Orange Peel Waste Research Articles

Simple and Efficient Process for Valorization of Orange Peel Waste for Isolation and Purification of Industrially Important Lipase

Simple and Efficient Process for Valorization of Orange Peel Waste for Isolation and Purification of Industrially Important Lipase

Utilization of Orange Peel Waste as a Functional Ingredient For Sustainable Environment: A Review

Utilization of Orange Peel Waste as a Functional Ingredient For Sustainable Environment: A Review

Implementation of solidified carbon dioxide to anaerobic co-digestion of municipal sewage sludge and orange peel waste

The waste production is closely related with human activity. Various approaches have been applied to manage and reduce its increasing volume (Paranjpe et al. 2023). One of the possibilities that comply with the assumptions of circular economy is utilization of wastes in anaerobic digestion (AD) process. This technology is common worldwide and it is recognized as the cost-effective methods of energy generation that also allow for nutrient recovery, as well as effective waste management (Alharbi et al. 2023). The biogas generated within this process is considered as a multifunctional renewable source that might be a promising alternative to the depleting traditional fuels. It finds various applications such as heat and power generation, fuel in automobiles, and substrate in chemical industry (Shitophyta et al. 2022, Pradeshwaran 2024). Typically, biogas contains 50–70% of CH4, 30–50% of CO2, and 1–10% of other trace gases like H2, H2S, CO, N2. Its composition mainly depends on the feedstock characteristics, operational conditions, and adopted technology (Gani et al. 2023, Archana et al. 2024). Considering further application, the priority action should be increasing its volume and methane content. There are several strategies to achieve these goals, including implementing codigestion strategy, adding additional component to the main substrate, introducing trace elements essential in AD, pretreatment strategies, and introducing enzymes and microbial strains to digesters (Zhang et al. 2019). Each method has limits related to the implementation costs, changes in the adopted technology, operator training needs, and additional energy input, which might negatively influence the energy balance of wastewater treatment plants (WWTPs) (Meng et al. 2022). Therefore, recent scientific attention has focused on combining various strategies to achieve intended goals. Moreover, such combinations might allow for an effective utilization of various wastes, the earlier use of which in AD was difficult. Orange waste could be an example of such a substrate. The previous studies indicated that its application in AD resulted in poor process efficiency, mainly due to the presence of limonene, recognized as the main inhibitor of biological activity (Calabro et al. 2020, Bouaita et al. 2022). In this study, the novel concept of implementing solidified carbon dioxide (SCO2) in the anaerobic co-digestion of municipal sewage sludge (SS) and orange peel waste (OPW) has been proposed. This approach may help overcome the disadvantages of the two-component AD of these wastes. Importantly, such studies have not been conducted thus far. However, the recent studies indicated that application of SCO2 to aerobic granular sludge improved biogas and methane yields and also enhanced the kinetics of biogas production (Kazimierowicz et al. 2023 a,b). Importantly, SCO2 might be generated in biogas upgrading technologies (Yousef 2019). Such solution is consistent with the principles of the circular economy and contributes to reducing the carbon footprint of WWTPs.

From waste to fuel: Metal-free carbon nanodots for selective CO2 photoreduction into methanol

Addressing the major challenge of global warming by implementing a circular carbon cycle involving CO2 conversion is currently an urgent priority for a more sustainable future. The design of efficient, stable, cheap and eco-friendly systems for such purpose is a remarkable challenge. This study reports an unprecedented metal-free, co-catalyst-free orange peel waste–derived carbon nanodot highly active and selective system for the photoreduction of CO2 into methanol. The waste-derived photocatalyst exhibited a maximum methanol production rate of 416.6 µmolMeOH.gcat-1.h−1 and a highly stable methanol production rate of 12.9 µmolMeOH.gcat-1.h−1 after 72 h. This work proposes a successful waste-to-fuel strategy that combines the valorization of orange peel waste and CO2 conversion for the synthesis of green methanol.

