Date Fruit Varieties Research Articles

Metabolomic fingerprints of 21 date palm fruit varieties from Egypt using UPLC/PDA/ESI–qTOF-MS and GC–MS analyzed by chemometrics

Date palm fruits of the species Phoenix dactylifera exhibit a great diversity in sensory attributes including skin color, smell and taste. This study attempts to elucidate the primary and secondary metabolite profiles of 21 date varieties from Egypt. A major difficulty is sugar rich matrix and skin-fibers embedding the secondary metabolites. A total of 49 metabolites extracted from the fruit skin were evaluated in a UPLC/PDA/ESI–qTOF-MS based metabolomics study. The total phenolic contents of the varieties varied from 233 to 1897mg/100g (2.3–19g/kg) dry weight. The predominant flavones were glycosides of luteolin and apigenin, quercetin conjugates were the principal flavonols, whereas caffeoyl shikimic acid was the main hydroxycinnamic acid conjugate. Aside from these major phenolic classes, a group of sphingolipids, fatty and other organic acids was also identified. The total non-fatty organic acid content correlates with reported shelf lives. GC–MS was further utilized to localize primary metabolites in fruits (i.e. sugars and organic acids) with glucose and fructose accounting for up to 95% of TIC among most varieties. Principal component and clustering analyses reveal that flavonols and sugars, both contribute the most to variety classification. This study provides the most complete map for polyphenol & sugar distribution in Egyptian date fruit varieties. By describing the metabolite profiles in a diverse dataset of P. dactylifera, this study provides the basis for future investigations of date fruit nutritional value beyond providing energy and its potential for nutraceutical enhancement or storability.

Production of date palm fruits free of acaricides residues by ozone technology as post-harvest treatment.

Distilled water and ozonated water as postharvest wash treatments for 15-60min as dipping times were tested to remove two acaricides namely, dicofol and amitraz from different varieties of date fruits. Recovered amount of the acaricides was extracted using solid phase extraction (SPE) and then analyzed by gas chromatography-mass spectrometry (GC-MS). Dicofol removal percentages in the presence of ozone increased in the order of Nabtet Aly > Nabout Seif > Khalas > Sakay, while amitraz removal increased in the order of Nabtet Aly > Nabout Seif > Sakay > Khalas, respectively, and the percentages of residues on date fruits depended on the dipping time. Kinetic studies revealed that dicofol and amitraz were easily removable from date fruits treated with ozonated water. Ozone-treated date palm fruits were not associated with significant changes in antioxidant capacity, and phenolic and sugar contents. Due to the large amount of dates consumed by Saudi residents, a higher risk of exposure to pesticides, especially in children and other vulnerable individuals may occur and the search for safety methods to remove pesticides with negligible residual deposits has always been preferred. Therefore, the present study validated that ozone technology as wash treatments is safe and promising processes for the removal of acaricides from date fruits surface under domestic conditions to reduce the impact over consumer's health.

English

Date fruits are consumed as traditional and ideal food in Saudi Arabia. It provides a wide range of essential nutrients and potential health benefits. Twelve (12) most consumed varieties of date fruits and their seeds available in the open markets of Riyadh, Medina and Kharj were screened for the presence of bacteria and fungi. Our study reveals that these fruits carry a heavy load of both fungal and bacterial pathogens. The variety Sukhari was found to be the most contaminant fruit with fungi while the bacterial contamination was highest in the variety Mabroon. The Genus Aspergillus was represented by seven species, amongst which Aspergillus niger was the most predominant fungi. Potential pathogens like Staphylococcus aureus and Escherichia coli were isolated besides six species of the genus Bacillus. Fruits were more contaminated than their seeds.   Key words: Date fruits, seed borne, fruit spoilage, open markets.

