Encapsulation of extract from roasted Kabkab date (Phoenix dactylifera L.) seed using freeze-drying

Document Type : Research Article


1 Ph.D. student, Department of Food Science and Technology, Sarvestan Branch, Islamic Azad University, Sarvestan, Fars, Iran

2 Assistant Professor, Department of Food Science and Technology, Sarvestan Branch, Islamic Azad University, Sarvestan, Fars, Iran.

3 Assistant Professor, Department of Fisheries, Faculty of Marine Natural Resources, Khorramshahr University of Marine Science and Technology, Khorramshahr, Iran


The present study aimed to investigate the physicochemical characteristics of the encapsulated roasted date-seed (180°C, 20 min) extract. Date-seed (Phoenix dactylifera L. cv Kabkab) extract was obtained using a combination of ultrasound- (25 ± 5 ºC, 15min.) and microwave- (2.30min.) assisted extraction. Phenolic-compounds of the extract were identified by HPLC. The encapsulation process was done by the freeze-drying method. Soy-protein concentrate and maltodextrin were used as wall materials (M(100): Pure Maltodextrin; S(100): Pure Soy-protein; MS(75:25): Maltodextrin: Soy-protein (75:25%); MS (50:50): Maltodextrin: Soy-protein (50:50%); MS (25:75): Maltodextrin: Soy-protein (25:75%)). Gallic-acid (536.87 mg 100 g-1dEx) and catechin (214.79 mg 100 g-1dEx) were the major phenolic and flavonoid compounds of the extract. The type of wall material had no significant effect on the moisture content and water-activity. The microparticle's bulk-density was varied from 0.232-0.178 g cm-3. The difference between M(100) and S(100) was significant. The microparticles showed a heterogeneous and irregular structure with flake- and sheet-shaped morphology. Several cracks were visible on the M(100) surface. The best encapsulation-efficiency was achieved for microparticles using a combination of maltodextrin and soy-protein (especially, MS(50.50)). While 68.88% of free-extract polyphenols were destroyed after 35 days at 35 °C, the encapsulation process caused retaining 61.79% (M(100)) to 76.69% (MS(50.50)). Overall, due to the appropriate solubility, low moisture, water-activity and the ability to preserve phenolic compounds of date-seed extract, encapsulation in maltodextrin-soy-protein (MS(50.50)) wall materials could be proposed as an efficient and cost-effective bioactive compound to preserve different food products and improve their nutritional value.

Graphical Abstract

Encapsulation of extract from roasted Kabkab date (Phoenix dactylifera L.) seed using freeze-drying


  • The phenolics of date-seed extracted by ultrasound-microwave-assisted method was identified.
  • Date-seed extract was encapsulated by maltodextrin (MD) and soy protein concentrate (SPC).
  • Encapsulation efficiency of MD-SPC samples was better than others.
  • Microparticles of date seed extract are an effective and affordable bioactive compound.


