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Food Waste from Restaurant Sector - Characterization for Biorefinery Approach
Abstract
The aim of this study is the analysis of food waste (FW) composition from local catering services to assess potential biorefinery development. Moisture content of different FW samples showed that 27-47% (w/w) was organic material. Main components were lipids (25.7-33.2, w/w), starch (16.2-29.4%, w/w) and proteins (23.5-18.3%, w/w) on a dry basis. A metal profile with Na and Mg as main components, followed by trace elements, i.e. Zn or Fe, was also found in food waste samples. Statistical tests in combination with principal component analysis provides an efficient methodology to establish specific composition variations between FW from different catering services, while relating them to FW typology. The combination of chemical characterization with statistical study constitutes a promising decision-making tool for FW processing and valorization. The innovative methodology presented in this study provides systematic evaluation of FW composition and variability to allow selection of the most appropriate valorization paths.
... Fermentable carbohydrates Peinemann et al., 2019;Carmona-Cabello et al., 2020;Yaradoddi et al., 2022 3 Wood and paper Sawdust, wood chips, and pulping residues can be enzymatically hydrolyzed to release sugars and ferment to produce lactic acid. Whey, a byproduct of cheese and yogurt production, contains lactose that can be enzymatically converted into lactic acid. ...
... proteins (10-20%), and dietary fibers (2%) (Peinemann et al., 2019). Due to its high content of fermentable carbohydrates, such food waste is widely utilized for lactic acid production through fermentation (Carmona-Cabello et al., 2020;Yaradoddi et al., 2022). ...
... Many researchers successfully produce waste-derived PLA with the same characteristics with commercially available PLA (Peinemann et al., 2019;Carmona-Cabello et al., 2020;Yaradoddi et al., 2022). It is well known that PLA is a biodegradable plastic that undergoes hydrolysis by moisture in the environment to become low molecular weight and is ultimately degraded to carbon dioxide and water by microbes. ...
This chapter presents a comprehensive study on the utilization of various waste sources as feedstocks for the production of polylactic acid (PLA), that is a biodegradable and biocompatible polymer with versatile applications. In the case of PLA, food products containing mainly starch are sources, so that the development of utilizing waste materials instead of relying on such plant resources contributes to securing food resources. This waste approach is discussed in depth in this chapter, including PLA chemical structure, thermal, mechanical, and rheological behaviours and biodegradability. In addition, processing methods of the PLA obtained by bioconversion, as well as its multifaced properties and its applications across various industries are highlighted. Since integration of sustainable waste- PLA strategies provides a deep understanding of PLA, sheds light on its strengths, and identifies its limitations and future prospects, this approach can contribute highly to both environmental protection and a circular economy.
... This variation in the composition of FW influences its biochemical properties, significantly impacting the efficiency and development of digestion processes (Bayard et al., 2018;Fisgativa et al., 2017). Typological analysis is recommended by previous literature (Bayard et al., 2018;Carmona-Cabello et al., 2020;Fisgativa et al., 2017) to evaluate the distribution of different foodstuff groups in the collected biowastes. ...
... Although there are many ways to handle problems with RFW management, prevention and valorization are two of the most essential options (Carmona-Cabello et al., 2020). To value RFW and reuse it as a culture medium for biological processes, identifying different foodstuffs in the RFW is necessary because it affects the chemical composition and possible paths for valorization (Carmona-Cabello et al., 2020). ...
... Although there are many ways to handle problems with RFW management, prevention and valorization are two of the most essential options (Carmona-Cabello et al., 2020). To value RFW and reuse it as a culture medium for biological processes, identifying different foodstuffs in the RFW is necessary because it affects the chemical composition and possible paths for valorization (Carmona-Cabello et al., 2020). ...
Annually, a substantial volume of food waste is being released into the environment. Restaurant food waste (RFW) valorization using microwave-assisted hydrolysis (MAH) is a sustainable approach to produce fermentable sugars. However, RFW is composed of different foodstuffs with different physicochemical, nutritional, and degradation rates. This study explored the typological, chemical, and elemental analysis of RFW. Results revealed that the four main types of RFW were vegetable (33.2 %), meat (19.3 %), rice (15.2 %), and bread waste (11.0 %). The key parameters impacting the MAH of typologically sorted RFW were identified using the Plackett–Burman design (PBD). Then the central composite design (CCD) with 30 runs was used to increase reducing sugar content (RSC). The optimized condition was as follows: temperature 96.0 °C, microwave power 340 W, HCl concentration of 1.45 %, and microwave heating time 11.1 min. The derived hydrolysates were characterized for their biochemical and monosaccharide composition.
... This variation in the composition of FW influences its biochemical properties, significantly impacting the efficiency and development of digestion processes (Bayard et al., 2018;Fisgativa et al., 2017). Typological analysis is recommended by previous literature (Bayard et al., 2018;Carmona-Cabello et al., 2020;Fisgativa et al., 2017) to evaluate the distribution of different foodstuff groups in the collected biowastes. ...
... Although there are many ways to handle problems with RFW management, prevention and valorization are two of the most essential options (Carmona-Cabello et al., 2020). To value RFW and reuse it as a culture medium for biological processes, identifying different foodstuffs in the RFW is necessary because it affects the chemical composition and possible paths for valorization (Carmona-Cabello et al., 2020). ...
... Although there are many ways to handle problems with RFW management, prevention and valorization are two of the most essential options (Carmona-Cabello et al., 2020). To value RFW and reuse it as a culture medium for biological processes, identifying different foodstuffs in the RFW is necessary because it affects the chemical composition and possible paths for valorization (Carmona-Cabello et al., 2020). ...
... From a legal point of view, the circular economy is an instrumental principle to achieve later and lofty goals. There is no uniformity in its definition, and it has a transversal character with a clear transformative vocation that extends to a multiplicity of interrelated (but different) economic activities, such as production, consumption, waste management and markets for secondary raw materials (Alenza García, 2020). ...
... They Ambaye et al., 2021) can often serve as cheap sources of carbon and nitrogen for the growth of microorganisms, which make them viable to be applied in a biorefinery. This minimizes the use of virgin resources and eliminates the need for treatment and transport of FLW through the 3Rs implementation action plan, contributing to the sustainable development goals established for the 2030 agenda: efficient conversion of biomass, use of renewable materials at industrial levels and food waste minimization, through sustainable agricultural production and food security (Awasthi et al., 2020;Beretta & Hellweg, 2019;Carmona-Cabello et al., 2020;Schütte, 2018). In this context, the 2020 European Strategy for smart, sustainable and inclusive growth indicates that the circular economy is a key strategy to achieve this; although the reduction, reuse and valorization of FLW for biofuel generation are at the early stages of the investigation, but it will certainly have a positive impact on the economy, food security and the environment. ...
... These wastes are influenced by geography, cultural and socioeconomic factors; for instance: some parts of the chicken such as offal and legs are consumed in some supply chains of food, but not in others whereby they can be used as a renewable raw material in the generation of biofuels and other value-added bioproducts Mak et al., 2020;Sarsaiya et al., 2019;Van Der Werf & Gilliland, 2017). Some examples of the use of FWL in biorefineries have involved their characterizations in the restaurant sector (Carmona-Cabello et al., 2020), the use of FWL coffee in a biorefinery for biofuel production (Zabaniotou & Kamaterou, 2019) and wastes of citrus peels as a promising and sustainable option to generate bioethanol due to its low lignin content (Jeong et al., 2021). It is estimated that by 2030, the total biomass supply worldwide will range from 97 to 147 EJ/year, which will remarkably be raised by 2050, where agricultural residues will continue to be the largest supply of biomass, providing up to 550 EJ/year (Ambaye et al., 2021). ...
This book provides a detailed coverage of how the circular economy aims to change the paradigm in relation to the linear economy, by limiting the environmental impact and waste of resources, as well as increasing efficiency at all stages of the product economy. It serves as the sole comprehensive overview of the role of biofuels in the circular economy. It contains updated information on the latest trends of techno-economic analysis of biofuels, economic transitions, low-carbon economies, green circular societies, and life cycle assessment of biofuels. This book delves deep into the economic security of the poor as well as the nexus between biofuel industry and global trade bodies, making it one of the few introductory books without bias toward the contribution of biofuels in circular economy. With its diverse contributions on themes such as biofuels as potential alternatives to fossil fuels, biofuel economics and policies; biofuel standards, blending, and future insecurities; economic transitions from biomass to biofuels; and biofuel economy, development, and food security, the book would be a great resource for a wide and multi-disciplinary readership base ranging from researchers to academics, policy makers, innovators, corporates, and non-profit organizations working in this area.
... From a legal point of view, the circular economy is an instrumental principle to achieve later and lofty goals. There is no uniformity in its definition, and it has a transversal character with a clear transformative vocation that extends to a multiplicity of interrelated (but different) economic activities, such as production, consumption, waste management and markets for secondary raw materials (Alenza García, 2020). ...
... They Ambaye et al., 2021) can often serve as cheap sources of carbon and nitrogen for the growth of microorganisms, which make them viable to be applied in a biorefinery. This minimizes the use of virgin resources and eliminates the need for treatment and transport of FLW through the 3Rs implementation action plan, contributing to the sustainable development goals established for the 2030 agenda: efficient conversion of biomass, use of renewable materials at industrial levels and food waste minimization, through sustainable agricultural production and food security (Awasthi et al., 2020;Beretta & Hellweg, 2019;Carmona-Cabello et al., 2020;Schütte, 2018). In this context, the 2020 European Strategy for smart, sustainable and inclusive growth indicates that the circular economy is a key strategy to achieve this; although the reduction, reuse and valorization of FLW for biofuel generation are at the early stages of the investigation, but it will certainly have a positive impact on the economy, food security and the environment. ...
... These wastes are influenced by geography, cultural and socioeconomic factors; for instance: some parts of the chicken such as offal and legs are consumed in some supply chains of food, but not in others whereby they can be used as a renewable raw material in the generation of biofuels and other value-added bioproducts Mak et al., 2020;Sarsaiya et al., 2019;Van Der Werf & Gilliland, 2017). Some examples of the use of FWL in biorefineries have involved their characterizations in the restaurant sector (Carmona-Cabello et al., 2020), the use of FWL coffee in a biorefinery for biofuel production (Zabaniotou & Kamaterou, 2019) and wastes of citrus peels as a promising and sustainable option to generate bioethanol due to its low lignin content (Jeong et al., 2021). It is estimated that by 2030, the total biomass supply worldwide will range from 97 to 147 EJ/year, which will remarkably be raised by 2050, where agricultural residues will continue to be the largest supply of biomass, providing up to 550 EJ/year (Ambaye et al., 2021). ...
Biofuels are getting attraction as an alternative to fossil fuels due to their environmental benefits and their renewable nature. Consumption of oil derivatives in combustion engines and boilers has increased carbon dioxide, resulting in the global warming effect. Besides this, oil production is reaching the near-term peak, and the subsequent decline in production has been already detected. The world production of liquid biofuels, mainly ethanol and biodiesel, has increased by over 160 billion litres (equivalent to 4 Exajoules). In addition, the production capacity of other fuels such as biomethane, biobutanol, bioethanol and biomethane is continuously increasing. In the transport sector, biofuel is a real alternative to fossil fuels with a contribution of just over 3% today. Indonesia, the USA and Brazil are the largest producers with more than 40% of the global production. Germany and France in Europe are increasing their production with a strategy based on biomethane. A case study is presented considering the economic revenues of the transformation of the most widespread agricultural wastes into the most promising common biofuels.
