.05 ± 0.00ab ND

0

ontiao

3

saf(f(a(

Clm9swtalaatps1oPcehMpTou

Calculated average for all varieties 10.23 ± 1.52 0.001 ± 0.0

a Different letters in a column denote significant differences, P < 0.05.

f ripeness, latitude, environmental conditions, processing tech-iques and storage conditions. In general, the composition of theotal carotenoid pigment content of the oils is an important qual-ty parameter because they correlate with color which is a basicttribute for the evaluation of the quality of oil, for example, oliveil (Aparicio et al., 1999).

.3. Fatty acid composition

Fatty acid composition of the 18 studied date seed varieties ishown in Tables 3, 4 and 5. Overall, 12 fatty acids were present inll of the 18 studied date seed varieties, 6 of which were saturatedatty acids, namely, myrsitic (C14:0), pentadeconic (C15:0), palmiticC16:0), heptadecanoic (C17:0), stearic (C18:0) and arachidic (C20:0),ollowed by palmitoleic (C16:1), cis-10-heptadeconic (C17:1), oleicC18:1) and cis-11-eicosenic (C20:1) the monounsaturated fatty acidsnd 2 polyunsaturated fatty acids, linoleic (C18:2), and linolenicC18:3).

The most significant fatty acids in date seed oil were oleic18:1 (47.47%), myrsitic C14:0 (14.52%), palmitic C16:0 (12.41%) and

inoleic C18:2 (10.23%), which together with other minor saturated,onounsaturated and polyunsaturated fatty acid constitute about

7.93% of the total fatty acids. Nehdi et al. (2010) reported that dateeed oil can be regarded as monounsaturated because oleic acidas most abundant, followed by linoleic, lauric, palmitic, myris-

ic and stearic. Our findings report similar concentrations of oleiccid, but myrsitic and palmitic were higher in concentration thaninoleic and lauric as reported by Nehdi et al. (2010). Oleic fattycid is the most widely distributed natural fatty acid (Zubr, 1997),nd high oleic oils normally have positive health aspects because ofheir low saturated fatty acid levels, minimal trans-isomer levels,otential to reduce LDL cholesterol in the blood and high oxidativetability (Nasri et al., 2005; Veeresh Babu et al., 2009; Liang and Liao,992). Olive oil is considered as flavor-stable oil because of the high-leic fatty acid content (∼75%) (Jayadas and Prabhakaran, 2006).eanut oil, lard, tallow and palm oil also have high oleic fatty acidsontents, typically 46.7, 43.9 and 42.5% respectively (Niederprumt al., 1994). Liquid oils with high oleic fatty acid contents normallyave good flavor and frying stability (Yong and Salimon, 2006).

oreover, various reports suggested that linolenic (C18:2) is indis-

ensable for the healthy growth of human skin (Bruckert, 2001).o abridge, the present fatty acid composition of the 18 date seedil varieties makes its prospects vital in terms of nutrition and itssage as edible oil, cooking oil and salad oil.

0.04 ± 0.07 0.12 ± 0.09 0.16 ± 0.25 0.01 ± 0.02

4. Conclusion

Considering the results of the analysis of the fatty acid profile,fat soluble vitamins and carotenoids of the 18 date seed oil vari-eties; we can conclude that date seed oil could be used in cosmetics,pharmaceuticals and food. However, the safety of this oil must betested before use for human nutrition. It is evident that date seedsdo not provide a high yield of oil (Habib and Ibrahim, 2008), butthe oil may serve as a potential source of natural antioxidants (vita-min E), carotenoids (�-carotene) and some phytochemicals (Habiband Ibrahim, 2011), thus this and previous studies (Besbes et al.,2004) consolidate the possibility of incorporating date seed oil asan essential oil.

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