Orange Peel Waste Research Articles

Development of plywood bonded with a novel adhesive film made from polystyrene foam waste dissolved in D-limonene

ABSTRACT The polystyrene film as a formaldehyde-free adhesive for plywood production was developed from polystyrene foam waste (PSF) and D-limonene, extracted from orange peel waste. The influence of the weight ratio of solvent (D-limonene) to foam in the range of 1, 1.5 and 2 (w/w) on the properties of adhesive film and plywood panels was studied. In addition, the effects of pressing temperatures of 150°C, 165°C and 180°C on the properties of the plywood were investigated. The adhesive film was characterized by measuring the melt flow index, the average molecular weight of the polymers and by FTIR. The bonding quality of the adhesive films was investigated by shear strength tests. Integrated gel permeation chromatography has also shown that the average molecular weight of PSF is drastically reduced by doubling the solvent content. Shear strength and bending properties were also significantly reduced by doubling the weight ratio of solvent to foam. The mechanical properties of plywood are positively affected with increasing press temperature to 165°C. In general, plywood bonded with an adhesive film prepared with a solvent to foam weight ratio of 1 and press temperature of 165°C was fulfilled the requirement according to EN314-2 for interior use.

Adsorption of harmful dyes and antimicrobial studies utilizing recyclable ZnO, its composites with conventionally used activated carbon, and waste orange peel as a greener approach

In this work, zinc oxide (ZnO) nanoparticles and its composites with activated carbon (AC) and orange peel (OP) were synthesized, characterized through scientific techniques such as FESEM, EDX, HRTEM, BET, FTIR, XRD etc, and used as adsorbents to treat methylene blue (MB) and methyl orange (MO) in wastewater. Different process parameters (like change in pH value, amount of adsorbent, concentration of dye, temperature, and contact time) were considered to examine the dye removal efficiency of ZnO and its composites. Maximum uptake capacity for MB/MO removal obtained was found to be 175.7/110.68 mg/g (ZnO), 180.03/107.97 mg/g (ZnO@AC) and 205.38/166.25 mg/g (ZnO@OP). Furthermore, thermodynamic, kinetic, and isothermic variables were calculated to get a clear vision about the mechanism involved during adsorption of both the dyes. The reusability examination of all adsorbents suggested continued reuse of adsorbents even after five cycles. Considering true adsorption performance, partition coefficient values were calculated for all adsorbents, e.g., 37.86/13, 41.1/12.45, and 73.61/32.48 mg.g-1.μM-1 in case of ZnO, ZnO@AC, and ZnO@OP for removal of MB/MO dyes, respectively. Furthermore, the zone of inhibition was estimated by performing antimicrobial experiments against Bacillus subtilis (ZnO@OP 19 mm ˃ ZnO & ZnO@AC 14 mm), Staphylococcus aureus (ZnO@OP 18 mm ˃ ZnO 17 mm ˃ ZnO@AC 12 mm), Pseudomonas aeruginosa (ZnO@OP 20 mm ˃ ZnO 16 mm ˃ ZnO@AC 13 mm), and Escherichia coli (ZnO@OP 19 mm ˃ ZnO 15 mm ˃ ZnO@AC 12 mm) respectively. Also, real water studies confirmed their promising future as adsorbents for real field applications.

Development and characterization of sustainable-active-edible-bio based films from orange and pomegranate peel waste for food packaging: Effects of particle size and acid/plasticizer concentrations

Sustainable packaging materials especially from food processing waste are of getting interest. The aim of the study was to develop edible bio based films from processing wastes of pomegranate and orange peels. For this purpose, pomegranate and orange peels were dried and processed into flour in different particle sizes. The effects of particle size, concentration of acid and plasticizer on physical and mechanical properties were investigated. Antimicrobial, antioxidant, morphological and thermal properties were further determined for the selected film formulations. Results showed that the particle size significantly affected mechanical properties of the films (p ≤ 0.05), with improvement of the mechanical properties for the reduced particle size. Pomegranate and orange peel based films showed very high antimicrobial activity against E. coli and S. aureus irrespective of particle sizes. The pomegranate and orange peel based films had homogeneous, smooth, and crack-free surfaces. Pomegranate and orange peel based films showed very similar thermal properties and major thermal degradation was observed between 160 and 300 °C for both type of films irrespective of particle sizes. Pomegranate and orange peels could be good potential as antioxidant and antimicrobial biopolymer sources for sustainable and active food coating/packaging.