... From a legal point of view, the circular economy is an instrumental principle to achieve later and lofty goals. There is no uniformity in its definition, and it has a transversal character with a clear transformative vocation that extends to a multiplicity of interrelated (but different) economic activities, such as production, consumption, waste management and markets for secondary raw materials (Alenza García, 2020). ...
... They Ambaye et al., 2021) can often serve as cheap sources of carbon and nitrogen for the growth of microorganisms, which make them viable to be applied in a biorefinery. This minimizes the use of virgin resources and eliminates the need for treatment and transport of FLW through the 3Rs implementation action plan, contributing to the sustainable development goals established for the 2030 agenda: efficient conversion of biomass, use of renewable materials at industrial levels and food waste minimization, through sustainable agricultural production and food security (Awasthi et al., 2020;Beretta & Hellweg, 2019;Carmona-Cabello et al., 2020;Schütte, 2018). In this context, the 2020 European Strategy for smart, sustainable and inclusive growth indicates that the circular economy is a key strategy to achieve this; although the reduction, reuse and valorization of FLW for biofuel generation are at the early stages of the investigation, but it will certainly have a positive impact on the economy, food security and the environment. ...
... These wastes are influenced by geography, cultural and socioeconomic factors; for instance: some parts of the chicken such as offal and legs are consumed in some supply chains of food, but not in others whereby they can be used as a renewable raw material in the generation of biofuels and other value-added bioproducts Mak et al., 2020;Sarsaiya et al., 2019;Van Der Werf & Gilliland, 2017). Some examples of the use of FWL in biorefineries have involved their characterizations in the restaurant sector (Carmona-Cabello et al., 2020), the use of FWL coffee in a biorefinery for biofuel production (Zabaniotou & Kamaterou, 2019) and wastes of citrus peels as a promising and sustainable option to generate bioethanol due to its low lignin content (Jeong et al., 2021). It is estimated that by 2030, the total biomass supply worldwide will range from 97 to 147 EJ/year, which will remarkably be raised by 2050, where agricultural residues will continue to be the largest supply of biomass, providing up to 550 EJ/year (Ambaye et al., 2021). ...
Today’s world faces two challenges: energy shortage and environmental pollution. Fossil fuels for power generation and transportation have caused high carbon dioxide emissions (CO2) to the environment. Renewable energy plays a vital role in the global and domestic approach to the mitigation of energy and environmental issues. Some renewable energy sources, including solar energy, wind, bioenergy, geothermal energy, hydroelectricity, and ocean energy, have a lower environmental impact than fossil fuels. In comparison with fossil fuels, biofuels are a source of renewable energy that can guarantee the country’s economy while preserving the natural climate. It appears that only microalgae can replace fossil fuels as feedstock. It's common to grow microalgae in photo-bioreactors or huge open ponds. The carbon dioxide produced due to the combustion of biofuel is recycled in photosynthesis for biodiesel production. In coal co-firing, microalgae can produce electricity to reduce greenhouse emissions and lower coal consumption. Moreover, bioethanol and biodiesel can replace two primary fossil fuels (gasoline and diesel) used in the transportation sector.
... FW is defined as food that has not been ultimately consumed by humans and, as a result, is discarded or recycled [6]. It has been widely documented that FW, without an efficient treatment process, is a potential contaminant of the environment and a source of greenhouse gas emissions, contributing to both global warming and climate change [7][8][9][10][11]. FW is defined as food that has not been ultimately consumed by hum result, is discarded or recycled [6]. ...
... Hence, its heterogeneous nature is a great challenge in the adoption of international standards for the FW disposal and recycling [40]. FW composition can change depending on several factors such as (i) geographical location, (ii) source, (iii) season, (iv) and socioeconomic factors including consumer preferences and habits [7,[40][41][42]. Therefore, as it has been indicated in the Introduction, there is a justified need to deepen the knowledge of the parameters of the FW used for the AD process. ...
There is a growing recognition that food waste (FW) comprises a significant amount of unused energy. Indeed, FW shows great potential to produce methane (CH 4)-rich biogas via an anaerobic digestion (AD) process. Nevertheless, to ensure high AD process performance, deepening the knowledge of FW characteristics is required. Furthermore, the biogas yield is strongly influenced by several operational parameters. Taking into account the above, in the current study, based on the data in the literature, the physicochemical parameters of FW generated throughout the world are presented and discussed. In addition, the performance profile of the single-stage anaerobic mono-digestion process with the use of FW as a feedstock was investigated. The performed analysis clearly demonstrated that FW is characterized by significant variations in several parameters, such as pH, the total solid (TS) and volatile solid (VS) contents, the volatile solids to total solids ratio (VS/TS), soluble chemical oxygen demand (sCOD), the concentrations of VFAs and ammonium nitrogen (NH 4 +-N), and the carbon-to-nitrogen ratio (C/N). Moreover, it was shown that the selected operational parameters, such as temperature, pH, the ratio of food waste to inoculum (I) (FW/I), and the organic loading rate (OLR), may have the most significant impact on the performance of the single-stage anaerobic mono-digestion process. In addition, it was found that most of the experimental investigations presented in the literature were conducted on a laboratory scale. Hence, in future research, more effort should be made to determine the biogas yield with the use of full-scale systems. To summarize, it should be clearly highlighted that the analysis presented in this study may have important implications for the management and application of FW as feedstock for an anaerobic mono-digestion process on an industrial scale.
... Cellulose, hemicellulose carbohydrates, and lignin are also abundant in these wastes. Carmona-Cabello et al. [36] showed that the protein content ranged from 13 to 18 %, the amount of fat from 26 to 33 %, and the overall carbohydrate content from 44 to 51 % during the food waste comparisons which were examined among numerous restaurants. ...
... Due to its high protein content and easily fermentable carbohydrates, food waste is utilized for lactic acid fermentation [36]. LA is produced using a variety of renewable feedstocks. ...
Due to its low carbon footprint and environmental friendliness, polylactic acid (PLA) is one of the most widely produced bioplastics in the world. Manufacturing attempts to partially replace petrochemical plastics with PLA are growing year over year. Although this polymer is typically used in high-end applications, its use will increase only if it can be produced at the lowest cost. As a result, food wastes rich in carbohydrates can be used as the primary raw material for the production of PLA. Lactic acid (LA) is typically produced through biological fermentation, but a suitable downstream separation process with low production costs and high product purity is also essential. The global PLA market has been steadily expanding with the increased demand, and PLA has now become the most widely used biopolymer across a range of industries, including packaging, agriculture, and transportation. Therefore, the necessity for an efficient manufacturing method with reduced production costs and a vital separation method is paramount. The primary goal of this study is to examine the various methods of lactic acid synthesis, together with their characteristics and the metabolic processes involved in producing lactic acid from food waste. In addition, the synthesis of PLA, possible difficulties in its biodegradation, and its application in diverse industries have also been discussed.
... They Ambaye et al., 2021) can often serve as cheap sources of carbon and nitrogen for the growth of microorganisms, which make them viable to be applied in a biorefinery. This minimizes the use of virgin resources and eliminates the need for treatment and transport of FLW through the 3Rs implementation action plan, contributing to the sustainable development goals established for the 2030 agenda: efficient conversion of biomass, use of renewable materials at industrial levels and food waste minimization, through sustainable agricultural production and food security (Awasthi et al., 2020;Beretta & Hellweg, 2019;Carmona-Cabello et al., 2020;Schütte, 2018). In this context, the 2020 European Strategy for smart, sustainable and inclusive growth indicates that the circular economy is a key strategy to achieve this; although the reduction, reuse and valorization of FLW for biofuel generation are at the early stages of the investigation, but it will certainly have a positive impact on the economy, food security and the environment. ...
... These wastes are influenced by geography, cultural and socioeconomic factors; for instance: some parts of the chicken such as offal and legs are consumed in some supply chains of food, but not in others whereby they can be used as a renewable raw material in the generation of biofuels and other value-added bioproducts Mak et al., 2020;Sarsaiya et al., 2019;Van Der Werf & Gilliland, 2017). Some examples of the use of FWL in biorefineries have involved their characterizations in the restaurant sector (Carmona-Cabello et al., 2020), the use of FWL coffee in a Sarsaiya et al., 2019) biorefinery for biofuel production (Zabaniotou & Kamaterou, 2019) and wastes of citrus peels as a promising and sustainable option to generate bioethanol due to its low lignin content (Jeong et al., 2021). It is estimated that by 2030, the total biomass supply worldwide will range from 97 to 147 EJ/year, which will remarkably be raised by 2050, where agricultural residues will continue to be the largest supply of biomass, providing up to 550 EJ/year (Ambaye et al., 2021). ...
The application of circular economy has positioned as one of the pillars of the sustainable global agenda through the insertion of waste biotransformation into a variety of high-value compounds such as biofuels, which significantly reduce the concerns associated with environmental pollution such as the generation of greenhouse gases and final disposal expenses. In this context, the production of biofuels using lignocellulosic biomass is attractive since they are generated in large volumes, as well as the minimization, generation, treatment and disposal of wastes. This review addresses the sustainable production of biofuels through the use of microbial consortia in consolidated bioprocesses (CBP), presenting advantages and drawbacks of the use of synthetic microbial consortia (e.g., those designed by different mechanisms such as genetic modification) against native consortia (NC) isolated from different ecosystems to reduce costs and residence times. In addition, challenges and current perspectives to apply NC towards the generation of biofuels are comprehensively revisited since these consortia present excellent stability and resistance to change in environmental conditions or system disturbances. This offers an outstanding capacity to biodegrade numerous biomass resources (i.e., substrate), since they split complex metabolic tasks to achieve a remarkable performance, replacing the metabolic design representing a cutting-edge option for CBPs implemented in a sustainable biorefinery to generate biofuels in order to potentiate the use of biomass in the circular economy. A circular economy which involves consolidated bioprocesses to produce biofuels. The circular process includes: food lost and waste, native consortia, biorefinery, biofuel and renewable biomass. A circular economy which involves consolidated bioprocesses to produce biofuels. The circular process includes: food lost and waste, native consortia, biorefinery, biofuel and renewable biomass.
... Therefore, food waste from industry is easier to use as fodder and as feedstock in biorefineries [38]. Municipal food waste (MFW) is categorized into four types: [39] Fruits and vegetables; Starchy foodstuff; Meat, fish and byproducts; Others, like dairy products, sweets and nonedible products; ...
... To improve the waste management also the discarding causes of MFWs has to be noted [39]; Nonedible food: out of date, not consumed full meals, excessive portion sizes, or not processed feedstock; Overproduction of food: in restaurants and other services; Waste, based on hygienic, quality, and storage standards; Aquatic biomass residues consist of seaweed, algae, and fish residues. Fish residues such as skin, heads, frames, and viscera account for 60% of the global fish production, which was 175 million tons in 2017 [40]. ...
In today’s linear economy, waste streams, environmental pollution, and social–economic differences are increasing with population growth. The need to develop towards a circular economy is obvious, especially since waste streams are composed of valuable compounds. Waste is a heterogeneous and complex matrix, the selective isolation of, for example, polyphenolic compounds, is challenging due to its energy efficiency and at least partially its selectivity. Extraction is handled as an emerging technology in biorefinery approaches. Conventional solid liquid extraction with organic solvents is hazardous and environmentally unfriendly. New extraction methods and green solvents open a wider scope of applications. This research focuses on the question of whether these methods and solvents are suitable to replace their organic counterparts and on the definition of parameters to optimize the processes. This review deals with the process development of agro-food industrial waste streams for biorefineries. It gives a short overview of the classification of waste streams and focuses on the extraction methods and important process parameters for the isolation of secondary metabolites.
