Food Waste Valorization Research Articles

Fast, sensitive, and sustainable colorimetric detection of chlorogenic acid in artichoke waste material

Caffeoylquinic acids (CQAs) are nutraceutical polyphenols highly represented in natural sources, including artichoke waste (AW). In this study a colorimetric method for rapid and sustainable detection of a 5-CQA isomer (Chlorogenic acid) in AW extract was developed by using alkaline Tris buffer (10 mmol L−1, pH 9) to generate a yellow color associated with 5- to 3-CQA isomerization reaction, as suggested by NMR and MS analyses. The strong absorbance at 360 nm was followed by standard UV–Vis methodology. The colorimetric assay was exploited for detection of 5-CQA into leaf extract from artichoke, obtaining a value of 15.2 ± 0.3 μg/mg of dry extract, in agreement with HPLC analysis (14.3 ± 0.7 μg/mg, 106 ± 2 % recovery) used as validation technique, with excellent linear correlation and precision (R2 = 0.9996, avRSD% = 3.2 %). The method is fast and selective, offering a valuable tool for nutraceuticals identification and food waste valorization.

Convert food waste into easily biodegradable liquid substrate: New insights into wet oxidation as a pretreatment for anaerobic digestion

This study is the first comprehensive investigation into the industrial application of wet oxidation (WO) for food waste (FW) valorization. We analyzed the physicochemical properties of WO products and performed a material flow analysis. WO achieved a 25.7 % reduction in chemical oxygen demand and produced liquid and solid products suitable for high-value applications. The liquid product featured high biodegradability (B/C ratio of 0.65), significant BOD5 (33 ± 9 g/L), low total solids (3.5 % ± 0.4 %), and low metal concentrations, making it ideal for high-efficiency anaerobic digestion or as a carbon source in wastewater treatment. The solid product, with a total solids content of 63.9 % ± 1.4 %, is a potential organic fertilizer alternative. Life cycle assessment showed that WO-related scenarios offered superior greenhouse gas (GHG) reduction compared to conventional anaerobic digestion (11.30 kg CO2-eq/t FW slurry). The most effective scenario, combining WO with a carbon source and organic fertilizer alternative, achieved a GHG reduction of −21.80 kg CO2-eq/t FW slurry. Consequently, this study demonstrates that WO, as a pretreatment for food waste valorization, is both technically feasible and environmentally sound, offering valuable engineering references for the implementation of high-efficiency anaerobic digestion processes for food waste.

Use of CO2 for enhanced carbon recovery in thermochemical processing of fruit peel waste

To address a supply variability associated with biomass, utilization of food waste provides a practical approach to consistently obtain carbon–neutral energy resource. Despite the technical merits of conventional biological process, the inevitable generation of less useful by-products, such as carbon dioxide (CO2) and sludge, remains a primary constraint. As an alternative, thermochemical process, such as pyrolysis, presents a promising solution for the comprehensive valorisation of food waste. In this study, citrus peel, one of the fruit processing wastes, was used as a model food waste. To enhance the eco-friendliness of the pyrolysis system, CO2 was introduced as a medium gas given the uncertainty regarding its behaviour as an inert or reactive agent at the pyrolysis temperatures. The pyrolysis approach demonstrated that CO2 interacts with volatile pyrogenic products, resulting in an increased formation of carbon monoxide (CO). Notably, this enhancement was observed at ≥ 400 °C, suggesting that CO2′s reactivity is limited at lower temperatures. To maximize the utility of CO2, the pyrolysis setup was modified by incorporating a heating block at 600 °C and a nickel-based catalyst (Ni/Al2O3). While these adjustments accelerated the thermal cracking of citrus peel, test setup modification led to an aromaticity increase of the resulting pyrogenic products. However, integrating CO2 into the catalytic pyrolysis created favourable conditions for detoxifying these aromatic compounds and further boosting CO production. Syngas productivity from catalytic pyrolysis in the presence of CO2 was 35.2 wt%, showing 3.67 times increase over that from conventional pyrolysis. In conclusion, CO2-assisted catalytic pyrolysis of the citrus peel offers significant technical benefits: it enhances carbon recovery in the form of CO and reduces the formation of undesirable aromatic pyrogenic products.

