Sustainable Development of Food Waste Biorefineries

A special issue of Fermentation (ISSN 2311-5637). This special issue belongs to the section "Industrial Fermentation".

Deadline for manuscript submissions: closed (30 April 2024) | Viewed by 23154

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Department of Environmental Technologies, Faculty of Sea and Environmental Sciences, University of Cádiz, 11510 Puerto Real, Spain
Interests: anaerobic digestion; biogas; anaerobic fermentation; composting; biohydrogen; valorisation of wastes
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Institute of Chemical and Environmental Technologies (ITQUIMA), Department of Chemical Engineering, University Castilla-La Mancha, 13071 Ciudad Real, Spain
Interests: anaerobic digestion; biogas; anaerobic fermentation; biohydrogen; microbial fuel cell; bioelectro systems; bioelectrochemistry; energetic valorisation of wastes
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

This Special Issue is framed within the application of the biorefinery concept to the management of waste and by-products from the agri-food sector. The current linear economic model has long since proven to be unsustainable. The planet's resources are finiteand we must look for alternatives to many of the products that are obtained from non-renewable raw materials. The new model of a circular economyproposes an alternative path to development more similar to natural cycles, one of its core principles being to to recycle as much of the material and energy contained in wastes and by-products as possible.

In many countries, organic wastes and by-products generated in the agri-food sector represent an alternative source of resources to be exploited. These wastes and by-products can be transformed through different ways into products with a high added value if we make an approach to their management based on the biorefinery model. A general definition of a biorefinery is a facility (or network of facilities) that integrates biomass conversion processes and equipment to produce biofuels for transportation, energy and chemicals from biomass.

The subject of this Special Issue includes all those works that use agri-food wastes and by-products as raw material to develop treatment and valorization proposals that can be integrated into the biorefinery concept, aiming to bring together research works falling under, yet not limited to, the following topics: composting, anaerobic digestion, solid-state fermentation, pyrolysis or gasification.

Prof. Dr. Jose Luis García-Morales
Prof. Dr. Francisco Jesús Fernández Morales
Guest Editors

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Keywords

  • biorefinery
  • anaerobic digestion
  • composting
  • solid state fermentation
  • agro-food wastes
  • characterization
  • management
  • energy conversion
  • operational conditions
  • modelization
  • business case

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Published Papers (11 papers)

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Editorial

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7 pages, 202 KiB  
Editorial
Sustainable Development of Food Waste Biorefineries
by José Luis García-Morales and Francisco Jesús Fernández-Morales
Fermentation 2024, 10(6), 301; https://doi.org/10.3390/fermentation10060301 - 5 Jun 2024
Viewed by 968
Abstract
The sustainable development of food waste biorefineries is crucial for a number of reasons, and these reasons have environmental, economic, and social dimensions [...] Full article
(This article belongs to the Special Issue Sustainable Development of Food Waste Biorefineries)

