Fortified wheat bread with dried three-phase olive pomace: effect on physicochemical, antioxidant, nutritional, and sensory characteristics

Olive pomace (OP), a key by-product of olive oil production, is recognized as a sustainable and cost-effective source of natural antioxidants. Rich in polyphenols with proven health benefits, OP shows considerable potential for application in functional foods to improve nutritional quality and oxidative stability. This study aims to evaluate the effect of dried OP (dOP) addition on the nutritional, physicochemical, rheological, antioxidant, and sensory properties of fortified wheat bread. Four different replacement levels (1%, 2%, 5%, and 7%) of dOP obtained from the three-phase process of extra-virgin olive oil production were incorporated into the bread. OP exhibited high levels of fiber (38.5%), carbohydrates (33.22%), monounsaturated fats (67.02%), oleic acid (67.78%), phenolic content (23.39 mg GAE/g dw), flavonoids (13.02 mg QE/g dw), and antioxidant activity (15.25 mg Trolox/g dw). The addition of dOP significantly increased phenolic content, flavonoids, and antioxidant activity of breads; the highest values were recorded at 7% dOP (2.34 mg GAE/g dw, 0.32 mg QE/g dw, and 1.10 mg Trolox/g dw, respectively). No significant differences were observed in rheological and most sensory attributes between the control bread and samples fortified with 1% and 2% dOP. However, fortification at high levels (5% and 7%) significantly affected the bread's texture, color, and sensory properties. Additionally, the sensory evaluation showed that bread fortified with 1%, 2%, and 5% dOP exhibited higher overall acceptability compared to the 7% formulation, which demonstrated a moderate acceptability due to a slight bitterness and sandy mouthfeel. The results suggest that OP can be utilized as a sustainable and functional ingredient in the formulation of high-value bakery products when added at moderate levels.

AACC, 2000. Approved methods of the american association of cereal chemists. 11th edition. St. Paul, USA.

Abdelaleem M, Al-azab K, 2020. Rheological assessment of different bread wheat genotypes induced via radiation and hybridization. Arab J Nucl Sci Appl 53:112-21. DOI: https://doi.org/10.21608/ajnsa.2020.23450.1326

Alkhalidi A, Halaweh G, Khawaja MK, 2023. Recommendations for olive mills waste treatment in hot and dry climate. J Saudi Soc Agric Sci 22:361-73. DOI: https://doi.org/10.1016/j.jssas.2023.03.002

AOAC, 2019. Official methods of analysis of the AOAC International. 21st ed. Washington DC, USA.

Azadfar E, Elhami Rad AH, Sharifi A, Armin M, 2023. Effect of olive pomace fiber on the baking properties of wheat flour and flat bread (Barbari Bread) quality. J Food Process Preserv 1:5758. DOI: https://doi.org/10.1155/2023/1405758

Azadmard-Damirchi S, Dutta PC, 2007. Stability of minor lipid components with emphasis on phytosterols during chemical refining of soybean oil. J Am Oil Chem Soc 85:13-21. DOI: https://doi.org/10.1007/s11746-007-1170-1

Benaddi R, Osmane A, Zidan K, El Harfi K, Ouazzani N, 2023. A Review on processes for olive mill waste water treatment. Ecol Eng Environ Tech 24:196-207. DOI: https://doi.org/10.12912/27197050/169876

Beqaj B, Gjipalaj J, Marko O, Shkurta E, 2025. An overview of the environmental problems of the used waters extracted from the factories of the olive oil production, and their treatment methods. Eur J Environ Earth Sci 6:10-6. DOI: https://doi.org/10.24018/ejgeo.2025.6.3.506

Bolek S. 2020. Olive stone powder: a potential source of fiber and antioxidant and its effect on the rheological characteristics of biscuit dough and quality. Innov Food Sci Emerg Technol 64:102423. DOI: https://doi.org/10.1016/j.ifset.2020.102423