Valorization of food waste into hydrogen energy through supercritical water gasification: Generation potential and techno-econo-environmental feasibility assessment

Food waste (FW) is a significant portion of the solid waste produced by cities, and it has become a global problem due to the poor management of food distribution and consumption. The improper disposal of FW in landfills precipitates pervasive global environmental predicamentsHowever, effective management strategies have the potential to convert this large amount of garbage into a very effective renewable energy source, particularly through the generation of environmentally friendly hydrogen. This study examines the capacity for energy generation and the practicality of hydrogen production in Bangladesh using supercritical water gasification technology. The findings indicate that approximately 489 MW of electricity can be extracted from approximately 23 million tons (Mt) of FW in 2023, with a projected escalation to around 2042 MW by 2042, coinciding with an anticipated surge in FW generation to approximately 110 Mt. Moreover, the study delves into the economic feasibility of these gasification endeavors, employing diverse metrics encompassing total life cycle cost, net present value, investment payback duration, levelized cost of energy, and internal rate of return. Technoeconomic analyses divulge an investment with a net present value of 11,669.4 M$M$, an 11-year payback period, and an internal rate of return of 14 %. In addition, the research assesses the technological, economic, and environmental viability inherent in the establishment of gasification-based electricity-generating facilities in Bangladesh's preeminent eight cities by 2023. This examination postulates that a transition from coal-based power plants to those powered by food waste would precipitate an annual reduction of 3.59 Mt in carbon dioxide emissions.

Valorization of Food Waste Using Pulsed Electric Fields: Applications in Diverse Food Categories

Valorization of Food Waste Using Pulsed Electric Fields: Applications in Diverse Food Categories

Green directional conversion of food waste into glycerol in a two-step differentiation enzymolysis and facultative fermentation using Saccharomyces cerevisiae: Performance assessment and mechanism

Valorization of food waste into high value-added glycerol was designed and prepared via directional green transformation using multi-enzymolysis saccharification coupled facultative fermentation by Saccharomyces cerevisiae. The optimal conditions for the first step of multienzyme hydrolysis and the second step of facultative fermentation were 55 °C and pH 5.0 for 6 h, 30 °C and pH 7.0 for 70 h, respectively. The glycerol yield efficiency and kinetic rate constant were 73.6 % (w/w) and 0.681 h−1 for dry component of food waste, while the other 27.4 % was utilized as the growth energy substrate. The key points of transformation were the synergistic directed enzymolysis to produce 3 % glycerol and 95 % reducing sugars. Furthermore, the reducing sugars were converted into glycerol by switch the metabolic pathway from ethanol into glycerol through the quantitative expression of functional gpd1 and gpp2 genes activated GPD and GPP enzymatic activity and synchronous inhibition of adh gene for glycerol production with Na2SO3 regulation. The economic income was 135.52 USD/ton for converting 80 % water content of kitchen waste into glycerol. This finding provided an economic value-added approach to produce high-value glycerol for cost-effective recycling of food waste using commercial yeast.

Food Waste Processing Trends Worldwide and Valorization of Food Waste from Pune City

This article lays its primary focus on understanding waste from the domestic and commercial hotel kitchens. For researchers, deciding biotechnological treatment and valorization process, it is necessary to refer and understand the food waste (FW) composition and its processing trends worldwide. This paper mentions the FW compositional data from four different locations of “Pune” a metro city of India. Study-approved procedures for sample collection, preparation, and analysis were followed. The results indicate, the presence of carbohydrates, proteins, and fats in all samples and are sufficient to support the microbial growth and desired product formation. Being perishable, microbiological and compositional changes during handling and transportation, in FW are inevitable. The presence of high boiling, low boiling volatile compounds and volatile organic acids indicate the complexity of FW and microbial activity taking place within it. Abundant amount of trace elements essential for enzymatic reactions and building block molecule formation are present. Average important figures to mention, starch- 7.27% w/w, free sugars- 3.39% w/w, proteins- 7.99% w/w and fats- 12.84% w/w. In addition, essential trace elements Zn- 4 mg/lit, Mn- 4 mg/lit, Mg- 239 mg/lit, S-433 mg/lit and P- 922 mg/lit. The numbers help to realize the nutritional richness of the FW in reality and provide fundamental statistical data for researchers. Treatment and recycling can be done to contribute toward a circular bio-economy. Remarkable variations observed in almost all components on day-to-day basis. However, pretreatment process parameters can be decided to account for compositional variations.

