Olive Mill Solid Waste Research Articles

Catalytic Effects of Potassium Concentration on Steam Gasification of Biofuels Blended from Olive Mill Solid Wastes and Pine Sawdust for a Sustainable Energy of Syngas

The effect of potassium impregnation at different concentrations during gasification, under nitrogen/water steam atmosphere, of char produced via pyrolysis of olive mill residues blended or not with pine sawdust was investigated. Three concentrations (0.1 M, 0.5 M, and 1.5 M) of potassium carbonate solution (K2CO3) were selected to impregnate samples. First, four types of pellets were prepared; one using exhausted olive mill solid waste (G) noted (100G) and three using G blended with pine sawdust (S) in different percentages (50%S–50%G (50S50G); 60%S–40%G (60S40G); 80%S–20%G (80S20G)). Investigations showed that when isothermal temperature increases during the gasification conducted with two water steam percentages of 10% and 30%, the reactivity increases with potassium concentration up to 0.5 M, especially for 100G. Still, higher catalyst concentration (1.5 M) showed adverse effects attributable to silicon release and char pore fouling. Moreover, the effect of the steam concentration on the gasification reactivity was significant with the non-impregnated sample 100G. Finally, a kinetic study was carried out to determine the different kinetic parameters corresponding to the Arrhenius law.

Assessing the potential of olive mill solid waste as feedstock for methane and volatile fatty acids production via anaerobic bioprocesses

The extensive production of olive mill solid waste (OMSW) from olive oil industry in the Mediterranean basin claims effective treatments and valorization strategies. This study aims to elucidate the potential of anaerobic digestion (AD) and anaerobic fermentation (AF) to convert pre-treated OMSW into biogas (CH4) and volatile fatty acids (VFA), respectively. The two thermal treatment conditions (65 °C and 180 °C) that are being implemented in the industry that manages the OMSW were tested. Comparing the two treatments aims to demonstrate the influence on the AD process of the degree of solubilization and degradation of the metabolites produced from the same substrate. AD of OMSW treated at low-temperature (65 °C) exhibited similar methane yields (195 ± 8 mL CH4/g volatile solid (VS)) to raw OMSW. AD of the solid phase (SP) after high-temperature treatment with acid addition at 180 °C resulted in methane yields comparable to raw OMSW while the liquid phase (LP) exhibited low methane yields (85 ± 10 mL CH4/g VS). Nevertheless, LP/180 °C exhibited the highest VFA bioconversion at 27.6 %, compared to less than 10 % for SP/180 ºC, SP/65 °C, and raw OMSW. The VFA profile showed notable variations with thermal treatment temperatures. Propionic acid dominated at SP/65 °C, while acetic acid became the primary VFA at 180 °C. Furthermore, significant degradation rates of phenolic compounds and furans were observed during the final day of both anaerobic processes. Overall, these findings suggest that AD is more suitable for raw OMSW, treated at low temperature and SP at high temperature, while AF offers a promising alternative for high-temperature-treated LP.

Palliative Effect of Phenolic Extract Derived from Olive Mill Solid Wastes on Pomegranate Plants Submitted to Water Stress

Palliative Effect of Phenolic Extract Derived from Olive Mill Solid Wastes on Pomegranate Plants Submitted to Water Stress

Development of a Novel Adsorbent Derived from Olive Mill Solid Wastes for Enhanced Removal of Methylene Blue.

Industrial wastewater discharge, tainted with hazardous substances, including dyes like methylene blue (MB) from the textile sector, further emphasizes the need for water treatment to produce safe drinking water. This study explores the potential of olive mill solid waste, an abundant and cost-effective agricultural waste in Mediterranean regions, to yield high-quality activated carbon (AC) with zinc chloride activation for MB adsorption. The activation process, carried out at a modest temperature of 500 °C without the need for an inert atmosphere, resulted in AC with remarkable characteristics, boasting a substantial surface area of 1184 cm2·g-1 and a total pore volume of 0.824 cm3·g-1. Extensive characterization of the AC was carried out through a large range of surface techniques. The pH of the solution had minimal influence on MB adsorption, the maximum removal was 95%, which was under slightly acidic pH conditions (5.8), and the adsorbent dose was 0.4 g·L-1 for a 50 mg·L-1 MB concentration. Equilibrium data pertaining to MB adsorption were subjected to fitting with different models, namely Langmuir, Freundlich, and Temkin. Notably, the Langmuir model exhibited the best fit, revealing a maximum monolayer adsorption capacity of 500 mg·g-1 at 25 °C, and the adsorption kinetics closely followed a pseudo-second-order model.

