Challenges for Upcycled Foods: Definition, Inclusion in the Food Waste Management Hierarchy and Public Acceptability

Metabolomic study of marketable and unmarketable chili peppers (Capsicum annuum L.) classified by the fruit size and shape

Research on appearance and nutritional value of peppers is limited. Therefore, we compared nutritional metabolites in marketable and unmarketable red/green chili peppers. Unmarketable peppers were categorized as UM1 (curved-shaped), UM2 (small-sized), and UM3 (curved, small) referring international standards. Most metabolites in unmarketable peppers were comparable to those in marketable for both colors. Metabolites like capsaicinoids, vitamin C, and phenolics in UM1 were similar to those in marketable peppers. Targeted phenolic acids sum was at least six-fold higher in green UM2 and UM3 than in marketable. Besides, capsaicinoids of three- to five-fold and α-tocopherol of ∼30 % higher contents were found in red UM2 and UM3 compared to in their marketable. Therefore, pepper size can be considered a more crucial determining factor of nutritional value rather than curvature, possibly making unmarketable peppers potential nutrient sources. These results enhance nutritional understanding of unmarketable peppers and contribute to improving the perception of unmarketable produce.

Consumers acceptance of new food ingredients from the food industry's by-products-a focus group study

Food industry by-products can be valorized by extracting various nutritional components, like proteins, dietary fiber or other bioactive compounds, depending on the type of by-products. By adding these to new or already existing food products, the consumers' health and wellbeing may increase due to a more nutritional diet while at the same time increasing the sustainability of the food chain. However, for a successful market implementation of products containing ingredients from by-products, the consumer perception and consumer acceptance are one of the most important aspects that need to be considered. Therefore, focus group studies were organized in four European countries, namely Italy, Germany, Romania and Norway, to investigate the perception, acceptance and willingness of the general population (ages 18-60) to buy these new products. When possible, individual purchasing and consumption trends were analyzed as well to get a deeper insight into the decision-making processes during grocery shopping. In summary, the acceptance of new food ingredients from by-products was high in all four studied countries, and most participants were interested in enriched bakery, meat or dairy products. The main reason for the interest in these new products were health benefits due to an increased nutrient uptake, and to contribute to reducing food waste. However, participants were afraid of new food allergies and intolerances as well as increased concentrations of food contaminants like pesticides or mycotoxins, which makes food safety an important point to consider before developing new products.

An Upcycling Approach from Fruit Processing By-Products: Flour for Use in Food Products

The growing global population has led to increased food consumption and a significant amount of food waste, including the non-consumed parts of fruits (e.g., stems, rinds, peels, seeds). Despite their nutrient richness, these by-products are often discarded. With the rising interest in nutrient-dense foods for health benefits, fruit by-products have potential as nutritious ingredients. Upcycling, which repurposes waste materials, is one solution. White flour, which is common in food products like bread and pasta, has good functional properties but poor nutritional value. This can be enhanced by blending white flour with fruit by-product flours, creating functional, nutrient-rich mixtures. This review explores using flours from common Brazilian fruit by-products (e.g., jaboticaba, avocado, guava, mango, banana, jackfruit, orange, pineapple, and passion fruit) and their nutritional, physical-chemical properties, quality and safety, and applications. Partially replacing wheat flour with fruit flour improves its nutritional value, increasing the amount of fiber, protein, and carbohydrates present in it. However, higher substitution levels can alter color and flavor, impacting the sensory appeal and acceptability. While studies showed the potential of fruit by-product flours in food formulation, there is limited research on their long-term health impacts.

The high-value and sustainable utilization of grape pomace: A review

A large portion of global grape production has been utilized for wine production, accompanied by tremendous pressure to dispose grape pomace. To achieve circular economy, the high-value recycling of grape pomace must be considered. The social level barriers to circular economy promotion are also important constraints, like the acceptability of upcycled products. The main components of grape pomace and their utilization are summarized, and critical reviews of green extraction methods analyzed the key points of grape pomace recycling process to achieve the goal of sustainability in the production process, culminating in discussions of the factors affecting the acceptability of upcycled products. Grape pomace bioactive substances have higher added value. To realize its green extraction, various emerging technologies need to be made a comprehensive choice. Nevertheless, the acceptability of upcycled products is influenced by personal, context and product factors, optimizing them is essential to remove the constraints of circular economy development.