Restaurant food waste valorization by microwave-assisted hydrolysis: Optimization, typological and biochemical analysis

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.

Optimization of peapod peel biochar amendment for sustainable agriculture by surface response methodology towards water-food-environment nexus

Valorization of food waste to biochar offers economic and environmental opportunities for sustainable agriculture production. Peapod (Pisum sativum) peel is a high-content lignocellulose vegetable waste and was used in this study to produce biochar through pyrolysis temperatures of 350, 450, and 550 °C, with a heating rate of 5 °C/min for 30 min and thereafter characterized for its various properties. The biochar produced at 350 °C, exhibiting the best soil amendment properties was used for pot testing with mung bean (Vigna radiata). The optimization of plant growth, soil water retention capacity, and microbial activity were determined using response surface methodology (RSM) with three design factors: (a) biochar loading rates (0 %, 0.5 %, and 1 %), (b) temperature (30–40 °C), and (c) quantity of water supplied (50–60 mL/day). The results showed that applying 0.5 % biochar with a water supply of 55 mL/day at 35 °C resulted in optimal responses for seed germination, plant height, and leaf development. Applying 1 % biochar with a water supply of 55 mL/day at 35 °C showed optimal responses for leaf area and leaf chlorophyll content. Stomatal conductance and catalase activity showed optimal responses for 1 % biochar applied with a water supply of 60 mL/day at 40 °C. Urease activity and water retention capacity showed optimal responses when 1 % biochar was applied with a water supply of 60 mL/day at 30 °C, respectively. This study demonstrates the potential use of peapod peel biochar in water-food-environment nexus, with a lower dose and lesser volume of water demand.

Food waste: analysis of the complex and variable composition of a promising feedstock for valorisation

There are global concerns about the environmental, social, and economic consequences associated with the generation of food waste. To effectively address this challenge, and particularly to develop food waste valorisation approaches, it is necessary to acquire understanding of the physicochemical and biochemical characteristics of food waste. This study comprises a systematic overview and quantitative assessment of the characteristics of food waste biomass, and this was achieved through a comprehensive literature review. The resulting database encompasses the physicochemical, biochemical, and elemental composition of food waste. The study evaluates food waste variability, analyses correlations between components, and highlights patterns in composition. Overall, food waste is a rather variable material. Typology, collection source and geographical origin of food waste streams are the main contributing factors to variation in physicochemical, biochemical and elemental compositions of food waste, while collection season and storage temperature appear not to be contributing substantially to variation. A clear distinction between plant-based and animal-based food waste biomass can be observed with animal-matter enriched food waste having high contents of protein, lipid and ash, but a low starch content. On the other hand, plant-based food waste can be either high in lignin and low in starch or high in carbohydrates, starch and higher heating value. Fibre content appears an indicative parameter, distinguishing plant from animal enriched food waste, and correlating strongly with lignin-rich, starch-poor plant biomass. The heterogeneity of food waste biomass composition will create challenges in developing and scaling up appropriate food waste management. The current study shows that the analysis of specific food waste parameters, such as fibre content, can be used, to inform the choice of the most appropriate valorisation route.

Efficient technology for food waste valorization: an integrated anaerobic digestion—microbial electrolysis cell for biomethane production

Efficient technology for food waste valorization: an integrated anaerobic digestion—microbial electrolysis cell for biomethane production

The Impact of Fermentation on the Antioxidant Activity of Food Products.