Calvano CD, Tamborrino A, 2021. Valorization of olive by-products: innovative strategies for their production, treatment and characterization. Foods 11:768. DOI: https://doi.org/10.3390/foods11060768

Cardinali F, Belleggia L, Reale A, Cirlini M, Boscaino F, Renzo TD, Vecchio LD, Cavalca N, Milanović V, Garofalo C, Cesaro C, Rampanti G, Osimani A, Aquilanti L, 2024. Exploitation of black olive (Olea europaea L. Cv. Piantone di Mogliano) pomace for the production of high-value bread. Foods 13:460. DOI: https://doi.org/10.3390/foods13030460

Cedola A, Cardinali A, D’Antuono I, Conte A, Del Nobile MA, 2020. Cereal foods fortified with by-products from the olive oil industry. Food Biosci 33:100490. DOI: https://doi.org/10.1016/j.fbio.2019.100490

Centrone M, Ranieri M, Di Mise A, D’Agostino M, Venneri M, Valenti G, Tamma G, 2021. Health benefits of olive oil and by-products and possible innovative applications for industrial processes. Funct Food Health Dis 11:295-309. DOI: https://doi.org/10.31989/ffhd.v11i7.800

Chandrasekara N, Shahidi F, 2011. Effect of roasting on phenolic content and antioxidant activities of whole cashew nuts, kernels, and testa. J Agric Food Chem 59:5006-14. DOI: https://doi.org/10.1021/jf2000772

Contreras-Angulo LA, Laaroussi H, Ousaaid D, Bakour M, Lyoussi B, Ferreira-Santos P, 2025. Sustainable valorization of olive oil by-products: green extraction of phytochemicals, encapsulation strategies, and food applications. J Food Sci 90:e70412. DOI: https://doi.org/10.1111/1750-3841.70412

Dahdah P, Cabizza R, Farbo MG, Fadda C, Del Caro A, Montanari L, Hassoun G, Piga A, 2024a. Effect of partial substitution of wheat flour with freeze-dried olive pomace on the technological, nutritional, and sensory properties of bread. Front Sustain Food Syst 8:1400339. DOI: https://doi.org/10.3389/fsufs.2024.1400339

Dahdah, P, Cabizza R, Farbo M G, Fadda C, Mara A, Hassoun G, Piga A, 2024b. Improving the rheological properties of dough obtained by partial substitution of wheat flour with freeze-dried olive pomace. Foods 13:478. DOI: https://doi.org/10.3390/foods13030478

de Gennaro G, Difonzo G, Summo C, Pasqualone A, Caponio F, 2022. Olive cake powder as functional ingredient to improve the quality of gluten-free breadsticks. Foods 11:552. DOI: https://doi.org/10.3390/foods11040552

Delgado-Andrade C, Conde-Aguilera JA, Haro A, Pastoriza de la Cueva S, Rufián-Henares JÁ, 2010. A combined procedure to evaluate the global antioxidant response of bread. J Cereal Sci 52:239-46. DOI: https://doi.org/10.1016/j.jcs.2010.05.013

Difonzo G, Troilo M, Squeo G, Pasqualone A, Caponio F, 2021. Functional compounds from olive pomace to obtain high-added value foods - a review. J Sci Food Agric 101:15-26. DOI: https://doi.org/10.1002/jsfa.10478

Elkatry HO, Ahmed AR, El-Beltagi HS, Mohamed HI, Eshak NS, 2022. Biological activities of grape seed by-products and their potential use as natural sources of food additives in the production of Balady bread. Food Secur 11:31948. DOI: https://doi.org/10.3390/foods11131948

Falsafi SR, Aaliya B, Demirkesen I, Kemerli-Kalbaran T, Dehnad D, Şahin S, Yildirim-Yalcin M, Alarcon-Rojo AD, 2025. Recent trends in fortifying bread with nutrients: comprehensive insights into chemical, physical, functional, and nutritional attributes. Future Foods 11:100674. DOI: https://doi.org/10.1016/j.fufo.2025.100674

FAO, 2021. World Food and Agriculture - Statistical Yearbook 2021. Rome. Available from: https://doi.org/10.4060/cb4477en DOI: https://doi.org/10.4060/cb4477en

FAO, 2024. World food and agriculture – statistical yearbook 2024. Available from: https://openknowledge.fao.org/items/43ef9f2c-a023-4130-81ce-dc5ac3f825ef.