Physicochemical properties and mineral contents of seven different date fruit (Phoenix dactylifera L.) varieties growing from Saudi Arabia

The date (Phoenix dactylifera L.) fruits (Soukari, Soulag, Barhi, Khulas, Rozaiz, Soughi and Monaif) were evaluated with respect to some physical and chemical properties. While crude protein contents of fruits change between 1.51% (Soulag) to 2.41% (Soughi), crude fibre contents ranged between 1.91% (Soukari) to 3.90% (Barhi). Vitamin C contents of date samples changed between 971.82 mg/kg (Soughi) to 1,453.15 mg/kg (Barhi). Antioxidant activity of date fruits ranged from 80.07 IC50 (Soukari) to 81.21 IC50 (Soulag). The highest phenolic content was found in Khulas with a mean value of 198 mg GAE/100 g. Energy values of date fruits ranged from 3,725 kcal/kg (Soulag) to 3,870 kcal/kg (Soukari). Sucrose contents of date fruits changed between 1.02% (Soulag) to 55.71% (Soukari). Mineral contents of several date fruits were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Date samples contain potassium at a range between 7,468 mg/kg (Khulas) to 9,619 mg/kg (Soulag). Phosphorus contents of fruits were found between 1,848 mg/kg (Soulag) to 3,066 mg/kg (Rozaiz) and followed by magnesium and calcium. The highest Zn (9.33 mg/kg), Cu (4.27 mg/kg) and Mn (3.26 mg/kg) were found in Rozaiz, Soukari and Barhi samples, respectively.

Phenolic Profile and Antioxidant Activity of Date-Pits of Seven Algerian Date Palm Fruit Varieties

The total phenolic content of methanol and ethyl-acetate extracts of pits from seven Algerian palm date (Phœnix dactylifera L.) fruit varieties was estimated by the Folin-Ciocalteau method. Their respective antioxidant activities were evaluated by the DPPH· and the Co(II)-EDTA luminol chemiluminescence tests and their phenolic profile was established by LC-DAD-MS (ESI− and ESI+). The total phenolic content of the methanolic extracts ranged from 27.2 to 38.5 mg of caffeic acid equivalents CAE/100 g fresh weight, while the ethyl acetate extracts gave contents ranging from 22.8 to 42.6 mg CAE/100 g fresh weight. The antiradical and the hydroxyl scavenging activities of the methanolic extracts were much higher than those of the ethyl acetate extracts. The different varieties that were studied did not show any major difference in their phenolic profile. Indeed, all the varieties contained mainly catechin or epi catechin derivatives, sinapic, cinnamic, and coumaric acid derivatives. However, it should be noted that, unexpectedly, a glycosylated aurone was tentatively identified in the Tazizaout variety. Further investigations are required to characterise the non-identified flavonoids.

Differentiation of post harvest date fruit varieties non‐destructively using FT‐NIR spectroscopy

SummaryThe world production of dates has more than doubled over the last two decades. Presently, the industrial sorting of dates is a difficult operation, affected by a high level of losses. As a consequence, the objective of this article is to study the variety discrimination capabilities of Fourier Transform‐Near Infrared (FT‐NIR) reflectance spectroscopy for post‐harvest sorting purposes. The same methodology was tested on six commercial date varieties named Estamaran, Kabkab, Mazafati, Piarom, Deglet nour and Zahedi. For each cultivar, 100 fruits were analysed using the FT‐NIR spectrometer, subsequently characterised by destructive measurements. A multivariate analysis of the FT‐NIR spectra appears a feasible tool for cultivar discrimination and even to estimate the soluble solid content (SSC) and dry matter (DM) of dates at their optimal harvesting conditions. FT‐NIR, as a non‐destructive techniques, could be a suitable way for on‐line screening of different dates varieties.

Carotenoids, fat soluble vitamins and fatty acid profiles of 18 varieties of date seed oil

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 profiles. 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 oleic acid (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. β-Carotene was found to be the most occurring carotenoid in all of the 18 date seed oil varieties and ranged between 1.18mg and 2.68mg/100g. Moreover, the 18 date seed oils depicted considerable concentrations of vitamin E (ranged between 1.01mg and 1.86mg/100g α-tocopherol; 0.61mg and 0.98mg/100g α-tocopheryl acetate; 0.40mg and 0.70mg/100g γ-tocopherol), and vitamin K1 (ranged between 0.10mg and 0.19mg/100g). The results obtained indicate a strong potential for date seed oil to be used as a source of essential fatty acids in healthy edible oil, as well as in cosmetics and pharmaceutical applications.

