High-value Products Research Articles

Production of Bio-Oil via Pyrolysis of Banana Peel and Tire Waste for Energy Utilization

The energy crisis and environmental degradation are pressing challenges, intensified by population growth and the excessive generation of solid waste. Converting waste into energy, especially through pyrolysis, is a viable and sustainable alternative. This thermal process transforms waste such as banana peels and used tires into high-value products, such as gas, char, and bio-oil. This study aims to evaluate the production of bio-oil from the pyrolysis and co-pyrolysis of these materials, considering different proportions and temperatures, as well as using an Artificial Neural Network (ANN) to predict the composition of the bio-oils. The pyrolysis tests with 100% banana peel and 75% banana peel mixed with 25% tire showed a decrease in bio-oil yield with increasing temperature, with a drop of around 30% when comparing 500 °C to 400 °C. In contrast, co-pyrolysis with 50% of each material and 100% of the tire resulted in increases in bio-oil yield as the temperature rose. A Fourier Transform Infrared Spectroscopy (FTIR) analysis of the bio-oils showed the presence of relevant functional groups, while an elemental analysis and ANN provided accurate predictions of carbon, hydrogen, and nitrogen content. The results suggest that the co-pyrolysis of waste tires and banana peels is a viable alternative for the production of bio-oil.

Valorization of Arbutus unedo L. Bark Through Chemical Composition Analysis, Liquefaction, and Bio-Based Foam Production

Arbutus unedo (strawberry tree) is a small Mediterranean tree capable of vigorous regrowth after disturbances like fire. Traditionally used for biomass fuel, its bark and branches hold potential for higher-value products through ecovalorization into liquid mixtures that could replace petroleum-based materials. This study aimed to explore the chemical composition of various components of Arbutus unedo and to produce a liquefied material from its internal (IB) and external bark (EB). Chemical compositions of internal and external bark were determined using TAPPI standards including ash, extractive content, lignin, and cellulose. Metal cations were analyzed by ICP. Liquefaction of bark was optimized in a PARR reactor, evaluating factors such as particle size, temperature, and time, and the best polyols were monitored by FTIR-ATR. Polyurethane foams were made with internal and external bark materials liquefied by polymerization with isocyanate, a catalyst, and water as a blowing agent. Results showed that EB has a higher extractive and lignin content, while IB contains more cellulose. Liquefaction yields were higher for IB (74%) than EB (68%), with IB yielding polyols that produced stronger and more resilient foams with higher compressive strength and modulus of elasticity. Mechanical properties of the foams were influenced by the NCO/OH ratio and catalyst levels. Overall, the internal bark demonstrated superior performance for foam production, highlighting its potential as an eco-friendly alternative to petroleum-derived materials.

Transform Sustainable: Innovating for a Sustainable Future

The Transform Sustainable Program of the Federal Institute of Education, Science and Technology of the South of Minas Gerais (IFSULDEMINAS) is an example of how creativity and innovation can transform challenges into solutions. Through the transformation of donated and seized materials into high-value products, the program contributes to environmental protection, income generation and social development. The program's main focus is on sustainability, reducing material disposal, promoting reuse and recycling, and contributing to the circular economy. Technological innovation is also fundamental, with the development of innovative solutions to transform discarded materials into high-value products. The program has a partnership with several institutions, such as the Brazilian Federal Revenue Service (RFB), city halls, schools and NGOs, demonstrating the power of collaboration to generate positive social impact. By generating income for local communities, promoting environmental education and social development, the program contributes to building a fairer and more prosperous future for everyone. Transform Sustainable is an inspiring model that demonstrates the potential of sustainability, innovation and collaboration to build a greener, fairer and more prosperous future for all. Through the union of efforts between IFSULDEMINAS and several institutions, the program is transforming the present and building a more sustainable future for the next generations.

