Extraction of Phenolic Compounds from Olive Fruit and Olive Byproducts

Abstract

Phenolic compounds are bioactive substances found in plants that exhibiting antioxidant, antimicrobial, and anticarcinogenic properties. Olive fruits contain a variety of phenolic compounds, including phenolic acids (caffeic, ferulic, p-hydroxyphenylacetic, p-coumaric, and 3,4-dihydroxyphenylacetic), phenolic alcohols (hydroxytyrosol, tyrosol), flavonoids (Luteolin-7 glycoside, Apigenin), and secoiridoids (oleuropein).The phenolic content and quantity of the fruit are affected by olive variety, production, maturity, and ecological factorsAlongside traditional techniques, green biorefinery technologies have been implemented for phenolic compound retrieval in recent years. These technologies include ohmic heating, pulsed electric field (PEF), ultrasound (UAE) and microwave-assisted extraction (MAE). These methods not only increase extraction efficiency and quality but also reduce extraction time and energy consumption. This review paper examines the significance of phenolic compounds present in olive fruit and its by-products, as well as the environmentally friendly bio-refinery technologies employed for extracting these compounds.

Keywords

• Olive (Olea europaea L.)
• Phenolic Compounds
• Green Biorefinery Technologies

Zeytin Meyvesi ve Zeytin Yan Ürünlerinden Fenolik Bileşiklerin Ekstraksiyonu

Abstract

Fenolik bileşikler, bitkilerde bulunan ve antioksidan, antimikrobiyal, antikarsinojenik gibi biyoaktiviteleri olan biyoaktif bileşiklerdir. Zeytin meyveleri, kafeik, ferulik, p-hidroksifenilasetik, p-kumarik ve 3,4-dihidroksifenilasetik gibi fenolik asitler, hidroksitirosol ve tirosol gibi fenolik alkoller, Luteolin-7 glikozit ve Apigenin gibi flavonoidler ve oleuropein gibi sekoiridoidler de dahil olmak üzere çeşitli fenolik bileşikler içerir. Meyvenin fenolik içeriği ve miktarı, zeytin çeşidi, üretim, olgunluk ve ekolojik faktörlerden etkilenir. Son yıllarda fenolik bileşiklerin ekstraksiyonunda geleneksel yöntemlerin yanı sıra yeşil biyo-rafine teknolojiler kullanılmaktadır. Bu teknolojiler arasında ohmik ısıtma, darbeli elektrik alan (DEA), ultrason (UDE) ve mikrodalga destekli ekstraksiyon (MDE) teknolojileri yer almaktadır. Bu yöntemler, ekstraksiyon süresini ve enerji kullanımını azaltırken, yüksek verim ve kalite sağlar. Bu derleme çalışması, zeytin meyvesi ve yan ürünlerindeki fenoliklerin önemini ve bu bileşiklerin çıkarılmasında kullanılan çevre dostu biyo-rafineri teknolojilerini ele almaktadır.

Keywords

• Zeytin (Olea europaea L.)
• Fenolik Bileşikler
• Yeşil Biyo-rafine Teknolojiler

References

1. [1] Preedy, V.R. and Watson, R.R., (2010). Olives and Olive Oil in Health and Disease Prevention. Academic Press, 5 p, San Diego, USA.
2. [2] Parlak, S., (2007). Molecular Systematic Analysis of Some Olive (Olea europaea L.) Cultivars Grown in the Marmara Region. MSc thesis (Unpublished), Balıkesir Universty, Balıkesir, Türkiye, (In Turkish).
3. [3] Anonim, (2019). 2018 Yılı Zeytin ve Zeytinyağı Raporu. https://ticaret.gov.tr/data/5d41e59913b87639ac9e02e8/3acedb62acea083bd15a9f1dfa551bcc.pdf, (Access date: September 5,2020).
4. [4] Anonim, (2016). Türk Zeytin Yağı Sektörü. Olivae-Uluslar Arası Zeytin Konseyi Resmi Dergisi.http://koop.gtb.gov.tr/data/58244e541a79f57caca402ad/OLIVAE%20Eyl%C3%BCl%202016%20T%C3%BCrk%C3%A7e%20Versiyon.pdf,(Access date: September 10, 2020).
5. [5] Tokuşoğlu, Ö., (2016). "The Special Fruit: Chemistry, Quality, and Technology of Olives". Sidas Media Co. Ltd., İzmir,Türkiye, (In Turkish).
6. [6] Anonim, (2024). World Table Olıve Fıgures. World Olıve Oıl And Table Olıve Fıgures. https://www.internationaloliveoil.org/what-we-do/economic-affairs-promotion-unit/#figure, (Access date: August1,2024)
7. [7] Albuquerque, B. R., Heleno, S. A., Oliveira, M. B. P., Barros, L., & Ferreira, I. C., (2021). Phenolic compounds: Current industrial applications, limitations and future challenges. Food & function, 12(1), 14-29. DOI: 10.1039/D0FO02324H.
8. [8] Zhang, Y., Cai, P., Cheng, G., & Zhang, Y. (2022). A brief review of phenolic compounds identified from plants: Their extraction, analysis, and biological activity. Natural product communications, 17(1), https://doi.org/10.1177/1934578X211069721.

