An increasing global population, rising energy demands, and the shift toward a circular bioeconomy are driving the need for more resource-efficient waste management. The increase in the world population—now exceeding 8 billion as of 2024—results in an increased need for alternative proteins, both human and feed grade proteins, as well as for biopolymers and bioenergy. As such, agricultural, forest, and marine waste biomass represent a valuable feedstock for production of food and feed ingredients, biopolymers, and bioenergy. However, the lack of integrated and efficient valorization strategies for these diverse biomass sources remains a major challenge. This literature review aims to give a systematic approach on the recent research status of agricultural, forest, and marine waste biomass valorization, focusing on cascade processing (a sequential combination of processes such as pretreatment, extraction, and conversion methods). Potential products will be identified that create the most economic value over multiple lifetimes, to maximize resource efficiency. It highlights the challenges associated with cascade processing of waste biomass and proposes technological synergies for waste biomass valorization. Moreover, this review will provide a comprehensive understanding of the potential of waste biomass valorization in the context of sustainable and circular bioeconomy.

Foodborne challenges, including, the ingestion of pathogens, toxins, and allergens, trigger a series of physiological and endocrine responses that are essential for maintaining homeostasis and protecting the body from harm. The endocrine system plays a key role in mediating these responses through the activation of various hormonal pathways. Upon exposure to foodborne pathogens, hormones such as cortisol, insulin, ghrelin, leptin, and glucagon are involved in modulating immune function, metabolic processes, and gastrointestinal motility. Additionally, the hypothalamic-pituitary-adrenal (HPA) and the gut-brain axes play crucial role in coordinating systemic responses to stress and infection. These endocrine alterations help manage inflammation, enhance immune defences, and regulate energy balance. However, prolonged or exaggerated responses to foodborne challenges may lead to metabolic dysregulation, immune dysfunction, and an increased susceptibility to chronic diseases. This chapter explores the complex interplay between foodborne challenges and endocrine responses, emphasizing the importance of these processes in health and disease.

Corncobs, produced globally at over 200 million tons annually with 11–18% lignin content, represent an abundant and underexploited lignocellulosic resource for sustainable lignin valorization. In this study, two distinct extraction methodologies, alkaline treatment using sodium hydroxide and an organosolv process with a 50:50 ethanol/water mixture, were systematically compared for their efficiency in isolating lignin from corncobs. Both protocols achieved high yields, up to 82% for alkaline and 84% for organosolv extraction under optimized conditions. The resulting lignins displayed notable differences in chemical structure and physical properties, as revealed by spectroscopic and thermal analyses, highlighting their divergent potential for downstream applications. To evaluate the suitability of these lignins to biocatalytic upgrading, post-extraction enzymatic treatment was performed using Pycnoporus cinnabarinus laccase (EC 1.10.3.2). Significant structural modifications were observed in alkaline-extracted lignin, as determined by FTIR spectroscopy, while organosolv lignin remained largely unaltered, a difference attributed to its lower aqueous solubility at the enzyme’s optimal pH. These results demonstrate the critical impact of extraction conditions on lignin reactivity and suitability for enzymatic tailoring. This work underscores the potential for holistic corncob valorization within integrated biorefinery frameworks. Selective extraction and targeted enzymatic modification not only facilitate efficient by-product utilization but also expand the prospects for producing versatile bio-based materials, thereby advancing the transition toward a sustainable, circular bioeconomy.

The wine industry generates significant amounts of white grape pomace (WGP), a lignocellulosic byproduct with untapped potential for valorisation. This study presents an integrated biorefinery approach to maximize the utilization of WGP through a combination of hydrothermal and organosolv treatments, followed by solid state fermentation (SSF). Hydrothermal pretreatment was optimized to maximize sugar extraction, achieving up to 80.94 g L⁻¹ of reducing sugars, which can serve as a substrate for microalgae cultivation. Organosolv treatment enabled the selective recovery of polyphenols and lignin, with the highest polyphenol yield (2.27 g kg⁻¹ DW) obtained at 150 °C and a lignin yield of 34.72 % at 200 °C. The remaining solid fractions were subjected to SSF using Aspergillus oryzae, Neurospora intermedia, and Rhizopus oryzae, leading to a significant increase in protein content, with A. oryzae achieving a protein content of 17.6 % on dry weight basis. This multi-step integrated approach demonstrates a scalable and sustainable strategy for converting WGP into multiple high-value bioproducts, promoting circular economy principles in the food sector.

Pulp and paper manufacturing ranks as one of the most water and energy-intensive sectors globally, invariablyleading to significant environmental pollution e.g. issues related to air pollution and waste disposal. Also, asglobal competition intensifies, prices of forest products are expected to keep decreasing. To ensure their viability,traditional producers must augment their revenue streams by diversifying into the production of bioenergy andbiomaterials, alongside traditional wood, pulp, and paper products. A feasible solution is the integrated productsbiorefineries which provide a distinctive chance to pulp and paper industry to enhance revenues as well asreduce their environmental impact. Since pulp and paper stands as the predominant industry in Sweden, thisreview article explores the emerging biorefinery process options and main technological pathways beingdeveloped within Swedish pulp and paper mills. It also delves into the significant challenges that are beingencountered in this evolving landscape and what possibilities lie ahead for responsible and sustainable pulp andpaper operations. 