Valorization routes of citrus waste in the orange value chain through the biorefinery concept: The Argentina case study

Orange peel waste (OPW) creates challenges regarding environmentally sustainable disposal and potential valorization. Argentina is a major Citrus sp. fruit producer in Latin America. A share of the OPW is used to produce a colloid stabilizer in the beverage industry. However, large amounts of this waste are disposed of in landfills, reducing the orange value chain sustainability. The OPW chemical composition would allow the generation of valuable sub-fractions by applying different upgrading pathways. This review is addressed to summarize the most current and important pathways to upgrade OPW by applying the biorefinery concept. Moreover, this paper highlights the importance of the chemical composition when defining valorization routes. Polyphenols were identified as the most promising and reliable option to increase the sustainability of the orange industry. Then, an overview of extraction conditions, and extracted molecules is included. Biocatalysis is highlighted as a promising way to upgrade polyphenols in other added-value products. A case study is analyzed considering further processing of OPW produced by the citrus agroindustry in Argentina. The case study is related to the design and simulation of a biorefinery addressed to produce juice, essential oil, peel juice, polyphenols, and biogas. The case study is analyzed involving yields and economic performance demonstrating the high potential of essential oil, polyphenols, and biogas as promising products in a near future. As practical implications of this study, an analysis of different pathways to upgrade OPW is given. Moreover, the present study reinforces the chemical characterization as a crucial step before selecting upgrading pathways.

Boosting short-chain fatty acids production from co-fermentation of orange peel waste and waste activated sludge: Critical role of pH on fermentation steps and microbial function traits

The anaerobic co-fermentation of orange peel waste (OPW) and waste activated sludge (WAS) for useful short-chain fatty acids (SCFAs) generation presents an environmentally friendly and efficient method for their disposal. This study amied to investigate the effects of pH regulation on OPW/WAS co-fermentation, and found that the alkaline pH regulation (pH 9) significantly enhanced the promotion of SCFAs (11843 ± 424 mg COD/L), with a high proportion of acetate (51%). Further analysis revealed that alkaline pH regulation facilitated solubilization, hydrolysis, and acidification while simultaneously inhibiting methanogenesis. Furthermore, the functional anaerobes, as well as the expressions of corresponding gene involved in SCFAs biosynthesis, were generally improved under alkaline pH regulation. Alkaline treatment might played a critical role in alleviating the toxicity of OPW, resulting in improving microbial metabolic activity. This work provided an effective strategy to recover biomass waste as high-value products, and insightful understanding of microbial traits during OPW/WAS co-fermentation.

Improving the Chemical Quality of Compost from Bioconversion of Multi Types of Organic Waste Using Black Soldier Fly Larvae and EM-4

Waste that is not handled properly will have a negative impact on the quality of the environment in society. Organic waste is the main problem that is often faced by Indonesian people. Waste management using the bioconversion method with the help of Black soldier Fly (BSF) larvae and EM-4 bioactivators can reduce waste capacity and benefit the community. This study aims to compare the ability of bioconversion agents and the quality of various types of organic waste used for bioconversion. This study used a factorial randomized block design with 2 factors. The first factor was a bioconversion agent consisting of 3 levels, P0 (control), P1 (EM-4 activator) (15 ml), P2 (Black Soldier Fly) (5 gram/bio-pond). The second factor is the type of organic waste which consists of 3 levels, namely L1 (pineapple peel waste), L2 (orange peel waste) and L3 (bagasse). The results showed that BSF larvae have the potential as bioconversion agents and their ability to approach EM-4. In general, the application of bioconverting agents improves the quality of compost compared to that without the application of bioconverting agents. The application of a bioconversion agent combined with pineapple peel waste has a quality close to the standard of Minister of Agriculture No. 261 of 2019

Kinetic and Thermodynamic Studies on the Use of Waste Orange Peel in the Removal of Pb2+ Ions from Aqueous Solutions

