This study evaluated the anaerobic digestion suitability of bio-waste from different sources by comparing their biochemical methane potential (BMP), biodegradability (BI), and content of contaminants (heavy metals and physical impurities) - an often-overlooked factor but one of particular concern in bio-waste. Predominant heavy metals included Cu and Zn, while recurring physical impurities comprised plastics and organic non-biodegradable matter. Food waste from food processing plants were most suitable, exhibiting low contamination and high biogas conversion (BMP>549 NmLCH4/gVS and BI>86 %). Conversely, organic fractions from mechanical biological treatment were highly contaminated, while green waste displayed low biogas conversion (BMP<368 NmLCH4/gVS and BI<72 %). Food waste from households and medium/large-sized producers also demonstrated high biogas conversion, but variable contamination levels could compromise their suitability. Assessing contaminants alongside BMP and BI provides a comprehensive approach for selecting suitable bio-waste feedstocks that can be introduced in biogas plants.

Consumers are interested in new sustainable ingredients but are unwilling to accept undesirable sensory properties in their food products. Luffa (Luffa cylindrica) is mainly harvested and processed for its fibrous network, which is used as an exfoliator, while its seeds are usually discarded. However, the seeds have been found to have various nutritional benefits. As such, this study investigated the sensory properties of luffa seed powder added to yogurt and compared it to other seed powder (flax, sunflower, chia, and hemp). Consumers (n = 107) evaluated their liking of the different seeds added to yogurt using hedonic scales and the sensory properties using check-all-that-apply (CATA). The luffa seeds when mixed with yogurt were associated with off-colour, off-flavour, metallic, strong flavour, bitter, salty, earthy and decreased consumer liking. The flax and sunflower seeds were found to be sweet, nutty, cooked, mild flavour, and to have a smooth texture. The overall liking scores for the flax and sunflower seed samples were significantly higher than the luffa and hemp samples. Future studies should investigate different drying and roasting treatments to improve the sensory properties of the luffa seeds.

Anaerobic co-digestion of source-separated blackwater (BW) and food and kitchen waste (FW) offers decentralized circular economy solutions by enabling local production of biogas and nutrient-rich byproducts. In this study, a 2 m3 pilot-scale continuously stirred tank reactor (CSTR) operated under mesophilic conditions was utilized for co-digestion of BW and FW. The process obtained a CH4 yield of 0.7 ± 0.2 m3/kg influent-volatile solid (VS), reaching a maximum yield of 1.1 ± 0.1 m3/kg influent-VS, with an average organic loading rate of 0.6 ± 0.1 kg-VS/m3/d and HRT of 25 days. The CH4 production rate averaged 0.4 ± 0.1 m3/m3/d, peaking at 0.6 ± 0.1 m3/m3/d. Treatment of digestate through flocculation followed by sedimentation recovered over 90% of ammonium nitrogen and potassium, and 80-85% of total phosphorus in the liquid fraction. This nutrient-rich liquid was used to cultivate Chlorella vulgaris, achieving a biomass concentration of 1.2 ± 0.1 g/L and 85 ± 3% and 78 ± 5% ammonium nitrogen and phosphorus removal efficiency, respectively. These findings not only highlight the feasibility of anaerobic co-digestion of source-separated BW and FW in local biogas production but also demonstrate the potential of microalgae cultivation as a sustainable approach to converting digestate into nutrient-rich algae biomass.

Apples are among the most commonly cultivated fruits globally. Approximately 65% of annual apple production is transformed into apple juice concentrate generating a large amount of waste material named apple pomace, which includes seeds, skin, and other components. Disposing of apple by-products directly into the environment constitutes a source of environmental pollution due to its high-water content and easily fermentable nature. Apple pomace is rich in polyphenols that can be utilized as active components in cosmetic, nutraceutical, or pharmaceutical products. The present study aims to describe and compare different physical methods for the extraction of polyphenols from apple pomace. Water was used as the extraction solvent in thermal-stirred extraction (TSE), ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE). The best extraction conditions were identified in terms of solid to solvent ratio, temperature, power, and time through a kinetic study. The best extraction parameters were compared environmentally on a pilot scale through a life cycle assessment (LCA). All the results demonstrated the MAE is the best technique to extract polyphenol from apple pomace in terms yield and environmental impact proving that it is possible to transform waste into a sustainable source of bioactive ingredients.

Given the urgent climate change and food security challenges, upcycled food products are crucial for sustainable food production and waste management. This study investigates Taiwanese consumer behavior towards upcycled foods using the value-attitude-behavior (VAB) theory, focusing on \"product knowledge\", \"green perceived quality\", and \"price sensitivity\". Of the 335 distributed surveys, 320 valid responses (95.5% effectiveness) were analyzed. The results indicated that eco-conscious values strongly influenced consumer attitudes and anticipated guilt (β = 0.647, p < 0.001; β = 0.691, p < 0.001), shaping behavioral intentions (β = 0.290, p < 0.001). Attitudes significantly correlated with intentions, validating the VAB framework. However, anticipated guilt showed a minimal impact (β = 0.029, p = 0.629), revealing complex consumer emotions. Green perceived quality and product knowledge were the key decision-making factors (β = 0.193, p < 0.001; β = 0.146, p < 0.001). Surprisingly, price sensitivity positively influences intentions (β = 0.764, p < 0.001), suggesting the consumer prioritization of quality and environmental values over price. These insights inform strategies for businesses to enhance consumer engagement and sustainability alignment, advancing progress towards Sustainable Development Goals (SDGs).