Co-gasification of Jordanian olive mill solid waste and RTC coal for thermochemical treatment: characterization and equilibrium modelling

Co-gasification of Jordanian olive mill solid waste and RTC coal for thermochemical treatment: characterization and equilibrium modelling

Unraveling the effect of phenolic extract derived from olive mill solid wastes on agro-physiological and biochemical traits of pomegranate and its associated rhizospheric soil properties

Agricultural waste management poses a significant challenge in circular economy strategies. Olive mill wastes (OMW) contain valuable biomolecules, especially phenolic compounds, with significant agricultural potential. Our study evaluate the effects of phenolic extract (PE) derived from olive mill solid wastes (OMSW) on pomegranate agro-physiological and biochemical responses, as well as soil-related attributes. Pomegranate plants were treated with PE at doses of 100 ppm and 200 ppm via foliar spray (L100 and L200) and soil application (S100 and S200). Results showed increased biomass with PE treatments, especially with soil application (S100 and S200). Proline and soluble sugar accumulation in leaves suggested plant adaptation to PE with low-level stress. Additionally, PE application reduced malondialdehyde (MDA) and hydrogen peroxide (H2O2) contents. Higher doses of PE (S200) significantly improved net photosynthesis (Pn), transpiration rate (E), water use efficiency (WUEi), and photosynthetic efficiency (fv/fm and PIabs). Furthermore, PE treatments enhanced levels of chlorophylls, carotenoids, polyphenols, flavonoids, and antioxidant activity. Soil application of PE also increased soil enzyme activities and microbial population. Our findings suggest the beneficial impact of PE application on pomegranate agro-physiological responses, laying the groundwork for further research across various plant species and soil types to introduce nutrient-enriched PE as an eco-friendly biostimulant.

Evaluation of biochar and hydrocar energy potential derived from olive mills waste: The case of Montenegro

Three different waste streams from olive oil production from Montenegro are utilized energetically by hydrothermal carbonization (HTC – hydrochar) and pyrolysis (biochar). Pyrolysis experiments of three-phase olive mill solid waste (3POMSW) were conducted for different pyrolysis temperatures of 450, 550, and 700 °C and a residence of 60 min for each experiment. HTC experiments for two-phase olive mill waste (2POMW) and a mixture of olive mill wastewater (3POMWW) and 3POMSW were carried out at 180, 200, and 220 °C, autogenous pressure of (1, 1.6, and 2.3 MPa) for 60 min. Increasing reaction temperature led throughout all experiments to a lower carbon recovery. Furthermore, all hydrochar and biochar samples had energy densification of more than one, indicating a higher mass-energy density than the initial feedstock. The highest energy yields were achieved for the 3POMW, with 46.48 % in hydrochar treated at 180 °C and 44.09 % in biochar treated at 450 °C. Concerning the hydrochar from 2POMW, the highest energy and mass yields of 62.53 % and 49.65 %, respectively obtained at 180 °C. Summarizing, the energy potential of Montenegro's olive mill waste (OMW) was estimated at 43.69 PJ, which roughly could cover the whole energy demand of the olive oil industry in Montenegro.

Application of olive mill waste-based biochar for improving wheat response to salt stress

The production of olive mill solid waste (OMSW) raises concerns due to its toxicity and negative environmental impact. However, by utilizing pyrolysis, OMSW can be converted into biochar, a carbon-rich material that detoxifies the waste and preserves its nutrient content. The OMSW-based biochar possesses alkaline properties (pH 9.6), low electrical conductivity (EC), high cation exchange capacity (CEC), a porous surface morphology, various surface functional groups, and high mineral content. This study assessed the influence of two concentrations (5% and 10%) of OMSW-based biochar on wheat plants' growth biomarkers and physiological characteristics subjected to salt stress conditions (150 mM NaCl). Findings of the study revealed that salt stress had deleterious effects on various parameters, including shoot height, fresh and dry weights of shoots and roots, relative water content (RWC%), membrane stability index (MSI%), photosynthetic pigments, and photosynthetic parameters such as the coefficient of the effective quantum yield of photochemical energy conversion of PSII (ØPSII), photochemical quenching (qP), and photochemical efficiency of PSII (Fo, Fm, Fv/Fo, and Fv/Fm). Furthermore, the levels of lipid peroxidation (MDA), hydrogen peroxide (H2O2), superoxide dismutase (SOD), and peroxidase (POD) activities significantly increased in stressed plants. On the other hand, applying both concentrations of OMSW-based biochar effectively improved the overall performance of wheat plants, irrespective of the presence of salinity. OMSW-based biochar is a promising strategy for promoting wheat growth in salt-stressed soil by improving various growth parameters and mitigating plant oxidative stress.