Assessing baby leaf kale (Brassica oleracea) waste production mitigation in the transition to sustainable packaging with the application of silicon through an integrative model of quality

This research builds a mathematical modelling to assess food waste production when designing sustainable packaging solutions integrated with an agricultural intervention in kale production. The model utilizes experimental data obtained from simulated retail and distribution storage conditions to assess the probability of the product to be found out of technical specification and becoming waste. The packaging design was made using a system of differential equations describing the gas exchanges inside the packaging. The waste was estimated fitting linear mixed effect models to the postharvest experimental data, accounting for the variability between and within groups. A field experiment with kale treated with silicon during growth as a bio stimulant was used with the aim to make the product more resilient to packaging conditions. The Kale was then packaged in polylactic acid and oriented polypropylene for postharvest testing. Technological thresholds that indicate out-of-specification product were used to estimate the percentage of product that would likely end up as food waste. In total 7.2% of the product was found to be out of specification with the PLA film after 7 days. Silicon treatment was able to reduce this value to negligible, demonstrating the ability of agricultural interventions to facilitate sustainable packaging and reducing food waste in horticultural products.

The green revolution of food waste upcycling to produce polyhydroxyalkanoates

This review emphasizes the urgent need for food waste upcycling as a response to the mounting global food waste crisis. Focusing on polyhydroxyalkanoates (PHAs) as an alternative to traditional plastics, it examines the potential of various food wastes as feedstock for microbial fermentation and PHA production. The upcycling of food waste including cheese whey, waste cooking oil, coffee waste, and animal fat is an innovative practice for food waste management. This approach not only mitigates environmental impacts but also contributes to sustainable development and economic growth. Downstream processing techniques for PHAs are discussed, highlighting their role in obtaining high-quality materials. The study also addresses sustainability considerations, emphasizing biodegradability and recycling, while acknowledging the challenges associated with this path.

Upcycling fruit waste into microalgae biotechnology: Perspective views and way forward

Fruit and vegetable wastes are linked to the depletion of natural resources and can pose serious health and environmental risks (e.g. eutrophication, water and soil pollution, and GHG emissions) if improperly managed. Current waste management practices often fail to recover high-value compounds from fruit wastes. Among emerging valorization methods, the utilization of fruit wastes as a feedstock for microalgal biorefineries is a promising approach for achieving net zero waste and sustainable development goals. This is due to the ability of microalgae to efficiently sequester carbon dioxide through photosynthesis, utilize nutrients in wastewater, grow in facilities located on non-arable land, and produce several commercially valuable compounds with applications in food, biofuels, bioplastics, cosmetics, nutraceuticals, pharmaceutics, and various other industries. However, the application of microalgal biotechnology towards upcycling fruit wastes has yet to be implemented on the industrial scale due to several economic, technical, operational, and regulatory challenges. Here, we identify sources of fruit waste along the food supply chain, evaluate current and emerging fruit waste management practices, describe value-added compounds in fruit wastes, and review current methods of microalgal cultivation using fruit wastes as a fermentation medium. We also propose some novel strategies for the practical implementation of industrial microalgal biorefineries for upcycling fruit waste in the future.

Biotechnological Innovations Unleashing the Potential of Olive Mill Wastewater in Added-Value Bioproducts

Byproducts and wastes from the food processing industry represent an important group of wastes generated annually in large quantities. It is important to note that the amount of this waste will increase with industrialization, and effective solutions must be found urgently. Many wastes that cause environmental pollution are evaluated by their low-tech conversion into products with little economic value, such as animal feed and fertilizer. Therefore, the evaluation of food processing waste using effective recycling techniques has become an interesting subject with increasing population, ongoing biotechnological studies, and advances in technology. The conversion of food waste into biotechnological products via fermentation is a sustainable, environmentally friendly, and economical method in line with the principles of green chemistry. This approach promotes the reuse of food waste by supporting the principles of a circular economy and offers sustainable alternatives to fossil fuels and synthetic chemicals. This contributes to reducing the carbon footprint, preserving soil and water quality, and providing economic sustainability through the production of high-value products. In this study, the properties of olive mill wastewater, an important and valuable waste in the olive oil industry, its environmental aspects, and its use in biotechnological applications that integrate green chemistry are evaluated.