Foti P, Pino A, Romeo FV, Vaccalluzzo A, Caggia C, Randazzo CL, 2022. Olive pomace and pâté olive cake as suitable ingredients for food and feed. Microorganisms 10:237. DOI: https://doi.org/10.3390/microorganisms10020237

Galanakis CM, Tsatalas P, Charalambous Z, Galanakis IM, 2018. Control of microbial growth in bakery products fortified with polyphenols recovered from olive mill wastewater. Environ Technol Innov 10:1-15. DOI: https://doi.org/10.1016/j.eti.2018.01.006

Gill SK, Rossi M, Bajka B, Whelan K, 2021. Dietary fibre in gastrointestinal health and disease. Nat Rev Gastroenterol Hepatol 18:101-16. DOI: https://doi.org/10.1038/s41575-020-00375-4

Gullón P, Gullón B, Astray G, Carpena M, Fraga-Corral M, Prieto MA, Simal-Gandara J, 2020. Valorization of by-products from olive oil industry and added-value applications for innovative functional foods. Food Res Int 137:109683. DOI: https://doi.org/10.1016/j.foodres.2020.109683

Harasym J, Satta E, Kaim U, 2020. Ultrasound treatment of buckwheat grains impacts important functional properties of resulting flour. Molecules 25:3012. DOI: https://doi.org/10.3390/molecules25133012

Ismaili H, 2017. Albanian olive cultivars. Flesh Publishing House, Tirana, Albania.

ISO, 2017. Animal and vegetable fats and oils — gas chromatography of fatty acid methyl esters. Part 2: preparation of methyl esters of fatty acids. ISO Norm 12966-2:2017. International Standardization Organization ed., Geneva, Switzerland.

ISO, 2017. Foodstuffs—determination of water activity. ISO Norm 18787:2017. International Standardization Organization ed., Geneva, Switzerland.

Jovanovichs MRC, Dos Santos BA, Sant’Anna Monteiro C, Pedro D, Correa LP, Cordeiro MWS, Pinton MB, Cichoski AJ, Mallmann CA, Wagner R, Emanuelli T, Campagnol PCB, 2025. Micronized olive pomace: A sustainable and innovative strategy to improve the oxidative stability of omega-3 enriched salamis. Meat Sci 221:109715. DOI: https://doi.org/10.1016/j.meatsci.2024.109715

Kamiloglu S, Capanoglu E, Jafari SM, 2022. An overview of food bioactive compounds and their health-promoting features. In: Jafari SM, Capanoglu E, eds. Retention of bioactives in food processing. Food bioactive ingredients. Springer, Cham, Switzerland. DOI: https://doi.org/10.1007/978-3-030-96885-4_1

Katsinas N, Bento da Silva A, Enríquez-de-Salamanca A, Fernández, N, Rosário Bronze M, Rodríguez-Rojo S, 2021. Pressurized liquid extraction optimization from supercritical defatted olive pomace: a green and selective phenolic extraction process. ACS Sustainable Chem Eng 9:5590-602. DOI: https://doi.org/10.1021/acssuschemeng.0c09426

Kovač B, Martina A, Polak T, Možina SS, Šporin M, 2024. Exploring the impact of olive cake enrichment on wheat flour bread: a comprehensive study on quality parameters and nutritional enhancement. LWT 215:117279. DOI: https://doi.org/10.1016/j.lwt.2024.117279