Selective Colorimetric Detection of Pb(II) Ions by Using Green Synthesized Gold Nanoparticles with Orange Peel Extract

Gold nanoparticles (AuNPs) were prepared by using a green approach that employed orange (citrus sinensis) peel water extract (OPE) as a reducing agent. In this case, the organic compounds present in orange peel were able to reduce Au(III) to Au(0) and, at the same time, to act as a capping agent, functionalizing the surface of the AuNPs, stabilizing them in a water solution. This “green” approach valorizes orange peel waste as a resourceful material and makes the synthetic process of AuNPs more environmentally sustainable, safe, and economically feasible than the traditional methods. The obtained gold nanoparticles (AuNPs@OPE) were characterized by FT–IR, DLS, SEM analysis, and UV–Vis spectroscopy; the latter showed a characteristic surface plasmon resonance (SPR) band at 530 nm, typical of spherical gold nanoparticles. The AuNPs@OPE were then tested as colorimetric sensors for heavy metals in water, showing an affinity and selectivity toward Pb2+. In fact, in the presence of Pb2+, the added cation favors the aggregation process, and, in this case, nanoparticles form clusters due to the interactions between Pb2+ and the carboxyl/hydroxyl groups on the surface of the AuNPs@OPE, increasing the size of the nanostructure. This process is accompanied by a change in color of the AuNPs@OPE from pink to violet, with a formation of a second, new SPR band, at a higher wavelength, relative to the aggregate formation. The colorimetric assay was tested at different times with the addition of Pb2+ ions showing different LOD values of 13.31 µM and 0.05 µM after 15 min and 90 min, respectively. The proposed colorimetric assay was also tested for analyzing Pb2+ in drinking water samples demonstrating the reliability to use AuNPs@OPE with real samples.

Optimized Production of a Hesperidin-Enriched Extract with Enhanced Antioxidant Activity from Waste Orange Peels Using a Glycerol/Sodium Butyrate Deep Eutectic Solvent

Citrus processing side-streams are largely represented by waste orange peels (WOP), and there are several techniques developed for polyphenol extraction from WOP; yet, there are a significant lack of methodologies based on non-conventional, green solvents. On this basis, this study was performed to assess a deep eutectic solvent (DES) synthesized with glycerol and sodium butyrate, for its capacity to extract WOP polyphenols. Optimization of the process was carried out using a response surface methodology, which revealed that a maximum total polyphenol yield of 73.36 mg gallic acid equivalent (GAE) g−1 dry mass (DM) could be achieved with a solvent system of DES/water (80% w/w), a residence time of 120 min, and a temperature of 90 °C. Using these settings, the polyphenol extraction from WOP with the DES/water solvent system was found to have outstanding performance compared to aqueous or hydroethanolic extraction, while the extracts generated possessed significantly enhanced antioxidant properties. The chromatographic analyses of the extracts demonstrated that the DES/water extract was particularly enriched in hesperidin (21.81 mg g−1 dry mass), a bioflavonoid with promising pharmaceutical potential. This is a first report on the use of this particular DES for WOP polyphenol extraction, which may be used to produce hesperidin-enriched extracts, by implementing the methodology developed.

Pembuatan Karbon Aktif Dari Limbah Kulit Jeruk Manis (Citrus sinensis L) Sebagai Adsorben Ion Besi (Fe2+) Dalam Air Sumur

This research aims to utilize sweet orange peel waste as an adsorbent of Fe2+ in the form of activated carbon by reviewing the adsorbate characteristics based on absorption capacity of I2, moisture content and ash content, the effect of H2SO4 and KOH activators on adsorption capacity and removal efficiency of Fe2+ ion and adsorption kinetics of Fe2+ ion in well water samples. The fixed variable is the weight of the adsorbent, which is temperature of 315 ° C, 50 grams, particle size of 10 ± 32 mesh, volume of adsorbate 10 liters and flow rate of 4 liters / minute. The independent variable is H2SO4 and KOH activator and the adsorption time is 0; 10; 20; 30; 60; 90; 120; 150; 180; 210 and 240 minutes. The results showed that charcoal with H2SO4 activation met SNI 06-3730-1995 standards, while charcoal with KOH activation did not meet SNI standards. The equilibrium adsorption capacity (qe) for charcoal with H2SO4 activation of 0.284 mg/g occurred at 120 minutes, for charcoal with KOH activation of 0.587 mg/g occurred at 240 minutes. The highest removal efficiency of Fe2+ ions for activated charcoal H2SO4 was 91.35% and KOH 68.39%. Adsorption kinetics fulfills the second order pseudo kinetics model, which is H2SO4 activation charcoal with R2 is 0.998 and KOH with R2 is 0.9956.