... Наприклад, деякі автори розглядають перспективи використання ферментації у створенні нових страв, які відповідають вимогам сучасної гастрономії. Процес ферментації дозволяє експериментувати з різними інгредієнтами, відкриваючи нові можливості для шеф-кухарів та рестораторів у розробці унікальних меню [9,10]. ...
... About 50% of FWRs are semitreated in a suitable way, accounting 29% for recycling and 20% destined for composting or anaerobic digestion treatments, while the remaining percentage is just disposed in landfills or incinerated [1,2]. Nonetheless, these management strategies must change in the near future and follow the new European Directives that are currently being launched (article 11 and article 5) and are committed to decreasing landfilling to 10%, while assuring sustainable managements of FWR to 65% by 2030 [3,4]. Therefore, the development of suitable strategies for food-waste management under the biorefinery approach plays an important role in increasing sustainability and achieving the challenges that food-to a micro-scale level [24,26,27]. ...
Residual melon by-products were explored for the first time as a bioresource of microcrystalline cellulose (MCC) obtention. Two alkaline extraction methods were employed, the traditional (4.5% NaOH, 2 h, 80 °C) and a thermo-alkaline in the autoclave (2% NaOH, 1 h, 100 °C), obtaining a yield of MCC ranging from 4.76 to 9.15% and 2.32 to 3.29%, respectively. The final MCCs were characterized for their chemical groups by Fourier-transform infrared spectroscopy (FTIR), crystallinity with X-ray diffraction, and morphology analyzed by scanning electron microscope (SEM). FTIR spectra showed that the traditional protocol allows for a more effective hemicellulose and lignin removal from the melon residues than the thermo-alkaline process. The degree of crystallinity of MCC ranged from 51.51 to 61.94% and 54.80 to 55.07% for the thermo-alkaline and traditional processes, respectively. The peaks detected in X-ray diffraction patterns indicated the presence of Type I cellulose. SEM analysis revealed microcrystals with rough surfaces and great porosity, which could remark their high-water absorption capacity and drug-carrier capacities. Thus, these findings could respond to the need to valorize industrial melon by-products as raw materials for MCC obtention with potential applications as biodegradable materials.
... Readily available organic content in waste from green markets and restaurants makes it an ideal co-substrate for decentralized anaerobic digestion. Synthetic green market waste (GW S ) and synthetic restaurant waste (RW S ) were prepared according to Song et al. (2020) and Carmona-Cabello et al. (2020), respectively, and their recipes are included in the supplemental information (Tables S1 and S2). Restaurant food waste (RW R ) was collected from the restaurant at Eawag and comprised of rice, pasta, vegetables, and meat. ...
There is limited understanding of the potential for anaerobic digestion and biogas production from fecal sludge. In this study, biomethane potential (BMP) tests from fresh, stored, and dewatered fecal sludge, together with co-digestion with fresh foodwaste, revealed that fresh fecal sludge produced similar cumulative biogas (CBG) to fresh foodwaste (615–627 mL/gVS), while stored fecal sludge showed a wide range of gas production (13–449 mL/gVS). Co-digestion significantly enhanced the CBG production of fresh (1.2×), dewatered (1.5×), and stored (29–36×) fecal sludge. In BMP tests with the higher range of gas production, a biphasic CBG production was observed, with degradation of readily biodegradable organics occurring during the first week. The first-order rate coefficients indicated hydrolysis limitation, which was also confirmed by the presence of slow-growing methanogens (Halobacterota). Priming with co-digestion significantly enhanced CBG from stored fecal sludge. The physical–chemical metrics VS/TS and TOC/TN were not predictors of biogas production, while BOD/COD and sCOD were better indicators, suggesting that metrics of stabilization representing biologically available fractions are more representative than metrics of entire pools of organic matter. This study suggests that biogas production from anaerobic digestion is viable for fresh fecal sludge, whereas for stored fecal sludge, this requires co-treatment or pretreatment.
... Waste valorisation has gained prominence in academic and policy discussions to tackle the issue of climate change and to maximize the potential environmental, economic, and social benefits (Chen et al., 2020). Among the various organic wastes, food waste (FW) is emerging as a problem that can contaminate water and land while also contributing to greenhouse gas emissions (Carmona-Cabello et al., 2020). There are limited studies available on the use of FW feedstock due to its diverse composition which requires a wide range of process temperature (Bonga et al., 2020). ...
Slow pyrolysis, a widely recognized thermochemical technique, is employed to produce biochar usually under inert atmospheres. Recently, there is a growing interest in utilizing CO2 as a carrier gas during pyrolysis as an alternative to inert atmospheres, aiming to modify the resulting pyrolytic products and make them suitable for different applications. This study investigated and compared the impact of CO2 atmosphere with N2 on pyrolysis of food waste, rice husk, and grape tree branches waste via slow pyrolysis at temperatures of 400, 500, and 600 °C at 5 and 15 °C/min for 1 h, to evaluate biochar production and its properties. The results demonstrate that CO2 atmosphere increased the biochar yield for all feedstocks and significantly influenced the physicochemical properties of biochar. Compared to N2, CO2-derived biochar exhibited less volatile matter, higher carbon content, lower O/H and O/C molar ratios and enhanced textural properties. This study highlighted the potential of utilizing CO2 for biochar production and tailoring biochar properties for specific applications and the findings contribute to the establishment of sustainable and efficient waste management systems and the production of value-added biochar products.
... Because of this rich composition, food waste is categorised as an inexpensive, high-potential second-generation raw material [39]. The foundation of any procedure for valorising food waste is the composition of the generated food waste [40]. Food waste has a diverse and inconsistent composition that depends on a specific population's region, season, and dietary patterns. ...
Hunger (811 million people, 2020) and food waste (931 million tonnes annually, 2020) are long-standing interconnected challenges that have plagued humankind for centuries. Food waste originates from various sources, including consumption habits and failures within the food supply chain. Given the growing concerns regarding food insecurity, malnutrition, and hunger, there is a pressing need to recover and repurpose as much food waste as possible. A growing body of knowledge identifies the valorisation (including upcycling) of food waste as one of the strategies to fight hunger by positively impacting food availability and food security. This paper evaluates the potential role of food waste valorisation, including upcycling, in reducing global hunger. A literature search was conducted to examine how converting food waste into value-added products, such as food formulations and farming inputs, can contribute to increasing food availability. The benefits of waste-to-food operations in improving food availability through producing food ingredients and products from materials that would have been wasted or discarded otherwise were discussed.
... It is becoming a significant global issue, as the components of biowaste release CO2 and other greenhouse gases in the process of breaking down, in addition to the economic and moral factors of throwing food away. Up to 30% of food biowaste globally is leftovers from restaurants, grocery stores, and households [2]. ...
Coffee is one of the most popular beverages, with around 10.5 million tons manufactured annually. The same amount of spent coffee grounds (SCGs) might harm the environment if disposed of carelessly. On the other hand, pesticide contamination in food and biowaste is a rising problem. Because pesticides are hazardous and can cause serious health consequences, it is critical to understand how they interact with food biowaste materials. However, it is also a question if biowaste can be used to remediate rising pesticide residues in the environment. This study investigated the interactions of SCGs with the organophosphate pesticides malathion (MLT) and chlorpyrifos (CHP) and addressed the possibility of using SCGs as adsorbents for the removal of these pesticides from water and fruit extracts. The kinetics of MLT and CHP adsorption on SCGs fits well with the pseudo-first-order kinetic model. The Langmuir isotherm model best describes the adsorption process, giving the maximal adsorption capacity for MLT as 7.16 mg g −1 and 7.00 mg g −1 for CHP. Based on the thermodynamic analysis, it can be deduced that MLT adsorption on SCGs is exothermic, while CHP adsorption is an endothermic process. The adsorption efficiency of MLT and CHP using SCGs in a complicated matrix of fruit extracts remained constant. The neurotoxicity results showed that no more toxic products were formed during adsorption, indicating that SCGs are a safe-to-use adsorbent for pesticide removal in water and fruit extracts.
... Peels are a common residue discarded as food waste by catering services (Carmona-Cabello et al., 2020). Potato peels have been evaluated due to their starch content which facilitates the performance of amylolytic enzymes (Carmona-Cabello et al., 2021;Mojumdar and Deka, 2019). ...
... Restaurants with quality information, will have satisfaction in using existing information. In addition, the accounting information system that runs on the software makes it easier for restaurants to control revenue and quickly see how much profit or loss is generated and can also predict the survival of restaurants in the future (Carmona-Cabello et al., 2020). ...
The purpose of this study is to determine whether the design of an accounting system in a restaurant or franchise business can provide benefits in realizing the creation of accounting reporting that has a positive impact on management. In this study, the application of accounting system design using accounting information system applications was taken from the results of research conducted by previous researchers on restaurants and franchise businesses. The study was conducted based on the literature review of the ten previous studies by making a summary of the results and conclusions. Some of the criteria used in selecting articles to be material in this study are as follows: the method used, trends and topics in related research, factors that influence financial reporting and the next best method used in writing financial reports.The design of an accounting information system using a PHP program and a MySQL database can help companies make financial accounting reports which include the calculation of profit and loss from restaurant companies. PHP applications and MySQL databases used by restaurant companies must comply with applicable accounting standards. Technical competence of employees needs to be given support from the top management of the company to receive special training in the use of financial accounting programs, so that the performance of accounting information systems can be measured for success. The involvement of users of the financial accounting information system program in the company has a positive impact on the performance of the financial accounting system.
... Food waste is mainly composed of cellulose, hemicellulose, and lignin by chemical structure and proteins, lipids, and carbohydrates by classification or category. It is an organic compound containing trace amounts of elements such as nitrogen, phosphorous, and potassium [9]. Food waste contains moisture which when subjected to HTC under increased temperature and pressure serves as an organic solvent owing to its decreased dielectric constant. ...
This review critically discussed recent developments in hydrothermal carbonization (HTC) of food waste and its valorization to solid fuel. Food waste properties and fundamentals of the HTC reactor were also covered. The review further discussed the effect of temperature, contact time, pressure, water–biomass ratio, and heating rate on the HTC of food waste on the physiochemical properties of hydrochar. Literature review of the properties of the hydrochar produced from food waste in different studies shows that it possesses elemental, proximate, and energy properties that are comparable to sub-bituminous coal and may be used directly as fuel or co-combusted with coal. This work conclusively identified the existing research gaps and provided recommendation for future investigations.
... It varies significantly depending on the season, the region, and the population's dietary habits. Despite the inevitability of diversity in the content of food waste, it is undeniably rich in carbohydrates, lipids, minerals and proteins, making it an attractive raw material for the manufacture of biofuels via microbial conversion [6,7]. Generally, mixed food wastes are utilised in the production of ethanol. ...