Valorization of olive mill solid waste-derived biochar: An efficient approach for simultaneous adsorption and oxidation of micropollutant in surface water

This study explores the utilization of olive mill solid waste (OMSW) as a source of biochar (BC) for effective removal of micropollutants during surface water treatment. The conversion of OMSW into BC was accomplished via pyrolysis conducted at varying temperatures ranging from 400 to 600 °C. To improve its performance, BC was subjected to activation through either physical-thermal or chemical techniques. BC samples were characterized by SEM microscopy revealing a porous structure, surface area analysis showed an increase in surface area for biochar samples subjected to physical-thermal activation (BC-T) (20 m2/g) and chemical activation using potassium hydroxide (BC-KOH) (70 m2/g) or zinc/iron (BC-Zn/Fe) (456 m2/g). The zero point of charge range from <3 to 4.2 for the different BC samples whereas FTIR measurements showed that physical activation at 900 °C favors a graphitic structure in BC.The catalytic properties of the biochar samples were investigated in the activation of sodium persulfate (PSF) for the oxidation of micropollutants (MPS), including ciprofloxacin (CPX), sulfamethoxazole (SMZ), and paracetamol (PCM), in natural Lake Kinneret water. BC-KOH exhibited the highest removal efficiency, and the removal of MPS increased with higher dosages of BC and PSF. Under optimized conditions ([biochar]: 500 mg/L and [PSF]: 200 mg/L), significant removal efficiencies were achieved for PCM (88.2 % ± 0.7), CPX (80.8 % ± 1.9), and SMZ (64.1 % ± 3.2) after a 5-hour treatment. Finally, MPS adsorbed on BC experienced significant surface oxidation, resulting in removal efficiencies for PCM (97.9 %), CPX (92 %), and SMZ (77.9 %). This oxidation process is expected to enhance the treatment effectiveness prior to regeneration.

Impact on the microbial population during biological volatile fatty acid production from olive mill solid waste

Volatile fatty acids (VFAs) revalorisation from waste products are key in achieving industrial sustainability and circular economic goals. Hence, the objective of this work was to correlate the adaptability of the microbial community in olive mill solid waste (OMSW) anaerobic fermentation processes, to the production of VFAs under different pH conditions, i.e. under acidic (pH 4 &5), neutral (pH 6 & 7) and alkaline conditions (pH 9 & 10). At neutral conditions, anaerobic digestion exhibited minimal accumulation of VFAs, as they were primarily biotransformed to methane, where no significant changes in the microbial community were observed. At acidic conditions, a diverse profile of VFAs were present in the reactors, although the VFA production was limited to around 20 % of fed OMSW. Despite the low accumulation, the VFA profile at pH 5 was more complex than those at alkaline conditions, accounting propionic acid as the main VFA compound produced at pH 5 (60 % of the total VFAs). Acidic conditions entailed a shift in the microbial composition compared to the initial inoculum, although the reactors maintained similar diversity indices. At alkaline conditions, around 50 % of the fed OMSW was accumulated as VFAs, mainly as acetic acid. Overall, a lower diversity and higher dominance corresponded to a less diverse VFAs profile, such as the preponderance of acetic acid correlated with a microbial diversity decrease and the increased dominance of Tissirella.