Bu çalışmada, Pb2+ iyonlarının sulu çözeltilerden uzaklaştırılmasında atık portakal kabuğunun (APK) etkin bir şekilde değerlendirilmesi ve geri dönüşüme kazandırılması anlatılmaktadır. Adsorpsiyon verimliliği için; metal iyonu başlangıç derişimi, temas süresi, pH etkisi gibi farklı parametrelerin sonuçları incelendi. Pb2+ iyonunun uzaklaştırılmasında en uygun çalışma koşulları; metal iyonu başlangıç derişimi 800 mg/L, temas süresi 90 dakika ve çözelti pH'ı 4,32 olarak belirlendi. APK’nın yüzey özellikleri, Fourier dönüşümlü kızılötesi spektroskopisi (FTIR), taramalı elektron mikroskobu (SEM) ve enerji dağılım spektroskopisi ile araştırıldı. Elde edilen veriler (izoterm verileri) incelendiğinde, işlemin olası tersinmezliğine ve kimyasal adsorpsiyona karşılık gelen Langmuir izoterm modeline uygun olduğunu gösterdi. 298, 308 ve 318 K'de Pb2+ iyonu için adsorpsiyon kapasitesi sırasıyla 35,842, 35,714 ve 35,087 mg/g olarak hesaplandı. En iyi kinetik veriler, Pb2+ adsorpsiyonu için en yüksek regresyon katsayısına sahip yalancı ikinci dereceden denklem ile tanımlandı. Termodinamik çalışmalar, APK kullanılarak Pb2+ iyonlarının uzaklaştırılması işleminin doğal ve endotermik bir süreç olduğunu gösterdi. APK 'nın yüksek uzaklaştırma kapasitesi, kolay bulunması ve ucuz olması nedeniyle sulu ortamdan Pb2+ iyonlarının uzaklaştırılmasında etkili ve umut verici bir malzeme olduğu tespit edildi.

Electrochemical bottom-up synthesis of biomass-derived carbon dots for promoting Knoevenagel condensation

Natural raw materials such as biomass and plant wastes are the most interesting feedstocks for the synthesis of carbonaceous nanomaterials due to their high availability, environmental compatibility, and affinity with Green Chemistry principles. Carbon dots (CDs), a new type of carbon nanomaterials, perform an important role in this matter by serving in the development of environmentally friendly catalysts. In this study, CDs were synthesized in good yields by using the electrochemical bottom-up synthesis starting from the liquid phase that is separated during the hydrothermal carbonization (HTC) process involving orange peel waste (OPW). The electrochemical setup was also optimized to synthesize CDs based on 5-hydroxymethylfurfural, which represents one of the main components of the liquid phase obtained by HTC. The comprehensive optical and chemo-physical characterization of CDs samples carried out by several techniques such as SEM, TEM, XRD, PL, TGA, and FTIR, highlighted their distinctive morphological and microstructural features. The obtained CDs were successfully employed to catalyse the Knoevenagel condensation, showing excellent results in terms of yield and reproducibility. In addition, the sustainable nature of the CDs was demonstrated by recycling the catalysts up to five cycles without significant activity loss.

Effect of TiO2 on Orange Peel Activated Carbon Composite in Reducing Carbon Monoxide and Hydrocarbon Gas Emissions

study aims to see the effect of adding TiO2 on activated carbon as a material for reducing CO and HC gas emissions. Activated carbon (AC) was synthesized from orange peel waste at a carbonization temperature of 600 with a 10% (w/v) ZnCl2 activator. Composite AC/TiO2 was prepared by a simple mixing method. This process obtained TiO2-modified activated carbon material with variations in TiO2 concentrations of 0%, 10%, 15%, 20%, and 25%. Scanning Electron Microscope (SEM) was performed to obtain information on the AC/TiO2 surface morphology. In the application as a CO and HC gas emission reduction material, the results of mixing AC/TiO2 are mixed with a 10% (w/v) solution of Polyvinyl Alcohol (PVA) as an adhesive and molded in the shape of a filter with two variations hole sizes with a diameter of 1 cm and 0.3 cm. Composite filter performance tests were carried out using a gas analyzer. The best result for reducing gas emissions occurred at a concentration of TiO2 15% with reduction power to reduce CO gas emission up to 53.79% and HC gas emission up to 55.57%.

Utilizing orange peel waste biomass in textile wastewater treatment and its recyclability for dual biogas and biochar production: a techno-economic sustainable approach

Orange peel is a fruit-based biomass produced in huge quantities worldwide, requiring an appropriate management strategy to meet the waste-to-wealth approach. In the current study, this agricultural waste was used (as an adsorbent) to treat dye-laden wastewater, followed by its regeneration and recyclability for dual biogas and biochar production. An adsorbent material was prepared by mixing orange peel powder (OPP) with biochar (1:1, w/w) and used to remove various pollutants from textile wastewater (TWW) within 30 min. This adsorption system achieved chemical oxygen demand (COD), total dissolved solids (TDS), turbidity, and color removal efficiencies of 38.56±1.73%, 29.31±1.25%, 91.92±4.75%, and 74.81±3.96%, respectively. The spent adsorbent was cleaned and mixed with cow dung (as inoculum) to generate biogas via anaerobic co-digestion. This system maintained a bio-CH4 of 411.5±21.7 mL/g volatile solids (VS), equivalent to 14.3±1.1% of CODinitial. Because the digestate of the co-digestion process contained volatile suspended solids (VSS), with a VSS/CODinitial percentage of 45.2±3.2%, it was efficiently pyrolyzed to obtain biochar. The adsorption/co-digestion/pyrolysis combined system revealed a financially feasible scenario, with a payback period of 7.5 years. The study outputs would fulfill various sustainable development goals (SDGs) related to waste minimization, environmental protection, and affordable energy supply.Graphical abstract