Lu Y, Zhao J, Xin Q, Yuan R, Miao Y, Yang M, Mo H, Chen K, Cong W, 2024. Protective effects of oleic acid and polyphenols in extra virgin olive oil on cardiovascular diseases. Food Sci Human Wellness 13:529-40. DOI: https://doi.org/10.26599/FSHW.2022.9250047

Marinopoulou A, Papageorgiou M, Irakli M, Gerasopoulos D, 2020. Effect of olive pulp enrichment on physicochemical and antioxidant properties of wheat bread. Int J Food Stud 9:178-92. DOI: https://doi.org/10.7455/ijfs/9.1.2020.a4

Medouni-Haroune L, Zaidi F, Medouni-Adrar S, Kecha, M, 2018. Olive pomace: from an olive mill waste to a resource, an overview of the new treatments. J Critical Rev 5:1-6. DOI: https://doi.org/10.22159/jcr.2018v5i5.28840

Morina A, Kongoli R, 2022. Qualitative parameters and fatty acid profile of Albanian virgin olive oils produced by autochthonous cultivars. J Hyg Eng Des 39:137-42.

Moya M, Espínola F, Fernández DG, de Torres A, Marcos J, Josue J, Sánchez T, Castro E, 2010. Industrial trials on coadjuvants for olive oil extraction. J Food Eng 97:57-63. DOI: https://doi.org/10.1016/j.jfoodeng.2009.09.015

Nedviha S, Harasym J, 2025. Characteristics of soft wheat and tiger nut (Cyperus esculentus) composite flour bread. Foods, 14:229. DOI: https://doi.org/10.3390/foods14020229

Nikolić NC, Krasić MS, Šimurina O, Cakić S, Mitrović J, Pešić M, Karabegović, I, 2022. Regression analysis in examination the rheology properties of dough from wheat and Boletus edulis flour. J Food Comp Anal 115:105022. DOI: https://doi.org/10.1016/j.jfca.2022.105022

Nunes MA, Costa AS, Bessada S, Santos J, Puga H, Alves RC, Freitas V, Oliveira MB, 2018. Olive pomace as a valuable source of bioactive compounds: a study regarding its lipid-and water-soluble components. Sci Total Environ 644:229-36. DOI: https://doi.org/10.1016/j.scitotenv.2018.06.350

Nunes MA, Palmeira JD, Melo D, Machado S, Lobo JC, Costa ASG, Alves RC, Ferreira H, Oliveira MBPP, 2021. Chemical composition and antimicrobial activity of a new olive pomace functional ingredient. Pharmaceuticals 14:913. DOI: https://doi.org/10.3390/ph14090913

Pampuri A, Casson A, Alamprese C, Di Mattia CD, Piscopo A, Difonzo G, Conte P, Paciulli M, Tugnolo A, Beghi R, Casiraghi E, Guidetti R, Giovenzana V, 2021. Environmental impact of food preparations enriched with phenolic extracts from olive oil mill waste. Foods 10:980. DOI: https://doi.org/10.3390/foods10050980

Paulo F, Santos L, 2021. Deriving valorization of phenolic compounds from olive oil by-products for food applications through microencapsulation approaches: a comprehensive review. Crit Rev Food Sci Nutr 61:920-945. DOI: https://doi.org/10.1080/10408398.2020.1748563

Pikuli K, Devolli A, 2024. Total phenolic content and antioxidant activity evaluation of olive mill pomace extract. Sci Bull Series F Biotechnol.

Pikuli K, Devolli A, 2025. Physıcochemıcal composıtıon of olıve pomace for a sustaınable valorızatıon. 8th ICONST LST - Life Science and Technology, May 28-30, 2025; Budapest, Hungary. pp 46-54.

