The future in the litter bin - bioconversion of food waste as driver of a circular bioeconomy

Bioconversion of organic waste requires the development and application of rather simple, yet robust technologies capable of transferring biomass into energy and sustainable materials for the future. Food waste plays a significant role in this process as its valorisation reduces waste and at the same time avoids additional exploitation of primary resources. Nonetheless, to literally become "litterate". extensive research into such robust large-scale methods is required. Here, we highlight some promising avenues and materials which fulfill these "waste to value" requirements, from various types of food waste as sustainable sources for biogas, bioethanol and biodiesel to fertilizers and antioxidants from grape pomace, from old-fashioned fermentation to the magic of anaerobic digestion.

Food waste-based bio-fertilizers production by bio-based fermenters and their potential impact on the environment

Increasing food waste is creating a global waste (and management) crisis. Globally, ∼1.6 billion tons of food is wasted annually, worth ∼$1.2 trillion. By reducing this waste or by turning it into valuable products, numerous economic advantages can be realized, including improved food security, lower production costs, biodegradable products, environmental sustainability, and cleaner solutions to the growing world's waste and garbage management. The appropriate handling of these detrimental materials can significantly reduce the risks to human health. Food waste is available in biodegradable forms and, with the potential to speed up microbial metabolism effectively, has immense potential in improving bio-based fertilizer generation. Synthetic inorganic fertilizers severely affect human health, the environment, and soil fertility, thus requiring immediate consideration. To address these problems, agricultural farming is moving towards manufacturing bio-based fertilizers via utilizing natural bioresources. Food waste-based bio-fertilizers could help increase yields, nutrients, and organic matter and mitigate synthetic fertilizers' adverse effects. These are presented and discussed in the review.

Valorization of sugarcane bagasse for high-yield production of laccase through Aspergillus terreus for effective azo dye decolourization

Synthetic dyes such as azo dyes are significant pollutants in the wastewater released from various textile industries. The low biodegradability and production from synthetic sources with high shelf life make azo dyes a challenging material for degradation. This study used chemically mutated Aspergillus terrus in the laccase production under solid-state fermentation using sugarcane bagasse. Initially, the wild-type strain produced a laccase activity of 4.12 U/mL. Later, the alkaline pretreatment of sugarcane bagasse showed a significant increase in laccase activity by 38.9%. Further, random mutagenesis treatment with 100 mM EMS generated a hyper laccase-producing strain with a 2.3-fold increment in laccase activity compared to the wild-type strain. The enzyme displayed optimal activity at pH 6.5 and 35 °C. The metal ions such as Fe3+ (29.4 U/mL), Fe2+ (20.8 U/mL) and Cu2+ (18.05 U/mL) showed positive effects on laccase activity. The crude laccase was used to bioremediate Congo red, a prominent azo dye used in textile and pharmaceutical industries. The preliminary studies with a crude enzyme displayed 68.86% dye decolourization after 24 h of incubation. Additionally, with Taguchi orthogonal array optimization experiments, the maximal dye decolorization of 78.24% was achieved by maintaining crude enzyme concentration (20 U), dye concentration (25 mg/L) and pH 4.5.

Flow control by circular cavities in lateral flow porous membranes

This research explores the flow penetration in porous media by virtue of capillary action and geometric control of the liquid imbibition rate in microfluidic paper-based analytical devices (μPADs) having applications in food quality management, medical diagnostics, and environmental monitoring. We examine changes in flow resistance and membrane geometry, aiming to understand factors influencing capillary penetration rates for various practical applications. We conducted experiments and simulations using lateral porous membranes and altered the flow resistance by changing the liquids or the paper channel geometry by adding cavities. From experiments, it was revealed that by creating a circular cavity in the paper channel, the penetration rate was sufficiently altered. Moreover, increasing the cavity size and type of liquid (w.r.t. viscosity) also caused a decrease in the flow rate. Imbibition rates were also influenced by the position of the cavities in the paper channel. The maximum delay for water was almost 2 times with a 16 mm circular cavity located at 3 cm from strip bottom edge. Overall, we attained a maximum delay in the case of castor oil which was almost 85 times slower than water and 3.7 times slower than olive oil. A good agreement was observed with CFD analysis. We believe that this research would help in developing advance techniques to enhance the flow control strategies in μPADs and indicators.