Microbial Population Dynamics during Unstable Operation of a Semicontinuous Anaerobic Digester Fed with a Mild-Treated Olive Mill Solid Waste

This research evaluates process instability together with microbial population dynamics of the startup of an anaerobic digestion of a mild pretreated solid olive oil waste. The pretreatment consisted of a mild thermal treatment called thermo-malaxation and a subsequent dephenolized process of the olive mill solid waste. The anaerobic digestion process of the mild pretreated and partially dephenolized biomass was studied for three Hydraulic Retention Times (HRTs), with 21 days each HRT, with an organic load rate of 1 g VS/L d, carried out at mesophilic temperature (35 ± 1 °C). The average value of methane yield decreased from 204 ± 9 mL CH4/g VS d on day 21, the last day of the first HRT, to 87 ± 24 mL CH4/g VS d on day 60, the last day of the third HRT. The alkalinity decreased drastically, indicating instability of the anaerobic digestion process. Although phenolic compounds were partially extracted in the pretreatment, the observed increase in phenolic compounds during reactor operation might be contributed to the methane production decay. Interestingly, volatile fatty acids decreased with time, indicating that not only the methanogenic stage but also the hydrolysis stage was affected. Indeed, the microbial analysis showed that the abundance of hydrolytic bacteria decreased over time. It is also worth noticing that hydrogenotrophic methanogens, while present during the first two HRTs, were not observed at the end of the last HRT. This observation, together with the increase in the relative abundance of acetoclastic methanogens, showed a shift in the methane production pathway from hydrogenotrophic methanogenesis to acetotrophic methanogenesis.

Experimental investigation on the mechanical strength and thermal conductivity of concrete lightened by olive mill solid waste

The objective of this study is to explore the feasibility of producing lightweight concrete using olive mill solid waste as Olive Pomace Aggregates (OPA), an agricultural by-product. The use of these co-products as a substitute for natural aggregates, such as natural sand, would create additional economic, social, and environmental value while also facilitating their management and handling. To carry out this research, we took into account our previous understanding of lightweight concrete production, the characteristics of natural aggregates and their potential substitutes, and also explored the potential utilization of OPA as a sustainable building material.The study evaluates the mechanical strength and thermal conductivity of lightweight concrete made with OPA to determine if it can be used as a raw material to produce cementitious materials. The concrete mixtures studied contain OPA as a partial substitute for fine aggregates (natural sand), Ordinary Portland cement, natural gravel, natural sand, and water. The research studies various proportions of sand substitution by OPA, ranging from 0% (reference concrete) to 15% with a step of 5%. The experimental assessment focuses on determining whether the mechanical and thermal properties of the developed lightweight concrete can be improved compared to the reference concrete. The results indicate that the concrete mixture containing 5% OPA achieved the most favorable outcomes. After a maturation period of 28 days, the compressive strength reached 25 MPa, while the density decreased by 5.69% compared to the density of the reference concrete.The concrete containing 5% pf OPA achieves a thermal conductivity of 0.86 W/m.K, resulting in a reduction of approximately 34% compared to the reference concrete.This study demonstrates that using 5% of OPA can be a viable substitute for natural sand in lightweight concrete production, offering benefits in terms of both mechanical and thermal properties. Moreover, the resulting concrete mixture satisfied the minimum strength requirements for structural use as a construction material.

The Recovery of Bioactive Compounds from Olive Pomace Using Green Extraction Processes

In this study, solid olive mill waste (SOMW) was used to obtain antioxidant compounds using solid–liquid extraction. The effect of different extraction methods, namely microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), Soxhlet, and conventional solvent extraction, on the yield, total phenolics, and total antioxidant activity of SOMW extracts was investigated. Untreated and dried SOMW were subjected to extraction with water and methanol. The antioxidant activity of the extracts was evaluated using the DPPH assay, while their total phenolic content was measured using the Folin–Ciocalteu method. For the characterisation of the extracts, HPLC-DAD analysis was performed. The results showed that the extraction yield was significantly influenced (p &lt; 0.05) by the solvent used, the material treatment prior to extraction, the moisture content of SOMW samples, and the extraction time. The optimised parameters were water, as the extraction solvent, and MAE as the extraction technique (extraction temperature of 50 °C and time of 1 h). The evaluation of the antioxidant activity of the extracts indicated that phenolics were the dominant bioactive compounds. The extracts were found to be rich in several hydroxytyrosol derivatives. Therefore, SOMW can be a valuable resource for bioactive compounds using conventional and innovative extraction techniques.