From ancient times to the present day, fermentation has been utilized not only for food preservation but also for enhancing the nutritional and functional properties of foods. This process is influenced by numerous factors, including the type of microorganisms used, substrate composition, pH, time, and temperature, all of which can significantly alter the characteristics of the final product. Depending on the parameters, fermentation enhances the bioactive content of the products and imparts the necessary properties, such as antioxidant characteristics, for the products to be considered functional. The enhancement of these properties, particularly antioxidant activity, enriches foods with bioactive compounds and functional attributes, contributing to improved health benefits. Through a review of recent research, this study elucidates how different fermentation processes can enhance the bioavailability and efficacy of antioxidants, thereby improving the nutritional and functional qualities of foods. This study investigated the multifaceted effects of fermentation on antioxidant properties by exploring various types and conditions of fermentation. It highlights specific examples from dairy products and other food categories as well as the valorization of food waste and byproducts. The findings underscore the potential of fermentation as a sustainable method to produce health-promoting foods with elevated antioxidant activities, offering new perspectives for food science and technology.

Development of hydrogels from cell wall of Aspergillus oryzae containing chitin-glucan and wet spinning to monofilaments

Fungal mycelium is emerging as a source for sustainable bio-based materials. Fungal biomass of Aspergillus oryzae was prepared by cultivation on bread waste hydrolysate to valorize this abundant food waste. Chitin-glucan-rich alkali-insoluble material (AIM) was isolated from fungal biomass, formed into hydrogels, and wet spun into monofilaments. AIM in the form of fungal microfibers containing 0.09 g polymer of glucosamine (GlcN)/g AIM was subjected to freeze–thaw and deacetylation treatments to increase the amount of GlcN. The GlcN fraction was 0.19 and 0.34 g polymer of GlcN/g AIM, for AIM subjected to deacetylation (AIM-DAC) and freeze–thaw cycles and deacetylation (AIM-FRTH-DAC), respectively. The increased GlcN fraction enabled the formation of hydrogels via the protonation of amino groups after the addition of lactic acid. Morphological differences in the hydrogels included aggregation of the fungal microfibers in the AIM-DAC hydrogel, whereas the microfibers in the AIM-FRTH-DAC hydrogel had a porous and interconnected network. Rheological assessment revealed shear thinning behavior and gel properties of the produced hydrogels. Wet spinning of the hydrogels resulted in monofilaments with tensile strengths of up to 70 MPa and 12 % elongation at break. This demonstrates promising avenues for biomaterial development from fungal cell walls containing chitin-glucan via food waste valorization.

Valorization of Food Waste: Utilizing Natural Porous Materials Derived from Pomelo-Peel Biomass to Develop Triboelectric Nanogenerators for Energy Harvesting and Self-Powered Sensing.

Food waste is an enormous challenge, with implications for the environment, society, and economy. Every year around the world, 1.3 billion tons of food are wasted or lost, and food waste-associated costs are around $2.6 trillion. Waste upcycling has been shown to mitigate these negative impacts. This study's optimized pomelo-peel biomass-derived porous material-based triboelectric nanogenerator (PP-TENG) had an open circuit voltage of 58 V and a peak power density of 254.8 mW/m2. As porous structures enable such triboelectric devices to respond sensitively to external mechanical stimuli, we tested our optimized PP-TENG's ability to serve as a self-powered sensor of biomechanical motions. As well as successfully harvesting sufficient mechanical energy to power light-emitting diodes and portable electronics, our PP-TENGs successfully monitored joint motions, neck movements, and gait patterns, suggesting their strong potential for use in healthcare monitoring and physical rehabilitation, among other applications. As such, the present work opens up various new possibilities for transforming a prolific type of food waste into value-added products and thus could enhance long-term sustainability while reducing such waste.