Physical and chemical properties, antioxidant activity, total phenol and mineral profile of seeds of seven different date fruit (Phoenix dactylifera L.) varieties

The physical and chemical properties of the date (Phoenix dactylifera L.) fruit seeds from seven date samples (Soukari, Soulag, Barhi, Khulas, Rozaiz, Soughi and Monaif) were evaluated. Energy values of dried and ground seeds were found between 4340 kcal/kg (Barhi cv) and 4795 kcal/kg (Rozaiz cv). Also, while crude oil content of seeds were established between 4.68% (Khulas cv) and 7.96% (Monaif cv), crude protein contents were found at the levels between 3.71% (Soulag cv) and 5.47% (Barhi cv). The antioxidant activity of seeds obtained from different date fruits changed between 78.03 (mg/ml) (Monaif cv) and 79.94 (mg/ml) (Barhi cv). In addition, the total phenol contents of seeds were found between 1.98 mg gallic acid equivalents (GAE)/100 g (Barhi cv) and 4.65 mg GAE/100 g (Soughi cv). The most abundant fatty acids of the date seed oils were oleic, lauric, myristic, palmitic and stearic acids. Ca, Mg, K and P contents of date seeds were found at the high concentrations.

Nutritional quality of 18 date fruit varieties

The aim of the present study was to analyze and compare the chemical and physical properties of 18 varieties of the date fruits from date palm (Phoenix dactylifera), which are regarded as popular fruit commodities among the populace of the Middle Eastern peninsula. Dietary fiber, proximate analysis, micronutrients (micro-elements and macro-elements) and physical properties (weight, length, and density) of the selected 18 leading varieties of dates cultivated in the United Arab Emirates—namely Khalas, Barhe, Lulu, Shikat alkahlas, Sokkery, Bomaan, Sagay, Shishi, Maghool, Sultana, Fard, Maktoomi, Naptit saif, Jabri, Khodary, Dabbas, Raziz and Shabebe—were determined and compared. Significant differences (P < 0.05) in the measured parameters were observed among the different varieties. However, the results depict that date fruits, depending on the variety, contain significant but quite variable amounts of macro-elements and micro-elements. The macro-elements measured are calcium, phosphorous, sodium, potassium and magnesium, while the essential micro-elements and the possibly essential micro-elements are iron, zinc, copper, manganese, cobalt and molybdenum, and aluminum, arsenic, barium, cadmium, chromium, nickel, lead, strontium and vanadium, respectively.

Nutritional Composition and in vitro Evaluation of the Antioxidant Properties of Various Dates Extracts (Phoenix dactylifera L.) from Libya

The aim of this study was to examine the nutritional content and antioxidant potential of three date fruit varieties (Phoenix dactylifera L.) native to Libya, namely, Bekraray, Deglet-nour and Khathori. The fruits were collected from three districts of Libya covering the northern, southern and eastern areas, respectively. The fruits were pitted and the flesh was extracted at 60° C for 6 h. The antioxidant activity of the extract was measured using 1-diphenyl-2-picrylhydrazyl (DPPH) method and iron (3) reduction (FRAP) assay. The Total Phenolic Content (TPC) of the date was measured using the Fohn-Ciocalteau method. The results showed that the nutritional content of dates varied by source. The flesh of Bekraray dates contained high percentage of carbohydrates (76.97%), vitamin C (8.50 mg 100 g) and potassium (6043.2 mg kg-1) whereas, Deglet-nour variety demonstrated the high percentage of total sugar (73.25%), vitamin A (10.50 μ/100g) and vitamin E (12.98 mg kg-1). On the other hand, Khathori variety showed high percentage of vitamin B2, magnesium, calcium, sodium and ferum with concentrations of 824.98, 660.74, 614.21,485.86 and 20.29mg kg-1, respectively. The Bekraray dates exhibited a significantly high concentration of TPC (p<0.05) from those of the two other varieties. The antioxidant activity correlated positively with the TPC of the extracts. The Bekraray also showed high FRAP value and free radical scavenging activity (DPPH) among the studied date varieties and the values corresponded to 13.46±0.11 umol (Fe)/g and 78.9%, respectively. These results suggest that Libyan dates varieties have a high nutritional value and possess beneficial antioxidant properties. Bekraray date was found to be superior than Deglet-nour and Khathori variety.