9. [9] Artık, N., Anlı, E., Konar, N., & Vural, N. (2016). Phenolic Compounds Found in Foods. Section: Structures of Phenolic Compounds. Sidas Media Co. Ltd., İzmir, Türkiye. (In Turkish).
10. [10] Cosme, P., Rodríguez, A. B., Espino, J., & Garrido, M. (2020). Plant phenolics: Bioavailability as a key determinant of their potential health-promoting applications. Antioxidants, 9(12), 1263.https://doi.org/10.3390/antiox9121263.
11. [11] Zhang, Y., Cai, P., Cheng, G., & Zhang, Y. (2022). A brief review of phenolic compounds identified from plants: Their extraction, analysis, and biological activity. Natural product communications, 17(1), https://doi.org/10.1177/1934578X211069721.
12. [12] Campus, M., Sedda, P., Cauli, E., Piras, F., Comunian, R., Paba, Daga, E., Schirru, S., Angioni, A., Zurru, R. & Bandino, G. (2015). Evaluation of a single strain starter culture, a selected inoculum enrichment, and natural microflora in the processing of Tonda di Cagliari natural table olives: Impact on chemical, microbiological, sensory and texture quality. LWT- Food Science and Technology,64:671-677. http://dx.doi.org/10.1016/j.lwt.2015.06.019.
13. [13] Uylaşer, V. (2015). Changes in phenolic compounds during ripening in Gemlik variety olive fruits obtained from different locations. CyTA-Journal of Food, 13(2), 167-173. https://doi.org/10.1080/19476337.2014.931331.
14. [14] Bekmez, A. S. (2019). Characterization of Phenolic Components of Gemlik Variety Green Olive With Lc-Dad-Ms/Ms And Effects of Fermantation on These Components MSc thesis (Unpublished),Adana Alpaslan Türkeş University, Adana, Türkiye, (In Turkish).
15. [15] Keceli, T. M., Celik, F. H., & Koseoglu, O. (2024). Effect of growing regions on discrimination of Turkish-style black table olives from Gemlik cultivar. Journal of Oleo Science, 73(3), 321-331. https://doi.org/10.5650/jos.ess23057.
16. [16] Khalil, A. A., Rahman, M. M., Rauf, A., Islam, M. R., Manna, S. J., Khan, A. A., ... & Simal-Gandara, J. (2024). Oleuropein: Chemistry, extraction techniques and nutraceutical perspectives-An update. Critical Reviews in Food Science and Nutrition, 64(27), 9933-9954. https://doi.org/10.1080/10408398.2023.2218495.
17. [17] Atli, C. S. (2020). The Effect of Processing Methods on Total Phenolic Content, Antioxidant Capacity And Bioavailability of Table Olives, MSc Thesis (Unpublished), Bursa Uludağ Univesyt,Bursa, Türkiye, (In Turkish).
18. [18] Pino, A., Vaccalluzzo, A., Solieri, L., Romeo, F., V., Todaro, A., Caggia, C., Arroyo-López, F. N., Bautista-Gallego, J., & Randazzo C. L. (2019). Effect of Sequential Inoculum of Beta-Glucosidase Positive and Probiotic Strains On Brine Fermentation to Obtain Low Salt Sicilian Table Olives. Front Microbiol, 10, 174, doi: 10.3389/fmicb.2019.00174.
19. [19] Comlekcioglu, S., Elgudayem, F., Nogay, G., Kafkas, N. E., Ayed, R. B., Ercisli, S., ... & Najda, A. (2022). Biochemical characterization of six traditional olive cultivars: A comparative study. Horticulturae, 8(5), 416. https://doi.org/10.3390/horticulturae8050416.
20. [20] Özdemir, Y. (2011). Determination of Physicochemical Properties of Some Crossed Olives And Their Convenience To Table Olive Fermentation By Using Lactobacillus plantarum As A Starter Culture. PhD thesis (Unpublished), Namık Kemal University, Tekirdağ, Türkiye, (In Turkish).
21. [21] Ummak Meral, B., (2019). The Effects of Naturel Brined And Alkaline Processing Methods on Quality of Table Black Olive Production, MSc Thesis (Unpublished), Çukurova University, Adana, Türkiye, (In Turkish).