Innovative Strategies for Microalgae-Based Bioproduct Extraction in Biorefineries: Current Trends and Future Solutions Integrating Wastewater Treatment

Recently, microalgae have emerged as a promising feedstock for biorefineries, offering significant potential for producing high-value bio-based products in areas such as biofuels, nutraceuticals, and environmental management. This study, therefore, undertook an in-depth bibliometric review of 535 articles out of 736 publications published between 2010 and 2024 and sourced from the Scopus database. With the use of the VOS-viewer software, this work identified the major trends within significant research areas in terms of focus and global collaboration networks that pertain to microalgae-based bioproducts. Also, it explored cutting-edge techniques for bioproduct extraction and processing that are both efficient and eco-friendly. This analysis also showed a remarkable growth in output, with peaks in the year 2022, reflecting an interest in renewable energy and methods of sustainable production. The main keywords identified deal with subject areas such as energy, environmental science, and chemical engineering. The dominant technologies referred to dealing with lipid extraction, bio-crude production, and nutrient recycling. While addressing cost, scale-up, and environmental concerns, there is still a need to improve extraction techniques like ultrasonic treatment, supercritical fluid treatment, and enzymatic treatment. Other emerging areas of research include genetic engineering and integrated biorefinery models, which are expected to provide a roadmap for future advancements in the field. The challenges innate in meeting this through innovation and optimization will be the key to realizing the full potential of microalgae to contribute to the circular bioeconomy.

Microalgae biomass: A multi-product biorefinery solution for sustainable energy, environmental remediation, and industrial symbiosis

The rapid expansion of industrialization and the depletion of non-renewable fossil fuel have urged the search for alternative and sustainable renewable resources to fulfil the escalating energy demand while reducing water pollution and greenhouse gas emissions. Microalgae have emerged as a promising and sustainable solution, capable of not only treating wastewater but also yielding valuable products. This study aimed to explore the primary applications of microalgae, including wastewater treatment and CO2 sequestration, while assessing the viability of utilizing the resultant microalgae biomass (MB) across diverse sectors such as liquid and gaseous biofuels, bioplastics, animal and aquatic feed, nutraceuticals and pharmaceuticals, biofertilizers, and cosmetics production. Additionally, the study discusses the importance of assessing the environmental impacts of these applications through life cycle assessment (LCA) studies and elaborate the concept of a multi-products biorefinery system. To address the contemporary challenges of the bio-economy in simultaneously producing multiple high-value products, the biorefinery complexity index (BCI) was estimated to be 37, highlighting the need for further research to establish the practicability of a multi-products biorefinery system.

Direct low concentration CO2 electroreduction to multicarbon products via rate-determining step tuning

Direct converting low concentration CO2 in industrial exhaust gases to high-value multi-carbon products via renewable-energy-powered electrochemical catalysis provides a sustainable strategy for CO2 utilization with minimized CO2 separation and purification capital and energy cost. Nonetheless, the electrocatalytic conversion of dilute CO2 into value-added chemicals (C2+ products, e.g., ethylene) is frequently impeded by low CO2 conversion rate and weak carbon intermediates’ surface adsorption strength. Here, we fabricate a range of Cu catalysts comprising fine-tuned Cu(111)/Cu2O(111) interface boundary density crystal structures aimed at optimizing rate-determining step and decreasing the thermodynamic barriers of intermediates’ adsorption. Utilizing interface boundary engineering, we attain a Faradaic efficiency of (51.9 ± 2.8) % and a partial current density of (34.5 ± 6.4) mA·cm−2 for C2+ products at a dilute CO2 feed condition (5% CO2 v/v), comparing to the state-of-art low concentration CO2 electrolysis. In contrast to the prevailing belief that the CO2 activation step (CO2+e−+*→CO2−*\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${{CO}}_{2}+{e}^{-}+\\, * \\,\ o {}^{ * }{CO}_{2}^{-}$$\\end{document}) governs the reaction rate, we discover that, under dilute CO2 feed conditions, the rate-determining step shifts to the generation of *COOH (CO2−*+H2O→C*OOH+OH−(aq)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${}^{ * } {{CO}}_{2}^{-}+{H}_{2}O\ o {}^{ * } {COOH}+{{OH}}^{-}({aq})$$\\end{document}) at the Cu0/Cu1+ interface boundary, resulting in a better C2+ production performance.

Boosting CO2 photoreduction to acetic acid via the van der waals heterostructures of monolayer Nb2O5 modified TiO2 nanotubes

Photoreduction of CO2 to hydrocarbons encounters two significant challenges: low product yields and poor selectivity. Furthermore, the difficulty of C-C coupling reactions hinders the formation of higher-value two-carbon products. This paper presents a strategy to address these challenges by fabricating a van der Waals heterostructure photocatalyst through the surface modification of TiO2 nanotubes (TNTs) with monolayer Nb2O5, denoted as 3 %Nb2O5/TNTs. Compared with TNTs, the acetic acid yield of heterostructures reached 28.4 μmol gcat-1h−1, and the selectivity rose from 48 % to 69 %. The van der Waals heterostructures reduced the photogenerated electron-hole recombination, extending the lifetime of charge carriers. The reduction of resistance and the presence of built-in fields accelerated the migration of charge carriers, thereby showing an enhanced photocatalytic performance. Surface modification of monolayer Nb2O5 promoted the activation adsorption of CO2 to CO2·-, facilitating the following C-C coupling reaction. Furthermore, its surface acidity sites modulated the hydrogenation reactions following C-C coupling, thereby increasing both the yield and selectivity of acetic acid.