Orange Peel Waste as a Source of Bioactive Compounds and Valuable Products: Insights Based on Chemical Composition and Biorefining

Few valorization pathways have been implemented as alternatives to reduce the orange peel waste (OPW) disposal in landfills. OPW can be a source of income or economic savings in juice production factories since this waste is a potential source of value-added products (e.g., bioactive compounds) and energy vectors (e.g., biogas). Valorization alternatives should be based on (i) orange peel chemical composition, (ii) market analysis, and (iii) availability. Nevertheless, few literature papers have highlighted the chemical composition change caused by the different juice production schemes as a potential opportunity to obtain different value-added products and biorefinery schemes. Thus, the aims of this review paper are related to (i) reviewing different orange fruit processing pathways, (ii) analyzing several OPW chemical compositions reported in the open literature, (iii) providing a summary of OPW extraction pathways for bioactive compounds production, and (iv) evaluating the effect of applying different extraction methods on bioactive compound extraction performance. This review includes a description of the OPW matrix, market insights, packaging, physicochemical characterization, processing technologies, and suggested biorefinery approaches. Finally, different extraction methods for obtaining bioactive compounds from OPW are compared. As a result, the supercritical fluid extraction process has the highest extraction performance and selectivity since this method extracted a high amount of hesperidin (8.18 g/kg OPW db.). In conclusion, OPW is a source of bioactive compounds and valuable products that can be introduced in juice-producing factories to increase product portfolio or economic savings by changing the energy matrix.

PEMBUATAN CAIRAN PEMBERSIH ALAMI DARI KULIT JERUK

One of the problems in environmental management is waste. Waste has a bad impact on humans and the environment. However, rubbish/waste can have benefits by being sorted and reprocessed. Most of the waste comes from households. The service team provides education about the use of orange peel waste which can be used as a natural cleaning fluid. Community service activities are one of the Tri Dharma of Higher Education in addition to carrying out education and research. With the community service program, it is hoped that mothers and the community of Tomang Village, West Jakarta will gain knowledge about processing household waste/garbage. Implementation method with counseling and demonstration/practice. The results achieved are very good. With the demonstration, participants can practice directly making natural cleaning fluids that can be used to clean stoves, clean sinks, freshen toilets and so on. The knowledge and skills presented provide provisions for mothers and the community in processing waste at a basic level (self-processing) which can later be used by themselves and become economically valuable and can also become a business opportunity to improve family welfare.

Production of mannooligosaccharides from orange peel waste with β-mannanase expressed in Trichosporonoides oedocephalis

A large quantity of orange peel waste (OPW) is generated per year, yet effective biorefinery methods are lacking. In this study, Trichosporonoides oedocephalis ATCC 16958 was employed for hydrolyzing OPW to produce soluble sugars. Glycosyl hydrolases from Paenibacillussp.LLZ1 which can hydrolyze cellulose and hemicellulose were mined and characterized, with the highest β-mannanase activity of 39.1 U/mg at pH 6.0 and 50 ℃. The enzyme was overexpressed in T. oedocephalis and the sugar production was enhanced by 16 %. The accumulated sugar contains 57 % value-added mannooligosaccharides by the hydrolysis of mannans. The process was intensified by a pretreatment combining H2O2 submergence and steam explosion to remove potential inhibitors. The mannooligosaccharides yield of 6.5 g/L was achieved in flask conversion and increased to 9.7 g/L in a 5-L fermenter. This study improved the effectiveness of orange peel waste processing, and provided a hydrolysis-based methodology for the utilization of fruit wastes.

Graphene oxide-based sorbents modified with waste orange peel biochar for Cd(II) removal from aqueous waste streams

ABSTRACT Living organisms are at great risk from the highly toxic metal cadmium (II). It is not allowed to be in industrial effluent or drinking water that is dumped into cadmium-containing water bodies. It has been classified as a carcinogen by the IARC and the US EPA. Thus, it is essential to discover a practical and economical technique for removing cadmium from an aqueous solution. In the present work, a novel and easy-to-prepare component of graphene oxide/orange peel/chitosan composite (GO-OP-CS) was prepared and examined using various analytical techniques as a hybrid product with improved physicochemical properties and metal ion Cd(II) adsorption capabilities. The results showed that Cd (II) ion adsorption occurred initially fairly fast and that a pH of 6 was optimal for both adsorption and removal of Cd (II) ions. The thermodynamic analysis revealed that the adsorption of Cd(II) is spontaneous and exothermic. The experimental results showed that the functional groups present on the adsorbent surfaces (such as hydroxyl, carboxyl, epoxy, amine, and so on) led to the improvement of the Cd(II) metal’s ability to absorb. This novel composite exhibited a high adsorption capacity (qmax) of 537.63 mg/g. The results of the toxic Cd(II) sorption using the synthesized composite showed that its adsorption kinetics and sorption isotherm confirmed the pseudo-second-order and Langmuir models, respectively. The proposed method is also reliable for Cd(II) sorption for preconcentration and remediation before Cd testing from genuine samples, such as wastewater, digested tobacco, and e-battery samples.