Upcycled canola meal extract mitigates UVB-induced skin wrinkling by regulating photoaging-related biomarkers in hairless mice

Canola meal, a by-product of processing canola into oil, reportedly contains high amounts of phenolic compounds and proteins. However, as canola meal is primarily used as feed for livestock, advances in multiple research fields are required to broaden its potential applications. Photoaging is caused by continuous exposure to ultraviolet (UV) radiation from sunlight. UV radiation generates reactive oxygen species and destroys collagen in the skin, thickening the epidermis, reducing elasticity, and causing wrinkles. We hypothesized that canola meal extract (CME) can mitigate the damage to skin associated with wrinkles induced by exposure to UVB radiation. To evaluate the anti-wrinkle effect, we administered CME orally to 40 female Hos:HR-1 hairless mice divided into 5 groups: (1) control mice, (2) a UVB group, and (3-5) CME-treated groups (CME-250, 500, and 1000 mg/kg body weight/day, respectively). All groups except the controls were irradiated with UVB 3 times a week to create wrinkles due to photoaging. CME administration inhibited the increase of the number, mean length, and mean depth of wrinkles induced by UVB radiation as assessed using a skin replica. Histopathological image analysis revealed that CME administration resulted in a decrease in epidermal thickness and an increase in collagen content, while increasing catalase activity and hydroxyproline content in skin tissues. CME administration inhibited the phosphorylation of mitogen-activated protein kinase and decreased the production of collagenase and gelatinase. These results suggest that CME, an upcycled material, has the potential to develop into a healthful and functional food ingredient with anti-wrinkling effects.

Upcycling of seafood side streams for circularity

The upcycling of seafood side streams emerges as a crucial facet in the quest for circularity within the food industry, surpassing other food sources in its significance. Seafood side stream plays an indispensable role in global food security and human nutrition. Nevertheless, losses ensue throughout the seafood supply chain, resulting in substantial waste generation. These underutilized seafood by-products contain valuable resources like edible proteins and nitrogenous compounds. Projections indicate that fishery products' utilization for human consumption will soar to 204 MT by 2030. Yet, the industry annually generates millions of tonnes of waste, predominantly from crab, shrimp, and lobster shells, leading to environmental impacts due to COD and BOD issues. A five-tier circular economic model offers a framework to manage seafood side-streams efficiently, with applications spanning pharmaceuticals, food production, animal feed, fertilizers, and energy fuel, thereby maximizing their potential and reducing waste in line with sustainability goals.

Impact of circular economy information on sensory acceptability, purchase intention and perceived value of upcycled foods by young consumers

The acceptability of upcycled foods is influenced by individual, context and product-related factors. This study aimed at investigating the impact of circular economy (CE) information on consumers' sensory acceptability, purchase intention and perceived value of upcycled foods, taking into account eating behaviours and personality traits that could be related to the consumers' sustainable consumption habits. To this aim, a group of young subjects (n = 80, 18-35 years old) participated in a two-step study. Firstly, an online questionnaire was administered to participants to gather information about their individual characteristics. Then, participants were divided into two groups, one receiving CE information (CE+) and one not receiving it (CE-), and they were asked to indicate the sensory acceptability, purchase intention and the perceived value of three upcycled foods, such as biscuits with grape pomace flour, beer brewed with leftover bread and a dairy product made from recovered crushed cheese. Questionnaire results showed that high individual responsibility, interest in healthy foods and high awareness of the social impact of their behaviours could be linked to a positive purchase intention for upcycled foods, as opposed to individual disgust sensitivity. No significant effect of CE information (p > 0.05) on sensory acceptability and purchase intention of all three upcycled foods was observed. Moreover, application of Principal Component Analysis (PCA) to the sensory data resulted in satisfactory classification of upcycled foods in terms of perceived values, explaining 86.83 % of data variability: the first principal component discriminated samples according to product category whereas the second principal component was able to clearly separate products according to CE information. Findings from this study provided valuable insights into the key individual characteristics that impact sustainable consumption habits, also highlighting the role of communication strategies in shaping consumer perceptions of upcycled foods so as to encourage a more sustainable consumption behaviour.