One-step pyrolysis of ZIF-8 after recovering rare earth elements from mining wastewater as a functional fenton-like catalyst

The management of rare earth elements (REEs) from mining wastewater has consistently a key issue. Our previous research has demonstrated the selective adsorption of REEs in mining wastewater by ZIF-8. Herein, one-step pyrolysis of ZIF-8 after recovering REEs from mining wastewater as a high-value product was further proposed. The resulting REEs-based magnetic nanoporous carbon materials (REEs-MPC) was utilized for the activation of peroxymonosulfate (PMS) in the removal of bisphenol A (BPA). Experimental results indicate substantial BPA removal efficiencies of 74.62 %, 83.57 %, and 70.06 % with REEs-MPC synthesized at different pyrolysis temperatures (700 °C, 800 °C, and 900 °C). The detailed characterizations reveal the REEs-MPC at 800 °C was obtained (REEs-MPC/800) exhibit prominent graphitic and defective characteristics. In addition, electrochemical analysis revealed that the REEs-MPC/800 demonstrate elevated conductivity and superior capacitive current, with Tafel slopes as high as 294 mV/dec. Functional theory (DFT) calculations demonstrate that the presence of graphitic-N and REEs-N species significantly enhance PMS activation. Finally, a neural network model constructed through machine learning techniques provided a comprehensive overview of the structure–property relationship. Overall, the proposal to synthesize a high-value product using mining wastewater has been put forward. This initiative is expected to contribute to the advancement of the green economy within the rare earth mining industry.

Characteristic lipids and their potential functions generated during the aging process of yak ghee

Yak ghee is an important food source for Tibetan herdsmen; however, the lipid composition, functional lipids changed and best consumption period during the aging process of yak ghee have not been determined. In this study, we identified a total of 386 lipids in Zhongdian yak ghee during aging, including glycerolipids (292 species), glycerophospholipids (47 species), sphingolipids (24 species), and fatty acyls (23 species). The lipids in yak ghee dynamically changed during aging, with the final product containing several polyunsaturated fatty acids (including linolenic acid, docosahexaenoic acid, and eicosapentaenoic acid), indicating its high nutritional value. Lipid fingerprints of yak ghee during aging revealed that triglyceride (16:0/16:0/20:5) and triglyceride (18:1/18:3/21:0) etc. were the characteristic lipids in aged yak ghee. The characteristic lipids in yak ghee were mainly enriched in the biosynthesis of unsaturated fatty acids, glycerolipid metabolism, and ether lipid metabolism pathways. This study provides insight into the lipid changes of yak ghee during aging, which offers a theoretical basis for the development of high-value yak ghee products.

Tailored Conceptual Frameworks for Early Supplier Involvement in High-Value Product Development: A Case-Based Approach

Tailored Conceptual Frameworks for Early Supplier Involvement in High-Value Product Development: A Case-Based Approach

TECHNOLOGICAL PROSPECTION OF THE USAGE OF BARU FRUIT (DIPTERYX ALATA VOG.) TO IMPROVE THE LIVING CONDITIONS OF QUILOMBOLAS, EXTRACTIVIST COMMUNITIES IN BRAZIL

Barueiro (Dipteryx alata Vog.) is an arboreal plant species native to Brazil's fertile Cerrado region. holds great promise for cultivation and technological development due to its versatile uses and the complete reuse of its parts. Given its local significance, increased research support is essential, as the species has the potential to generate high-value products and offer a sustainable income source for its producers. This study is a prospective analysis of articles and patents on barueiro (baru fruit), highlighting that most technologies have low technological readiness levels (TRL 3-4) and remain at the bench stage, with most patents filed by universities. Collaboration between extractive communities and academia is crucial for knowledge transfer, cooperative creation, and project development for processing centers, training, and decentralized energy generation, thereby supporting SDGs and circular economy principles by adding value and improving community well-being. Once these cooperatives and processes are established, applying for geographical indication could further enhance the value of baru-based products.