Tailored Informational Interventions for Reducing Surplus and Waste of Fruits and Vegetables in a Food Market: A Pilot Study

This pilot study explored the effectiveness of tailored informational interventions to reduce the surplus and waste of fruits and vegetables at the distribution level in Chile. Stalls from a fresh food market were randomized to intervention (n = 5 selling fruits, n = 5 selling vegetables) or control (n = 4 selling fruits, n = 4 selling vegetables) groups. The causes of surplus and waste were estimated by questionnaires. Surplus, avoidable waste, and unavoidable waste were measured using direct quantification before and after the intervention, and were expressed relative to the initial stock. Before the intervention, the surplus was (median [25th-75th percentile]) 46.2% [33.3-51.2] for fruits and 51.5% [41.3-55.0] for vegetables; avoidable waste was 0.1% [0.0-0.8] for fruits and 1.8% [0.7-5.3] for vegetables; and unavoidable waste was 0.0% [0.0-1.0] for fruits and 0.0% [0.0-1.3] for vegetables. Planning and storage represented the main causes explaining surplus and waste. After the intervention, the intervention group decreased the surplus of fruits compared to the control group (-17.8% [-29.0--11.0] vs. 5.8% [-0.6-7.8], respectively; p = 0.016), without other differences. In conclusion, tailored informational interventions based on the causes of surplus and waste may reduce the surplus of fruits in a fresh food market. Interventions might also include management strategies for the surplus to improve grocers' business operations.

Food and food-related waste management strategies in hospital food services: A systematic review

AIM

This review explored peer-reviewed and grey literature to describe the types and characteristics of food or food-related waste management strategies used in hospital food service settings; their financial, environmental and staffing outcomes; and the barriers and enablers associated with their implementation.

METHODS

Six electronic databases, 17 Google Advanced searches, and 19 targeted websites were searched for peer-reviewed and grey literature. Literature reporting the financial, environmental, or staffing outcomes of food or food-related waste management strategies that reused, recovered energy from, or recycled waste instead of sending it to landfill were eligible. Document screening and review were completed in duplicate, and included peer-reviewed literature were assessed for quality using the Mixed Methods Appraisal Tool. Data were synthesised narratively.

RESULTS

Four peer-reviewed and 81 grey literature records reported 85 strategies. When grouped from most to least favourable according to the food recovery hierarchy they managed waste by: donating surplus food (n = 21); feeding animals (n = 2); industrial use (n = 11); composting (n = 34) and other (n = 17). These approaches had the capacity to reduce waste hauling fees (n = 14), reduce staff handling of waste (n = 3), and decrease the amount of waste sent to landfill (n = 85). Barriers included contamination of waste streams, while enablers included leadership and time-neutral changes.

CONCLUSION

This review summarises the waste management strategies used by hospitals worldwide that divert food and food-related waste from landfill, their outcomes, and position in the food recovery hierarchy to enable hospital food services to implement appropriate practice and policy changes to decrease their environmental footprint.

Sustainability in food-waste reduction biotechnology: a critical review

Reduction of the $2.625 trillion USD global food-waste problem is a critical goal in combatting climate change and world hunger. However, the outcome analysis of theoretically 'sustainable' individual biotechnological approaches to food-waste reduction is neglected. This critical review applies the principles of the circular economy to the broader context of biotechnology innovations for food-waste reduction. The evaluation of sustainability and relationship to the food-waste management hierarchy are discussed with relevance to recent innovations in biotransformation of food waste and food-waste prevention. Comparison of these innovation categories reveals the challenges of impact at scale for food-waste reduction biotechnology, particularly in food-waste prevention technologies having low technology-readiness levels, and points to illustrative examples of efforts to meet and overcome these challenges.

Market power and food loss at the producer-retailer interface of fruit and vegetable supply chains in Germany

Food loss and waste are associated with an unnecessary consumption of natural resources and avoidable greenhouse gas emissions. The United Nations have thus set the reduction of food loss and waste on the political agenda by means of the Sustainable Development Goal Target 12.3. The German Federal Government committed itself to this goal by implementing the National Strategy for Food Waste Reduction in 2019. However, this policy approach relies heavily on voluntary action by involved actors and neglects the possible role of power imbalances along the food supply chain. While current research on food loss and waste in industrialised countries predominantly focuses on the consumer level, this study puts emphasis on the under-researched early stages of the food supply chain from the field to retailers' warehouses. Based on 22 expert interviews with producers, producer organisations and retailers, this article identifies major inter-stage drivers of food loss in the supply chains for fresh fruit and vegetables in Germany. Its main novelty is to demonstrate how market power imbalances and risk shifting between powerful and subordinate actors can reinforce the tendency of food loss on the part of producers further up the supply chain. Results indicate that prevalent institutional settings, such as contractual terms and conditions, trading practices, ordering processes, product specifications, and communication privilege retailers and encourage food loss. The mechanisms in which these imbalances manifest, go beyond the European Commission's current legislation on Unfair Trading Practices. This study suggests a research agenda that might help to formulate adjusted policy instruments for re-structuring the German fruit and vegetable markets so that less food is wasted.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s11625-021-01083-x.