EVALUATION OF ANTIOXIDANT ACTIVITY, PHENOLICS, SUGAR AND MINERAL CONTENTS IN DATE PALM FRUITS

ABSTRACT Sugar and mineral compositions of 10 Tunisian date varieties were investigated. Hydrophilic (aqueous extract) and hydrophobic extracts (ethanol extract) were used to determine the phenol contents and the total antioxidant activities of these dates. Results showed that date fruit varieties were rich in soluble sugars, which varied from 35.57 (Smiti variety) to 77.88 g/100 g fresh weight (FW) (Korkobbi variety). Several minerals were also present in the following order; K, Ca, P, Mg, Na, Fe, Cu, Zn and Mn. The potassium content reached 0.74 g/100 g dry weight in Smiti variety. For all date varieties, the phenol content did not exceed 9.70 (milligram of gallic acid equivalent/100 g FW). The original antioxidant activity reached 31.86 mg of ascorbic acid equivalent antioxidant capacity/100 g (FW) for Garn ghzal variety. However, it was only 17.77 for the Nefzaoui. Therefore, it can be deduced from these results that all these fruit varieties can be considered as high-energy food and only Garn ghzal seems to be interesting for technological purposes as food antioxidants. PRACTICAL APPLICATIONS The date palm (Phoenix dactylifera L.) has a very important economic, social and ecological role for the people of the arid and semiarid regions. The date world production tripled while passing from 2,289,511 tons in 1974 to 6,772,068 tons in 2004. In Tunisia, dates witnessed a remarkable development during the last years and the production reached an average of 110,000 tons per year. Unfortunately, this progress in production is accompanied by an increasing loss of secondary varieties. Among these abandoned varieties are those of Gabès oasis. In this context, our work focuses on valorizing these secondary varieties by determining their nutritional and medicinal properties.

Susceptibility of Some Varieties of Date Fruits to Support the Production of Aflatoxins: Analysis by High Performance Liquid Chromatography

Susceptibility of Some Varieties of Date Fruits to Support the Production of Aflatoxins: Analysis by High Performance Liquid Chromatography

The production of aflatoxins in fresh date fruits and under simulated storage conditions

AbstractSixteen varieties of date fruit (Phoenix dactylifera) at three stages of maturation (Kimri, Rutab and Tamr) were examined for the presence of fungi and analysed for aflatoxins B1, B2, G1 and G2 and sterigmatocystin. Single samples of each variety were used in the study. Samples as received were initially examined for mycoflora and toxin levels and then stored at 98% relative humidity and 30 °C for 14 days to investigate the effects of possible adverse storage conditions on mycoflora and, in particular, aflatoxin formation. All samples showed an absence of aflatoxins and their precusor, sterigmatocystin, after adverse storage for 14 days, although aflatoxin‐producing Aspergillus flavus isolates were identified in 10 varieties at the first stage of maturation (Kimri). High fungal counts were associated with the Rutab stage and low counts with the Tamr stage. The counts of A flavus ranged from 5.00 to 8.16 log10(cfu g−1) under simulated storage conditions, and three varieties contained significant levels of aflatoxin B1 or B2 ranging from 35 to 11 610 µg kg−1. Sterigmatocystin was not detected in any of the samples as received or under simulated storage conditions.© 2002 Society of Chemical Industry