22. [22] Benincasa, C., Muccilli, S., Amenta, M., Perri, E., & Romeo, F. V. (2015). Phenolic trend and hygienic quality of green table olives fermented with Lactobacillus plantarum starter culture. Food Chemistry, 186, 271-276. http://dx.doi.org/10.1016/j.foodchem.2015.02.010.
23. [23] Kaltsa, A., Papaliaga, D., Papaioannou, E. & Kotzekidou, P., (2015). Characteristics of oleuropeinolytic strains of Lactobacillus plantarum group and influence on phenolic compounds in table olives elaborated under reduced salt conditions. Food Microbiology, 48, 58-62. https://doi.org/10.1016/j.fm.2014.10.016.
24. [24] Demir, C., Yildiz, E., & Gurbuz, O. (2023). Profile phenolic compounds in Spanish-style and traditional brine black olives (‘Gemlik’cv.) provided from different regions of Türkiye. Processes, 11(8), 2412. https://doi.org/10.3390/pr11082412.
25. [25] Castillo-Luna, A., Miho, H., Ledesma-Escobar, C. A., & Priego-Capote, F. (2023). Comparison of drying techniques for extraction of bioactive compounds from olive-tree materials. Foods, 12(14), 2684. https://doi.org/10.3390/foods12142684.
26. [26] Mechi, D., Baccouri, B., Martín-Vertedor, D., & Abaza, L. (2023). Bioavailability of phenolic compounds in Californian-Style table olives with Tunisian aqueous olive leaf extracts. Molecules, 28(2), 707. https://doi.org/10.3390/molecules28020707.
27. [27] Ferreira, D. M., de Oliveira, N. M., Chéu, M. H., Meireles, D., Lopes, L., Oliveira, M. B., & Machado, J. (2023). Updated Organic Composition and Potential Therapeutic Properties of Different Varieties of Olive Leaves from Olea europaea. Plants, 12(3), 688. https://doi.org/10.3390/plants12030688.
28. [28] Feng, S., Zhang, C., Liu, L., Xu, Z., Chen, T., Zhou, L., ... & Ding, C. (2021). Comparison of phenolic compounds in olive leaves by different drying and storage methods. Separations, 8(9), 156. https://doi.org/10.3390/separations8090156.
29. [29] Wang, B., Shen, S., Qu, J., Xu, Z., Feng, S., Chen, T., & Ding, C. (2021). Optimizing total phenolic and oleuropein of Chinese olive (Olea europaea) leaves for enhancement of the phenols content and antioxidant activity. Agronomy, 11(4), 686. https://doi.org/10.3390/agronomy11040686.
30. [30] Šimat, V., Skroza, D., Tabanelli, G., Čagalj, M., Pasini, F., Gómez-Caravaca, A. M., ... & Generalić Mekinić, I. (2022). Antioxidant and antimicrobial activity of hydroethanolic leaf extracts from six mediterranean olive cultivars. Antioxidants, 11(9), 1656. https://doi.org/10.3390/antiox11091656.
31. [31] Ronca, C. L., Marques, S. S., Ritieni, A., Giménez-Martínez, R., Barreiros, L., & Segundo, M. A. (2024). Olive Oil Waste as a Source of Functional Food Ingredients: Assessing Polyphenolic Content and Antioxidant Activity in Olive Leaves. Foods, 13(2), 189. https://doi.org/10.3390/foods13020189.
32. [32] Soto-Maldonado, C., & Zúñiga-Hansen, M. E. (2017). Enzyme-assisted extraction of phenolic compounds. In Water extraction of bioactive compounds (pp. 369-384). Elsevier. https://doi.org/10.1016/B978-0-12-809380-1.00014-0.
33. [33] Carpentieri, S., Ferrari, G., & Pataro, G. (2022). Optimization of pulsed electric fields-assisted extraction of phenolic compounds from white grape pomace using response surface methodology. Frontiers in Sustainable Food Systems. 6, 854968. https://doi.org/10.3389/fsufs.2022.854968.
34. [34] Ferreira-Santos, P., Nobre, C., Rodrigues, R. M., Genisheva, Z., Botelho, C., & Teixeira, J. A. (2024). Extraction of phenolic compounds from grape pomace using ohmic heating: Chemical composition, bioactivity and bioaccessibility. Food Chemistry, 436, 137780. https://doi.org/10.1016/j.foodchem.2023.137780.
35. [35] Gündüz, M., & Çiçek, Ş. K. (2024). Extraction methods of phenolic compounds and their use as natural ingredients. Journal of Food and Feed Science Technology, (32), 37-47.(In Turkish).