Research

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14 pages, 2449 KiB  
Article
Anaerobic Conversion of Proteinogenic Amino Acids When Methanogenesis Is Inhibited: Carboxylic Acid Production from Single Amino Acids
by Leandro Conrado, Jacob McCoy, Leo Rabinovich, Mona Davoudimehr, Panagiota Stamatopoulou and Matthew Scarborough
Fermentation 2024, 10(5), 237; https://doi.org/10.3390/fermentation10050237 - 29 Apr 2024
Viewed by 1877
Abstract
Proteins are an abundant biopolymer in organic waste feedstocks for biorefining. When degraded, amino acids are released, but their fate in non-methanogenic microbiomes is not well understood. The ability of a microbiome obtained from an anaerobic digester to produce volatile fatty acids from [...] Read more.
Proteins are an abundant biopolymer in organic waste feedstocks for biorefining. When degraded, amino acids are released, but their fate in non-methanogenic microbiomes is not well understood. The ability of a microbiome obtained from an anaerobic digester to produce volatile fatty acids from the twenty proteinogenic amino acids was tested using batch experiments. Batch tests were conducted using an initial concentration of each amino acid of 9000 mg COD L−1 along with 9000 mg COD L−1 acetate. Butyrate production was observed from lysine, glutamate, and serine fermentation. Lesser amounts of propionate, iso-butyrate, and iso-valerate were also observed from individual amino acids. Based on 16S rRNA gene amplicon sequencing, Anaerostignum, Intestimonas, Aminipila, and Oscillibacter all likely play a role in the conversion of amino acids to butyrate. The specific roles of other abundant taxa, including Coprothermobacter, Fervidobacterium, Desulfovibrio, and Wolinella, remain unknown, but these genera should be studied for their role in fermentation of amino acids and proteins to VFAs. Full article
(This article belongs to the Special Issue Sustainable Development of Food Waste Biorefineries)
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18 pages, 2157 KiB  
Article
Enhancing Anaerobic Digestion with an UASB Reactor of the Winery Wastewater for Producing Volatile Fatty Acid Effluent Enriched in Caproic Acid
by M. Eugenia Ibáñez-López, Nicola Frison, David Bolzonella and José L. García-Morales
Fermentation 2023, 9(11), 958; https://doi.org/10.3390/fermentation9110958 - 9 Nov 2023
Cited by 3 | Viewed by 2035
Abstract
The production of Volatile Fatty Acids (VFAs) from wastewater holds significant importance in the context of biorefinery concepts due to their potential as valuable precursors for various bio-based processes. Therefore, the primary objective of this research is to investigate the fermentation of Winery [...] Read more.
The production of Volatile Fatty Acids (VFAs) from wastewater holds significant importance in the context of biorefinery concepts due to their potential as valuable precursors for various bio-based processes. Therefore, the primary objective of this research is to investigate the fermentation of Winery Wastewater (WW) in an Upflow Anaerobic Sludge Blanket (UASB) reactor to generate VFAs, with particular emphasis on Caproic Acid (HCa) production and the dynamics of the microbiota, under varying Hydraulic Retention Time (HRT) periods (8, 5, and 2.5 h). The change from an 8 h to a 5 h HRT period resulted in an approximately 20% increase in total VFA production. However, when the HRT was further reduced to 2.5 h, total VFA production decreased by approximately 50%. Concerning the specific production of HCa, expressed in grams of Chemical Oxygen Demand (gCOD), the maximum yield was observed at around 0.9 gCOD/L for a 5-h HRT. Microbial population analysis revealed that Eubacteria outnumbered Archaea across all HRTs. Population dynamics analysis indicated that the Firmicutes Phylum was predominant in all cases. Within this phylum, bacteria such as Clostridium kluyveri and Clostridium sp., known for their ability to produce HCa, were identified. Based on the results obtained, the application of the UASB reactor for WW treatment, within the biorefinery framework, has the potential to provide a practical alternative for HCa production when operated with a 5 h HRT. Full article
(This article belongs to the Special Issue Sustainable Development of Food Waste Biorefineries)
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16 pages, 1263 KiB  
Article
Biorefinery Approach for H2 and Acids Production Based on Uncontrolled pH Fermentation of an Industrial Effluent
by María Eugenia Ibañez-López, Encarnación Díaz-Domínguez, Miguel Suffo, Jacek Makinia, Jose Luis García-Morales and Francisco Jesús Fernández-Morales
Fermentation 2023, 9(11), 937; https://doi.org/10.3390/fermentation9110937 - 28 Oct 2023
Viewed by 1265
Abstract
In this work, the feasibility of uncontrolled pH acidogenic fermentation of industrial organic effluent from corn-bioethanol production was studied and modelled by using a Monod-based mathematical model. In order to do that, several tests were carried out at different initial pH values, ranging [...] Read more.