Main Subjects

[1] Urquiaga, I., & Leighton, F. (2000). Plant polyphenol antioxidants and oxidative stress. Biol. Res., 33(2), 55-64.
[2] Trivedi, M. R., Morecroft, M. D., Berry, P. M., & Dawson, T. P. (2008). Potential effects of climate change on plant communities in three montane nature reserves in Scotland, UK. Biol. Conserv., 141(6), 1665-1675.
[3] Copley, M. S., Rose, P. J., Clapham, A., Edwards, D. N., Horton, M. C., & Evershed, R. P. (2001). Detection of palm fruit lipids in archaeological pottery from Qasr Ibrim, Egyptian Nubia. Proc. R. Soc. B: Biol. Sci., 268 (1467), 593-597.
[4] Benton, M. J., & Donoghue, P. C. (2007). Paleontological evidence to date the tree of life. Mol. Biol. Evol., 24(1), 26-53.
[5] Hmidani, A., Bourkhis, B., Khouya, T., Ramchoun, M., Filali-Zegzouti, Y., & Alem, C. (2020). Phenolic profile and anti-inflammatory activity of four Moroccan date (Phoenix dactylifera L.) seed varieties. Heliyon. 6(2), e03436.
[6] Metoui, M., Essid, A., Bouzoumita, A., & Ferchichi, A. (2019). Chemical Composition, Antioxidant and Antibacterial Activity of Tunisian Date Palm Seed. Pol. J. Environ. Stud., 28(1), 1-8.
[7] FAOSTAT. (2021). Dates, World Food and Agriculture - Statistical Yearbook 2021. Rome, Italy: The Food and Agriculture Organization (FAO). Accessed 28 March 2021. Dates.
[8] Ashraf, Z., & Hamidi-Esfahani, Z. (2011). Date and date processing: a review. Food Rev. Int., 27(2), 101-133.
[9] Al-Farsi, M. A., & Lee, C. Y. (2011). Usage of date (Phoenix dactylifera L.) seeds in human health and animal feed. In  Preedy, V.P., Watson, R.R. & Patel, V.V. (Ed.s) Nuts and seeds in health and disease prevention (pp. 447-452). Netherlands: Elsevier.
[10] Maqsood, S., Adiamo, O., Ahmad, M., & Mudgil, P. (2020). Bioactive compounds from date fruit and seed as potential nutraceutical and functional food ingredients. Food Chem., 308, 125522. doi:https://doi.org/10.1016/j.foodchem.2019.125522
[11] Habib, H. M., Platat, C., Meudec, E., Cheynier, V., & Ibrahim, W. H. (2014). Polyphenolic compounds in date fruit seed (Phoenix dactylifera): characterisation and quantification by using UPLC‐DAD‐ESI‐MS. J. Sci. Food Agric., 94(6), 1084-1089.
[12] Al-Farsi, M. A., & Lee, C. Y. (2008). Optimization of phenolics and dietary fibre extraction from date seeds. Food Chem., 108(3), 977-985.
[13] Thouri, A., Chahdoura, H., El Arem, A., Hichri, A. O., Hassin, R. B., & Achour, L. (2017). Effect of solvents extraction on phytochemical components and biological activities of Tunisian date seeds (var. Korkobbi and Arechti). BMC Complement Altern Med., 17(1), 1-10.
[14] Hasan, M., & Mohieldein, A. 2016. In vivo evaluation of anti diabetic, hypolipidemic, antioxidative activities of Saudi date seed extract on streptozotocin induced diabetic rats. JCDR., 10(3), FF06.
[15] Giusti, M. M., & Wrolstad, R. E. (2003). Acylated anthocyanins from edible sources and their applications in food systems. Biochem. Eng. J., 14(3), 217-225.
[16] Sharif, N., Khoshnoudi-Nia, S., & Jafari, S. M. (2020). Nano/microencapsulation of anthocyanins; a systematic review and meta-analysis. Int. Food Res. J. 132, 109077. doi:https://doi.org/10.1016/j.foodres.2020.109077.
[17] Šaponjac, V. T., Ćetković, G., Čanadanović-Brunet, J., Djilas, S., Pajin, B., Petrović, J., Stajčić, S., & Vulić, J. (2017). Encapsulation of sour cherry pomace extract by freeze drying: Characterization and storage stability. Acta Chim. Slov., 64(2), 283-289.
[18] Khoshnoudi-Nia, S., Sharif, N., & Jafari, S.M. (2022). Loading of phenolic compounds into electrospun nanofibers and electrosprayed nanoparticles. Trends Food Sci. Technol., 95,  59-74.
[19] Samborska, K., Boostani, S., Geranpour, M., Hosseini, H., Dima, C., Khoshnoudi-Nia, S. Rostamabadi, H., Falsafi, R., Shaddel, R., Akbari-Alavijeh, S., Jafari, M. (2021). Green biopolymers from by-products as wall materials for spray drying microencapsulation of phytochemicals. Trends Food Sci. Technol., 108,  297-325.
[20] Comunian, T.A. & Favaro-Trindade, C.S. (2016). Microencapsulation using biopolymers as an alternative to produce food enhanced with phytosterols and omega-3 fatty acids: A review. Food Hydrocoll., 61, 442-457.