36. [36] Giacometti, J., Žauhar, G., & Žuvić, M. (2018). Optimization of ultrasonic-assisted extraction of major phenolic compounds from olive leaves (Olea europaea L.) using response surface methodology. Foods, 7(9), 149. https://doi.org/10.3390/foods7090149.
37. [37] Irakli, M., Chatzopoulou, P., & Ekateriniadou, L. (2018). Optimization of ultrasound-assisted extraction of phenolic compounds: Oleuropein, phenolic acids, phenolic alcohols and flavonoids from olive leaves and evaluation of its antioxidant activities. Industrial Crops and Products, 124, 382-388. https://doi.org/10.1016/j.indcrop.2018.07.070.
38. [38] Niknam, S. M., Kashaninejad, M., Escudero, I., Sanz, M. T., Beltrán, S., & Benito, J. M. (2021). Valorization of olive mill solid residue through ultrasound-assisted extraction and phenolics recovery by adsorption process. Journal of cleaner production, 316, 128340. https://doi.org/10.1016/j.jclepro.2021.128340.
39. [39] Rodríguez, Ó., Bona, S., Stäbler, A., & Rodríguez-Turienzo, L. (2022). Ultrasound-assisted extraction of polyphenols from olive pomace: Scale up from laboratory to pilot scenario. Processes, 10(12), 2481.https://doi.org/10.3390/pr10122481.
40. [40] Sahin, S. and R. Samli (2013). "Optimization of olive leaf extract obtained by ultrasound-assisted extraction with response surface methodology." Ultrason Sonochemistry. 20(1): 595-602. https://doi.org/10.1016/j.ultsonch.2012.07.029.
41. [41] Cifá, D., Skrt, M., Pittia, P., Di Mattia, C., & Poklar Ulrih, N. (2018). Enhanced yield of oleuropein from olive leaves using ultrasound‐assisted extraction. Food science & nutrition, 6(4), 1128-1137. https://doi.org/10.1002/fsn3.654.
42. [42] Gómez-Cruz, I., Contreras, M. D. M., Carvalheiro, F., Duarte, L. C., Roseiro, L. B., Romero, I., & Castro, E. (2021). Recovery of bioactive compounds from industrial exhausted olive pomace through ultrasound-assisted extraction. Biology, 10(6), 514. https://doi.org/10.3390/biology10060514.
43. [43] Eskilsson, C. S. and Björklund, E. (2000). Analytical-scale microwave-assisted extraction. Journal of chromatography A, 902(1), 227-250. https://doi.org/10.1016/S0021-9673(00)00921-3.
44. [44] İşçimen, E. M., and Hayta, M. (2023). Microwave-Assisted Extraction of Phenolic Components in Olive Leaves and its Kinetics, and Antioxidant Properties of Extracts. Academic Food, 21(3), 233-242.https://doi.org/10.24323/akademik-gida.1382919, (In Turkish)
45. [45] da Rosa, G. S., Vanga, S. K., Gariepy, Y., & Raghavan, V. (2019). Comparison of microwave, ultrasonic and conventional techniques for extraction of bioactive compounds from olive leaves (Olea europaea L.). Innovative Food Science & Emerging Technologies, 58, 102234.https://doi.org/10.1016/j.ifset.2019.102234.
46. [46] Djemaa-Landri, K., Hamri-Zeghichi, S., Belkhiri-Beder, W., Krisa, S., Cluzet, S., Richard, T., ... & Madani, K. (2021). Phenolic content, antioxidant and anti-inflammatory activities of some Algerian olive stone extracts obtained by conventional solvent and microwave-assisted extractions under optimized conditions. Journal of Food Measurement and Characterization, 15(5), 4166-4180. https://doi.org/10.1007/s11694-021-00992-w.
47. [47] Alifakı, Y. Ö., Yılmaz, M. S., Demirkol, Ö. Ş., & Yakan, A. İ. (2024). Kinetic Modelling of Ohmic, Microwave and Ultrasound Assisted Extractions of Phenolic Compounds From Olive Mill Waste Water. Food, 49(6), 1010-1027.https://doi.org/10.15237/gida.GD24075. (In Turkish)