In this work, the feasibility of uncontrolled pH acidogenic fermentation of industrial organic effluent from corn-bioethanol production was studied and modelled by using a Monod-based mathematical model. In order to do that, several tests were carried out at different initial pH values, ranging from 4 to 6. The experimental data showed a pH reduction during the fermentation process due to the generation of short-chain acids. When starting at initial pH of 5.0 and 6.0, the substrates were fully fermented reaching final pH s over 4 units in both cases and a final undissociated fatty acid concentration of about 80 (mmol·L−1) in both cases. Regarding fermentation at an initial pH of 4, the pH decreased to 3.5 units, and the organic substrates were not fully fermented due to the stoppage of the fermentation. The stoppage was caused by the very acidic pH conditions. The biomass showed an uncoupled growth as the operating conditions became more acidic, and, finally, the biomass growth was zero. Regarding the generation of fermentation products, in general terms, the highest economical value of products was obtained when fermenting at an initial pH of 5. More specifically, acetic acid was the acid that presented the highest yield at an initial pH value of 4. Butyric yield showed the highest values at initial pH values of 5 and 6. The highest H2 yield (1.1 mol H2·mol−1 dextrose) was achieved at an initial pH value of 5. Finally, the experimental data were modelled using a Monod-based model. From this model, the value of the main kinetics and stoichiometric parameters were determined. Full article
(This article belongs to the Special Issue Sustainable Development of Food Waste Biorefineries)
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18 pages, 1478 KiB  
Article
Exploitation of Cocoa Pod Residues for the Production of Antioxidants, Polyhydroxyalkanoates, and Ethanol
by Licelander Hennessey Ramos, Miluska Cisneros-Yupanqui, Diana Vanessa Santisteban Soto, Anna Lante, Lorenzo Favaro, Sergio Casella and Marina Basaglia
Fermentation 2023, 9(9), 843; https://doi.org/10.3390/fermentation9090843 - 14 Sep 2023
Cited by 7 | Viewed by 2620
Abstract
Cocoa pod husks (CPH) and cocoa bean shells (CBS) are the main by-products of the cocoa industry and a source of bioactive compounds. These residues are not completely used and thrown in the fields without any treatment, causing environmental problems. Looking for a [...] Read more.
Cocoa pod husks (CPH) and cocoa bean shells (CBS) are the main by-products of the cocoa industry and a source of bioactive compounds. These residues are not completely used and thrown in the fields without any treatment, causing environmental problems. Looking for a holistic valorization, the aim of this work was first to deeply characterize CPH and CBS in their chemical composition, amino acid, and fatty acid profiles, as well as their application as antioxidants. CBS had a high level of protein (17.98% DM) and lipids (16.24% DM) compared with CPH (4.79 and 0.35% DM respectively). Glutamic acid and aspartic acid were the predominant amino acids. The total phenolic compounds (TPC) detected in the ethanolic extracts of CPH and CBS were similar to pyrogallol as the main detected polyphenol (72.57 mg/L). CBS ethanolic extract showed a higher antioxidant activity than CPH. Both extracts increased the oxidation stability of soybean oil by 48% (CPH) and 32% (CBS). In addition, alkaline pretreatment of CPH was found suitable for the release of 15.52 ± 0.78 g glucose/L after subsequent saccharification with the commercial enzyme Cellic®. CTec2. Alkaline hydrolyzed and saccharified CPH (Ahs-CPH) was assessed for the first time to obtain polyhydroxy alkanoate (PHAs) and bioethanol. Ahs-CPH allowed the growth of both Cupriavidus necator DSM 545 and Saccharomyces cerevisiae Fm17, well-known as PHA- and bioethanol-producing microbes, respectively. The obtained results suggest that such agricultural wastes have interesting characteristics with new potential industrial uses that could be a better alternative for the utilization of biomass generated as million tons of waste annually. Full article
(This article belongs to the Special Issue Sustainable Development of Food Waste Biorefineries)
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15 pages, 1983 KiB  
Article
Recovery of Energy and Carbon Dioxide from Craft Brewery Wastes for Onsite Use
by Dhanashree Rawalgaonkar, Yan Zhang, Selina Walker, Paul Kirchman, Qiong Zhang and Sarina J. Ergas
Fermentation 2023, 9(9), 831; https://doi.org/10.3390/fermentation9090831 - 12 Sep 2023
Cited by 3 | Viewed by 3494
Abstract
Interest in craft beers is increasing worldwide due to their flavor and variety. However, craft breweries have high water, energy, and carbon dioxide (CO2) demands and generate large quantities of high-strength waste and greenhouse gases. While many large breweries recover energy [...] Read more.