The global demand for fuel keeps increasing daily. The massive depletion of fossil fuels and their influence on the environment as pollution is a severe problem. Meanwhile, food waste disposal is also a complex problem in solid-waste management since one-third of every food consumed is discarded as waste. The standard waste management methods, including food waste incineration and landfilling, are considered hazardous to the environment. Food waste constituents are majorly starch-based and contain various biomolecules, including sugar, lipids, proteins, vitamins, cellulose, etc. These polysaccharides can be hydrolysed into monosaccharides such as glucose, which can then be fermented using microorganisms to produce ethanol through the fermenting of sugars derived from enzymatic hydrolysis treatment of food wastes. The human food system is rich in starch, which can be a potential resource for bioethanol production.
... Furthermore, composition analysis of the FW shows that it is rich in carbohydrates (97.9 -138.3 mg/ml), proteins (19.8 -197.4 mg/ml) and lipids (2.5 -13.1 mg/ml) ( Hamzah et al., 2019 ). Carmona-Cabello et al. (2020) studied the physico -chemical properties of FW from restaurants as feedstock for biorefinery. The main components of the FW were reported as lipids (25.7-33.2, ...
Large amount of food and agricultural residues are discharged as municipal wastes. These feedstocks possess high sugar content and are being dumped into landfills or incinerated creating severe environmental challenges. Anaerobic co-digestion (AcD) of food waste and agricultural residues provides a sustainable valorisation route for biogas production. Biochar (BC), a widely flexible and unique material, promotes microbial activity, electrical conductivity, and molar interactions in the digester. The present review presents an overview of the influence of biochar on product yield during AcD. An overview of different classification of food waste and agricultural residues is presented. In addition, studies related to the application of biochar to enhance AcD were critically reviewed as well as the outlook. The conducted studies revealed that addition of biochar to the AcD process can mitigate the buffering capacity and toxic process inhibitors faced in AcD, and ultimately enhance biogas yields, shortening the lag-phase and biodegrading running time. Biochar has unique surface functional groups that can be modified by functionalization or by adjusting the pyrolysis temperature for optimal efficiency of specific co-substrate combinations of feedstocks. In AcD process, engineered biochar can be directed to specifically adsorb precise indirect (limonene) or direct (NH3, CO2) inhibitors for optimal process efficiency and methane production based on active surface functional groups, alkalinity of the material and hydrophobicity. Hence, BC enhanced with the right pore sizing and pH can offset AcD limitations and improve process efficiency. The presented review would provide an in- depth understand on the influence of biochar on product yield during AcD process.
... The digestate alone was not suitable as feedstock for housefly larvae, which is likely related to the low amount of DOC ( Fig. 3 b) available to their microorganisms. Accordingly, housefly larvae preferred RFW over HFW, since the former usually contained high amounts of protein and fat ( Carmona-Cabello et al., 2020 ). Given the high cost of vermicomposting in terms of maintaining the conditions for larval growth, HFW should be mixed with RFW to feed housefly larvae. ...
The development of methods for the efficient treatment and application of food waste digestate is an important research goal. Vermicomposting via housefly larvae is an efficient way to reduce food waste and achieve its valorization, however, studies on the application and performance of digestate in vermicomposting are rarely. The present study aimed to investigate the feasibility of the co-treatment of food waste and digestate as an additive via larvae. Restaurant food waste (RFW) and household food waste (HFW) were selected to assess the effects of waste type on vermicomposting performance and larval quality. Waste reduction rates of 50.9%–57.8% were observed in the vermicomposting of food waste mixed with digestate at a ratio of 25%, which were slightly lower than those for treatments without the addition of digestate (62.8%–65.9%). The addition of digestate increased the germination index, with a maximum value of 82% in the RFW treatments with 25% digestate, and decreased the respiration activity, with a minimum value of 30 mg-O2 g-TS−1. The larval productivity of 13.9% in the RFW treatment system with a digestate rate of 25% was lower that without digestate (19.5%). Materials balance shows that larval biomass and metabolic equivalent had decreasing trends as the amount of digestate increased and HFW vermicomposting exhibited lower bioconversion efficiency than that of RFW treatment system regardless of the addition of digestate. These results suggest that mixing digestate at a low ratio (25%) during vermicomposting of food waste especially RFW could lead to considerable larval biomass and generate relatively stable residues.
This study aims to identify key areas of consumer involvement in reducing food waste in the food service sector, with particular emphasis on the use of mobile applications. The article presents theoretical considerations alongside a quantitative analysis of the studied issue, based on a survey conducted in April 2024 using the CAWI method among 301 residents of the Podkarpackie region. The empirical section focuses on assessing consumer engagement in food waste reduction at food service establishments through two well-known platforms available on the Polish market: Too Good To Go and Foodsi, which allow users to purchase unsold food at a reduced price at the end of the day. The findings indicate that awareness and utilization of such solutions are moderate among respondents, particularly concerning the Foodsi app. No significant differences were observed in app usage based on gender or age. However, women showed a higher tendency to request their uneaten meals to be packaged when dining out. Overall, only one in four respondents reported always asking for their leftovers to be packed at restaurants. In this context, the authors suggest that social campaigns, along with educational and communication initiatives, should be implemented to encourage both consumers and food service employees to adopt the habit of packaging uneaten meals in food service establishments.
This study comprehensively investigates the potential of food industrial sludge as a renewable resource within the expanding global food industry. Grounded in the theoretical framework of the circular economy and sustainability sciences, it delves into the composition of sludge, comprising diverse organic (proteins, carbohydrates, lipids, and fibers) and inorganic elements (miner-als, heavy metals, and trace elements), highlighting its environmental and economic implications. The focus is on evaluating key utilization methods-anaerobic digestion, thermal treatment (pyrolysis and gasification), composting, and bioconversion-for transforming sludge into valuable resources such as biogas, biochar, and compost. These methods are assessed based on their alignment with sustainable waste management theories and practices, particularly concerning environmental sustainability and resource recovery. Empirical data from case studies and industry reports are incorporated to provide concrete examples of successful sludge utilization practices. For instance, empirical data indicate that anaerobic digestion can reduce sludge volume by up to 70% and generate biogas with an energy yield of approximately 25 MJ per kg of dry sludge. Pyrolysis can sequester up to 3 t of CO 2 per ton of biochar produced. These methods demonstrate considerable promise for energy production, nutrient recovery , and reducing greenhouse gas emissions, supporting a circular economy approach. The study addresses challenges in sludge management, including compositional variability, contaminant presence, and the necessity for effective treatment to mitigate environmental risks such as water and soil pollution and odor issues. Findings indicate that the sustainable utilization of food industrial sludge as a renewable resource is not only viable but also essential for minimizing environmental impact, conserving finite resources, and promoting sustainability in the food industry. This research contributes valuable insights for policymakers,
Waste cooking oils (WCOs) are generated globally from households, the hospitality industry, and other sectors. Presently, WCOs are mainly employed as feedstock for biodiesel and energy production, strongly depending on the availability of WCOs, which are often imported from other countries. The objective of this review is to give an overall comprehensive panorama of the impacts, regulations, and restrictions affecting WCOs, and their possible uses for producing high-value products, such as bio lubricants, bio surfactants, polymer additives, road and construction additives, and bio solvents. Interestingly, many reviews are reported in the literature that address the use of WCOs, but a comprehensive review of the topic is missing. Published studies, industry reports, and regulatory documents were examined to identify trends, challenges, production statistics, environmental impacts, current regulations, and uses for high-value polymer production. The data collected show that WCOs hold immense potential as renewable resources for sustainable industrial applications that are in line with global carbon neutrality goals and circular economy principles. However, achieving this shift requires addressing regulatory gaps, enhancing collection systems, and optimizing conversion technologies. This comprehensive review underlines the need for collaborative efforts among policymakers, industry stakeholders, and researchers to maximize the potential of WCOs and contribute to sustainable development.
The improper management of food waste (FW) in developing nations causes environmental and hygienic problems and is a major threat to sustainable development. It is projected that the production of FW will increase by 33% globally over the next 10 years, resulting in an estimated 1.6 billion tons of waste per year and an economic loss of $1.2 trillion, with between 50 and 60% coming from post-consumer sources. Moving from a linear to a circular economy, where waste is a resource for new products like fuels and chemicals, is essential to achieving sustainable waste management. The results of 119 studies published between 2010 and 2024 are compiled in this study, which offers a thorough examination of FW recycling options. These possibilities include the three thermal treatment processes—combustion, pyrolysis, and gasification—that can yield biofuels and biochar. The possibility of converting FW into biofuels, biofertilizers, charcoal, and bioplastics through biological and biochemical processes is also investigated. This study is novel in that it emphasizes decentralized, regionally-specific approaches to managing packaging waste, especially single-use plastics, and connects FW valorization to the sustainable development goals (SDGs) of the United Nations (UN).
La gestión de residuos alimenticios es un reto global con implicaciones sociales, económicas y ambientales. La optimización de rutas de recolección es una estrategia clave para mejorar la eficiencia en su manejo. El presente estudio tiene como objetivo analizar la eficiencia en la recolección de residuos alimenticios en establecimientos de Riobamba, Ecuador, evaluando el impacto en la reducción de tiempos y distancias recorridas a través del método de optimización de rutas Vehicle Routing Problem (VRP), con miras a fomentar una gestión de residuos más sostenible y alineada con los principios de la economía circular. Se evaluó un total de 26 establecimientos analizando la ruta original (RO) y tres rutas optimizadas: más corta (RMC), más rápida (RMR) y más rápida con tráfico (RMRT), mediante un enfoque cuantitativo y pruebas estadísticas no paramétricas (Shapiro-Wilk, Levene, Kruskal-Wallis y post-hoc de Dunn) usando el software R. Los resultados mostraron diferencias significativas en las medianas de los tiempos (chi-cuadrado=11.1308, p=0.01104), y el análisis post-hoc de Dunn reveló que la RO difiere significativamente de las rutas optimizadas (RMC: p = 0.0034; RMR: p = 0.002210; RMRT: p = 0.046415). Los resultados demostraron que la implementación del método VRP optimizó notablemente las rutas, mejorando la eficiencia operativa y reduciendo la huella ambiental, destacando su potencial como herramienta para la gestión sostenible de residuos.
Food waste (FW) is a common source of contamination, contaminating both soils and water bodies by releasing greenhouse gases. FW holds great potential for biofuel and bioproduct production, which can mitigate its environmental impact and become a valuable addition to the circular bioeconomy. Therefore, this work aimed to investigate the use of food waste as a substrate to produce fermentable sugars and bioethanol. FW was pretreated by lipid removal. Raw and treated FW was hydrolyzed by amylases. Also, FW was hydrolyzed using sulfuric acid under different residence times (20, 40, and 60 min), sulfuric acid concentrations (0.5, 1.0, and 1.5% v·v−1), solid loads (5, 10, and 15% m·v−1), and temperatures (111, 120, and 127 °C). The best reducing sugar concentration was obtained at a 1.5% concentration of sulfuric acid and a 15% solid load applied for 1 h at 127 °C. The acid hydrolysis process was more efficient (76.26% efficiency) than the enzymatic one (72.7%). Bioethanol production was carried out as static submerged fermentation, with Saccharomyces cerevisiae at 10% (humidity m·v−1) being used as the producer and the acid and enzymatic hydrolysates being used as carbon sources. Lipid removal from FW did not influence the acid or enzymatic hydrolytic processes. For fermentation, the highest bioethanol yield was obtained from the acid hydrolysate of raw FW (0.49 kg·kg glicose−1). Thus, the processes used were efficient for bioethanol production, presenting alternatives for sustainable food waste destinations and low-cost biofuel production.