Cheese whey is an industrial by-product that is generated in excess during the cheese production process in the dairy industry. Despite the potential utility of whey, it continues to pose environmental threats in the industry. This study comprehensively evaluates the utilization of two fermentation techniques (solid-state fermentation and submerged fermentation) for producing fungal biomass from cheese whey powder, employing Aspergillus oryzae, Rhizopus oryzae, and Neurospora intermedia for sustainable food production. It has been observed that submerged fermentation is more effective in increasing the protein content of whey powder compared to solid-state fermentation. The highest biomass yield was achieved with A. oryzae (5.29 g/L, 0.176 g biomass/g substrate), followed by N. intermedia (3.63 g/L, 0.121 g biomass/g substrate), and R. oryzae (1.9 g/L, 0.063 g biomass/g substrate). In the bubble column reactor, the protein content of the substrate (78.65 g/kg) increased by 165.54 and 176.69% with A. oryzae (208.85 g/kg) and N. intermedia (217.62 g/kg), respectively. This study has demonstrated that whey powder can be converted into protein-rich biomass through fungal bioconversion. The obtained biomass has the potential to be developed as an alternative food and feed source, contributing to waste management and sustainable food production. 

In this study, predominant bacterial and archaeal populations and their roles during anaerobic mono-digestion of food waste (FW) and co-digestion of FW with straw pellets (SP) at thermophilic temperature (53 ± 1 °C) were assessed by Next Generation Sequencing (NGS) analysis at organic loading rates (OLRs) of 3.0 and 7.0 gVS/L/d. Depending on the seed; results revealed that Firmicutes, Bacteroidetes, and Proteobacteria were, respectively the most prevalent bacterial phyla at both OLRs investigated. On the other hand, Euryarchaeota was dominated by methanogens playing crucial role in biogas production and correlated mainly with the activities of Methanobacteria and Methanomicrobia at class level. Acetoclastic Methanosaetae was the predominant genus at OLR = 3.0 gVS/L/d; however, shared the same predominance with hydrogenotrophic methanogens Methanospirillium at the highest OLR. Although no clear effect in response to straw addition at OLR of 3.0 gVS/L/d could be seen in terms of methanogenic archaea at genus level, hydrogenotrophic methanogens revealed some shift from Methanobacterium to Methanospirillium at higher OLR. Nevertheless, no prominent microbial shift in the presence of wheat straw at increased OLR was likely due to adapted inoculation at start-up which was also demonstrated by relatively stable biogas yields during co-digestion.

Brewer's spent grain (BSG) is a clean byproduct from the food sector, comprising 85% of the brewing process solid byproducts. BSG is mainly used as low-quality animal feed and often ends up in landfills due to its short shelf life. However, considering its abundant availability and high nutritional content, BSG holds the potential for biorefineries to produce valuable products. The recalcitrant nature of BSG poses a challenge, requiring pretreatment steps. Therefore, this study focused on valorizing BSG obtained from organosolv pretreatment by producing food- and feed-grade single-cell protein (SCP). The BSG was subject to organosolv pretreatment at 180C for 2 h with 50% v/v ethanol as solvent. Filamentous fungi N. intermedia and A. oryzae were cultivated on as-received and different fractions of organosolv-treated BSG to evaluate the effect of factors such as pretreatment, fungal strain, pretreated fraction content, and substrate loading on fungal biomass yield, biomass composition (protein content), and metabolite production. A. oryzae cultivation on all tested substrates yielded 7%-40% more biomass than N. intermedia. Cultivating A. oryzae on organosolv liquor resulted in the highest biomass protein content (44.8% ± 0.7%) with a fungal biomass concentration of 5.1 g/L. A three-fold increase in the substrate loading increased the ethanol-to-substrate yield by 50%, while protein content was decreased by 23%. Finally, a biorefinery concept was proposed to integrate the organosolv pretreatment of BSG with fungal cultivation for maximum yield of SCP while obtaining other products such as lignin and ethanol, providing a sustainable rout for managing BSG.

Thin stillage holds promise as a substrate for cultivating filamentous fungi. The suspended solids content of thin stillage directly influences biomass production. However, little attention has been given to its effects on fungal cultivation and composition, which is the focus of the current study. Various thin stillage dilutions were used to cultivate Zygomycete and Ascomycetes. Biomass and nutrient uptake were monitored during the cultivation. The harvested biomass was analyzed to assess nutrient composition in relation to fish dietary requirements. Thin stillage diluted to 75 % significantly enhanced fungal biomass production, with increases of 160 %, 213 %, and 235 % for A. oryzae, R. delemar, and N. intermedia, respectively. The harvested fungal biomass boasted approximately 50 % protein content, constituting 45 % essential amino acids. These findings underscore the potential of cultivating fungi in diluted thin stillage to boost biomass production and its high-quality nutritional composition positions it as a valuable candidate for fish feed formulations.

Sustainable provision of chemicals and materials is undoubtedly a defining factor in guaranteeing economic, environmental, and social stability of future societies. Among the most sought-after chemical building blocks are volatile fatty acids (VFAs). VFAs such as acetic, propionic, and butyric acids have numerous industrial applications supporting from food and pharmaceuticals industries to wastewater treatment. The fact that VFAs can be produced synthetically from petrochemical derivatives and also through biological routes, for example, anaerobic digestion of organic mixed waste highlights their provision flexibility and sustainability. In this regard, this review presents a detailed overview of the applications associated with petrochemically and biologically generated VFAs, individually or in mixture, in industrial and laboratory scale, conventional and novel applications.