Abstract
Drying pomegranate peels, a by-product of juice production, preserves their beneficial properties and minimizes waste. Using optimal drying conditions, such as controlled temperatures and thin layers, improves efficiency and ensures high quality. These dried peels can then be utilized in various industries, including food, pharmaceuticals, and cosmetics. To our knowledge, there are no existing studies that detail the effects of hybrid solar drying, drying temperatures, and layer thickness on the drying kinetics, power consumption, and economic and environmental aspects. In this study, a hybrid indirect SD (HISD) with a temperature and humidity control unit was used to dry pomegranate peels at three different temperatures—50 °C, 60 °C, and 70 °C—and three different thicknesses—1, 2, and 3 cm. The HISD was then compared to a conventional oven drying system (CODS). The obtained results indicated that increasing the drying temperature increased the weight loss of pomegranate peels. Also, the average initial moisture content of pomegranate peels was 76.5% (w.b.). The final MC ranged from 2.67 to 2.10% and from 2.97 to 2.84% for the CODS and HISD, respectively. The higher drying rates of the pomegranate peels dried using CODS and HISD were 169.79 and 196 kgwater/kgdrymatter/h, respectively, at a layer thickness of 3 cm and a drying temperature of 70 °C. Additionally, using HISD led to a reduction in power consumption by about 64.28% to 75.75% compared to the CODS. Furthermore, the environmental analysis results showed that the embodied energy is about 1270.463 kW.h. The energy payback period for HISD ranges between 2.38 and 6.34 years. The earned carbon credit for drying pomegranate peels using the HISD ranged between 770.1 and 2207.2 USD. Based on economic analysis, the lowest drying cost using the HISD was 144.5 USD per ton of pomegranate peels, achieved at layer thicknesses of 1 cm and a drying temperature of 70 °C.
Data availability
All data are provided within the article.
References
Venkateswarlu, K. & Reddy, S. V. K. Recent trends on energy-efficient solar dryers for food and agricultural products drying: a review. Waste Dispos. Sustain. Energy 6, 1–19 (2024).
Ezike, N. C. O., Johnson, N., Gabriel, S. B. & Pooja, P. Elevating Sustainability in Design: Advancing State-of-the-Art Food Drying Methods to Optimize Efficiency, Preserve Nutritional Value, and Minimize Waste in Contemporary Food Production. (2024).
Elwakeel, A. E., Villagran, E., Rodriguez, J., Aguilar, C. E. & Ahmed, A. F. Development, thermodynamic evaluation, and economic analysis of a PVT-based automated indirect solar dryer for date fruits. Sustainability 17, 4571 (2025).
Farag Taha, M. et al. Emerging technologies for precision crop management towards agriculture 5.0: A comprehensive overview. Agriculture 15, 582 (2025).
Mansour, N. E. et al. Automated vacuum drying kinetics, thermodynamics, and economic analysis of sage leaves. Sci. Rep. 15, 18779 (2025).
Acar, C., Dincer, I. & Mujumdar, A. A comprehensive review of recent advances in renewable-based drying technologies for a sustainable future. Drying Technol. 40, 1029–1050 (2022).
Pirasteh, G., Saidur, R., Rahman, S. M. A. & Rahim, N. A. A review on development of solar drying applications. Renew. Sustain. Energy Rev. 31, 133–148 (2014).
El-Mesery, H. S. et al. Optimization of dried garlic physicochemical properties using a self-organizing map and the development of an artificial intelligence prediction model. Sci. Rep. 15, 3105 (2025).
Elwakeel, A. E. et al. Advanced design and Engi-economical evaluation of an automatic sugarcane seed cutting machine based RGB color sensor. PLoS ONE 19, e0306584 (2024).
Mansour, N. E. et al. Effect of drying conditions on kinetics, modeling, and thermodynamic behavior of marjoram leaves in an IoT-controlled vacuum dryer. Sustainability https://doi.org/10.3390/su17135980 (2025).
Elwakeel, A. E., Elbeltagi, A., Salem, A. & Dewidar, A. Z. Optimized design and performance evaluation of a highly precise variable rate mis-planting and replanting potato electronic-metering mechanism. Front. Plant Sci. 16, 1531377 (2025).