Co-hydrothermal carbonization with process water recirculation as a valuable strategy to enhance hydrochar recovery with high energy efficiency

This study aims at valorizing the residual aqueous phase from hydrothermal carbonization (HTC) of Sicilian agro-wastes in order to enhance the hydrochar recovery, positively affecting the process energy balance. Process waters (PW) obtained from HTC and co-HTC using orange peel waste and fennel plant residues were used as recycled solvent in experiments carried out at the temperatures of 180 and 230 °C. The results showed that an additional hydrochar formation was promoted during recirculation of solvent, leading to average increments of solid mass yield of 10.5 wt% for tests conducted at 180 °C and 3.9 wt% for 230 °C. After five consecutive recirculation phases in co-HTC runs, the hydrochar yield increased up to 18.2 wt%. The low H/C and O/C atomic ratios values, found after recirculation, indicate that organic acids, accumulated in the PW, may catalyze the process and promote the biomass deoxygenation by boosting dehydration and decarboxylation. The recovered PWs from conversion steps with deionized water were also carbonized in absence of the solid feedstock in order to quantify their contribution in hydrochar formation during recirculation and thus the synergistic interactions. After recirculation, energy recovery averagely augmented by more than threefold, showing that the proposed strategy could significantly improve the sustainability of HTC.

NANOPARTICLE PREPARATION OF SIAM CITRUS PEEL EXTRACT (CITRUS NOBILIS L. VAR. MICROCARPA) USING SHORT-CHAIN CHITOSAN AND TRIPOLYPHOSPHATE AS CROSS LINKER AND CELLULAR UPTAKE STUDY ON MCF-7 CELL LINE BY IN VITRO

Objective: High consumption of oranges causes a lot of orange peel waste. Orange peel contains the compound naringenin, which has a cytotoxic effect on various cancer cells. This research aims to develop a preparation of Siamese orange peel extract nanoparticles with short-chain chitosan and tripolyphosphate carriers as an oral drug delivery system and determine its cytotoxic activity against the Michigan Cancer Foundation-7 (MCF-7) cell line. Methods: This research uses the micro tetrazolium (MTT) method to see the cytotoxic activity extract of methanol obtained from maceration extraction. The extract was then formulated into nanoparticles using chitosan and tripolyphosphate. Characterization and evaluation of nanoparticles were carried out, including particle size, zeta potential, entrapment efficiency, and stability in the stomach using 0.1 N HCl and in the intestine using Artificial Intestinal Fluid (AIF) in vitro. This research was also conducted to assess the ability of nanoparticles to enter MCF-7 cells (cellular uptake). Results: Nanoparticles were successfully developed from Siamese orange peel extract. The results of the day 0 nanoparticle characterization were spherical, with average particle size 284.3 nm, zeta potential 0.713 mV, entrapment efficiency 96.73%, and stability in 0.1 N HCl at the 0th hours, respectively. 1st, 2nd, and 3rd. 99.16%, 98.70%, 98.47%, 98.31%, stability on AIF at hours 0, 1, 2, 3 and 4 respectively 99.52%, 99.30%, 99.40%, 98.99%, 99.29%. Characterization of nanoparticles on day 25 showed that the average particle size was 196.2 nm, zeta potential 0.476 mV, entrapment efficiency 96.92%, stability in 0.1 N HCl at 0, 1, 2 and 3 h respectively 99.51%, 98.67%, 98.51%, 98.27%, stability in AIF at 0th, 1st, 2nd, 3rd, and 4th hours 99.24 respectively %, 98.76%, 98.46%, 97.93%, 97.58%. Cytotoxic activity of extract Siamese citrus peel against MCF-7 cells with IC50 of 290.58 µg/ml. The result shows that cellular uptake of Siamese citrus peel nanoparticles can penetrate MCF-7 cells. Conclusion: Stable nanoparticles were successfully developed from Siamese orange peel extract, and their stability was maintained throughout a 30-day storage period. This extract displayed cytotoxic effects and showcased the ability for cellular uptake in MCF-7 cell cultures in vitro.