Biochemical Methane Potential of Mechanically and Enzymatically Pretreated Solid Olive Mill Waste

Olive cake, the solid byproduct of three-phase centrifugation olive oil production, has a high organic and polyphenol content, rendering it an environmental threat when landfilled as well as limiting its animal feed potential. This residue can be a good candidate for biomethane production due to its rich polysaccharide content (pectin, hemicellulose, and cellulose). Two strategies were compared to maximize biomethane production: destoning (i.e., removal of the seed fragments via mechanical means) and enzymatic pretreatment of the pulp. After 30 days of batch anaerobic digestion at 35 °C, both enzymatically pretreated and destoned olive cakes produced similar amounts of methane (~295 mL CH4/g volatile solids (VS)), 42% more than the control. A comparison of olive cake’s biomethane yields with a broad range of agricultural residues in the literature demonstrated its suitability for biomethane production. Additionally, the digestate recovered from the anaerobic digestion of olive cake had high Kjeldahl nitrogen contents (3.6%, db) and low polyphenol concentrations (0.02 mg gallic acid equivalent (GAE)/g), qualifying it as an ingredient for soil amendment. This study demonstrated olive cake can be diverted from landfills for second-generation biofuel production, and that the resulting digestate may have value for soil amendment.

Aquaculture Sludge as Co-Substrate for Sustainable Olive Mill Solid Waste Pre-Treatment by Anthracophyllum discolor

Olive mill solid waste (OMSW) is an agro-industrial waste that has a high content of recalcitrant lignocellulose, which can adversely affect the environment. This study aimed to evaluate the phenol and lignin removal and the enzyme activity involved in the biological pre-treatment of OMSW supplemented with aquaculture sludge (AS) as an external nitrogen source by Anthracophyllum discolor. The highest lignin removal and enzymatic activity performance was obtained in the mixture of OMSW and AS prepared at a C/N ratio 45. In these conditions, the pre-treatment could remove 66% of lignin and 68% of phenols in the solid phase and 56% of phenols in the liquid phase and the maximum activity of laccase, manganese peroxidase and manganese independent peroxidase were of 10, 289 and 75 U L−1 in 25, 30, and 15 days of pre-treatment, respectively. These results propose that the addition of AS as a co-substrate for adjusting the C/N ratio allows a 41 and 141% increase in lignin removal and manganese peroxidase activity respectively, enabling the treatment of both OMSW and AS wastes and the possible recovery of an enzymatic extract of biotechnological interest.

Enhancing Biobased Volatile Fatty Acids Production from Olive Mill Solid Waste by Optimization of pH and Substrate to Inoculum Ratio

The pH and substrate-to-inoculum ratio (S/I) are important parameters in the anaerobic fermentation of agroindustrial residues, and therefore the optimization of these two parameters is needed for a stable, efficient, and sustainable reactor operation. In this work, the parameters pH (5–9) and S/I (0.5–3 gVS gVS−1) were optimized to produce biobased volatile fatty acids (VFAs) from hydrothermally pretreated olive mill solid waste (HPOMSW). The response variables evaluated in the Doehlert design were total VFAs concentration (tVFAs) (mg L−1) and amounts (%) of isobutyric, butyric, isovaleric, and valeric acids on the VFAs profile. The pH was the variable that most influenced the mixed culture fermentation of HPOMSW, proving to be a key parameter in the process. Microbial community analyses of conditions 1 (S/I = 3 gVS gVS−1 and pH = 7) and 4 (S/I = 1.13 gVS gVS−1 and pH = 5) showed that Proteobacteria and Firmicutes accounted for more than 87% of the total microorganisms identified for both conditions. In addition, the second-order model best fitted the experimental data for the VFAs production at the desirable condition (S/I = 3 gVS gVS−1 and pH = 8).

Olive mill solid waste gasification in a pilot-scale downdraft gasifier with three-stage air supply: performance, mass-energy balance and fate of inorganic elements

Olive mill solid waste (OMSW), also called olive pomace, is a biomass waste available in many Mediterranean countries, including developing countries. In this study, OMSW has been tested as a fuel in an original pilot-scale downdraft gasifier with three-stage air supply, and extensive metrology was implemented. After pelletizing and characterization of the biomass waste, gasification was investigated by operating a 2-day campaign using air as a gasifying agent. The evolution over time of operating parameters such as flowrates, temperatures and pressure drop were recorded. The syngas (including tars) and solid residues were analyzed. The fate of inorganic elements was investigated. Mass and energy balances were performed and the performance of the gasifier was evaluated. The syngas contained 14 % v/v H2 and 17 % v/v CO (dry and tar-free basis) and its lower heating value was 4.7 MJ/Nm3 (wet basis). The solid residues were rich in potassium and phosphorus and could be considered as an organic amendment. Cold gas efficiency was 68 % and carbon conversion efficiency was 89 %. The points of caution concerned the low melting point of the ash, the relatively high tar content in the syngas and the high NOx content of the flue gases after syngas combustion in a boiler. The energy potential of OMSW is substantial and could help reduce the pressure on fossil fuels.