Bal, L. M., Satya, S. & Naik, S. N. Solar dryer with thermal energy storage systems for drying agricultural food products: A review. Renew. Sustain. Energy Rev. 14, 2298–2314 (2010).
Sharma, A., Chen, C. R. & Lan, N. V. Solar-energy drying systems: A review. Renew. Sustain. Energy Rev. 13, 1185–1210 (2009).
Elwakeel, A. E. et al. Development, drying characteristics, and environmental analysis of a PV operated automatic solar dryer for drying date. Front. Sustain. Food Syst. 9, 1531601 (2025).
Elwakeel, A. E. et al. Quality evaluation of dried tomato fruit and optimization of drying conditions using a modified solar dryer integrated with an automatic solar collector tracker. Sci. Rep. 15, 7659 (2025).
Younis, O. S. et al. Drying characteristics, environmental and economic analysis of a solar dryer with evacuated tube solar collector for drying Nile Tilapia slices. Sci. Rep. 15, 9822 (2025).
Ghanem, T. H. M. et al. Thin-layer modeling, drying parameters, and techno-enviro-economic analysis of a solar dried salted tilapia fish fillets. Sci. Rep. 15, 5073 (2025).
Khater, E.-S.G. et al. Assessment of a LPG hybrid solar dryer assisted with smart air circulation system for drying basil leaves. Sci. Rep. 14, 23922 (2024).
Elwakeel, A. E. et al. Drying kinetics and thermo-environmental analysis of a PV-operated tracking indirect solar dryer for tomato slices. PLoS ONE 19, e0306281 (2024).
Tiwari, A. A review on solar drying of agricultural produce. J. Food Process Technol. 7, 1–12 (2016).
Belessiotis, V. & Delyannis, E. Solar drying. Sol. Energy 85, 1665–1691 (2011).
Lingayat, A., Zachariah, R. & Modi, A. Current status and prospect of integrating solar air heating systems for drying in various sectors and industries. Sustain. Energy Technol. Assess. 52, 102274 (2022).
Fudholi, A., Sopian, K., Ruslan, M. H., Alghoul, M. A. & Sulaiman, M. Y. Review of solar dryers for agricultural and marine products. Renew. Sustain. Energy Rev. 14, 1–30 (2010).
Khater, E.-S. Effect of distillation methods on essential oil yield and composition of basil dried by different drying systems. Ann. Agric. Sci. Moshtohor 58, 247–260 (2020).
Khater, E.-S. Effect of drying systems on the parameters and quality of dried basil. Ann. Agric. Sci. Moshtohor 58, 261–272 (2020).
Khater, E. G. & Bahnasawy, A. H. Basil drying performance and quality under different drying systems. Benha J. Appl. Sci. 2, 1–9 (2017).
Kaimal, A. M., Tidke, V. B., Mujumdar, A. S. & Thorat, B. N. Food security and sustainability through solar drying technologies: A case study based on solar conduction dryer. Mater. Circ. Econ. 4, 1–23 (2022).
Elmessery, W. M. et al. Deep regression analysis for enhanced thermal control in photovoltaic energy systems. Sci. Rep. 14, 30600 (2024).
Hoque, A. Artificial Intelligence in Post-Harvest Drying Technologies: A Comprehensive Review on Optimization, Quality Enhancement, and Energy Efficiency.
Krishna, H. et al. Navigating challenges and prospects in off-season vegetable production. Veg. Sci. 51, 97–105 (2024).
Champika, P. A. J. Prospects and Constraints of Off Season Big Onion Production Programme in Hambantota District (Hector Kobbekaduwa Agrarian Research and Training Institute, 2018).
Pomegranate Market Growth, Size & Share Analysis. https://www.skyquestt.com/report/pomegranate-market. (2025).
Salim Hassan. Egyptian pomegranate invades Europe and Russia and outperforms the Spanish and Israeli ones. https://www.alborsaanews.com/2021/12/07/1488315 (2021).
Derakhshan, Z. et al. Antioxidant activity and total phenolic content of ethanolic extract of pomegranate peels, juice and seeds. Food Chem. Toxicol. 114, 108–111 (2018).