Carbon nanodots from orange peel waste as fluorescent probes for detecting nitrobenzene

An integrated approach combining thermal and electrochemical technologies for the valorization of agro-industrial waste. The resulting carbon dots (CDs) show fascinating optical properties, enabling their application as fluorescent chemical probes.

Exploring hydrodynamic cavitation for citrus waste valorisation in Malta: from beverage enhancement to potato sprouting suppression and water remediation.

Introduction: The endorsement of circular economy, zero-waste, and sustainable development by the EU and UN has promoted non-thermal technologies in agro-food and health industries. While northern European countries rapidly integrate these technologies, their implementation in Mediterranean food-supply chains remains uncertain. Aims: We evaluated the usefulness of hydrodynamic cavitation (HC) for valorizing orange peel waste in the fresh orange juice supply chain of the Maltese Islands. Method: We assessed: a) the effectiveness of HC in extracting bioactive compounds from orange peels (Citrus sinensis) in water (35°C) and 70% (v/v) ethanol (-10°C) over time, compared to conventional maceration, and b) the potato sprouting-suppression and biosorbent potential of the processed peel for copper, nitrate, and nitrite binding. Results: Prolonged HC-assisted extractions in water (high cavitation numbers), damaged and/or oxidized bioactive compounds, with flavonoids and ascorbic acid being more sensitive, whereas cold ethanolic extractions preserved the compounds involved in radical scavenging. HC-processing adequately modified the peel, enabling its use as a potato suppressant and biosorbent for copper, nitrate, and nitrite. Conclusion: Coupling HC-assisted bioactive compound extractions with using leftover peel for potato-sprouting prevention and as biosorbent for water pollutant removal offers a straightforward approach to promoting circular economic practices and sustainable agriculture in Malta.

Characterization of Nanocellulose from Orange Peel Waste

Orange peel is a commercially available natural fiber with an increasing interest in using it as a raw material in a variety of applications due to its high cellulose concentration in the plant. This research aims to determine the preparation of nanocellulose from orange peel waste (OPW) by using chemical treatment of acid hydrolysis method. In order to provide the optimum conditions of nanocellulose of OPW which are possessed high crystallinity in their crystal structure by using acid hydrolysis method and the effects of various acid concentrations on the crystallinity index, crystallite size and morphology of cellulose nanocrystals were studied. However, based on the previous study, using OPW there is limited study has been reported on type of acid and optimum acid concentration as a parameter of using hydrolysis method. Therefore, in this study, the process of preparation OPW nanocellulose by using acid hydrolysis method with the best type of acid used of sulphuric acid (H2SO4) and hydrochloric acid (HCl), optimum acid concentration (30-40 wt%), constant hydrolysis time (120 min) and constant temperature (45 °C) is comprehensively studied. Based on the achieved outcomes, the H2SO4 emerges as the most favorable approach for acid hydrolysis technique, effectively yielding finely dispersed crystalline cellulose while mitigating undesirable aggregation effects. The optimal acid concentration of 30 wt%, coupled with a 120 minute hydrolysis duration and a temperature of 45 °C, yields the most favorable results in terms of both crystallinity index and crystallite size, reaching remarkable values of 87.69 % and 3.19 nm, respectively. The nanocellulose derived from OPW holds significant potential as an environmentally sustainable material, aligning harmoniously with prevailing global trends in design and development for enhanced sustainability.

Orange Peel and Cauliflower Residues Supplementation Induce Morphological and Physiological Tolerance in Common Bean under Drought Stress

Drought is one of the most harmful abiotic stresses affecting the development and yield of the common bean (Phaseolus vulgaris L.). The current climate change and the resulting increased drought will worsen the negative impact of water stress on the plant. The powder of orange peel and cauliflower waste were added as soil supplementation at rates of 7 and 15 g/pot to pots of Phaseolus vulgaris L. under different drought conditions. The growth and physiological analysis were estimated after flowering period of common bean. In the pots where drought will be applied, irrigation was stopped for 2, 4, 6, 8 and 10 days during the flowering period and irrigation was performed again after water stress application. To measure moisture percentage of pots, first dry pots were weighed and after irrigation, their moisture variation in terms of percent was measured during stress from 2 to 10 days. The highest plant height was obtained from control. Leaf area decreased significantly despite the application of different powder, especially after 4 days of drought conditions. The highest root fresh and dry weight, raw ash were observed under control with the application of 7.5 g orange peel powder. Shoot dry weight decreased as the number of days exposed to drought increased, and the application of 15 g orange peel and cauliflower powder gave the highest results compared to control conditions. The highest dry matter was obtained from the application of 7.5 g and 15 cauliflower powder in the absence of drought. It has been revealed that as the duration of exposure to drought increases, the value decreases and plant powders are effective in increasing this value. Chlorophyll a, chlorophyll b and total chlorophyll values decreased significantly with drought, and the highest value was obtained from control conditions, followed by 15 cauliflower powder applications.