[21] Ince, A.E., Sahin, S. & Sumnu, G. (2014). Comparison of microwave and ultrasound-assisted extraction techniques for leaching of phenolic compounds from nettle. J. Food Sci. Technol., 51(10), 2776-2782.
[22] Araujo, C. d. S., Vimercati, W. C., Macedo, L. L., Saraiva, S. H., Teixeira, L. J. Q., da Costa, J. M. G., & Pimenta, C. J. (2022). Encapsulation of phenolic and antioxidant compounds from spent coffee grounds using spray‐drying and freeze‐drying and characterization of dried powders. J. Food Sci., 87(9), 4056-4067.
[23] Ballesteros, L. F., Ramirez, M. J., Orrego, C. E., Teixeira, J. A., & Mussatto, S. I. (2017). Encapsulation of antioxidant phenolic compounds extracted from spent coffee grounds by freeze-drying and spray-drying using different coating materials. Food Chem. 237, 623-631.
[24] Cai, X., Du, X., Cui, D., Wang, X., Yang, Z., & Zhu, G. (2019). Improvement of stability of blueberry anthocyanins by carboxymethyl starch/xanthan gum combinations microencapsulation. Food Hydrocoll., 91, 238-245.
[25] Esmaeili, F., Hashemiravan, M., Eshaghi, M. R., & Gandomi, H. (2022). Encapsulation of Arctium lappa L. root extracts by spray-drying and freeze-drying using maltodextrin and Gum Arabic as coating agents and it’s application in synbiotic orange-carrot juice. J. Food Meas. Charact, 1-14.
[26] Ahmed, I. A. M., Al Juhaimi, F. Y., Osman, M. A., Al Maiman, S. A., Hassan, A. B., Alqah, H. A., Babiker, E. E., & Ghafoor, K. (2020). Effect of oven roasting treatment on the antioxidant activity, phenolic compounds, fatty acids, minerals, and protein profile of Samh (Mesembryanthemum forsskalei Hochst) seeds. LWT. 131, 109825.
[27] Fikry, M., Yusof, Y. A., M. Al-Awaadh, A., Abdul Rahman, R., Chin, N. L., & Ghazali, H. M. (2019). Antioxidative and quality properties of full-fat date seeds brew as influenced by the roasting conditions. Antioxidants. 8(7), 226.
[28] Pourshoaib, S. J., Ghatrami, E. R., & Shamekhi, M. A. (2022). Comparing ultrasonic-and microwave-assisted methods for extraction of phenolic compounds from Kabkab date seed (Phoenix dactylifera L.) and stepwise regression analysis of extracts antioxidant activity. Sustain. Chem. Pharm. 30, 100871.
[29] Ahmed, A., Arshad, M. U., Saeed, F., Ahmed, R. S., & Chatha, S. A. S. (2016). Nutritional probing and HPLC profiling of roasted date pit powder. PJN., 15(3), 229.
[30] Chen, C. (2003). Evaluation of air oven moisture content determination methods for rough rice. Biosyst. Eng., 86 (4), 447-457.
[31] Høstmark, Ø., & Teigland, S. (2009). Role of Water Activity of Liquid in Controlling Evaporation Rate of Low-Viscosity Liquids. Dry. Technol. 27(10), 1152-1155.
[32] Abdullah, E. C., & Geldart, D. (1999). The use of bulk density measurements as flowability indicators. Powder Technolo., 102(2), 151-165.
[33] Anema, S., Pinder, D., Hunter, R., & Hemar, Y. 2006. Effects of storage temperature on the solubility of milk protein concentrate (MPC85). Food Hydrocoll., 20 (2-3), 386-393.
[34] Der Want, V. (1998). A comparative study of thin coatings of Au/Pd, Pt and Cr produced by magnetron sputtering for FE‐SEM. J. Microsc., 189(1), 79-89.
[35] Singleton, V. L., Orthofer, R., & Lamuela-Raventós, R. M. (1999).  Analysis of total phenols and other oxidation substrates and antioxidants by means of folin-ciocalteu reagent. Meth. Enzymol., 299, 152-178.
[36] Altunkaya, A., Hedegaard, R. V., Harholt, J., Brimer, L., Gökmen, V., & Skibsted, L. H. (2013). Oxidative stability and chemical safety of mayonnaise enriched with grape seed extract. Food Funct., 4(11), 1647-1653.
[37] Al Juhaimi, F., Özcan, M. M., Adiamo, O. Q., Alsawmahi, O. N., Ghafoor, K., & Babiker, E. E. (2018). Effect of date varieties on physico‐chemical properties, fatty acid composition, tocopherol contents, and phenolic compounds of some date seed and oils. J. Food Process. Preserv., 42(4), e13584.
[38] Nayak, C. A., & Rastogi, N. K. (2010). Effect of selected additives on microencapsulation of anthocyanin by spray drying. Dry. Technol. 28(12), 1396-1404.