This study aimed to develop a value-added bio-based polymer product for food packaging. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a promising bioplastic with limitations in processability and brittleness, which our group previously addressed by incorporating high-molecular-weight natural rubber (NR) compatibilized with peroxide and coagent. Yet, processability in an industrial setting proved difficult. Coffee oil epoxide (COE), a waste-derived plasticizer, was incorporated into the PHBV/NR/peroxide/coagent matrix via extrusion, and properties of resulting sheets were evaluated. COE incorporation significantly decreased the oxygen and water permeability of the PHBV/NR sheets. Maximum degradation temperature Tpeak (°C) increased by ~4.6 °C, and degree of crystallinity decreased by ~15.5% relative to pristine PHBV, indicating good thermal stability. Melting (Tm) and glass transition temperatures (Tg) of the PHBV/NR blend remained unchanged with COE incorporation. X-ray diffraction (XRD) revealed ~10.36% decrease in crystal size for the plasticized blend. Energy-dispersive X-ray analysis (EDAX) and scanning electron microscopy (SEM) confirmed good dispersion with no phase separation. The water uptake capacity of the plasticized blend was reduced by 61.02%, while surface contact angle measurements showed improved water resistance. The plasticized PHBV sheet shows promise for environmentally friendly packaging films due to its high thermal stability, effective barrier properties, and industrial scalability.

With growing awareness of the environmental, economic, and social costs associated with food waste, there is a concerted effort on multiple scales to recover the nutrient value of discarded food. These developments are positive, but the rapid movement toward alternatives and the complexity of solving problems located at the intersection of economic, social, and environmental systems also have the potential to produce unanticipated risks. This paper draws upon long-term stakeholder-engaged research throughout New England, with a focus on Maine, to develop a transdisciplinary, systems-based model of the potential social, economic, and environmental risks of food waste nutrient cycling. Our effort is intended to help inform the creation of safe, functional, and environmentally benign circular food systems.

This study comprehensively investigated the abundance, morphologies, and polymer types of plastics, larger (1-5 mm) and smaller (< 1 mm) microplastics (MPs), in organic fertilizers using spectroscopic and microscopic methods. MPs abundance varied depending on the type of waste employed. MPs were detected in 80% of the investigated compost samples, while macro/meso plastics were found in only four samples. Compost from mixed municipal solid waste exhibited the highest MPs contamination (23100 ± 3615 items/kg dry weight), whereas compost produced from canteen waste had the lowest contamination (100 ± 65 items/kg dry weight). Smaller MPs were dominant in all samples. The estimated loads of MPs introduced into agricultural soil exceeded the previous studies. Common morphologies observed were sheet, film, fragment, and fiber, while dominant polymer types were polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), and polystyrene (PS). Heavy metals, including Cr, Cu, Ni, and Pb, were identified in association with MPs. Results indicate that the utilization of appropriate waste for composting and upgrading fertilizer regulations is crucial to protect the environment and human health from smaller MPs.

BACKGROUND: To improve the healthfulness of foods offered while accelerating the use of environmental sustainability practices, it is important to engage hospital food service operators in the adoption of such practices. The purpose of this study was to explore barriers, facilitators and best practices for implementing environmental sustainability standards in food service among veterans affairs (VA) hospitals in the United States.
METHODS: We conducted an online survey with 14 VA hospital food service directors and then 11 qualitative interviews. The survey assessed motivations for initiating sustainability standards and included a self-rating of implementation for each of five standards: increasing plant-forward dishes, procuring and serving sustainable foods that meet organic/fair trade and other certifications, procuring and serving locally produced foods, reducing food waste and reducing energy consumption. Interviews were transcribed verbatim. Qualitative analysis, including coding of themes and subthemes, was conducted by two coders to determine barriers, facilitators and best practices for each of these five standards. Quantitative methods (counts and frequencies) were used to analyse the survey data.
RESULTS: Participants had an average of 5 years of experience implementing sustainability standards. The top three motivators cited were reducing food waste, serving healthier foods and increasing efficiency or cost savings. Barriers revolved around patient preferences, contractual difficulties and costs related to reducing waste. Facilitators included taste testing new recipes that include more sustainable food options and easy access to sustainable products from the prime vendor. Best practices included making familiar dishes plant-forward and plate waste studies to prevent overproduction.
CONCLUSIONS: Although there were many barriers to implementation, food service directors had solutions for overcoming challenges and implementing food service sustainability standards, which can be tested in future sustainability initiatives.

Techno-economic assessment (TEA) of a valorization of bulking agent (BA) ratios on the food waste compost value chain is made to assess economic feasibility. TEA was performed with two plans (Plan A: existing composting facilities; Plan B: new composting facilities) and each plan was under four scenarios. The BA (i.e. corn stalks, garden waste, and watermelon seedlings) ratio of 5 % (S1), 10 % (S2), 20 % (S3), and garden waste with a ratio of 20 % (S4). Results indicate that S2, with a net present value (NPV) of 128.9 million, represents Plan A\'s most economically viable scenario. Although the total operating costs of S4 were 18.9 %-23.5 % higher, 25.6 %-42.2 % higher total revenue made S4 have an NPV of 92.9 million, making it the most viable scenario in Plan B. All scenarios show positive NPV within a ± 20 % fluctuation range. Organic fertilizer price, government subsidies, and processing capacity were the key factors influencing NPV.