Utilization of Mandarin Orange Peel Waste as an Adsorbent for Methylene Blue Dye

Utilization of mandarin orange peel waste as an adsorbent for methylene blue dye is carried out to minimize methylene blue contamination. The research was conducted by using spike method samples then analyte was adsorbed. This research aims to make an adsorbent with chemical activation, which has a particle size of 100 mesh, and the quality of the adsorbent based on SNI 06-3730-199 to determine the optimum time and weight required to adsorb methylene blue. This research use Freundlich isotherm data processing and analysis of variance ANOVA. Making adsorbent is done by cleaning, then drying in an oven at a temperature of 150˚C, then put into the furnace with a temperature of 600˚C, then continued the process of testing the quality of the adsorbent based on SNI 06-3730-199. The adsorbent based on parameters contained in SNI 06-3730-1995, including 9,13% for water content, 7,26% for ash content, and 959,2 mg/g for absorption of iodine. These results have met the requirements. The optimum weight from the research is 1,5 grams, and the optimum time required for the adsorbent to absorb the analyte is 90 minutes. The efficiency of the adsorbent for absorbing methylene blue at optimum weight and interaction time is 98,93%.

Manajemen Kesehatan Lingkungan Pada Kelompok Pemindang Di Tempat Pemindangan Ikan (TPI) Kusamba

Like as the fish processing industry in general, the traditional processing industry also has a significant environmental impact. This community service was aimed to provide counselling related to environmental health management to a group of “pemindang” at central “pemindangan” industry Kusamba. The material provided is in the form of the benefit and importance of personal hygiene and environmental sanitation in fish processing, especially pindang, demonstration and exercise of 7 steps of hand washing, socialization on the use of personal protective equipment (PPE) and eco enzyme based on orange peel waste, and provision in providing garbage containers to improve environmental sanitation in the area of “pemindangan”. The participants had high enthusiasm in following the activities and from 10 participants who took the posttest, all of participants received score > 70. This empowerment activities are expected to be able to increase the knowledge of the group of “pemindang” on the importance of environmental health for fish processing industry, including “pemindangan” industry.

Edukasi dan Pembuatan Produk Eco Enzyme dari Limbah Kulit Jeruk di Kelurahan Limau Manis Kota Padang

Eco Enzymes can accelerate biochemical reactions to produce enzymes that break down fruit or vegetable waste. It was from this waste is one way of waste management that utilizes kitchen scraps to produce beneficial liquids. Community service was conducted in the Limau Manis Village of Padang City. Pre-tests and post-tests in the form of questions were conducted to assess the community's understanding of the Eco Enzyme material provided. Educational materials about the theory and importance of the Eco Enzyme product were provided by a lecturer in Pharmaceutical Chemistry from the Faculty of Pharmacy at Universitas Andalas regarding its uses and the products that can be sold. The theory material was made into a booklet and given to participants to take home and read again. Direct practice was conducted on making Eco Enzyme from orange peel waste obtained from fruit sellers. The T-Test results obtained a t-value of -5.047 with a p-value of 0.0001 (smaller than the alpha of 0.05). This value shows that this community service activity significantly improves the community's understanding of Eco Enzyme. In the future, an Eco Enzyme product in the form of a liquid that can be used will be obtained.

Artificial Coalification of Orange Peel for Extraction of Value Added Chemicals

Waste to value added products is the aim of circular economy. Typical waste to value processes such as composting, briquetting, digestion are time consuming and gasification, and pyrolysis only produces energy. In the present research, a thermochemical process called as hydrothermal carbonization process is used to convert the organic wet waste to useful products. The HTC process converts the organic wet waste into coal like high carbon content material called hydrochar and the liquid component called as biocrude. The biocrude is a mixture of chemicals such as 5-HMF, Levulinic acid, Furfural and other chemicals used in pharmaceutical and cosmetic industry. Orange peel waste is processed in a HTC reactor in temperatures ranging between 180 to 220 o C, with the autogenous pressure. The calorific value of hydrochar produced is measured using bomb calorimeter, and is found to have enhancement over the feedstock. The biocrude is analysed using UV spectrometer and gas chromatography and mass spectroscopy to identify the components present. Compounds including anti-fungal, and anti-bacterial molecules are identified and reported.