Derivation of Kokumi γ-Glutamyl Peptides and Volatile Aroma Compounds from Fermented Cereal Processing By-Products for Reducing Bitterness of Plant-Based Ingredients

Current food production methods and consumption behaviours are unsustainable and contribute to environmental harm. One example is food waste-around 38% of food produced is wasted each year. Here, we show that two common food waste products, wheat bran and brewer's spent grain, can successfully be upcycled via miso fermentation. During the fermentation process, kokumi γ-glutamyl peptides, known to increase mouthfulness, are produced; these include γ-ECG (oxidized), γ-EVG, γ-EV, γ-EE, γ-EF, and γ-EL. The profiles of kokumi peptides and volatile aroma compounds are correlated with koji substrate, pH, and enzymatic activity, offering straightforward parameters that can be manipulated to increase the abundance of kokumi peptides during the fermentation process. Correlation analysis demonstrates that some volatile aroma compounds, such as fatty acid ethyl esters, are correlated with kokumi peptide abundance and may be responsible for fatty, greasy, and buttery aromas. Consumer sensory analysis conveys that the bitter taste of vegetables, such as that in endives, can be dampened when miso extract containing kokumi peptides is added. This suggests that kokumi peptides, along with aroma volatile compounds, can enhance the overall flavour of plant-based products. This study opens new opportunities for cereal processing by-product upcycling via fermentation, ultimately having the potential to promote a plant-based diet.

Current Perceptions of Sustainable Diets in Ireland and the Outlook of Circular Eating Practices

Encouraging sustainable dietary practices is a positive step towards alleviating the negative impact of increasing food waste. This study explores consumers' perceptions of sustainable diets and factors influencing their adoption of sustainable practices, such as circular eating. Fifteen consumers in Ireland aged 18-65+ years were recruited for a qualitative study exploring their views on sustainable diets and their opinions on the use of peels, trimmings, and other by-products from fruit and vegetables as potential new ingredients or new circular food products. Age, gender, dietary preferences and educational background were important considerations during recruitment. Online interviews were conducted, and the data were analyzed using thematic analysis managed by NVivo 12. The results highlighted two overarching themes impacting circular eating, namely, food choice motives and awareness of food waste. These were linked to the participants' knowledge of and potential adoption of sustainable diets. Daily trade-offs were evident, linked to the product and the person who was also strongly influenced by their micro-environment. Consumer education from credible sources would be required to create awareness of circular eating. Most respondents were positively disposed to the concept of circular eating, as long as food safety concerns and affordability considerations were addressed through industry transparency.

Sustainable Isolation of Bioactive Compounds and Proteins from Plant-Based Food (and Byproducts)

Plant-based food produces significantly less greenhouse gases, and due to its wealth of bioactive components and/or plant-based protein, it becomes an alternative in a sustainable food system. However, the processing and production of products from plant sources creates byproducts, which can be waste or a source of useful substances that can be reused. The waste produced during the production and processing of food is essentially nutrient- and energy-rich, and it is recognized as an excellent source of secondary raw materials that could be repurposed in the process of manufacturing and preparing food, or as feed for livestock. This review offers an overview of the sources and techniques of the sustainable isolation of bioactive substances and proteins from various sources that might represent waste in the preparation or production of food of plant origin. The aim is to uncover novel approaches to use waste and byproducts from the process of making food to provide this waste food an additional benefit, not forgetting the expectations of the end user, the consumer. For the successful isolation of bioactive ingredients and proteins from food of plant origin, it is crucial to develop more eco-friendly and efficient extraction techniques with a low CO2 footprint while considering the economic aspects.

Effect of heat treatment on microbiological safety of supermarket food waste as substrate for black soldier fly larvae (Hermetia illucens)

Supermarket food waste, constituting 13% of global food waste, can be upcycled as substrate for black soldier fly larvae (BSFL) and converted into larval biomass. Since presence of food pathogens in supermarket food waste is likely, microbiological safety should be ensured when using waste as insect substrate. Heat treatment provides a suitable pre-treatment to reduce microbiological contaminations. This study investigated the effect of different temperature-time combinations on the microbiological safety of supermarket food waste as BSFL substrate. Artificial supermarket food waste without meat and fish (SFW) was inoculated with both Salmonella and Staphylococcus aureus (7.0log cfu/g) and treated at 50 and 60 °C for 10, 20 and 30 min. While 50 °C was insufficient for adequate pathogen reduction, 60 °C only required 10 min to reduce the Enterobacteriaceae and S.aureus counts to < 1.0logcfu/g and for absence of Salmonella in 25 g. Heat-treated SFW could be stored for two days at ambient temperature or refrigerated without pathogen growth. Treatment of supermarket food waste containing meat and fish at 60 °C for 10 min caused similar results as for SFW, but S.aureus persisted (2.4logcfu/g), possibly by protective effects of fat and/or proteins. Finally, BSFL rearing experiments on SFW revealed significantly higher larval mass, bioconversion efficiency and waste reduction than on Gainesville diet, with no notable differences between untreated and heat-treated SFW. Rearing BSFL on supermarket food waste is possible, and unsafe food waste can be heated to obtain safety without eliminating nutrients necessary for rearing.