Valorization of food waste: A comprehensive review of individual technologies for producing bio-based products

BackgroundThe escalating global concerns about food waste and the imperative need for sustainable practices have fuelled a burgeoning interest in the valorization of food waste. This comprehensive review delves into various technologies employed for converting food waste into valuable bio-based products. The article surveys individual technologies, ranging from traditional to cutting-edge methods, highlighting their respective mechanisms, advantages, and challenges. Scope and approachThe exploration encompasses enzymatic processes, microbial fermentation, anaerobic digestion, and emerging technologies such as pyrolysis and hydrothermal processing. Each technology's efficacy in transforming food waste into bio-based products such as biofuels, enzymes, organic acids, prebiotics, and biopolymers is critically assessed. The review also considers the environmental and economic implications of these technologies, shedding light on their sustainability and scalability. The article discusses the role of technological integration and synergies in creating holistic approaches for maximizing the valorization potential of food waste.Key finding and conclusion: This review consolidates current knowledge on the valorization of food waste, offering a comprehensive understanding of individual technologies and their contributions to the sustainable production of bio-based products. The synthesis of information presented here aims to guide researchers, policymakers, and industry stakeholders in making informed decisions to address the global challenge of food waste while fostering a circular and eco-friendly economy.

Innovative biorefinery approaches for upcycling of post-consumer food waste in a circular bioeconomy context

Owing to the significant amounts produced each year, food waste is a critical issue that affects the economy, society, and environment. An estimated US$ 1 trillion food is wasted annually because of the supply chain and harvesting processes, which lose around one-third of the net production. This significant loss has sparked global concern, there is an urgent need for sustainable approaches to reduce food waste or to propose an economical route for its utilization. Major concerns associated with its improper management include environmental degradation and the exacerbation of greenhouse gases. This review provides a comprehensive understanding of the recent advances in measures to minimize food waste (FW) and its chemical and biotransformation into valuable products. Food waste comprises mainly carbohydrates, proteins, and oils; the former two components are commonly used as microbial feedstock, leaving behind the residual oil fraction which poses a greater environmental risk. Microbial transformation of these hydrophobic materials present in food waste into value-added products proves to be a sustainable and economical strategy. Thus, this study proposes an integrated biorefinery strategy for holistic valorization of FW, whereby all its components were used to produce value-added compounds such as biofuels, bioplastics, nutraceuticals, and biomaterials using microbial biocatalysis. Compared to conventional methods, an integrated biorefinery will be more sustainable and uplift the microbial processes by switching from ‘pure’ to food waste-derived substrates and thereby pave ways to achieve ‘green’ transition.

Valorization of food waste via surface modification by loading Fe to obtain an adsorbent for Cr(V) removal

Fe-loaded food waste (Fe-FW) utilization is an environmentally friendly and effective approach for eliminating Cr(VI). FW was blended with iron to enhance its adsorption capacity for Cr(VI) removal from aqueous solutions. The Fe-FW was characterized by examining its elemental composition, specific surface area, morphological properties, functional groups, and zeta potential. The Cr(VI) adsorption properties of Fe-FW were examined using batch experiments. Cr(VI) adsorption onto the Fe-FW occurred according to the pseudo-second-order model at various contact times, indicating that the Cr(VI) adsorption rate was primarily constrained by chemical adsorption. The coefficient of determination was more suitable for the Langmuir model than for the Freundlich model. Fe-FW achieved a maximum Cr(VI) adsorption capacity of 100.6 mg/g, comparable to that of adsorbents investigated in other studies. Thermodynamic experiments indicated that Cr(VI) adsorption onto Fe-FW occurs spontaneously, is endothermic, and follows a physical adsorption mechanism. As the solution pH increased from 3 to 11, the amount of Cr(VI) adsorbed decreased considerably (from 39.6 mg/g to 2.5 mg/g). HPO42- had a stronger negative effect on Cr(VI) adsorption compared to SO42-, NO3-, and HCO3-. HCl effectively facilitated the regeneration of Fe-FW. This study confirmed that FW treated with Fe is an effective adsorbent for improving Cr(VI) removal.