John, K. M. M., Bhagwat, A. A. & Luthria, D. L. Swarm motility inhibitory and antioxidant activities of pomegranate peel processed under three drying conditions. Food Chem. 235, 145–153 (2017).
Valero-Mendoza, A. G. et al. The whole pomegranate (Punica granatum L), biological properties and important findings: A review. Food Chem. Adv. 2, 100153 (2023).
Sharma, P. et al. Valorization of citrus peel waste for the sustainable production of value-added products. Bioresour. Technol. 351, 127064 (2022).
Osorio, L. L. D. R., Flórez-López, E. & Grande-Tovar, C. D. The potential of selected agri-food loss and waste to contribute to a circular economy: Applications in the food, cosmetic and pharmaceutical industries. Molecules 26, 515 (2021).
Sharma, M., Singh, M. & Sharma, R. Transforming pomegranate waste into value-added products: An innovative approach to sustainability. J. Surv. Fish Sci. 10, 120–127 (2023).
Ko, K., Dadmohammadi, Y. & Abbaspourrad, A. Nutritional and bioactive components of pomegranate waste used in food and cosmetic applications: A review. Foods 10, 657 (2021).
Metwally, K. A. et al. The mathematical modeling, diffusivity, energy, and enviro-economic analysis (MD3E) of an automatic solar dryer for drying date fruits. Sustainability 16, 3506 (2024).
Menon, A., Stojceska, V. & Tassou, S. A. A systematic review on the recent advances of the energy efficiency improvements in non-conventional food drying technologies. Trends Food Sci. Technol. 100, 67–76 (2020).
Jangam, S. V. An overview of recent developments and some R&D challenges related to drying of foods. Drying Technol. 29, 1343–1357 (2011).
Pandey, S., Kumar, A. & Sharma, A. Sustainable solar drying: Recent advances in materials, innovative designs, mathematical modeling, and energy storage solutions. Energy 308, 132725 (2024).
Tyagi, V. V. et al. Sustainable growth of solar drying technologies: Advancing the use of thermal energy storage for domestic and industrial applications. J. Energy Storage 99, 113320 (2024).
Kimaro, D., Nyangarika, A. & Kivevele, T. Uncovering socioeconomic insights of solar dryers for sustainable agricultural product preservation: A systematic review. Heliyon (2024).
Malik, A. & Kumar, M. Assessment of a mixed-mode vertical solar dryer for experimental turmeric drying. Sol. Energy 282, 112980 (2024).
Shimpy, K. M. & Kumar, A. Performance assessment and modeling techniques for domestic solar dryers. Food Eng. Rev. 15, 525–547 (2023).
Darvishi, H., Zarein, M., Minaei, S. & Khafajeh, H. Exergy and energy analysis, drying kinetics and mathematical modeling of white mulberry drying process. Int. J. Food Eng. 10, 269–280 (2014).
Tiwari, S. et al. Environmental and economic sustainability of PVT drying system: A heat transfer approach. Environ. Prog. Sustain. Energy 40, e13535 (2021).
Shimpy, K. M., Sahdev, R. K., Manchanda, H. & Kumar, A. Experimental investigations on latent heat storage based modified mixed-mode greenhouse groundnuts drying. J. Food Process Preserv. 46, e16725 (2022).
Malik, A. & Kumar, M. Experimental ginger drying by a novel mixed-mode vertical solar dryer under partial and fully loaded conditions. Innov. Food Sci. Emerg. Technol. 95, 103736 (2024).
Sharma, M., Atheaya, D. & Kumar, A. Performance evaluation of indirect type domestic hybrid solar dryer for tomato drying: Thermal, embodied, economical and quality analysis. Therm. Sci. Eng. Prog. 42, 101882 (2023).
Nayak, S., Naaz, Z., Yadav, P. & Chaudhary, R. Economic analysis of hybrid photovoltaic-thermal (PVT) integrated solar dryer. Int. J. Eng. Invent. 1, 21–27 (2012).
Sajith, K. G. & Muraleedharan, C. Economic analysis of a hybrid photovoltaic/thermal solar dryer for drying amla. Int. J. Eng. Res. Technol. (IJERT) 3, 907–910 (2014).