Interest in craft beers is increasing worldwide due to their flavor and variety. However, craft breweries have high water, energy, and carbon dioxide (CO2) demands and generate large quantities of high-strength waste and greenhouse gases. While many large breweries recover energy using anaerobic digestion (AD) and recapture CO2 from beer fermentation, little is known about the economic feasibility of applying these technologies at the scale of small craft breweries. In addition, compounds in hops (Humulus lupulus), which are commonly added to craft beer to provide a bitter or “hoppy” flavor, have been shown to adversely affect anaerobic microbes in ruminant studies. In this study, biochemical methane potential (BMP) assays and anaerobic sequencing batch reactor (ASBR) studies were used to investigate biomethane production from high-strength craft brewery waste, with and without hop addition. A spreadsheet tool was developed to evaluate the economic feasibility of bioenergy and CO2 recovery depending on the brewery’s location, production volume, waste management, CO2 requirement, energy costs, and hop waste addition. The results showed that co-digestion of yeast waste with 20% hops (based on chemical oxygen demand (COD)) resulted in slightly lower methane yields compared with mono-digestion of yeast; however, it did not significantly impact the economic feasibility of AD in craft breweries. The use of AD and CO2 recovery was found to be economically feasible if the brewery’s annual beer production is >50,000 barrels/year. Full article
(This article belongs to the Special Issue Sustainable Development of Food Waste Biorefineries)
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19 pages, 5204 KiB  
Article
Modelling of Amino Acid Fermentations and Stabilization of Anaerobic Digestates by Extracting Ammonium Bicarbonate
by Alejandro Moure Abelenda, George Aggidis and Farid Aiouache
Fermentation 2023, 9(8), 750; https://doi.org/10.3390/fermentation9080750 - 12 Aug 2023
Cited by 4 | Viewed by 2065
Abstract
With the current increase in demand for animal and agricultural products, management of agrowaste has become critical to avoid greenhouse gas emissions. The present article investigates the applicability of ammonium bicarbonate synthesis via flash distillation to valorize and stabilize several types of anaerobic [...] Read more.
With the current increase in demand for animal and agricultural products, management of agrowaste has become critical to avoid greenhouse gas emissions. The present article investigates the applicability of ammonium bicarbonate synthesis via flash distillation to valorize and stabilize several types of anaerobic digestates which are produced from individual fermentations of amino acids. The content of CO2 in the digestate was found to be responsible for the OH alkalinity (0.4 equivalents of acid/kg digestate), while the partial and total alkalinities (0.8 eq/kg digestate) were essentially derived from the content of NH3. The most suitable conditions for the flash distillation were 95 °C and 1 bar with the condensation occurring at 25 °C. However, in order to attain the precipitation of NH4HCO3 in the distillate, it was necessary to consider digestates with a moisture content of 50 wt.%, since saturation levels of inorganic nitrogen and inorganic carbon were not attained otherwise. Even under these conditions, few amino acids (i.e., arginine, glycine, and histidine) were able to provide an anaerobic digestate upon fermentation that would be suitable for NH4HCO3 stabilization. The process of stabilization with a capacity of a t of digestate per h was improved by adding hydrochloric acid or sodium hydroxide at a rate of 44 kg/h, leading to production of 34 kg NH4HCO3/h. Given the role of the volatile elements of the biogas as endogenous stripping agents, it is recommended to use a fresh and saturated digestate as feed for the flash distillation. Full article
(This article belongs to the Special Issue Sustainable Development of Food Waste Biorefineries)
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15 pages, 1060 KiB  
Article
Induced Autolysis of Engineered Yeast Residue as a Means to Simplify Downstream Processing for Valorization—A Case Study
by Joana F. Fundo, Teresa Deuchande, Daniela A. Rodrigues, Lígia L. Pimentel, Susana S. M. P. Vidigal, Luís M. Rodríguez-Alcalá, Manuela E. Pintado and Ana L. Amaro
Fermentation 2023, 9(7), 673; https://doi.org/10.3390/fermentation9070673 - 18 Jul 2023
Cited by 4 | Viewed by 2102
Abstract
The objective of this work was to study the efficiency of different autolysis processes, combining different temperatures and pH conditions, when applied to a genetically engineered yeast residue. The determination of the supernatants’ dry weight showed that the autolysis time could be reduced [...] Read more.
The objective of this work was to study the efficiency of different autolysis processes, combining different temperatures and pH conditions, when applied to a genetically engineered yeast residue. The determination of the supernatants’ dry weight showed that the autolysis time could be reduced to half, from 4 to 2 h, if the residue pH was increased from 5 to 8 at 50 °C (18.20% for 4 h and 18.70% for 2 h with a higher pH). This result allowed us to select a short autolysis time to proceed with the second part of the experiments. The application of this faster induced autolysis process enabled us to obtain supernatants with higher concentrations of relevant compounds, such as some amino acids and minerals. An increase in leucine (of around 7%), aspartic acid, valine, phenylalanine, isoleucine and serine (approximately 2%) was observed in the autolyzed samples, when compared to the untreated ones. Also, regarding minerals, the autolysis process allowed us to obtain significantly higher amounts of potassium in the treated samples’ supernatants. This work allowed the selection of a fast and low-cost induced autolysis process for synthetic biotechnology-derived spent yeast residue to attain a product rich in high-value compounds, which can be used in commercial applications, for example, as an animal feed additive. Full article