Characterization and performance of carbon supported platinum-bismuth bimetallic catalysts tested in 5-hydroxymethylfurfural aerobic oxidation to 2,5-furandicarboxylic acid

The increasing demand for sustainable alternatives to petroleum-based chemicals has driven research towards the utilization of renewable feedstock, such as lignocellulosic biomass (LCB), to produce high-value products. Among LCB-derived platform molecules, 5-hydroxymethylfurfural (HMF) has become a key building block for bio-based monomers such as 2,5-furandicarboxylic acid (FDCA), among many others. This study reports the successful synthesis of various Pt-Bi catalysts supported on activated carbon (C) and investigates their role in the HMF conversion to FDCA.The catalytic performance of the Pt-Bi/C catalysts was evaluated in batch reactors, using HMF in an aqueous reaction medium, with 1 M of Na2CO3 to provide alkalinity, and under 10 bar of O2. These results demonstrated a strong correlation between catalyst properties and their catalytic activity. Among the prepared catalysts, the 9Pt-3Bi/C catalyst was the most efficient one, achieving a yield to FDCA of 99.7 %. Further investigations revealed that the 9Pt-3Bi/C catalyst maintained its excellent performance even under reduced reaction times, lower temperatures, and reduced catalyst loadings, demonstrating its potential for practical applications.Across all reactions, it was observed that, under the tested reactions conditions, the existence of side reactions involving HMF degradation to other compounds was significant. This underscores the challenge of achieving quantitative HMF conversion to FDCA, enhancing the importance of catalyst properties and reaction conditions optimization to minimize by-product formation.

Using process modeling and simulation to determine the sustainability of a novel lactic acid biorefinery in Europe: Influence of process improvements, scale, energy source, and market conditions

The biorefinery concept aims to produce multiple high-value products from bio-based feedstocks. One such product is lactic acid, which is used across several industries such as food, pharmaceuticals, cosmetics, and chemicals. Lactic acid yield is influenced by several factors, and improvements in performance are often first demonstrated at lab-scale, requiring prospective models which make assumptions about how the system will be optimized to understand the potential of a commercial-scale plant. This study assesses the economic and environmental sustainability of a proposed lactic acid biorefinery through the combination of process modelling, techno-economic assessment, and life cycle assessment. The case study proposes producing high purity lactic acid from industrial candy waste and liquid digestate in Denmark through lactic acid fermentation and downstream membrane separations. A base case is first modelled to determine the economic and environmental hotspots of the system; scenarios are then modelled where improvement methods are implemented reducing consumption of energy, chemicals, water, and the production of waste, upscaling the system, and integrating bioenergy. Finally, a cost sensitivity analysis is run varying bioenergy, water, chemical, and labor costs based on the European market. By optimizing unit processes, scale, energy sources and market conditions, the lactic acid unit production cost and global warming potential can be lowered by 94% and 80% compared to the base case, respectively. However, these are optimized in different scenarios, indicating a trade-off in optimizing economic and environmental criteria. As even best-case lactic acid unit production cost is found to be 141–232% higher than market price, this production pathway will require further improvement or market changes before it can be commercially viable.

Exploring Entrepreneur Intention in the Mushroom Industry with Government Support in Malaysia

The mushroom industry in Malaysia is experiencing significant growth due to its high return value and low production costs. The Malaysian government has implemented initiatives to encourage entrepreneurial activities. However, the effectiveness of these initiatives in influencing entrepreneurial intention remains to be determined. This study investigates the relationship between entrepreneurial intention in the Malaysian mushroom industry and the moderating effect of government support, drawing insights from the interplay between entrepreneurial self-efficacy, intention, and external support mechanisms. Numerous factors influence entrepreneurship intentions in the mushroom industry. Entrepreneurial self-efficacy plays a crucial role in shaping entrepreneurial intentions and behaviors, and individuals with high self-efficacy are more likely to perceive themselves as capable of successfully starting and running a new business. Government support can provide funding, tax advantages, subsidies, skills development, and advice services and create enabling environments for entrepreneurial efforts. The literature on government support and its impact on entrepreneurship intention reveals gaps that need further exploration. The theory of Planned Behavior (TPB) offers a comprehensive framework for understanding how entrepreneurship education influences self-efficacy, attitudes, and intentions. This study examines the capacity of government assistance to impact entrepreneurial intention in the Malaysian mushroom business, providing vital knowledge on how to promote a more robust environment for sustainable mushroom production. Additionally, this research aims to bridge the gap by investigating how government support moderates the relationship between entrepreneurial self-efficacy and intention in the Malaysian mushroom industry, offering valuable conceptual insights to policymakers for fostering a sustainable mushroom production sector.