Quero J, Ballesteros LF, Ferreira-Santos P, Velderrain-Rodriguez GR, Rocha CMR, Pereira RN, Teixeira JA, Martin-Belloso O, Osada J, Rodríguez-Yoldi MJ, 2022. Unveiling the antioxidant therapeutic functionality of sustainable olive pomace active ingredients. Antioxidants 11:828. DOI: https://doi.org/10.3390/antiox11050828

Rapa M, Ciano S, 2022. A Review on life cycle assessment of the olive oil production. Sustainability 14: 654. DOI: https://doi.org/10.3390/su14020654

Ribeiro TB, Bonifácio-Lopes T, Morais P, Miranda A, Nunes J, Vicente AA, Pintado, M, 2021. Incorporation of olive pomace ingredients into yoghurts as a source of fibre and hydroxytyrosol: Antioxidant activity and stability throughout gastrointestinal digestion. J Food Eng 297:110476. DOI: https://doi.org/10.1016/j.jfoodeng.2021.110476

Rosell CM, Santos E, Collar C, 2005. Mixing properties of fiber-enriched wheat bread doughs: a response surface methodology study. Eur Food Res Technol, 223:323-40. DOI: https://doi.org/10.1007/s00217-005-0208-6

Sakanaka S, Tachibana Y, Okada Y, 2005. Preparation and antioxidant properties of extracts of Japanese persimmon leaf tea (kakinoha-cha). Food Chem 89:569-75. DOI: https://doi.org/10.1016/j.foodchem.2004.03.013

Saura-Martínez J, Tortosa-Díaz L, López-Avilés FJ, Juárez-Marín M, Hidalgo AM, Marín-Iniesta F, 2025. Application of high-quality dried olive with high polyphenol content for bread fortification: effects on nutritional, technological, and sensory properties. Molecules 30:3564. DOI: https://doi.org/10.3390/molecules30173564

Selim K, Badawy W, Smetanska I, 2020. Utilization of olive pomace as a source of bioactive compounds in quality improving of toast bread. Egypt J Food Sci 48:27-40. DOI: https://doi.org/10.21608/ejfs.2020.22871.1038

Shelton D, 2004. Wheat and flour testing methods: a guide to understanding wheat and flour quality. Available from: https://uswheat.org/wp-content/uploads/2024/07/Wheat-and-Flour-Testing-Methods-Book.pdf.

Thomaj F, Panajoti D, 2003. Olive cultivars. ILB, Tirana, Albania.

Topi D, Beqiraj I, Seiti B, Halimi E, 2014. Environmental impact from olive mills waste disposal, chemical analysis of solid wastes and wastewaters. J Hyg Eng Des 7:44-8.

Toumi O, Conte P, Moreira MG, da Silva A, João Barroca M, Fadda C, 2022. Use of response surface methodology to investigate the effect of sodium chloride substitution with Salicornia ramosissima powder in common wheat dough and bread. J Funct Foods 99:105349. DOI: https://doi.org/10.1016/j.jff.2022.105349

Vitali Čepo D, Radić K, Jurmanović S, Jug M, Grdić Rajković M, Pedisić S, Moslavac T, Albahari P, 2018. Valorization of olive pomace-based nutraceuticals as antioxidants in chemical, food, and biological models. Molecules 23:2070. DOI: https://doi.org/10.3390/molecules23082070

Vizitiu D, Danciou I, 2011. Evaluation of farinograph and mixolab for prediction of mixing properties of industrial wheat flour. Acta Univ Cibiniensis Ser E Food Technol XV:31-8.

Zantedeschi S, Casadei E, Mandrioli M, Barbieri S, Ferioli F, Hoxha F, Valli, E, Gallina Toschi T, 2025. Fatty acids, volatile and phenolic composition, quality and sensory profile of two Albanian Kalinjot extra virgin olive oils. Ital J Food Sci 37:277-89. DOI: https://doi.org/10.15586/ijfs.v37i1.2789

Zhao H, Avena-Bustillos RJ, Wang SC, 2022. Extraction, purification and in vitro antioxidant activity evaluation of phenolic compounds in California olive pomace. Foods 11:174. DOI: https://doi.org/10.3390/foods11020174