48. [48] Zeng, X. A., & Zhang, Z. (2019). Pulsed electric field assisted extraction of bioactive compounds. Advances in food processing technology, 125-135. https://doi.org/10.1007/978-981-13-6451-8_5.
49. [49] Tamborrino, A., Urbani, S., Servili, M., Romaniello, R., Perone, C., & Leone, A. (2019). Pulsed electric fields for the treatment of olive pastes in the oil extraction process. Applied Sciences, 10(1), 114. https://doi.org/10.3390/app10010114.
50. [50] Razola-Díaz, M. D. C., Sevenich, R., Schlüter, O. K., Verardo, V., & Gómez-Caravaca, A. M. (2025). Improving Olive Leaf Phenolic Extraction with Pulsed Electric Field Technology Pre-Treatment. Foods, 14(3), 368. https://doi.org/10.3390/foods14030368.
51. [51] Pappas, V. M., Lakka, A., Palaiogiannis, D., Athanasiadis, V., Bozinou, E., Ntourtoglou, G., ... & Lalas, S. I. (2021). Optimization of pulsed electric field as standalone “green” extraction procedure for the recovery of high value-added compounds from fresh olive leaves. Antioxidants, 10(10), 1554. https://doi.org/10.3390/antiox10101554.
52. [52] Pappas, V. M., Lakka, A., Palaiogiannis, D., Bozinou, E., Ntourtoglou, G., Batra, G., ... & Lalas, S. I. (2021). Use of Pulsed Electric Field as a low-temperature and high-performance “green” extraction technique for the recovery of high added value compounds from olive leaves. Beverages, 7(3), 45. https://doi.org/10.3390/beverages7030045.
53. [53] Saberian, H., Hamidi-Esfahani, Z., Gavlighi, H. A., & Barzegar, M. (2017). Optimization of pectin extraction from orange juice waste assisted by ohmic heating. Chemical Engineering and Processing: Process Intensification, 117, 154-161. https://doi.org/10.1016/j.cep.2017.03.025.
54. [54] Gavahian, M. and Chu, R. (2022). Ohmic heating extraction at different times, temperatures, voltages, and frequencies: a new energy-saving technique for pineapple core valorization. Foods, 11(14), 2015. https://doi.org/10.3390/foods11142015.
55. [55] Safarzadeh Markhali, F., Teixeira, J. A., & Rocha, C. M. (2022). Effect of ohmic heating on the extraction yield, polyphenol content and antioxidant activity of olive mill leaves. Clean Technologies, 4(2), 512-528. https://doi.org/10.3390/cleantechnol4020031.
56. [56] Quero, J., Ballesteros, L. F., Ferreira-Santos, P., Velderrain-Rodriguez, G. R., Rocha, C. M., Pereira, R. N., ... & Rodríguez-Yoldi, M. J. (2022). Unveiling the antioxidant therapeutic functionality of sustainable olive pomace active ingredients. Antioxidants, 11(5), 828. https://doi.org/10.3390/antiox11050828.
57. [57] Baccouri, B., Mechi, D., Rajhi, I., & Vertedor, D. M. (2023). Tunisian wild olive leaves: Phenolic compounds and antioxidant activity as an important step toward their valorization. Food Analytical Methods, 16(2), 436-444. https://doi.org/10.1007/s12161-022-02430-z.
58. [58] Martín-García, B., De Montijo-Prieto, S., Jiménez-Valera, M., Carrasco-Pancorbo, A., Ruiz-Bravo, A., Verardo, V., & Gómez-Caravaca, A. M. (2022). Comparative extraction of phenolic compounds from olive leaves using a sonotrode and an ultrasonic bath and the evaluation of both antioxidant and antimicrobial activity. Antioxidants, 11(3), 558. https://doi.org/10.3390/antiox11030558.
59. [59] Sani, I. K., Mehrnoosh, F., Rasul, N. H., Hassani, B., Mohammadi, H., Gholizadeh, H., ... & Jafari, S. M. (2024). Pulsed electric field-assisted extraction of natural colorants; principles and applications. Food Bioscience, 104746. https://doi.org/10.1016/j.fbio.2024.104746.
60. [60] Zhang, C., Xin, X., Zhang, J., Zhu, S., Niu, E., Zhou, Z., & Liu, D. (2022). Comparative evaluation of the phytochemical profiles and antioxidant potentials of olive leaves from 32 cultivars grown in China. Molecules, 27(4), 1292. https://doi.org/10.3390/molecules27041292.