Nwakuba, N., Okafor, V. C. & Okorafor, O. O. Environmental effects techno-economic analysis of a hybrid solar-electric dryer. Energy Sour. Part A Recovery Util. Environ. Effects 00, 1–25 (2020).
Qi, F., Zhao, X., Shi, Z., Li, H. & Zhao, W. Environmental factor detection and analysis technologies in livestock and poultry houses : A review. Agriculture 13, 1–16 (2023).
Lamrani, B., Khouya, A. & Draoui, A. Energy and environmental analysis of an indirect hybrid solar dryer of wood using TRNSYS software. Sol. Energy 183, 132–145 (2019).
Prabhu, N., Saravanan, D. & Kumarasamy, S. Eco-friendly drying techniques: A comparison of solar, biomass, and hybrid dryers. Environ. Sci. Pollut. Res. 30, 95086–95105 (2023).
Cabeza, L. F. et al. Low carbon and low embodied energy materials in buildings: A review. Renew. Sustain. Energy Rev. 23, 536–542 (2013).
Shahsavari, A. & Akbari, M. Potential of solar energy in developing countries for reducing energy-related emissions. Renew. Sustain. Energy Rev. 90, 275–291 (2018).
Mostafaeipour, A., Bidokhti, A., Fakhrzad, M.-B., Sadegheih, A. & Mehrjerdi, Y. Z. A new model for the use of renewable electricity to reduce carbon dioxide emissions. Energy 238, 121602 (2022).
Gupta, A., Das, B. & Mondol, J. D. Utilizing a novel method of sand-filled thermal energy storage system for performance enhancement in PVT solar dryer. Sol. Energy Mater. Sol. Cells 283, 113450 (2025).
Gupta, A. et al. Artificial neural networks based computational and experimental evaluation of thermal and drying performance of partially covered PVT solar dryer. Process Saf. Environ. Prot. 183, 1170–1185 (2024).
Gupta, A., Borah, P. P., Das, B. & Mondal, J. D. Energy and exergy based performance evaluation of an innovative PV-assisted solar dryer with and without modified absorber. Sol. Energy 272, 112464 (2024).
Gupta, A., Das, B., Biswas, A. & Mondol, J. D. Assessment of performance and quality parameters for drying neem leaves in photovoltaic-thermal solar dryer. Therm. Sci. Eng. Prog. 43, 101989 (2023).
de Wanderley, R. O. S. et al. The temperature influence on drying kinetics and physico-chemical properties of pomegranate peels and seeds. Foods 12, 286 (2023).
Cecchi, L. et al. Industrial drying for agrifood by-products re-use: Cases studies on pomegranate peel (Punica granatum L.) and stoned olive pomace (pâtè, Olea europaea L.). Food Chem. 403, 134338 (2023).
Mphahlele, R. R., Fawole, O. A., Makunga, N. P. & Opara, U. L. Effect of drying on the bioactive compounds, antioxidant, antibacterial and antityrosinase activities of pomegranate peel. BMC Complement Altern. Med. 16, 1–12 (2016).
Mphahlele, R. R., Pathare, P. B. & Opara, U. L. Drying kinetics of pomegranate fruit peel (cv. Wonderful). Sci. Afr. 5, e00145 (2019).
Galaz, P. et al. Effect of drum drying temperature on drying kinetic and polyphenol contents in pomegranate peel. J. Food Eng. 208, 19–27 (2017).
Marchi, L. B. et al. Evaluation of antioxidant and antimicrobial capacity of pomegranate peel extract (Punica granatuml.) under different drying temperatures. Chem. Eng. Trans. 44, 121–126 (2015).
Int, A. Official methods of analysis of AOAC Int. Preprint at (2007).
Masry, E. S., Hassan, M. A., Abdallah, Y. S. & Metwally, K. A. Effect of using a new automatic heating system powered by renewable energy on poultry houses. Zagazig J. Agric. Res. 50, 81–92 (2023).
Etim, P. J., Eke, A. B. & Simonyan, K. J. Effect of air inlet duct features and grater thickness on cooking banana drying characteristics using active indirect mode solar dryer. Niger. J. Technol. 38, 1056–1063 (2019).