Revalorisation of brewer's spent grain for biotechnological production of hydrogen with Escherichia coli.

Agro-industrial wastes are generated in huge amounts triggering damages to the environment and human health. Therefore, there is an urgent necessity for its revalorisation into high-value compounds, including biofuels. One such wastes is the brewer's spent grain (BSG), a by-product of the beer industry, which is produced in vast quantities worldwide. The rich-fibre and protein content of BSG makes this waste a valuable resource for biotechnological applications, although the main challenge of this approach is to make the carbohydrates and proteins available for bacterial metabolisation into high-value products. This work aims to optimise a thermal-hydrolysis process to revalorise BSG by bacterial conversion into hydrogen (H2), as a clean energy that can replace fossil fuels. A 2k full factorial design method was employed hydrolysation of BSG and showed that temperature and acid concentration are significant factors that affect the extraction of reducing sugars (RS) and proteins. Subsequently, steepest ascent and central composite design (CCD) statistical methods were applied to determine the optimal conditions for hydrolysis. The optimised hydrolysis condition were 0.047M H2SO4, 150°C, 30min and 15% BSG, leading to the theoretical concentrations of 54.8g RS/L and 20g/L proteins. However, 5'-hydroxymethylfurfural (HMF) was generated in thermal-hydrolysis conditions at higher temperatures exceeding 132°C. Therefore, a screening of HBSGs fermentation using Escherichia coli was conducted in order to identify the most suitable conditions for maximizing H2, as well as the production of volatile fatty acids (succinate and acetate) and ethanol. Among the tested conditions, HBSG A17 (117°C, 20min, and 0.1M H2SO4) yielded the highest H2 production of 48mmol/L in this work. This study provides valuable insights into the optimisation of BSG pre-treatment for biotechnological applications, which may help in the selection of the most appropriate hydrolysis conditions based on the desired end product.

Enhancing Lignin-Carbohydrate Complexes Production and Properties With Machine Learning.

Lignin-carbohydrate complexes (LCCs) present a unique opportunity for harnessing the synergy between lignin and carbohydrates for high-value product development. However, producing LCCs in high yields remains a significant challenge. In this study, we address this challenge with a novel approach for the targeted production of LCCs. We optimized the AquaSolv Omni (AqSO) biorefinery for the synthesis of LCCs with high carbohydrate content (up to 60/100 Ar) and high yields (up to 15 wt %) by employing machine learning (ML). Our method significantly improves the yield of LCCs compared to conventional procedures, such as ball milling and enzymatic hydrolysis. The ML approach was pivotal in tuning the biorefinery to achieve the best performance with a limited number of experimental trials. Specifically, we utilized Bayesian Optimization to iteratively gather data and examine the effects of key processing conditions-temperature, process severity, and liquid-to-solid ratio-on yield and carbohydrate content. Through Pareto front analysis, we identified optimal trade-offs between LCC yield and carbohydrate content, discovering extensive regions of processing conditions that produce LCCs with yields of 8-15 wt % and carbohydrate contents ranging from 10-40/100 Ar. To assess the potential of these LCCs for high-value applications, we measured their glass transition temperature (Tg), surface tension, and antioxidant activity. Notably, we found that LCCs with high carbohydrate content generally exhibit low Tg and surface tension. Our biorefinery concept, augmented by ML-guided optimization, represents a significant step toward scalable production of LCCs with tailored properties.

In Situ Phase Transformation-Enabled Metal-Organic Frameworks for Efficient CO2 Electroreduction to Multicarbon Products in Strong Acidic Media.