(This article belongs to the Special Issue Sustainable Development of Food Waste Biorefineries)
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17 pages, 3331 KiB  
Article
Sustainability Assessment of Food Waste Biorefineries as the Base of the Entrepreneurship in Rural Zones of Colombia
by Carlos Ariel Cardona, Mariana Ortiz-Sanchez, Natalia Salgado, Juan Camilo Solarte-Toro, Carlos Eduardo Orrego, Alexander Perez, Carlos Daniel Acosta, Eva Ledezma, Haminton Salas, Javier Gonzaga and Steven Delgado
Fermentation 2023, 9(7), 609; https://doi.org/10.3390/fermentation9070609 - 28 Jun 2023
Cited by 1 | Viewed by 1497
Abstract
The sustainability of food value chains is affected by the large amounts of waste produced with a high environmental impact. Food waste valorization applying the biorefinery concept has emerged as an alternative to reduce the generation of greenhouse gases and to promote the [...] Read more.
The sustainability of food value chains is affected by the large amounts of waste produced with a high environmental impact. Food waste valorization applying the biorefinery concept has emerged as an alternative to reduce the generation of greenhouse gases and to promote the socio-economic development of value chains at local, regional, and national levels. This paper analyzes the sustainability of food waste biorefineries designed for boosting rural economic development in Colombia. These biorefineries were designed following a strategy based on a portfolio of bioprocesses involving fractions based on the composition of the raw materials. The valorization of six food residues produced in three representative rural areas of Colombia (i.e., Chocó, Caldas, and Sucre) was analyzed. Acai, annatto, sugarcane bagasse, rejected plantain and avocado, and organic kitchen food waste (OKFW) were selected as food wastes for upgrading. The biorefinery design strategy comprised five steps for filtering the most promising bioprocesses to be implemented. The OKFW was analyzed in detail, applying the design strategy to provide a step-by-step guide involving a portfolio of bioproducts, the technological maturity index, and the socio-economic context. This strategy implementation for OKFW valorization resulted in a scenario where biorefineries with levulinic acid production were the most feasible and sustainable, with high techno-economic performances and low environmental impacts. For the valorization of the other food residues, the processes with the greatest feasibility of being implemented in rural areas were bioactive compounds, oil, flour, and biogas production. Full article
(This article belongs to the Special Issue Sustainable Development of Food Waste Biorefineries)
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14 pages, 3360 KiB  
Article
The Effect of pH on the Production and Composition of Short- and Medium-Chain Fatty Acids from Food Waste in a Leachate Bed Reactor at Room Temperature
by Pooja Radadiya, Ashika Latika, Xunchang Fei, Jangho Lee, Saurabh Mishra and Abid Hussain
Fermentation 2023, 9(6), 518; https://doi.org/10.3390/fermentation9060518 - 27 May 2023
Cited by 1 | Viewed by 2068
Abstract
This study evaluated the hydrolysis and acidogenesis of food waste at different operating pHs (uncontrolled, 5.5, 6.5, 7.5, 8.5) in a leachate bed reactor (LBR) at room temperature. LBR operation at pH 6.5–8.5 resulted in a hydrolysis yield of 718–729 g SCOD/kg VS [...] Read more.
This study evaluated the hydrolysis and acidogenesis of food waste at different operating pHs (uncontrolled, 5.5, 6.5, 7.5, 8.5) in a leachate bed reactor (LBR) at room temperature. LBR operation at pH 6.5–8.5 resulted in a hydrolysis yield of 718–729 g SCOD/kg VSadded, which was statistically (p ≤ 0.05) higher than that obtained at pH 5.5 (577 g SCOD/kg VSadded) and the uncontrolled pH (462 g SCOD/kg VSadded). The hydrolysis rate at pH 6.5 was the highest amongst all the pH values. Stabilization at pH at 6.5 also resulted in a high fatty acid (FA) yield of 643 g CODFA/kg VSadded. Butyrate was the main FA at the pH of 5.5–6.5, while acetate was the main FA at the pH of 7.5–8.5. At the uncontrolled pH, lactate production was the highest, indicating a shift in the microbial community from fatty-acid-producing bacteria to lactate-producing bacteria. The compositions of medium-chain fatty acids, such as caproate, were the highest at pH of 5.5. Full article
(This article belongs to the Special Issue Sustainable Development of Food Waste Biorefineries)
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Other