Oguntunji, A. O. & Alabi, O. M. Influence of high environmental temperature on egg production and shell quality: A review. Worlds Poult. Sci. J. 66, 739–750 (2010).
Fudholi, A. et al. Performance analysis of solar drying system for red chili. Sol. Energy 99, 47–54 (2014).
Usub, T. et al. Experimental performance of a solar tunnel dryer for drying silkworm pupae. Biosyst. Eng. 101, 209–216 (2008).
Bala, B. K. & Janjai, S. Solar drying of fish (Bombay duck) using solar tunnel dryer. Int. Energy J. 6, 91–102 (2005).
Hammond, G. P. & Jones, C. I. Embodied energy and carbon in construction materials. Proc. Inst. Civil Eng. Energy 161, 87–98 (2008).
Grazieschi, G., Asdrubali, F. & Thomas, G. Embodied energy and carbon of building insulating materials: A critical review. Clean. Environ. Syst. 2, 100032 (2021).
Prakash, O. & Kumar, A. Environomical analysis and mathematical modelling for tomato flakes drying in a modified greenhouse dryer under active mode. Int. J. Food Eng. 10, 669–681 (2014).
Vijayan, S., Arjunan, T. V. & Kumar, A. Exergo-environmental analysis of an indirect forced convection solar dryer for drying bitter gourd slices. Renew. Energy 146, 2210–2223 (2020).
Kassem, R. et al. A techno-economic-environmental feasibility study of residential solar photovoltaic/biomass power generation for rural electrification : A real case study. Sustainability 16, 2036 (2024).
Atheaya, D. Economics of Solar Drying. (2017) https://doi.org/10.1007/978-981-10-3833-4.
Lowenberg‐DeBoer, J. Economics of variable rate planting for corn. In: Proceedings of the Fourth International Conference on Precision Agriculture 1643–1651 (Wiley Online Library, 1999).
Yang, L. et al. A new automatic sugarcane seed cutting machine based on internet of things technology and RGB color sensor. PLoS ONE 19, e0301294 (2024).
Singh, P. & Gaur, M. K. Environmental and economic analysis of novel hybrid active greenhouse solar dryer with evacuated tube solar collector. Sustain. Energy Technol. Assess. 47, 101428 (2021).
Yang, L. et al. A new automatic sugarcane seed cutting machine based on internet of things technology and RGB color sensor. PLoS ONE 19, 1–25 (2024).
Suraparaju, S. K. et al. Assessing thermal and economic performance of solar dryers in sustainable strategies for bottle gourd and tomato preservation. Sci. Rep. 14, 27755 (2024).
Wang, J. et al. Effects of various blanching methods on weight loss, enzymes inactivation, phytochemical contents, antioxidant capacity, ultrastructure and drying kinetics of red bell pepper (Capsicum annuum L). Lwt 77, 337–347 (2017).
Mukherjee, S. & Chattopadhyay, P. K. Whirling bed blanching of potato cubes and its effects on product quality. J. Food Eng. 78, 52–60 (2007).
Kidmose, U. & Kaack, K. Changes in texture and nutritional quality of green asparagus spears (Asparagus officinalis L.) during microwave blanching and cryogenic freezing. Acta Agric. Scandinavica Sect. B Plant Soil Sci. 49, 110–116 (1999).
Elshehawy, S. M. & Mosad, G. A. Mathematical modeling of tilapia fish fillets dried in thin layer. J. Soil Sci. Agric. Eng. 13, 359–364 (2022).
Darvishi, H., Azadbakht, M., Rezaeiasl, A. & Farhang, A. Drying characteristics of sardine fish dried with microwave heating. J. Saudi Soc. Agric. Sci. 12, 121–127 (2013).
Kara, C. & Doymaz, I. Thin layer drying kinetics of by-products from pomegranate juice processing. J. Food Process Preserv. 39, 480–487 (2015).
El-Wahhab, A., Gomaa, G. & Darwish, E. A. Thin-layer drying from wastes pomegranate wpeel. Misr J. Agric. Eng. 37, 345–356 (2020).