The depletion of fossil fuel supplies, global warming, unabated population increase, and expensive and troublesome waste recycling necessitate using renewable energy and consumer goods. It is possible to create biomass-based industrial methods as an alternative to the 100% oil economy. Globally, enormous volumes of lignocellulosic wastes are generated each year. These consist of food farming residues, tree pruning residues, “greengrocer’s wastes,” agricultural residues, and urban solid waste’s organic and paper components. The prevalent methods used to dispose of this trash negatively affect the environment and the economy. As an alternative, procedures for upgrading wastes into high-value goods with economic and ecological benefits should be created. This is known as the upgrading concept, which adds value to waste by producing a product with desirable, repeatable features. Upgrading solid wastes can yield a wide range of high-value products, including organic acids, biofuels, enzymes, biopolymers, bioelectricity, and compounds for the food and pharmaceutical industries. This manuscript outlines the latest developments in biotechnological procedures for their manufacturing.
This study critically analyzes the literature on food waste in restaurants. Through a systematic literature review approach based on the evaluation and synthesis of articles, existing gaps in the literature and key research directions for the future research agenda were identified. Thematic analysis was applied to organize the selected articles around five themes representing various aspects of food waste. The themes ranged from food waste in restaurants' operational processes to best practices. Accordingly, it was found that the increase in empirical research has brought both new findings and new problems concerning food waste at the end-consumer level in restaurants. Consumer research on plate waste at the end-consumer level and the type of food on the plate, as well as on doggy bags and their use as one of the good practices, require a special emphasis on responsible production and consumption and good practices in line with sustainable development goals.
Enzymes are some of the most powerful and versatile biotools used as additives in the food industry. They can be used to improve a variety of different food processes and are increasingly being applied to food products to improve the quality and extend food shelf life. This chapter highlights the novel features of enzymes application in foods and food processes and how they are revolutionizing the food industry. It explores the advantages and disadvantages of enzyme-aided food processing and some of the potential applications of enzymes in food development. Additionally, it discusses the role of biotechnology in food processing and production and the potential for using food waste as resources for the development of new food additives, emphasizing their categorization, characteristics, and benefits, as well as their safety, regulation, and risks. Finally, it discusses some of the challenges and opportunities for the future of enzymes in the food industry.
Background: Flowers are not only for their ornamental, aesthetic purpose but it is a great nutritious to human diet and health. These are rich source of pigments and possess antibacterial and antioxidant properties. Few flowers are used traditionally in diet and there is huge scope to use edible flowers in nutraceutical, pharmaceutical and pigment industry. But very less research has been done till date for finding proximate constituent, antioxidant activity and mineral profiling of edible annual flowers. The present work investigated the proximate constituent analysis and antioxidant activity of few annual flowers. Methods: In this laboratory analysis, different annual flowers were used for the experiment. They were Celosia cristata var. Calendula officinalis. Proximate constituent analysis and antioxidant activity were performed using Association of Official Analytical Chemist (A.O.A.C) methods. Result: Among the different annual flowers, the maximum ash content (15.58%) the crude protein content (13.45%) and the crude fibre content (13.39%) were found in Gomphrena globosa flowers, whereas the minimum ash content (7.24%), the minimum crude protein (6.51%) and the minimum crude fibre content (6.63%) were reported in Calendula officinalis flowers. On the other hand, the antioxidant activity was found to be superior in the flowers of Tagetes patula (60.34%) followed by Tagetes erecta (57.99%) and the minimum antioxidant activity (43.89%) was found in flowers of Celosia cristata var. Twisted Orange.
Globally, food waste (FW) is found to be one of the major constituents which creating several hurdles in waste management. On the other hand, energy crisis increasing and the limited fossil fuel resources available are not sufficient for energy needed for emerging population. In this context, biohydrogen production approach through valorization of FW is emerging as one of the sustainable and eco-friendly options. Present review explores FW sources, characteristics, and dark fermentative production of hydrogen along with its efficiency. FW are highly biodegradable and rich in carbohydrates which can be efficiently utilized by anaerobic bacteria. Based on the composition of FW, several pretreatment methods can be adapted to improve the bioavailability of the organics. By-products of dark fermentation are organic acids which can be integrated in several secondary bioprocesses. The versatility of secondary products is ranging from energy generation to biochemicals production. Integrated approaches facilitate in enhanced energy harvesting along with extended wastewater treatment. The review also discusses various parameters like pH, temperature, hydraulic retention time and nutrient supplementation to enhance the process efficiency of biohydrogen production. The application of solid-state fermentation (SSF) in dark fermentation improves the process efficiency. Dark fermentation as the key process for valorization and additional energy generating process can make FW as the most suitable substrate for circular economy and waste based biorefinery.
The use of food waste (FW) for the production of biofuels and value-added compounds is growing worldwide. However, the significant chemical variability of this raw material is a major challenge for its use in biorefineries. This work aimed to investigate the chemical variability of FW in different regions of the world and evaluate how this variability may affect the production of biofuels and value-added chemical compounds. The variability of FW chemical composition in 163 samples, reported in 104 articles, was analyzed using descriptive statistics. The samples were divided into five regions (Industrialized Asia; USA, Canada, and Oceania; Europe; Latin America; and South and Southeast Asia) and four types of FW sources (canteen; household; municipal solid waste; and supermarket). There still needs to be more robust scientific data from some regions and different generating sources of FW. From the available data, we observe high variabilities (CV > 30%) in total carbohydrates, proteins, and mainly starch and lipids in most regions and sources, especially supermarkets (CVs > 100%). This variability may reduce the production of biofuels and chemical compounds during biorefinery processes based on FW. Estimated reductions considering maximum and minimum total carbohydrate contents were 83% for bioethanol and 87% for acetone, butanol, and ethanol (ABE). Lipid variation would reduce biodiesel production by almost 100%. The use of the protein fraction for insect growth or fish and animal feeding should be encouraged. The integration of biofuels and chemicals is an alternative to mitigate economic losses. This review indicates that the high variability of chemical composition is a significant challenge for energy and chemical recovery of food waste in biorefineries.Graphical abstract
Food residues (FR) have caused economic, environmental, and social issues. Few studies have integrated the biorefinery and value chain concepts for increasing FR valorization opportunities in a real context. This paper proposes a FR biorefineries design strategy involving limiting factors of the Food Value Chain (FVC). The strategy integrates key points such as links and actors, generation cycles, FR composition, and residues integration. Two case studies were analyzed by applying the proposed design strategy. The first case study valorizes rejected avocado and plantain generated in the producers link. The second case valorizes organic kitchen food waste (OKFW) into added-value products. The proposed design strategy introduces value chain analysis as a tool for designing feasible and reliable biorefineries. A possible integration mass ratio of 22:13:65 was identified considering rejected avocado, rejected plantain, and plantain pseudostem, respectively. The most promising alternative to upgrading the FR generated in the producers link is related to avocado oil and biogas production. The best results obtained for upgrading OKFW is to produce levulinic acid since low capital and operational expenditures are required compared with other bulk products. When involving context variables and a complete value chain analysis the opportunities to enhance sustainability and close open loops are increased.
Valorization of food waste (FW) is instrumental for reducing the environmental and economic burden of FW and transitioning to a circular economy. The FW valorization process has widely been studied to produce various end-use products and summarize them; however, their economic, environmental, and social aspects are limited. This study synthesizes some of the valorization methods used for FW management and produces value-added products for various applications, and also discusses the technological advances and their environmental, economic, and social aspects. Globally, 1.3 billion tonnes of edible food is lost or wasted each year, during which about 3.3 billion tonnes of greenhouse gas is emitted. The environmental (-347 to 2969 kg CO2 equiv/tonne FW) and economic (-100 to $138/tonne FW) impacts of FW depend on the multiple parameters of food chains and waste management systems. Although enormous efforts are underway to reduce FW as well as valorize unavoidable FW to reduce environmental and economic loss, it seems the transdisciplinary approach/initiative would be essential to minimize FW as well as abate the environmental impacts of FW. A joint effort from stakeholders is the key to reducing FW and the efficient and effective valorization of FW to improve its sustainability. However, any initiative in reducing food waste should consider a broader sustainability check to avoid risks to investment and the environment.
The inherent metal ions in food wastes have significant influences on the production of NOx precursors to affect the release of NOx during the incineration process. However, the detailed catalytic mechanism of metal ions remains unclear. Herein, 2,5-diketopiperazine (DKP) was employed as the N-containing model to study the effects of Na⁺ and K⁺ on the production of NOx precursors in the pyrolysis process. Based on density functional theory calculations and wave function analyses, all the energy barriers of the initial reactions decrease with the catalysis of Na⁺, whereas K⁺ can only promote part of the reactions and with weaker effects than Na⁺. Because of the varied influence on distinct reactions, Na⁺/K⁺ can change the rate-determining steps of the production pathways of NOx precursors. As for the same pathway, Na⁺ usually results in a relatively lower energy barrier than K⁺. Elevated temperatures lead to higher rate constants of K⁺ than Na⁺ for the favorable production pathways of NOx precursors. With the catalysis of Na⁺ and K⁺, the formation of NH3 is always more competitive than HCN and HNCO based on the comparison of overall energy barriers and the rate constants. Particularly, the competitiveness for NH3 production is enhanced by the catalysis of Na⁺ and K⁺ according to the increased rate constant advantage over other pathways.
The adverse impact that restaurants have on the environment has received widespread attention in the last decade from both practice and academia. The current study aims to find, catalog, and synthesize the research body addressing green issues in the restaurant industry. We utilize the systematic literature review method to identify and analyze 68 research articles addressing environmental unsustainability problems in the restaurant industry. The research profile identifies the time trends of publication, key journals, countries studied, methods used, and restaurant types discussed in these studies. The results indicate that green restaurant research has grown exponentially recently and is now past its infancy. Through a detailed qualitative content analysis, we uncover five key thematic foci: stakeholders and their roles, sources of environmental unsustainability, green initiatives adopted by restaurants to address environmental unsustainability, outcomes of adopting green practices, and various ways of measuring greening practices. Research limitations and gaps of each of the themes are presented, with potential future research questions proposed for each gap. We then summarize the results of our review in a green restaurant ecosystem research framework.
Determining thermochemical properties and eliminating inorganic components of municipal solid waste (MSW) are crucial to its thermochemical treatment. Traditional characterization and classification technologies have shortcomings including long duration, complex operation, and inevitable sample consumption. This study proposed a hyperspectral imaging and machine learning models based method to solve these problems. Under the optimal parameter conditions, the identification accuracy of inorganic components by F1 scoring reached nearly 100% in MSW, and the prediction accuracy of carbon, hydrogen, oxygen, nitrogen contents and low heating value (LHV)of organic components by mean relative error value reached 92.6%, 86.9%, 80.4%, 54.7% and 90.5%, respectively. The results validated the hypothesis that combination of hyperspectral imaging and machine learning models are promising to accomplish fast characterization and classification of components in MSW, where principal component analysis was capable to abstract crucial information from the spectral pattern, and artificial neural network presented satisfactory classification and regression performance.
Every day, a large amount of food waste (FW) is released into the environment, causing financial loss and unpredictable consequences in the world, highlighting the urgency of finding a suitable approach to treating FW. As moisture content makes up 75% of the FW, hydrothermal carbonization (HTC) is a beneficial process for the treatment of FW since it does not require extensive drying. Moreover, the process is considered favorable for carbon sequestration to mitigate climate change in comparison with other processes because the majority of the carbon in FW is integrated into hydrochar. In this work, the reaction mechanism and factors affecting the HTC of FW are scrutinized. Moreover, the physicochemical properties of products after the HTC of FW are critically presented. In general, HTC of FW is considered a promising approach aiming to attain simultaneously two core benefits on economy and energy in the sustainable development strategy.