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9 pages, 979 KiB  
Brief Report
Modelisation of the Biomethane Accumulation in Anaerobic Co-Digestion of Whey and Sugarcane Molasse Mixtures
by Huaita Pacari Arotingo Guandinango, Rosario del Carmen Espín Valladares, Jimmy Núñez Pérez, Marco Vinicio Lara Fiallos, Ileana Pereda Reyes and José Manuel Pais-Chanfrau
Fermentation 2023, 9(9), 834; https://doi.org/10.3390/fermentation9090834 - 13 Sep 2023
Viewed by 1303
Abstract
The biomethane accumulation of several combinations of whey and sugarcane molasses, inoculated with sludge from a treatment facility of one of the dairy enterprises of the Imbabura province in Ecuador, was assessed in the current experiment at a constant COD0/VSin [...] Read more.
The biomethane accumulation of several combinations of whey and sugarcane molasses, inoculated with sludge from a treatment facility of one of the dairy enterprises of the Imbabura province in Ecuador, was assessed in the current experiment at a constant COD0/VSin ratio of 0.5. The whey/molasses (W:M) ratios for each treatment were (in % (m/m)) 0:100, 25:75, 50:50, 75:25, and 100:0, with a constant temperature of 37 °C and an initial pH adjustment of 7.5. Half a litre of total mixes was used for each treatment in duplicate. Six kinetic models were evaluated to account biomethane accumulation in anaerobic co-digestion processes in batch of whey and sugarcane molasses. Five of these have been tested by other researchers, and one was developed by modifying a first-order model to consider changes in the biomethane accumulation profile. This proposed model, along with the modified two-phase Gompertz model, resulted in the ones that were best able to adjust the experimental data, obtaining in all cases an R2 ≥ 0.949, indicating the accuracy of both models. In addition, the proposed here model has five parameters, one less than the modified two-phase Gompertz model, making it more straightforward and robust. Full article
(This article belongs to the Special Issue Sustainable Development of Food Waste Biorefineries)
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