The electrochemical CO2 reduction reaction (CO2RR) has been acknowledged as a promising strategy to relieve carbon emissions by converting CO2 to essential chemicals. Despite significant progresses that have been made in neutral and alkaline media, the implementation of CO2RR in acidic conditions remains challenging due to the harsh conditions, especially in producing high-value multicarbon products. Here, we report that Cu-btca (btca = benzotriazole-5-carboxylic acid) metal-organic framework (MOF) nanostructures can act as a stable catalyst for the CO2RR in an acidic environment. The Cu-btca MOF undergoes phase transformation and morphology evolution during electrolysis, forming a stable porous Cu-btca MOF network. The resultant MOF network exhibits excellent selectivity toward ethylene and multicarbon products with Faradaic efficiencies of 51.2% and 81.9%, respectively, in a strong acidic electrolyte with a flow cell at 300 mA/cm2. Mechanism studies uncover that the Cu-btca MOF network can limit the proton reduction to suppress hydrogen evolution and maintain high local *CO concentration to promote CO2RR. Theoretical calculations suggest that two adjacent Cu sites in the Cu-btca MOF provide a favorable microenvironment for carbon-carbon coupling, facilitating the multicarbon production. This work reveals that rational structure control of MOFs can enable highly selective and efficient CO2 electroreduction to multicarbon products in strong acidic conditions toward practical applications.

Low‐Temperature Catalytic Approaches for Upcycling Plastics into Oxygenated Aromatic Compounds

Plastic upcycling is an emerging strategy to address the global plastic waste crisis, where these abundant polymers are converted into products of higher economic value. This not only complements and adds to existing recycling efforts, but also offers opportunities to retain the inherent chemical value of the plastics within circular loops, albeit in different forms for alternative uses. With aromatics constituting a major component of current petrochemical production, the production of aromatics from post‐synthetic conversion of plastics can potentially alleviate the demand on fossil fuels. Although BTX (benzene, toluene, xylenes) production has been a major focus of these efforts, oxygenated aromatic compounds (OACs), such as benzoic acids, are also highly‐valued across various industrial sectors, and necessitate fundamentally different processes from BTX synthesis from plastics. Herein, some of the most promising emerging methods for direct synthesis of OACs from commodity petroleum‐based plastics are spotlighted, including from non‐oxygenated hydrocarbon polymers such as polystyrene. With a special emphasis on emerging low temperature technologies (<150 oC), which encompass but are not limited to photo‐ and biocatalysis, this Concepts article aims to position plastics as a viable source of OACs accessible under sustainable conditions for future industrial translations.

Fermentation for Revalorisation of Fruit and Vegetable By-Products: A Sustainable Approach Towards Minimising Food Loss and Waste.

In a world increasingly focused on sustainability and integrated resource use, the revalorisation of horticultural by-products is emerging as a key strategy to minimise food loss and waste while maximising value within the food supply chain. Fermentation, one of the earliest and most versatile food processing techniques, utilises microorganisms or enzymes to induce desirable biochemical transformations that enhance the nutritional value, digestibility, safety, and sensory properties of food products. This process has been identified as a promising method for producing novel, high-value food products from discarded or non-aesthetic fruits and vegetables that fail to meet commercial standards due to aesthetic factors such as size or appearance. Besides waste reduction, fermentation enables the production of functional beverages and foods enriched with probiotics, antioxidants, and other bioactive compounds, depending on the specific horticultural matrix and the types of microorganisms employed. This review explores the current bioprocesses used or under investigation, such as alcoholic, lactic, and acetic acid fermentation, for the revalorisation of fruit and vegetable by-products, with particular emphasis on how fermentation can transform these by-products into valuable foods and ingredients for human consumption, contributing to a more sustainable and circular food system.

The composition and bioactivity of bound polyphenols from coffee dietary fiber during in vitro Simulating digestion

Dietary fiber from coffee peel is rich in bound polyphenols good for human health due to the antioxidant activity. In this study, we evaluated the bound polyphenol release conditions and activities in coffee peel soluble dietary fiber (CPSDF) in the process of in vitro simulation digestion. The CPSDF structure became loose and porous due to simulated digestion but retained the polysaccharide backbone. Widely-targeted metabolomics analysis identified 550 metabolites, with phenolic acids and flavonoids being main differentially expressed metabolites in digested products (82.18% in total). The most significant increase in the 5,7,8,3′,4′-pentamethoxyflavanone content and decrease in the 3,5-dihydroxyacetophenone content were observed after digestion (undigested vs S-intestine). Additionally, the changes in antioxidant and enzyme inhibitory activities followed the same pattern as that observed for total phenolic content. The enzyme inhibitory and antioxidant activities of gastric digestion products were greater than those of the oral and small intestinal digestion products. The present work provided the theoretical foundation for developing high-value CPSDF products and reusing coffee peel waste.