Lead removal from aqueous solutions by olive mill wastes derived biochar: Batch experiments and geochemical modelling.

In this study, lead removal from aqueous solutions using biochar derived from olive mill solid and liquid wastes has been investigated by applying batch experiments and geochemical modelling. The batch adsorption experiments included the assessment of several key parameters such as the contact time (kinetic), initial concentration (isotherm), pH, adsorbent dose, and the presence of competitive cations, whilst the geochemical modelling focused on the involved adsorption mechanisms using the PHREEQC code. The kinetic studies showed that lead adsorption is a relatively fast process, where intraparticle diffusion is the rate-limiting step. Biochar dose, solution pH and the presence of competitive ions significantly affected the Pb adsorption effectiveness by the biochar. Especially the higher Pb removal percentages were observed in mono-elemental solutions with high biochar dose at mildly acidic solution pH values. The maximum Pb adsorption capacity of biochar was estimated as 40.8mgg-1 which is higher than various biochars derived from sludge, lignocellulosic and animal biomasses. On the other hand, the geochemical modelling employing the PHREEQC code showed that ion exchange and Pb precipitation are the main reactions controlling its removal from aqueous solutions, whilst surface complexation is insignificant, mainly due to the low surface functional groups on the used biochar.

Biochemical methane potential of three-phase olive mill solid waste: Influence of temperature and supplemental enzymes

Methane potential of three-phase olive mill solid waste (3POMSW) was evaluated by biochemical methane potential (BMP) tests at temperatures of 37.5 °C and 55 °C. The results have shown, that thermophilic processing has a higher methane and biogas yield by 10% and 17.2%, respectively, compared to mesophilic conditions. Concluding thermophilic conditions of 3POMSW results in higher conversion of the feedstock into biogas. The result of addition of enzymes (MethaPlus, Hemicellulase, PectinaseL, Amylase S and Lipase) and their mixtures to 3POMSW at 55 °C has shown that the optimum mixture of enzymes was Metha Plus and Hemicellulase, which resulted in an increase of methane yield by 1.3% compared to the base case without addition of enzymes. Simple model equations were developed based on first-order kinetic in order to calculate the biogas yield versus the time as a function of reaction rate constant (k) and the maximum biogas yield (ymax). In this study, results have shown two different reaction rates obtained for the mixtures of enzymes with 3POMSW of 0.130 d−1 from t = 0…14 days and 0.034 d−1 from t = 28…63 days. The developed simple model equations can be applied for calculating the biogas yield at the time and by optimizing the process improving biological nutrient removal.

Introduction to Novel Approaches in the Valorization of Agricultural Wastes and Their Applications.

Sustainable food production, waste minimization, and valorization are critical concerns for the agricultural and food industry considering their environmental, social, and economic impacts. Foods are processed to prolong shelf life, make products available out of season, produce new products, and improve nutritional value. During processing, a significant amount of waste is generated, which attracts the attention of scientists and industrialists to valorize the value-added components, including dietary fibers, proteins, and bioactive components. This special issue focuses on the latest developments in waste valorization, covering different industries and methodologies. Within the special issue, waste valorization of some specific food groups, including fruit juice wastes, honeybee byproducts, soybean processing waste, grape pomace materials, and olive mill solid waste, are evaluated. On the other hand, novel approaches to valorizing agricultural wastes and their applications, also covering the recovery of natural pigments with potential health effects, are considered. Besides, nanotechnological and microbial bioconversion methods are used to improve the bioavailability and bioactivity of phytochemicals derived from wastes. It can be concluded that there are still some challenges in waste management and valorization concerning economic, safety, sensory, consumer acceptance, and regulative aspects, and further research is required to overcome these challenges and improve the quality and quantity of value-added products obtained from agricultural wastes and byproducts.