Food waste (FW) generated through various scenarios from farm to fork causes serious environmental problems when either incinerated or disposed inappropriately. The presence of significant amounts of carbohydrates, proteins, and lipids enable FW to serve as sustainable and renewable feedstock for the biorefineries. Implementation of multiple substrates and product biorefinery as a platform could pursue an immense potential of reducing costs for bio-based process and improving its commercial viability. The review focuses on conversion of surplus FW into range of value-added products including biosurfactants, biopolymers, diols, and bioenergy. The review includes in-depth description of various types of FW, their chemical and nutrient compositions, current valorization techniques and regulations. Further, it describes limitations of FW as feedstock for biorefineries. In the end, review discuss future scope to provide a clear path for sustainable and net-zero carbon biorefineries.
The food-energy-water (FEW) nexus presents an opportunity to rethink predominant approaches to household behavior change science. We linked emerging FEW nexus research with existing literature examining household consumption and pro-environmental behaviors. While a large body of work examines the environmental impacts of household life and explores pathways to behavior change for sustainability, the literature lacks studies that test interventions in multiple FEW resource categories, leaving researchers unable to identify tensions and tradeoffs in the household system. To guide this developing field and accumulate findings on household behavior across disciplines, we proposed a conceptual typology that synthesizes interdisciplinary analytic traditions to classify behavioral interventions targeting the household FEW nexus. The typology synthesizes behavioral interventions as active, passive, or structural, and household-specific or non-specific, illustrating six distinct categories: information, tailored information, action, gamification, policy/price change, and material/technology provision. A review of 40 studies that guided the typology identifies four significant lessons for future intervention research: household non-specific information and tailored information work better together, feedback is more effective when it is persistent, price-based interventions (information or incentives) are often ineffective, and material/technology provision is very effective but utilized in few household studies. To push forward household resource consumption science, we advocated for a holistic nexus focus that is rooted in interdisciplinarity, coalition building with stakeholders, and data reporting that facilitates knowledge accumulation.
Contributing to environmental pollution and resources depletion, food waste represents a considerable inefficiency of the global food system. Within the United Nations Sustainable Development Goal 12.3, countries committed to halve per-capita food waste generated at retail and consumer levels and to decrease food waste along the food supply chain by 2030. Reliable and detailed information on food waste is of utmost importance for the actors of the food supply chain, organizations and governments willing to implement and monitor effective reduction strategies. The present paper is a review of existing studies on food waste generation at the global and European scales and aims primarily at describing and comparing the approaches adopted, and secondarily at analysing their potential in supporting food waste related European interventions and policies. Ten studies were selected among relevant scientific papers and grey literature and their underlying quantification methodologies were systematically analysed. Methodological elements discussed in the paper include type of waste streams captured by estimations, distinction between edible and inedible food waste along the agro-food supply chain, reported units of measure, overall inefficiencies of the food system, and uncertainty of data. Current estimations of food loss and waste generation range between 194-389 kg per person per year at the global scale, and between 158-298 kg per person per year at the European scale. However, further efforts are needed to improve their level of detail and reliability and to foster their support to food loss and waste-related strategies.
A critical factor in implementing microalgal biofuels for mass production is the nutrient requirements. The current study investigated the fate of macro- and micronutrients and their availability in a sequential phototrophic-heterotrophic production process for the lipid rich microalga Auxenochlorella protothecoides. More than 99 % (by weight) of overall process nutrients were supplied during the initial photoautotrophic stage reflecting its significantly larger volume. Under photoautotrophic growth conditions only 9-35 % of supplied Mn, S, Fe, N, Mg, and Cu and less than 5 % of P, Mo, Co, B, Zn, and Ca were consumed by the algae. The rest of these nutrients remain in the spent growth media during the culture concentration-down from an 800 L phototrophic pond to a 5 L heterotrophic fermenter. In contrast, Zn, Mo, Mn, Mg, Ca, and N were exhausted (90-99 % removal) during the first 25 h of the heterotrophic growth stage. The depletion of these key nutrients may have ultimately limited the final biomass density and/or lipid productivity achieved. Approximately 10-20 % of the total supplied S, Mn, Fe, N, and Cu and 5 % of Ca and Zn were assimilated into algal biomass. Several elements including N, P, Mn, B, Cu, Ca, Mg, S, and Fe were released back into the liquid phase by anaerobic digestion (AD) of the residual biomass after lipid extraction. The nutrients recovered from the AD effluent and remaining in the spent medium should be recycled or their initial concentration to the phototrophic stage decreased to enhance process economics and sustainability for future commercialization of algal-derived biofuels.
Instant noodle manufacturing waste was used as feedstock to convert it into two products, bioethanol and biodiesel. The raw material was pretreated to separate it into two potential feedstocks, starch residues and palm oil, for conversion to bioethanol and biodiesel, respectively. For the production of bioethanol, starch residues were converted into glucose by α-amylase and glucoamylase. To investigate the saccharification process of the pretreated starch residues, the optimal pretreatment conditions were determined. The bioethanol conversion reached 98.5 % of the theoretical maximum by Saccharomyces cerevisiae K35 fermentation after saccharification under optimized pretreatment conditions. Moreover, palm oil, isolated from the instant noodle waste, was converted into valuable biodiesel by use of immobilized lipase (Novozym 435). The effects of four categories of alcohol, oil-to-methanol ratio, reaction time, lipase concentration and water content on the conversion process were investigated. The maximum biodiesel conversion was 95.4 %.
Statistical errors are common in scientific literature and about 50% of the published articles have at least one error. The assumption of normality needs to be checked for many statistical procedures, namely parametric tests, because their validity depends on it. The aim of this commentary is to overview checking for normality in statistical analysis using SPSS.
"We need to use our water prudently – no one will argue with this statement. But in fact we are wasteful. This need will become more pronounced, and the cost of bad water management will get higher in the future with increasing water demands from increasing population, cities, agriculture, and the environment. Moreover water management will become more difficult with climate change. New solutions and fast actions are required now. Agriculture is the largest human use of water. Clearly, agricultural practices need to be targeted to reduce wastage of water. This has been the center of attention for water saving practices for years. But there are additional ways to save water. Food consumers and businesses have a key role. Losses of food between the farmers’ field to our dinner table – in food storage, transport, food processing, retail and in our kitchens – are huge. This loss of food is equivalent to a loss in water. Reducing food loss and wastage lessens water needs in agriculture. We need to pay more attention to this fact. Our Key Message: Make the Food Chain More Efficient to Save Water to Facilitate the Achievement of Multiple Development Objectives"
The effects of different concentration of MgSO4.7H2O, FeCl3.6H2O, ZnSO4.7H2O, CuSO4.5H2O and MnSO4.5H2O on lipid and GLA production by Cunninghamella sp. 2A1 were studied in submerged culture fermentation. Cultivation was performed in 250 ml conical flask (100mlworking volume), at 30°C and 250 rpm agitation for 120h. Mg2+, Fe2+ and Zn2+ have significant effect on lipid accumulation as inclusion of each ions resulted in a 64, 43 and 33% increase in lipid contentcompared to cultures which was cultivated with the omission of each ions, respectively. All three metal ions also affected GLA production by Cunninghamella sp. 2A1 with Zn2+ having the most profound effect with an increase of up to 74% of GLA yield (g GLA/g lipidless biomass) achieved. As omission of any single metal ions did not affect biomass concentration achieved, we concluded that metal ions components in production media may have affected lipid and GLA production by affecting pathways involved in the biosynthesis of lipid and GLA. This study reports the critical concentrationof each metal ion for optimal lipid and GLA production by Cunninghamella sp. 2A1.
For nutritional purposes, starch in foods may be classified into rapidly digestible starch (RDS), slowly digestible starch (SDS) and resistant starch (RS). RS may be further divided into three categories according to the reason for resistance to digestion. A method is reported for the measurement of total starch, RDS, SDS, RS and three RS fractions in starchy foods, using controlled enzymic hydrolysis with pancreatin and amyloglucosidase. The released glucose is measured by colorimetry, using a glucose oxidase kit. Values for RDS and SDS in foods obtained by the method reflect the rate of starch digestion in vivo. Values for RS are similar to the amounts of starch escaping digestion in the small intestine of ileostomates, and are a guide to the amounts of starch likely to enter the colon for fermentation. Results are given for a number of starchy foods.
Food wastes are mixtures constituted from different phases, whereas their components can be divided into macro- and micromolecular groups. In a third level of division, components can be further classified according to their structural characteristics and physicochemical properties. This simple consideration, moving from macroscopic to micromolecular level, allows the separation of target and nontarget compounds gradually in different streams. Based on these principles, a holistic methodology (the so-called 5-Stage Universal Recovery Process) was herein designed to ensure an optimized management of the available technologies and recapture several kinds of valuable compounds from any waste source. This methodology was further developed to a more general approach (the so-called Universal Recovery Strategy), which includes all the relevant information in each case (e.g., waste distribution, availability, and production data, and microstructure) for the designing of a particular application.
The capacity of cetyl trimethylammonium bromide to dissolve proteins in acid solution has been utilized in development of a method, called acid-detergent fiber method (ADF), which is not only a fiber determination in itself but also the major preparatory step in the determination of lignin. The entire procedure for determining fiber and lignin is considerably more rapid than presently published methods. Compositional studies show ADF to consist chiefly of lignin and polysaccharides. Correlations with the new fiber method and digestibility of 18 forages (r = —0.79) showed it to be somewhat superior to crude fiber (r = —0.73) in estimating nutritive value. The correlation of the new lignin method and digestibility was -0.90 when grass and legume species were separated.
Contents lists available atScienceDirectFueljournal homepage:www.elsevier.com/locate/fuelFull Length ArticleOptimization of solid food waste oil biodiesel by ultrasound-assistedtransesterificationM. Carmona-Cabello, J. Sáez-Bastante, S. Pinzi, M.P. Dorado⁎Department of Physical Chemistry and Applied Thermodynamics, EPS, Edificio Leonardo da Vinci, Campus de Rabanales, Universidad de Córdoba, Campus de ExcelenciaInternacional Agroalimentario ceiA3, 14071 Córdoba, SpainARTICLE INFOKeywords:BiofuelFood wasteFAMEBiorefineryAuxiliary energyABSTRACTSubstitution of fossil diesel fuel by biodiesel is a realistic alternative due to its compatibility with commercialdiesel engines. However, detractors consider that traditional raw materials used for biodiesel production maycompete with human feeding (edible vegetables oils), land and water. So, new raw materials are needed.Annually, around 1.3 billion ton of food are discarded or wasted. This hugefigure has led researchers to seek fornew applications to this carbon source. The main goal of this work is biodiesel production optimization (withand without auxiliary energy assistance), and further characterization, by using the lipid fraction included insolid food waste, collected from local restaurants. Solid food waste oil (SFWO) characterization showed a fattyacid profile rich in oleic (C18:1), palmitic (C16:0) and linolenic (C18:2) acids, a remarkable fatty acid com-position suitable for biodiesel production. Due to high free fatty acid content, acid esterification pre-treatmentwas conducted, followed by a basic transesterification optimization, by both conventional and ultrasound (US)assisted reactions. Response surface methodology was selected to perform the experimental design; optimalconditions for conventional transesterification were achieved at 6.08:1 methanol-to-oil molar ratio, 1.28% w/wcatalyst and 52.5 °C reaction temperature, providing 93.23% w/w fatty acid methyl esters (FAME) conversion.Biodiesel quality was also analyzed with excellent results considering cold properties (coldfilter plugging pointbelow−3 °C), although oxidation stability did not fulfill European standard limit. US-assisted reaction was alsocompared with conventional transesterification in terms of energy consumption and reaction time, providingsignificant savings in both energy and reaction time (40 min reduction). As a conclusion, US-assisted SFWObiodiesel meets most European standard limits, following circular economy. To extend its use, blends with dieselfuel and antioxidant addition are recommended, besides long-term engine tests.