61. [61] Rahman, M.M., Byanju, B., Grewell, D. and Buddhi, P.L. (2021). High-power sonication of soy proteins: Hydroxyl radicals and their effects on protein structure. Ultrasonics Sonochemistry, 64, 105019. https://doi.org/10.1016/j.ultsonch.2020.105019.
62. [62] Deng, Y., Wang, W., Zhao, S., Yang, X., Xu, W., Guo, M., Xu, E., Ding, T., Ye, X., & Liu, D. (2022). Ultrasound-assisted extraction of lipids as food components: Mechanism, solvent, feedstock, quality evaluation and coupled technologies – A review. Trends in Food Science & Technology, 122, 83-96. https://doi.org/10.1016/j.tifs.2022.01.034.
63. [63] Ben Othman, N., Roblain, D., Thonart, P., & Hamdi, M. (2008). Tunisian table olive phenolic compounds and their antioxidant capacity. Journal of Food Science, 73(4), C235-C240. https://doi.org/10.1111/j.1750-3841.2008.00711.x.
64. [64] Palmeri, R., Parafati, L., Trippa, D., Siracusa, L., Arena, E., Restuccia, C., & Fallico, B. (2019). Addition of olive leaf extract (OLE) for producing fortified fresh pasteurized milk with an extended shelf life. Antioxidants, 8(8), 255.
65. [65] Nunes, M. A., Pimentel, F. B., Costa, A. S., Alves, R. C., & Oliveira, M. B. P. (2016). Olive by-products for functional and food applications: Challenging opportunities to face environmental constraints. Innovative Food Science & Emerging Technologies, 35, 139-148.
66. [66] Roselló-Soto, E., Koubaa, M., Moubarik, A., Lopes, R. P., Saraiva, J. A., Boussetta, N., ... & Barba, F. J. (2015). Emerging opportunities for the effective valorization of wastes and by-products generated during olive oil production process: Non-conventional methods for the recovery of high-added value compounds. Trends in Food Science & Technology, 45(2), 296-310.
67. [67] Vilkhu, K., Mawson, R., Simons, L., & Bates, D. (2008). Applications and opportunities for ultrasound assisted extraction in the food industry—A review. Innovative Food Science & Emerging Technologies, 9(2), 161-169. https://doi.org/10.1016/j.ifset.2007.04.014
68. [68] Guzik, P., Kulawik, P., Zając, M., & Migdał, W. (2022). Microwave applications in the food industry: An overview of recent developments. Critical Reviews in Food Science and Nutrition, 62(29), 7989-8008. https://doi.org/10.1080/10408398.2021.1922871.
69. [69] Nour, A. H., Oluwaseun, A. R., Nour, A. H., Omer, M. S., & Ahmed, N. (2021). Microwave-assisted extraction of bioactive compounds. In Microwave Heating-Electromagnetic Fields Causing Thermal and Non-Thermal Effects. IntechOpen. DOI: 10.5772/intechopen.96092.
70. [70] Wang, N., Zhu, H., Wang, M., Zhao, S., Sun, G., & Li, Z. (2025). Recent advancements in microwave-assisted extraction of flavonoids: a review. Food and Bioprocess Technology, 18(3), 2083-2100. https://doi.org/10.1007/s11947-024-03574-y.
71. [71] Naliyadhara, N., Kumar, A., Girisa, S., Daimary, U. D., Hegde, M., & Kunnumakkara, A. B. (2022). Pulsed electric field (PEF): Avant-garde extraction escalation technology in food industry. Trends in Food Science & Technology, 122, 238-255. https://doi.org/10.1016/j.tifs.2022.02.019.
72. [72] Talha, M., Khalid, S., Maan, A. A., Tanveer, N., Khan, M. K. I., Asif, M., ... & Sarwar, A. (2024). Ohmic assisted extraction: a sustainable and environment friendly approach to substitute conventional extraction methods. Food Reviews International, 40(10), 3508-3529. https://doi.org/10.1080/87559129.2024.2366841.
73. [73] Kaya, O., & İçier, F. (2019). Comparison of the Applicability of Induction and Ohmic Heating Processes to Foods. Academic Food, 17(1), 111-120. DOI: 10.24323/akademik-gida.544844. (In Turkısh).