The Role of the Food Banks in Saving Freshwater Resources through Reducing Food Waste: The Case of the Food Bank of Navarra, Spain

In the year 2011, the FAO estimated that food loss and waste reached one third of the total food produced worldwide. Since then, numerous studies have been published characterizing this problem and reflecting on its repercussions, not only social, but also environmental. Food wastage triggers unnecessary greenhouse gas emissions, deforestation or loss of biodiversity. This study aims to quantify the water-related benefits associated with food loss and waste reduction by studying the Food Bank of Navarra (FBN). For this purpose, the water footprint assessment manual has been followed. First, the water footprint of the activities of the FBN has been analysed for the year 2018 (scenario with the FBN). A comparative analysis has been carried out between the scenario with the FBN and a theoretical scenario without the action of the FBN. This has allowed us to highlight the benefits associated with the activity of this entity. The FBN not only avoided the waste of 2.7 thousand tons of food suitable for consumption in 2018, but also avoided the unnecessary use of more than 3.2 million m³ of freshwater. As a result of the present investigation, it can be stated that promoting food banks, which avoid food waste, would be an effective way to contribute to the protection and conservation of water resources.

Efficiency of microbial fuel cells in the treatment and energy recovery from food wastes: Trends and applications - A review

The rising global population and their food habits result in food wastage and cause an obstacle in its treatment and disposal. Due to the rapid shift in the lifestyle of the human population and urbanization, almost one-third of the food produced is wasted from various sectors like domestic sources, agricultural sectors, and industrial sectors. These food resources squandered are rich in organic biomolecules which can cause complications upon direct disposal in the environment. Conventional disposal methods like composting, landfills and incineration demand high costs besides causing severe environmental and health issues. To overcome these demerits of the conventional methods and to avoid the loss of rich organic food resources, there is an immediate need for a sustainable and eco-friendly solution for the valorization of the food wastes. Microbial fuel cells (MFCs) are gaining attention, due to their ideal approach in the production of electricity and parallel treatment of organic food wastes. The MFCs are significant as an innovative approach using microorganisms and oxidizing the organic food wastes into bio-electricity. In this review, the recent advancements and practices of the MFCs in the field of food waste treatment and management along with electricity production are discussed. The major outcome of this work highlights the setting up of MFC for the treatment of higher volumes of food waste residues and enhancing the bioelectricity production in an optimal condition. For further improvements in the food waste treatments using MFCs, greater understanding and more research needs are to be focused on the commercialization, different operational modes, operational types, and low-cost fabrication coupled with careful examination of scale-up factors.

Eco-Inefficiency Formula: A Method to Verify the Cost of the Economic, Environmental, and Social Impact of Waste in Food Services

This study aimed to develop an Eco-Inefficiency (Ely) formula to verify the cost of the economic, environmental, and social impact of waste, applicable to food services (FS). Six stages were performed: identification of the terms that characterize food waste; definition of constructs influenced by food waste; identification of the variables that make up each construct; indicators capable of measuring the impact generated by food waste; definition of the mathematical formula; and EIy pilot test. The formula was based on eco-efficiency but focused on food waste. The constructs were translated into three dimensions of sustainability: environmental, social, and economic. Researchers created a score for the dimensions and the entire evaluation, based on a literature review. Water footprint, cleaning material, food production waste, the amount of rest-intake, and the amount of distribution leftover were evaluated on the environmental impact. The economic dimension variables were energy consumption to produce the wasted food, cost of raw material used in wasted food, and food handlers’ wages for the economic impact measurement. The social impact variables were: energy density (ED), rest-intake (kcal/g), distribution of leftover ED (kcal/g), use of organic food, and food surpluses’ donation. With an EIy application in each item, we have the item’s score in each dimension. The higher value of an item, the higher is its influence on the dimension, allowing us to identify those with the most significant impact in the restaurant. The Environmental dimension presented the most significant problems in the assessed scenario. The eco-inefficiency formula identifies food waste’s main critical points, allowing us to trace strategies to reduce food waste.

Green and Sustainable Public Procurement—An Instrument for Nudging Consumer Behavior. A Case Study on Romanian Green Public Agriculture across Different Sectors of Activity

Green Public Procurement (GPP) became an efficient instrument to achieve the objectives of environmental policy expressed by the European Commission in its Communications. At the same time, it must be addressed by the public authorities as a complex process, in which all purchased goods and services must integrate perfectly into an entire puzzle-like system of legislation, the construction field, innovation, healthcare, food, and education. Scientific references published in the Web of Science (WoS) mainly between 2017 and 2020 were investigated, and they analyze the implications of green public procurement in various fields, as presented by scientific communities. This article brings as a novelty in this context the identification of some barriers in the adoption of these processes, so that they can be overcome. Based on good practices and international standards and trends, the article shows how aspects related to the implementation of green procurement in society can be taken into account. In the second stage, we added a case study on Romanian green agriculture and discussions regarding inter-correlation between different fields and GPP.