The aim of this study was to utilize the whole food waste in two stages. In the first stage, the carbohydrate and protein fractions of food waste recovered after enzymatic hydrolysis was used to cultivate heterotrophic microalgae, resulting in biomass yield of 0.346 ± 0.09 g/gsugars and lipid yield of 0.216 ± 0.06 g/gsugars. In the second stage, oil (14.15% w/w) was extracted from food waste after hydrolysis and converted to biodiesel by a two-step transesterification reaction that generated 135.8 g/kgfood waste of fatty acid methyl esters and 13.8 g/kgfood waste of crude glycerol. Finally, crude glycerol obtained from both processes was used at 20 g/L to cultivate heterotrophic microalgae, resulting in a cell dry weight and total lipid concentration of 6.23 g/L and 2.91 g/L, respectively. A total 248.21 g of fatty acid methyl esters were obtained from the 1 kg of food waste through this integrated process.
Purpose
The purpose of this paper is to examine the knowledge, awareness and concern of young consumers towards avoidable and “edible” food waste, and identify groups of individuals based on their attitudes. In addition, this study describes demographic and behavioural characteristics of each group.
Design/methodology/approach
The data were collected by a questionnaire conducted among university students in Croatia. Factor and cluster analyses were applied to identify the groups of individuals with similar attitudes towards food waste.
Findings
Results show that there are five factors that represent the knowledge, awareness and concern about food waste of young people – awareness of food waste problem; concern about economic aspects of food waste; health concern; concern about environmental impact of food waste; and awareness and concern about expiration date. Based on those factors, four groups of consumers were identified: consumers concerned about economic effects of food waste; unaware consumers neglecting food waste; well-informed consumers; and fully aware consumers, but not ready to take health risk.
Practical implications
The results of the study can be used by marketers and policy makers when planning food waste reduction activities to focus their campaigns towards consumer niches, based on the typology of young consumers.
Originality/value
This study provides a typology of university students based on their knowledge, awareness and concern about food waste in Croatia, as an example of a transition and new EU member state, where the issues about food waste are relatively new and underexplored topic.
This work proposes a new treatment approach involving both food waste disposal and sewerage treatment called MOWFAST i.e. Municipal Organic Waste management by combined Food waste disposal and Sewerage Treatment. MOWFAST involves mixing of food waste directly with raw sewage instead of separate addition to sludge and their combined anaerobic digestion (AD). Compared to conventional sludge digestion, MOWFAST exhibited better digestion capability and allowed a greater degradation of organic material along with higher production of methanogenic-favourable products from the beginning of digestion. This resulted in producing higher specific methane yields (7.86 LCH4/kg VSadded versus 0.95 LCH4/kg VSadded) and 1.4-fold higher cumulative methane yield over sludge AD. Furthermore, compared with conventional food waste-sludge co-digestion, MOWFAST gave higher solubilization of organic material (0.82 g sCOD/g VSadded versus 0.23 g sCOD/g VSadded) and specific methane yields (7.86 LCH4/kg VSadded versus 3.2 LCH4/kg VSadded). This proves its feasibility for digestion and methane generation potential.
The Anaerobic Digestion and Composting Plant of the Vallès Oriental Waste Treatment Centre processes source-selected organic fraction of municipal solid wastes generated in its surrounding area. To promote Circular Economy between Municipal Solid Waste and industrial waste management systems, the Treatment Centre is looking for complementary wastes to be valorised through co-digestion with its main substrate. The study includes waste characterization and a complete treatment cost analysis, that jointly with the biogas potential and the mass balance of the Plant allows to calculate the price of each waste to be treated in the Plant. Up to 13 industrial wastes have been characterised for its biogas potential and its treatment cost calculated. Treatment prices ranged between 83 and 51 € t ⁻¹ .
Waste management is one of the most significant challenges of EU policies for the coming decades. Our changing food habits carries an inherent increase in waste nutrients, that worth recycling. The traditional method of waste management is not adapted to meet future energy and environmental requirements. Food waste (FW)-based biorefinery allows new approaches in waste recovery, while improving industrial processes. However, interactions between FW nutrients, their derivates and subsequent treatment methodologies may lead to negative effects and bioprocess low yield. This work aims to state the importance of new strategies in biorefineries, based on FW nutrients and their interactions.
Approximately one third of global food production is wasted along the food supply chain causing economic, environmental and social impacts. At EU level, restaurants occupy the second highest position in the classification of bodies responsible for food waste generation and a significant share of restaurant costs “goes” to waste. However, few studies have been carried out on the factors and managerial implications associated to this type of waste.
By introducing the GME estimator, this paper focuses on data collected in 127 restaurants located in the regions of Lazio and Tuscany (Italy) with two specific aims. Firstly, to propose a theoretical framework for exploring factors that make restaurants waste food. Secondly, to comprehend whether food waste in restaurants is related to cooking and to clients.
The results show that the attitude of restaurant managers as well as types of menus served and restaurant size play significant roles.
Enormous quantity of food waste (FW) is becoming a global concern. To address this persistent problem, sustainable intervention with green technologies is essential. FW can be used as potential feedstock in biological processes for the generation of various biobased products along with its remediation. Enabling bioprocesses like acidogenesis, fermentation, methanogenesis, solventogenesis, photosynthesis, oleaginous process, bio-electrogenesis, etc., that yields various products like biofuels, platform chemicals, bioelectricity, biomaterial, biofertilizers, animal feed, etc can be utilized for FW valorisation. In order to economise these bioprocesses, a biorefinery strategy needs to be adapted for the utilization of residual organic waste towards diverse product recovery. The present review highlights various enabling bioprocesses that can be employed for the generation of energy and various commodity chemicals in an integrated approach addressing sustainability. The waste biorefinery approach for FW needs optimization of the cascade of the individual bioprocesses for the transformation of linear economy to circular economy.
Bio-stability is a key feature for the utilization and final disposal of biowaste-derived residues, such as aerobic compost or vermicompost of food waste, bio-dried waste, anaerobic digestate or landfilled waste. The present paper reviews conventional methods and advanced techniques used for the assessment of bio-stability. The conventional methods are reclassified into two categories. Advanced techniques, including spectroscopic (fluorescent, ultraviolet-visible, infrared, Raman, nuclear magnetic resonance), thermogravimetric and thermochemolysis analysis, are emphasized for their application in bio-stability assessment in recent years. Their principles, pros and cons are critically discussed. These advanced techniques are found to be convenient in sample preparation and to supply diversified information. However, the viability of these techniques as potential indicators for bio-stability assessment ultimately lies in the establishment of the relationship of advanced ones with the conventional methods, especially with the methods based on biotic response. Furthermore, some misuses in data explanation should be noted.
Biological treatments of Residual Municipal Solid Waste (RMSW) allow to divert biodegradable materials from landfilling and recover valuable alternative resources. The biodegradability of the waste components needs however to be assessed in order to design the bioprocesses properly. The present study investigated complementary approaches to aerobic and anaerobic biotests for a more rapid evaluation. A representative sample of residual MSW was collected from a Mechanical Biological Treatment (MBT) plant and sorted out into 13 fractions according to the French standard procedure MODECOM™. The different fractions were analyzed for organic matter content, leaching behavior, contents in biochemical constituents (determined by Van Soest's acid detergent fiber method), Biochemical Oxygen Demand (BOD) and Bio-Methane Potential (BMP). Experimental data were statistically treated by Principal Components Analysis (PCA). Cumulative oxygen consumption from BOD tests and cumulative methane production from BMP tests were found to be positively correlated in all waste fractions. No correlation was observed between the results from BOD or BMP bioassays and the contents in cellulose-like, hemicelluloses-like or labile organic compounds. No correlation was observed either with the results from leaching tests (Soluble COD). The contents in lignin-like compounds, evaluated as the non-extracted RES fraction in Van Soest's method, was found however to impact negatively the biodegradability assessed by BOD or BMP tests. Since cellulose, hemicelluloses and lignin are the polymers responsible for the structuration of lignocellulosic complexes, it was concluded that the structural organization of the organic matter in the different waste fractions was more determinant on biodegradability than the respective contents in individual biopolymers.
The heating values, particularly lower heating values of burning municipal solid waste are critically important parameters in operating circulating fluidized bed incineration systems. However, the heating values change widely and frequently, while there is no reliable real-time instrument to measure heating values in the process of incinerating municipal solid waste. A rapid, cost-effective, and comparative methodology was proposed to evaluate the heating values of burning MSW online based on prior knowledge, expert experience, and data-mining techniques. First, selecting the input variables of the model by analyzing the operational mechanism of circulating fluidized bed incinerators, and the corresponding heating value was classified into one of nine fuzzy expressions according to expert advice. Development of prediction models by employing four different nonlinear models was undertaken, including a multilayer perceptron neural network, a support vector machine, an adaptive neuro-fuzzy inference system, and a random forest; a series of optimization schemes were implemented simultaneously in order to improve the performance of each model. Finally, a comprehensive comparison study was carried out to evaluate the performance of the models. Results indicate that the adaptive neuro-fuzzy inference system model outperforms the other three models, with the random forest model performing second-best, and the multilayer perceptron model performing at the worst level. A model with sufficient accuracy would contribute adequately to the control of circulating fluidized bed incinerator operation and provide reliable heating value signals for an automatic combustion control system.
The pursuit of sustainable hydrocarbon alternatives to fossil fuels has prompted an acceleration in the development of new technologies for biomass processing. Microwave pyrolysis of biomass has long been recognised to provide better quality bio-products in shorter timescales compared to conventional pyrolysis. Although this topic has been widely assessed and many investigations are currently ongoing, this article gives an overview beyond the physico-chemical pyrolysis process and covers engineering aspects and the limitations of microwave heating technology. Herein, we provide innovative scalable concepts to perform the microwave pyrolysis of biomass on a large scale, including essential energy and material handling requirements. Furthermore, some of the possible socio-economic and environmental implications derived from the use of this technology in our society are discussed. Such potential concepts are expected to assist the needs of the industrial bioenergy community to move this largely studied process upwards in scale.
A food additive is a substance (or a mixture of substances) which is added to food and is involved in its production, processing, packaging and/or storage without being a major ingredient. Additives or their degradation products generally remain in food, but in some cases they may be removed during processing. The following examples illustrate and support the use of additives to enhance the:
Nutritive Value of Food Additives such as vitamins, minerals, amino acids and amino acid derivatives are utilized to increase the nutritive value of food. A particular diet may also require the use of thickening agents, emulsifiers, sweeteners, etc.