Rifna, E. & Dwivedi, M. Microwave vacuum drying of pomegranate peel: evaluation of specific energy consumption and quality attributes by response surface methodology and artificial neural network. J. Food Process Preserv. https://doi.org/10.1111/jfpp.16325 (2022).
Dwivedi, M. & Rifna, E. Optimization and validation of microwave–vacuum drying process variables for recovery of quality attribute and phytochemical properties in pomegranate peels (Punica granatum L. cv. Kabul). J. Food Meas. Charact. 15, 4446–4464 (2021).
Badr, M. Infrared/convection dryer utilization for drying of pomegranate peels. J. Soil Sci. Agric. Eng. 11, 817–823 (2020).
Cankurtaran, E. & Atalay, H. Energy, exergy, exergoeconomic and exergo-environmental analyses of a large scale solar dryer with PCM energy storage medium. Energy https://doi.org/10.1016/j.energy.2020.119221 (2020).
Palamanit, A., Sharma, M., Sharma, A., Kumar, A. & Jain, A. Computational fluid dynamics simulation and energy analysis of domestic direct-type multi-shelf solar dryer. J. Therm. Anal. Calorim. 136, 173–184 (2019).
Farhadi, R., Marzban, A., Daliran, A., Taki, M. & Rahnama, M. Performance evaluation of greenhouse solar dryer: Energy-exergy analysis, CFD simulation and eco-environmental assessment. Renew. Energy https://doi.org/10.1016/j.renene.2024.121946 (2025).
Ndukwu, M., Tagne, A. T., Marouani, M. E., Etala, H. D. T. & Simo-Tagne, M. Energy, environmental and economic analyses of an indirect cocoa bean solar dryer: A comparison between natural and forced convections. Renew. Energy https://doi.org/10.1016/j.renene.2022.02.015 (2022).
El-Messery, T. et al. The mathematical modeling, diffusivity, energy, and enviro-economic analysis (MD3E) of an automatic solar dryer for drying date fruits. Sustainability https://doi.org/10.3390/su16083506 (2024).
Madhankumar, S., Sekar, S. & Rajesh, S. Energy and environmental analysis in an indirect solar dryer with flat coil inserted phase change material. Sustain. Energy Technol. Assess. https://doi.org/10.1016/j.seta.2024.103805 (2024).
Acknowledgements
The authors would like to extend their sincere appreciation to the Researchers Supporting Project (RSPD2025R752) at King Saud University, Riyadh, Saudi Arabia.
Funding
Open access funding provided by University of Pécs. This research was funded by the Researchers Supporting Project number (RSPD2025R752), King Saud University, Riyadh, Saudi Arabia.
Author information
Authors and Affiliations
Contributions
Conceptualization, K.A.M., E.G.K., and A.H.B., methodology, K.A.M., E.G.K., A.H.B., and A.E.E., software, K.A.M., E.G.K., A.H.B., and A.E.E., formal analysis, A.E., A.S., S.A.M., and A.M.O., investigation, K.A.M., A.E.E., and A.A.T., resources, K.A.M., A.E.E., K.A.M.A., and A.A.T., data curation, K.A.M., A.E.E., A.E., A.S., S.A.M., and A.M.O., writing original draft, K.A.M., E.G.K., A.H.B., and A.E.E., writing-review and editing, K.A.M., E.G.K., A.H.B., A.A.T., and A.E.E., visualization, K.A.M., A.A.T., K.A.M.A., and A.E.E., supervision, K.A.M., E.G.K., A.H.B., and A.E.E., project administration, K.A.M., E.G.K., A.H.B., and A.E.E., funding, A.E., A.S., S.A.M., and A.M.O., all authors have read and agreed to the published version of the manuscript.
Corresponding authors
Ethics declarations
Competing interests
The authors declare no competing interests.
Additional information
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
About this article
Cite this article
Metwally, K.A., Khater, ES.G., Bahnasawy, A.H. et al. Drying kinetics, power consumption, economic and environmental analysis of pomegranate peels drying using a hybrid SD compared with oven dryer. Sci Rep (2026). https://doi.org/10.1038/s41598-025-22464-7
Received:
Accepted:
Published:
DOI: https://doi.org/10.1038/s41598-025-22464-7