Voltammetric Sensor Based on Waste‐Derived Carbon Nanodots for Enhanced Detection of Nitrobenzene

AbstractCarbon dots (CDs) samples were synthesized from orange peel waste (OPW) via a simple and eco‐friendly hydrothermal carbonization (HTC) and electrochemical (EC) bottom‐up synthesis integrated approach. The comprehensive chemical‐physical characterization of CDs samples, carried out by various techniques such as TEM, EDX, XRD, FT‐IR, underlined their morphological and microstructural features. The CDs exhibited attractive electrochemical properties, and thus an electrochemical sensor by modifying a screen printed carbon electrode (CDs/SPCE) for the detection of nitrobenzene (NB) in water was developed. Electroanalytical performances of CDs/SPCE sensor using differential pulse voltammetry (DPV) demonstrated its high sensitivity (9.36 μA μM−1 cm−2) towards NB in a wide linear dynamic range (0.1–2000 μM) and a low limit of detection (LOD=13 nM). The electrochemical sensor also shown high selectivity, long‐term stability, and repeatability. This paper might open the way to a new synergistic HTC‐EC approach for the synthesis of CDs from waste biomass material and their advanced application in highly efficient electrochemical sensors.

Synthesis of porous carbon from orange peel waste for effective volatile organic compounds adsorption: role of typical components

Synthesis of porous carbon from orange peel waste for effective volatile organic compounds adsorption: role of typical components

Waste Orange Peels as a Source of Cellulose Nanocrystals and Their Use for the Development of Nanocomposite Films.

To date, approximately 30-50% of food is wasted from post-harvesting to consumer usage. Typical examples of food by-products are fruit peels and pomace, seeds, and others. A large part of these matrices is still discarded in landfills, while a small portion is valorized for bioprocessing. In this context, a feasible strategy to valorize food by-products consists of their use for the production of bioactive compounds and nanofillers, which can be further used to functionalize biobased packaging materials. The focus of this research was to create an efficient methodology for the extraction of cellulose from leftover orange peel after juice processing and for its conversion into cellulose nanocrystals (CNCs) for use in bionanocomposite films for packaging materials. Orange CNCs were characterized by TEM and XRD analyses and added as reinforcing agents into chitosan/hydroxypropyl methylcellulose (CS/HPMC) films enriched with lauroyl arginate ethyl (LAE®). It was evaluated how CNCs and LAE® affected the technical and functional characteristics of CS/HPMC films. CNCs revealed needle-like shapes with an aspect ratio of 12.5, and average length and width of 500 nm and 40 nm, respectively. Scanning electron microscopy and infrared spectroscopy confirmed the high compatibility of the CS/HPMC blend with CNCs and LAE®. The inclusion of CNCs increased the films' tensile strength, light barrier, and water vapor barrier properties while reducing their water solubility. The addition of LAE® improved the films' flexibility and gave them biocidal efficacy against the main bacterial pathogens that cause foodborne illness, such as Escherichia coli, Pseudomonas fluorescens, Listeria monocytogenes, and Salmonella enterica.

Waste Orange Peels as a Feed Additive for the Enhancement of the Nutritional Value of Tenebrio molitor

Lately, additional attention is being placed on edible insects, since they constitute an excellent, cost-efficient source of proteins with a low ecological footprint. Tenebrio molitor was the first insect that was considered edible by EFSA in 2021. This species can replace conventional protein sources and thus, it has the potential to be used in many different food products. In the present study, a food by-product that is commonly produced (i.e., albedo orange peel waste) was used as a feed additive for T. molitor larvae, in an effort to further improve the circular economy and enhance the nutritional value of the insects. To this end, bran, which is commonly used as feed for T. molitor larvae, was fortified with the albedo orange peel waste (up to 25% w/w). Larval performance, in terms of larval survival and growth, as well as the larval nutritional value, i.e., the content of protein, fat, carbohydrates, ash, carotenoids, vitamins A and C, and polyphenols, was evaluated. Based on the results, the increase in the percentage of orange peel albedos in T. molitor feed resulted in a subsequent increase in the content of larvae in carotenoids and vitamin A up to 198%, in vitamin C up to 46%, and an increase in the protein and ash content up to 32% and 26.5%, respectively. Therefore, the use of albedo orange peel waste for feeding of T. molitor larvae is highly recommended, since it results in larvae with enhanced nutritional value and at the same time, the utilization of this feeding substrate further lowers the cost of insect farming.