Sensory Value of Food Color, odor, taste and consistency or texture, which are important for the sensory value of food, may decrease during processing and storage. Such decreases can be corrected or readjusted by additives such as pigments, aroma compounds or flavor enhancers. Development of “off-flavor”, for instance, derived from fat or oil oxidation, can be suppressed by antioxidants. Food texture can be stabilized by adding minerals or polysaccharides, and by many other means.
Shelf Life of Food The current forms of food production and distribution, as well as the trend towards convenient foods, have increased the demand for longer shelf life. Furthermore, the world food supply situation requires preservation by avoiding deterioration as much as possible. The extension of shelf life involves protection against microbial spoilage, for example, by using antimicrobial additives and by using active agents which suppress and retard undesired chemical and physical changes in food. The latter is achieved by stabilization of pH using buffering additives or stabilization of texture with thickening or gelling agents, which are polysaccharides.
Food waste recycling via fungal hydrolysis and lactic acid (LA) fermentation has been investigated. Hydrolysates derived from mixed food waste and bakery waste were rich in glucose (80.0–100.2 g L−1), fructose (7.6 g L−1) and free amino nitrogen (947–1081 mg L−1). In the fermentation with Lactobacillus casei Shirota, 94.0 g L−1 and 82.6 g L−1 of LA were produced with productivity of 2.61 g L−1 h−1 and 2.50 g L−1 h−1 for mixed food waste and bakery waste hydrolysate, respectively. The yield was 0.94 g g−1 for both hydrolysates. Similar results were obtained using food waste powder hydrolysate, in which 90.1 g L−1 of LA was produced with a yield and productivity of 0.92 g g−1 and 2.50 g L−1 h−1. The results demonstrate the feasibility of an efficient bioconversion of food waste to LA and a decentralized approach of food waste recycling in urban area.
In order to determine the variability of food waste (FW) characteristics and the influence of these variable values on the anaerobic digestion (AD) process, FW characteristics from 70 papers were compiled and analysed statistically. Results indicated that FW characteristics values are effectively very variable and that 24% of these variations may be explained by the geographical origin, the type of collection source and the season of the collection. Considering the whole range of values for physicochemical characteristics (especially volatile solids (VS), chemical oxygen demand (COD) and biomethane potential (BMP)), FW show good potential for AD treatment. However, the high carbohydrates contents (36.4%VS) and the low pH (5.1) might cause inhibitions by the rapid acidification of the digesters. As regards the variation of FW characteristics, FW categories were proposed. Moreover, the adequacy of FW characteristics with AD treatment was discussed. Four FW categories were identified with critical characteristics values for AD performance: (1) the high dry matter (DM) and total ammonia nitrogen (TAN) content of FW collected with green waste, (2) the high cellulose (CEL) content of FW from the organic fraction of municipal solid waste, (3) the low carbon-to-nitrogen (C/N) ratio of FW collected during summer, (4) the high value of TAN and Na of FW from Asia. For these cases, an aerobic pre-treatment or a corrective treatment seems to be advised to avoid instabilities along the digestion. Finally, the results of this review-paper provide a data basis of values for FW characteristics that could be used for AD process design and environmental assessment.
The capacity of cetyl trimethylammonium bromide to dissolve proteins in acid solution has been utilized in development of a method, called acid-detergent fiber method (ADF), which is not only a fiber determination in itself but also the major preparatory step in the determination of lignin. The entire procedure for determining fiber and lignin is considerably more rapid than presently published methods. Compositional studies show ADF to consist chiefly of lignin and polysaccharides. Correlations with the new fiber method and digestibility of 18 forages (r = —0.79) showed it to be somewhat superior to crude fiber (r = —0.73) in estimating nutritive value. The correlation of the new lignin method and digestibility was —0.90 when grass and legume species were separated.
Food wastes are mixtures constituted from different phases, whereas their components can be divided into macro- and micromolecular groups. In a third level of division, components can be further classified according to their structural characteristics and physicochemical properties. This simple consideration, moving from macroscopic to micromolecular level, allows the separation of target and nontarget compounds gradually in different streams. Based on these principles, a holistic methodology (the so-called "5-Stage Universal Recovery Process") was herein designed to ensure an optimized management of the available technologies and recapture several kinds of valuable compounds from any waste source. This methodology was further developed to a more general approach (the so-called "Universal Recovery Strategy"), which includes all the relevant information in each case (e.g. waste distribution, availability, and production data, microstructure, etc.) for the designing of a particular application.
The designations employed and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United nations concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitations of its frontiers or boundaries. The opinions expressed in this publication are those of the author(s) alone and do not imply any opinion on the part of the FAO.
Food wastes with typical US food composition were analyzed to characterize different constituents in both particulate and soluble phases i.e., solids, chemical oxygen demand (COD), 5-day biochemical oxygen demand (BOD), nitrogen (N), phosphorus (P). Relationships between various pollutants were also investigated using 50 samples. One gram of dry food waste generated 1.21g COD, 0.58g BOD5, 0.36g Total SS, 0.025g Total N, and 0.013g Total P. Distribution of constituents between particulate and aqueous phases indicated that 40% of COD and 30% of nitrogen were present in soluble form. Relative mass ratios of COD and nitrogen to solids were three to five times higher in particulates than in aqueous phase. However, COD/N ratios were higher in aqueous form than particulates at 63:1 versus 42:1. Detailed relationships between parameters showed that COD, nitrogen, and phosphorus in particulates are 200%, 3.6%, and 3.5% of the volatile suspended solids.
Copyright © 2015 Elsevier Ltd. All rights reserved.
To understand the applicability of the termination indicators for landfill municipal solid waste (MSW) with low initial lignin content, four different accelerated landfill stabilization techniques were applied to anaerobic landfilled waste, including anaerobic flushing with water, anaerobic flushing with Fenton-treated leachate, and aerobic flushing with Fenton-treated and UV/H2O2-treated leachate. Termination indicators, including total organic carbon (TOC), ammonia-N (NH4(+)-N), the ratio of UV absorbance at 254nm to TOC concentration (SUVA254), fluorescence spectra of leachate, methane production, oxygen consumption, lignocellulose content, and humus-like content were evaluated. Results suggest that oxygen consumption related indicators used as a termination indicator for low-lignin-content MSW were more sensitive than methane consumption related indicators. Aeration increased humic acid (HA) and (HA+FA)/HyI content by 2.9 and 1.7 times compared to the anaerobically stabilized low-lignin-content MSW. On the other hand, both the fulvic acid (FA) and hydrophilic (HyI) fractions remained constant regardless of stabilization technique. The target value developed for low-lignin-content MSW was quite different than developed countries mainly due to low residual biodegradable organic carbon content in stabilized low-lignin-content MSW.
Copyright © 2014 Elsevier Ltd. All rights reserved.
A trace element dosing strategy for the anaerobic digestion of wheat stillage was developed in this study. Mesophilic CSTR reactors were operated with the sulfuric substrate wheat stillage in some cases under trace element deficiency. After supplementing trace elements during the start-up, one of the elements of Fe, Ni, Co, Mo, and W were depleted in one digester while still augmenting the other elements to determine minimum requirements for each element. The depletion of Fe and Ni resulted in a rapid accumulation of volatile fatty acids while Co and W seem to have a long-term effect. Based on the results it was possible to reduce the dosing of trace elements, which is positive with reference to economic and environmental aspects.
Solid food processing wastes and by-products are cofermented with cheese whey to produce ethanol. The experimental procedure involves the use of an enzymatic process to convert starch and lactose into fermentable sugars. These reducing sugars are then fermented to alcohol by distiller’s dried yeast and a high-ethanol tolerant yeast, Saccharomyces cerevisiae. Cheese whey is used as a wetting agent and provides macro- and micronutrients for the microorganisms. Cofermenting food processing wastes with cheese whey, in the presence of high- and low-temperature enzymes, induces a 33-36% increase in alcohol yield. This procedure also significantly reduces the fermentation time from 60 to 12 h.
The characterization of solid wastes is a necessary step before they can be used in anaerobic digestion. The quantities of different compounds (carbohydrates, proteins, lipids and fibers) and anaerobic biodegradability (capacity to produce methane) are important information required to characterize waste. The Biochemical Methane Potential (BMP) test is one of the most relevant tests for assessing the biodegradability of waste materials. The BMP test is run under anaerobic conditions, using bacteria populations, which makes it very time consuming, i.e., about 30 days. This paper presents alternative methods for determining the anaerobic biodegradability of solid waste. First, we describe the already existing tests for characterizing organic matter. Then we correlate an aerobic test with an anaerobic test in order to estimate anaerobic biodegradability and biogas production. This shortens the analysis time to 5 days. Models using physico-chemical characteristics as input data (total carbohydrate, total nitrogen, fiber, etc.) can predict the amount of methane produced by correlation. Pyrolysis is a very fast analytical test that can be used to characterize solid waste. Lastly, spectroscopy techniques seem to be useful for determining biodegradability, in particular by taking into account the interaction between different molecules in the organic matter.
A synthetic waste was used to study the effect of waste composition on anaerobic degradation of restaurant waste. It was made by blending melted pork lard, white cabbage, chicken breast, and potato flakes, to simulate lipids, cellulose, protein, and carbohydrates, respectively. Four blends of the four constituents with an excess of each component were assayed and compared with a fifth blend containing an equal amount of chemical oxygen demand (COD) of each of the four components. The methane production and the time course of soluble COD and volatile fatty acids were assessed in batch assays. A high reduction of volatile solids (between 94% and 99.6%) was obtained in all the assays. The methane yield was between 0.40 m(3) CH(4)/kg VS(initial) (excess of carbohydrates) and 0.49 m(3) CH(4)/kg VS(initial) (excess of lipids). The degradation of the lipid-rich assays differed from the others. Fifty percent of the biochemical methane potential was obtained after 3-6 days for all of the assays, except for the one with excess of lipids which achieved 50% methanation only after 14.7 days of incubation. In the assay with excess of lipids, a considerable fraction of COD remained in the liquid phase, suggesting an inhibition of the methanogenic process that was likely due to the accumulation of long chain fatty acids. The hydrolysis rate constants, assuming first order kinetics, over the first 6 days were between 0.12d(-1) (excess of lipids) and 0.32 d(-1) (excess of carbohydrates). The results indicate that anaerobic digestion facilities with large variations in lipid input could have significant changes in process performance that merit further examination.
In this study, a novel generic feedstock production strategy based on solid-state fermentation (SSF) has been developed and applied to the fermentative production of succinic acid. Wheat was fractionated into bran, gluten and gluten-free flour by milling and gluten extraction processes. The bran, which would normally be a waste product of the wheat milling industry, was used to produce glucoamylase and protease enzymes via SSF using Aspergillus awamori and Aspergillus oryzae, respectively. The resulting solutions were separately utilised for the hydrolysis of gluten-free flour and gluten to generate a glucose-rich stream of over 140gl(-1) glucose and a nitrogen-rich stream of more than 3.5gl(-1) free amino nitrogen. A microbial feedstock consisting of these two streams contained all the essential nutrients required for succinic acid fermentations using Actinobacillus succinogenes. In a fermentation using only the combined hydrolysate streams, around 22gl(-1) succinic acid was produced. The addition of MgCO3 into the wheat-derived medium improved the succinic acid production further to more than 64gl(-1). These results demonstrate the SSF-based strategy is a successful approach for the production of a generic feedstock from wheat, and that this feedstock can be efficiently utilised for succinic acid production.
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