Identification, extraction, and application of orange peel color extracts for silk fabric coloration

Under-utilized orange peel waste contains natural colorants that might be used for textile dyeing. Research into orange peel waste as natural colorants provides benefits for both the agricultural and fashion industry with a creative and sustainable solution. This research performed the extraction of colorants from the orange peel as plant dyes and investigated their potential dyeing capability of silk fabrics. With full factorial analysis, we determined the optimal extraction conditions by comparing 100 % ethanol, 70 % ethanol, and water, aiming to achieve the highest absorbance for the extracted solution. Conditions obtained with the best performance include an extraction temperature of 60 °C, an extraction time of 120 min, and a material-to-liquor ratio of 1:20 (wt/vol) for both 100 % and 0 % ethanol. To attain the highest K/S values on textiles with orthogonal experimental design, the optimal dyeing profiles of silk fabrics with water solution were found to be 100 °C, 60 min, pH 3, and Liquid Ratio of 1:15. Colorfastness results of crocking, washing, and sunlight are in favor of the usage of orange peel color extracts for textile application.

Orange peel derived hierarchical porous carbon/sulfur composite cathode material for Li–S battery

A hierarchical porous carbon (HPC) structure was developed from the waste orange peel using KOH as an activating agent. In HPC, the carbon has interconnected hierarchical pores size of which lies between 2 nm and 5 μm. HPC/S composite was prepared by melt-diffusion method and analysed for electrochemical performance. HPC/S exhibits a high initial discharge capacity of 870 mAhg−1 at 0.2C and 734 mAhg−1 at 0.4C. The Carbon-black (CB)/Sulfur (S) composite was also prepared and characterized. A comparative study was done with the CB/S composite, which shows poor cyclability and a discharge capacity of 332 mAhg−1 at 0.2C rate considering 1C = 1672 mAhg−1. Sulfur confinement in the HPC structure leads to superior electrochemical performance of the HPC/S composite ensuring a promising cathode material.

Recovery of Phenolic Compounds from Orange Peel Waste by Conventional and Assisted Extraction Techniques Using Sustainable Solvents.

The valorization of orange peel waste (OPW) through the extraction of bioactive compounds is a clear example of the circular economy. OPW contains many value-added compounds, among which bioactive phenolic compounds (flavonoids and phenolic acids) could be extracted and used for industrial applications, such as pharmaceuticals or cosmetics. In this work, the extraction of phenolic compounds from orange peel was carried out by conventional (orbital shaker) and assisted (ultrasound and microwave) extraction techniques using deionized water, 80% (v/v) ethanol in water, and ethyl acetate as solvents. The effect of temperature, extraction time, and type of technique was evaluated and discussed following spectrophotometric (total phenolic content and total flavonoid content) and high-performance liquid chromatography (HPLC) analyses of the extracts. The most effective extraction in terms of efficiency was achieved by microwave-assisted extraction using 80% (v/v) ethanol in water as the extraction solvent, at 373 K for 6 min, which obtained 7.2 ± 0.1 mg gallic acid equivalent (GAE)/g OPW and 13.3 ± 0.1 mg quercetin equivalent (QE)/g OPW, with the main bioactive compound extracted being hesperidin (58.2 ± 0.2 mg/g OPW). The most effective extraction in terms of energy consumption was achieved using ultrasound-probe-assisted extraction, yielding 8.8 ± 0.0 mg GAE/g OPW; 17.1 ± 0.1 mg QE/g OPW; 40.0 ± 0.2 mg hesperidin/g OPW, with an energy consumption of 18 kJ. Ultrasound and microwave-assisted extractions can be considered efficient extraction technologies for the valorization of OPW as they reduce extraction time and energy consumption and increase extraction yield.