Effect of D-limonene additive in copper redox-based quasi-solid-state electrolytes on the performance of dye-sensitized solar cells

In dye-sensitized solar cells (DSSCs), the copper redox mediator has been proven to enhance power conversion efficiency (PCE) due to the fairly low driving force for dye regeneration. In this work, we prepared six blended biopolymer-based electrolytes (E1 to E6) to regenerate N3 Dye absorbed in TiO2 for dye-sensitized solar cell application. The regeneration behavior of three different electron-withdrawing substituents on 2-(pyridin-2-yl)− 1 H-benzo[d]imidazole ligands coordinated with copper metal, its forms [Cu(mpimb)2]1+/2+ (methyl 4-((2-(pyridin-2-yl)− 1 H-benzo[d]imidazol-1-yl)methyl) benzoate), [Cu(pbimb)2]1+/2+ (4-((2-(pyridin-2-yl)− 1 H- benzo[d]imidazol-1-yl)methyl) benzonitrile) and [Cu(ptpbi)2]1+/2+ (2-(pyridin-2-yl)− 1(4-(trifluoromethyl)benzyl)− 1 H-benzo[d]imidazole). Commencing their electrochemical and photophysical properties determines the molecular orbital energy level of the complex. A quasi-solid-state electrolyte (QSSE) medium is blended in a biopolymer host (pectin and 2-hydroxyethylcellulose). Additionally, a comparison study has been performed between commercially available pyridine-based-additive [tert-butyl pyridine (TBP)], and a bio-organic compound extracted from orange peel waste (1-methyl-4-(prop-1-en-2-yl) cyclohex-1-ene (limonene)) used as an additive material. Using these newly designed copper redox mediators and additives, the six sets of DSSCs devices has constructed. The cell structure is assembled as TiO2/N3 dye/electrolyte (E1 to E6)/Pt. Among the fabricated devices, C1 and C2 redox couples [Cu(ptpbi)2]1+/2+ having CF3 substituent exhibit maximum Voc and Jsc. Interestingly, the device with limonene additive exhibited PCE up to 4.4 %, whereas with TBP, it showed 4.0 % efficiency. The PCE results of the C2 device sustained some electrochemical factors such as Bulk Resistance (Rb =142.0 Ω), Recombination Resistance (Rrec = 191.4 Ω), Charge Transfer Resistance (Rct = 98.84 Ω), Chemical capacitance (Cμ = 7.882 μF), Ionic Conductivity (σ = 2.816 ×10−04 S cm−1), electron lifetime (τn = 16.24 μs), Diffusion length (Ln =1.39 × 10−01 mm).

One-Step Oxidation of Orange Peel Waste to Carbon Feedstock for Bacterial Production of Polyhydroxybutyrate.

Orange peels are an abundant food waste stream that can be converted into useful products, such as polyhydroxyalkanoates (PHAs). Limonene, however, is a key barrier to building a successful biopolymer synthesis from orange peels as it inhibits microbial growth. We designed a one-pot oxidation system that releases the sugars from orange peels while eliminating limonene through superoxide (O2• -) generated from potassium superoxide (KO2). The optimum conditions were found to be treatment with 0.05 M KO2 for 1 h, where 55% of the sugars present in orange peels were released and recovered. The orange peel sugars were then used, directly, as a carbon source for polyhydroxybutyrate (PHB) production by engineered Escherichia coli. Cell growth was improved in the presence of the orange peel liquor with 3 w/v% exhibiting 90-100% cell viability. The bacterial production of PHB using orange peel liquor led to 1.7-3.0 g/L cell dry weight and 136-393 mg (8-13 w/w%) ultra-high molecular weight PHB content (Mw of ~1900 kDa) during a 24 to 96 h fermentation period. The comprehensive thermal characterization of the isolated PHBs revealed polymeric properties similar to PHBs resulting from pure glucose or fructose. Our one-pot oxidation process for liberating sugars and eliminating inhibitory compounds is an efficient and easy method to release sugars from orange peels and eliminate limonene, or residual limonene post limonene extraction, and shows great promise for extracting sugars from other complex biomass materials.