What influences buffet leftovers at event caterings? A German case study

In recent years, a growing number of investigations have examined food waste in the food service sector, in which the catering of individual events received little attention. We aimed to contribute to fill this knowledge gap by presenting insights from a case study based on data from 239 event caterings. The case study presents findings about the influences of four variables, namely event type, season, event size, and menu prices, on buffet leftovers. We used a waste tracking system that allowed kitchen staff to quantify buffet leftovers for 4 years: from the beginning of 2014 until the end of 2017. Among the studied variables, the event size demonstrated the strongest influence on the generation of buffet leftovers in the case study. Buffet leftovers showed a trend of decreasing quantities relative to the number of guests for increasing event sizes. For instance, smaller events with less than 100 participants recorded the highest quantities of approximately 280 g of buffet leftovers per guest, and larger events of more than 500 participants recorded the lowest quantities of approximately 74 g per guest. In addition, we found that three food product groups-meat & poultry, finger food, and side dishes-caused approximately 54% of the overall quantity of buffet leftovers and approximately 65% of the corresponding monetary equivalents. Our findings emphasize that further research is necessary on food waste reduction strategies.

No time to waste: assessing the performance of food waste prevention actions

As a result of the growing awareness of the need to prevent food waste, several initiatives have been launched in the last few years to reduce food waste generated across the food supply chain. However, the evaluation of food waste prevention interventions is still at an early stage of development and appropriate methods to assess their effectiveness are missing, hampering the identification of best practices amongst existing initiatives and the prioritisation of those that are most promising. To address such needs and provide a common approach to consistently assess the performance of food waste prevention initiatives, the European Commission Joint Research Centre has developed an evaluation framework for food waste prevention actions. The framework supports the EU Platform on Food Losses and Food Waste, which has been established to identify best practices and share knowledge on food waste prevention initiatives. Additionally, a food waste prevention calculator, based on life cycle thinking, has been developed to support such an evaluation by a consistent assessment of the environmental and economic benefits of such initiatives, and the identification of potential trade-offs at early design stages. The main goal of this paper is to present the evaluation framework and the calculator developed, critically discussing how future initiatives should be designed, monitored and reported, to ensure sufficient and relevant data is made available to enable their proper assessment. Crucially, this would enable practitioners and decision makers to evaluate the success of existing initiatives and give priority to the implementation of the best performing ones.

Evaluation of Food Waste Prevention Measures—The Use of Fish Products in the Food Service Sector

This study presents two food waste prevention measures focusing on the interface between the food service sector and its food suppliers. Through a case study on procuring salmon by a hotel kitchen, the use of food products with different convenience grades is examined. The convenience grade of the fish bought (whole salmon, fillets or portions) determines where along the food chain filleting and/or portioning takes place and thus where food waste from cut-offs occurs. To reduce food waste, we propose purchasing filleted or portioned salmon rather than whole salmon. For both measures, effectiveness is calculated by looking at food waste reductions along the food chain, achieved by a better use of filleting and portioning cut-offs. Next, sustainability across the environmental, economic and social dimension is evaluated by calculating (a) avoided embodied environmental impacts and economic costs, (b) avoided food waste disposal environmental impacts and economic costs and (c) environmental, economic and social impacts and costs associated with implementing the measures. Purchasing fillets or portions instead of whole salmon leads to food waste reductions of −89% and −94%, respectively. The interventions further lead to net climate change impact savings along the salmon chain of −16% (fillets) and −18% (portions). Whereas the kitchen saves costs when switching to fillets (−13%), a switch to portions generates additional net costs (+5%). On a social level, no effects could be determined based on the information available. However, good filleting skills would no longer be needed in the kitchen and a time consuming preparation can be sourced out.

Approaches to Reduce Food Losses in German Fruit and Vegetable Production

Food losses occur in all agricultural value chains, but are especially high in the fruit and vegetable sector. This study quantifies losses of selected fruits (strawberries, apples) and vegetables (lettuce, carrots), identifies the main reasons for food losses, and assesses effective measures for the reduction of these losses. Data were collected in structured interviews with value chain actors from production to food retail and validated in regional expert workshops. Results show that in average years, about 25% of the analysed vegetables are lost at farm level. The range of fruit losses differs widely, from 15% to 20% for strawberries and only 6% to 16% for apples. Weather is a major factor for crop losses, since it can strongly affect product appearance and hence marketability in the food retail sector. There is a lack of alternative market channels for products, which do not meet the high-quality standards for fresh products in the retail sector. Effective measures to reduce food losses are protected cultivation in greenhouses or under hail nets, continuous cooling systems, improved packaging and training of staff. More cooperation and coordination between producers, wholesalers and retailers could also increase the share of marketable products.