Upcycling in the context of biotechnology-based solutions for food quality, loss, and consumer perception

Wasted food is the single biggest contributor to greenhouse gases. Globally, attempts are being made to both reduce surplus food and divert it into food-to-food operations. This opinion piece covers upcycling and biotechnology-mediated solutions on a technology continuum as a part of the bigger whole to solve this problem. Upcycling is an approach to divert foods that would otherwise be wasted into higher uses that would also have tangible benefits to the environment and society. Likewise, biotechnology can help farmers produce crops with longer shelf life and that satisfy cosmetic standards. Uncertainty, either in the form of food safety, technology, or neophobia in the case of upcycled foods or genes (cisgenic or transgenic) in the case of biotechnology, is a hurdle. Communication and consumer perception should be researched. Both upcycling and biotechnology can provide practical solutions, but their acceptance depends on communication strategies and consumer perception.

From food waste to functional component: Cashew apple pomace

Globally, large numbers of people suffer from undernourishment and food insecurity, while a third of food produced is lost or wasted. The widely cultivated cashew nut produces large quantities of waste in early processing. It grows on an edible peduncle called the cashew apple which contains many essential nutrients. An estimated 36.9 million tons of cashew apples are produced annually, but only small amounts are used to make juice. The remainder is considered production waste. This review presents the potential of cashew apple pomace as a food ingredient and examines the effects of incorporation on chemical composition, physical properties and sensory evaluation. Inclusion in optimized amounts into food products is a strategy proven to produce palatable results with high acceptability. Transforming this manufacturing by-product into a functional food component will have economic benefits, improve resource-utilization, promote sustainability and potentially increase the nutritional value of foods.

Feasibility study for estimating optimal substrate parameters for sustainable green roof in Sri Lanka

In twenty-first century buildings, green roof systems are envisioned as great solution for improving Environmental sustainability in urban ecosystems and it helps to mitigate various health hazards for humans due to climatic pollution. This study determines the feasibility of using five domestic organic wastes, including sawdust, wood bark, biochar, coir, and compost, as sustainable substrates for green roofs as compared to classical Sri Lankan base medium (fertiliser + potting mix) in terms of physicochemical and biological parameters associated with growing mediums. Comprehensive methodologies were devised to determine the thermal conductivity and electric conductivity of growing mediums. According to preliminary experimental results, the most suitable composition for green roof substrates comprised 60% organic waste and 40% base medium. Sawdust growing medium exhibited the highest moisture content and minimum density magnitudes. Biochar substrate was the best performing medium with the highest drought resistance and vegetation growth. The wood bark substrate had the highest thermal resistance. Growing mediums based on compost, sawdust, and coir produced the best results in terms of nitrate, phosphate, pH, and electric conductivity (EC) existence. This study provided a standard set of comprehensive comparison methodologies utilising physicochemical and biological properties required for substrate characterization. The findings of this research work have strong potential in the future to be used in selecting the most suitable lightweight growing medium for a green roof based on stakeholder requirements.

Upcycled foods: A nudge toward nutrition

One of the aims of the United Nations Sustainable Development Goals (SDG) is to end hunger and ensure access by all people to safe, nutritious, and sufficient food all year round. An obvious synergy exists between the second SDG “Zero Hunger” and SDG target 12.3 which focuses on halving food waste and reducing food losses. In addition to helping improve global food security, reducing food waste provides financial and environmental benefits. Upcycling food is a technical solution for food waste reduction that retains the nutritional and financial value of food by-products. However, many of the upcycled foods produced are discretionary foods such as biscuits, crackers, and other snack food that are not part of a healthy dietary pattern, and should only be eaten sometimes in small amounts. Given the importance of ensuring a sustainable healthy diet, this paper discusses opportunities for upcycled food manufacturers to produce more nutritious products.