[39] Mansour, M., Salah, M., & Xu, X. (2020). Effect of microencapsulation using soy protein isolate and gum arabic as wall material on red raspberry anthocyanin stability, characterization, and simulated gastrointestinal conditions. Ultrason. Sonochem, 63, 104927.
[40] Alifakı, Y. Ö., Şakıyan, Ö., & Isci, A. (2022). Investigation of Storage Stability, Baking Stability, and Characteristics of Freeze-Dried Cranberrybush (Viburnum opulus L.) Fruit Microcapsules. Food Bioproc. Tech., 15 (5), 1115-1132.
[41] Tonon, R. V., Baroni, A. F., Brabet, C., Gibert, O., Pallet, D., & Hubinger, M. D. (2009). Water sorption and glass transition temperature of spray dried açai (Euterpe oleracea Mart.) juice. J. Food Eng., 94 (3-4), 215-221.
[42] Navarro-Flores, M. J., Ventura-Canseco, L. M. C., Meza-Gordillo, R., Ayora-Talavera, T. d. R., & Abud-Archila, M. (2020). Spray drying encapsulation of a native plant extract rich in phenolic compounds with combinations of maltodextrin and non-conventional wall materials. J. Food Sci. Technol. 57(11), 4111-4122.
[43] Cortés-Rojas, D. F., Souza, C. R. F., & Oliveira, W. P. (2015). Optimization of spray drying conditions for production of Bidens pilosa L. dried extract. Chem Eng Res Des., 93, 366-376.
[44] Grabowski, J., Truong, V.-D., & Daubert, C. (2008). Nutritional and rheological characterization of spray dried sweetpotato powder. LWT-Food Sci. Technol. 41(2), 206-216.
[45] Murali, S., Kar, A., Mohapatra, D., & Kalia, P. (2015). Encapsulation of black carrot juice using spray and freeze drying. FSTI., 21(8), 604-612.
[46] Papoutsis, K., Golding, J. B., Vuong, Q., Pristijono, P., Stathopoulos, C. E., Scarlett, C. J., & Bowyer, M. (2018). Encapsulation of citrus by-product extracts by spray-drying and freeze-drying using combinations of maltodextrin with soybean protein and ι-Carrageenan. Foods, 7(7), 115.
[47] González-Ortega, R., Faieta, M., Di Mattia, C. D., Valbonetti, L., & Pittia, P. (2020). Microencapsulation of olive leaf extract by freeze-drying: Effect of carrier composition on process efficiency and technological properties of the powders. J. Food Eng., 285, 110089.
[48] Sassi, C. B., Marcet, I., Rendueles, M., Díaz, M., & Fattouch, S. (2020). Egg yolk protein as a novel wall material used together with gum Arabic to encapsulate polyphenols extracted from Phoenix dactylifera L pits. LWT., 131, 109778.
[49] Šturm, L., Črnivec, I. G. O., Istenič, K., Ota, A., Megušar, P., Slukan, A., Humar, M., Levic, S., Nedović, V., & Deželak, M. (2019). Encapsulation of non-dewaxed propolis by freeze-drying and spray-drying using gum Arabic, maltodextrin and inulin as coating materials. Food Bioprod. Process., 116, 196-211.
[50] Mahdavi, S. A., Jafari, S. M., Assadpoor, E., & Dehnad, D. (2016). Microencapsulation optimization of natural anthocyanins with maltodextrin, gum Arabic and gelatin. Int. J. Biol. Macromol., 85, 379-385.
[51] Dadi, D. W., Emire, S. A., Hagos, A. D., & Eun, J.-B. (2020). Physical and functional properties, digestibility, and storage stability of spray-and freeze-dried microencapsulated bioactive products from moringa stenopetala leaves extract. Ind. Crops Prod., 156, 112891.
[52] Tao, Y., Wang, P., Wang, J., Wu, Y., Han, Y., & Zhou, J. (2017). Combining various wall materials for encapsulation of blueberry anthocyanin extracts: Optimization by artificial neural network and genetic algorithm and a comprehensive analysis of anthocyanin powder properties. Powder Technolo., 311, 77-87.
[52] Souza, A. C. P., Gurak, P. D., & Marczak, L. D. F. (2017). Maltodextrin, pectin and soy protein isolate as carrier agents in the encapsulation of anthocyanins-rich extract from jaboticaba pomace. Food Bioprod. Process. 102, 186-194.
[53] Jafari, S.-M., Mahdavi-Khazaei, K., & Hemmati-Kakhki, A. (2016). Microencapsulation of saffron petal anthocyanins with cress seed gum compared with Arabic gum through freeze drying. Carbohydr. Polym., 140, 20-25.
Volume 10, Issue 3
May 2023
Pages 249-265
  • Receive Date: 18 February 2023
  • Revise Date: 18 June 2023
  • Accept Date: 30 June 2023
  • First Publish Date: 30 June 2023