Valorisation of food waste into bio-based polyurethane rigid foams: From experimental investigation to techno-economic analysis

Food waste (FW) constitutes a significant portion of municipal solid waste and thus requires proper treatment. A ‘waste-to-wealth’ concept, in this case, urges the valorisation of FW to produce value-added products, given that such waste contains significant quantities of diverse nutrients. While most of these efforts have been focused on the recovery of carbohydrates, this paper introduces an FW biorefinery scheme to valorise FW lipids (FWLs) into bio-based polyols for polyurethane rigid foams (PURF). Considering economic viability, cost-effective dosages of enzymes for FW hydrolysis were first investigated. Subsequently, the obtained FWLs were converted into bio-based polyols through stepwise epoxidation and oxirane ring-opening. Characterisation results showed that FW hydrolysis aided the development of FWL-derived polyols into PURF. Moreover, the obtained PURF exhibited excellent properties that are suitable for thermal insulation applications in the fields of civil engineering and appliances. A further techno-economic analysis demonstrated a promising profitability of valorising FW into PURF. Proven as material-intensive, critical cost drivers of the proposed valorisation scheme mainly included the price of the PURF and the chemicals required for the synthesis. The FW processing rate also significantly influenced the economic viability. By providing a successful valorisation pathway from FW to PURF and highlighting vital economic variables, this work aims to provide insights to promote the sustainable development of FW biorefineries and relevant bio-based polymer industries.

Valorizing Fruit and Vegetable Waste: The Untapped Potential for Entrepreneurship in Sub-Saharan Africa—A Systematic Review

Valorizing food waste (FW) in sub-Saharan Africa (SSA) can enhance the efficiency of limited resources, make healthy diets more affordable, and foster the creation of innovative enterprises. The vast quantities of FW from the agri-food chain significantly threaten food security. To address this issue and maximize potential environmental and socio-economic benefits, valorizing waste, a value-adding process for waste materials, has emerged as a sustainable and efficient strategy. Valorizing FW reduces greenhouse gas emissions, mitigates climate change, enhances resource efficiency, and improves planetary health. As a pivotal player in the transition toward the circular economy, this study investigates the potential of converting FW into value-added products, offering entrepreneurial opportunities for SSA’s unemployed youth. A systematic literature review is conducted to identify and filter relevant articles over five years by applying inclusion and exclusion criteria. A total of 33 articles were included for in-depth analysis to address the study’s aim. The findings highlight a range of value-added products derived from FW, including renewable energy sources, nutraceuticals, and heavy metal adsorbents. These products present promising entrepreneurial prospects within SSA. Nonetheless, overcoming barriers to FW valorization adoption is crucial for fully realizing its potential as a profitable business avenue.

Unlocking value: circular economy in ngos' food waste reduction efforts in Brazil and Togo

This article delves into the intriguing realm of food waste valorization conducted by nongovernmental organizations (NGOs) in two distinct locales—Brasilia, Brazil, and Lomé, Togo. The primary focus of this exploration is the lens of the Circular Economy (CE), a concept that emphasizes the sustainable utilization of resources within closed loops. The discourse is further enriched by introducing the notion of upcycling, a complementary force to the Circular Economy, particularly within the intricate web of food supply chains. The ReSOLVE framework, a strategic approach for managing food waste, is a guiding light in this research. Upon dissecting the outcomes, noteworthy limitations come to the forefront, shedding light on the challenges of aligning NGOs from both countries with the principles of the Circular Economy in their food waste management endeavors. These challenges assume heightened significance against the backdrop of the intricate global food security landscape, effectively underlining the intricacies of harmonizing the Circular Economy's ambitions with the pragmatic goal of diminishing food waste. The overarching objective of this study is to galvanize circular-oriented initiatives that can effectively curtail and prevent food wastage on a global scale, with a particular emphasis on developing nations. This pursuit is underscored by the triad of benefits such initiatives confer: economic advancement, social amelioration, and a positive ecological footprint. In an era where sustainability stands as a paramount concern, this research advocates for concerted efforts to harmonize the noble ideals of the Circular Economy with the pressing need for food waste reduction, especially within regions striving for holistic growth and development.