Sustainable utilization of pineapple wastes for production of bioenergy, biochemicals and value-added products: A review

Chitosan suspension enriched with phenolics extracted from pineapple by-products as bioactive coating for liposomes: Physicochemical properties and in vitro cytotoxicity

The physicochemical stability of liposomes (L) loaded with bioactive compounds can be improved by coating them with chitosan, to give chitosomes (Ch). In addition, crosslinked chitosan can be obtained by using sodium tripolyphosphate (TPP). This study aimed to prepare L enriched with bioactive compounds extracted from pineapple by-products (PB) without coating or coated with chitosan or crosslinked chitosan-enriched with PB bioactive compounds, to obtain Ch and TPP-Ch, respectively. Then, we evaluated the encapsulation efficiency (EE) of total phenolic compounds (TPC), physicochemical properties, antioxidant and antimicrobial activities, and in vitro cytotoxicity. Ch and TPP-Ch had threefold larger content of TPC (331 μg of GAE/mL) and higher antioxidant activity than L (102 μg of GAE/mL) even though L had slightly higher EE than TPP-Ch (66 ± 10 % and 53 ± 9 %, respectively). Ch had the lowest EE (36 % ± 4), which highlights that Ch crosslinking is important for encapsulating bioactive compounds. Regarding in vitro cytotoxicity, avian fibroblast viability started to decrease 48 h after the cells were treated with 5 % L, Ch, or TPP-Ch suspension. Ch and TPP-Ch led to lower cell viability than L. Although Ch and TPP-Ch partially inhibited Staphylococcus aureus growth, only L showed antimicrobial activity against this microorganism, even 170 days after L was prepared. These results suggest that the novel methodology we used to prepare Ch and TPP-Ch can improve certain properties of chitosan-coated liposomes, which is significant for future advancements in food and pharmaceutical applications.

Chemically Modified Pineapple Leaf Fibre as a Filler of Polyurethane-Based Composites

Pineapple leaf fibres represent a biodegradable raw material sourced from renewable resources whose use contributes to reducing the carbon footprint and limiting the amount of waste generated. Their potential applications can effectively decrease the industry's dependence on plastics and support sustainable development, which should accompany the production of modern materials. In this study, polyurethane-based composites reinforced with various types of natural cellulose fillers were developed and investigated. Microcrystalline cellulose and unmodified and chemically modified pineapple leaf fibres were used as reinforcements. The mechanical and thermal properties of the produced materials were determined and compared. The results of the tests indicated that both microcrystalline cellulose and pineapple leaf fibres contributed to a reduction in the mechanical properties of polyurethane. A varying impact of fillers on the Young's modulus of the biocomposites was observed. The presence of natural modifiers influenced an increase in the melting temperature of the composite compared to the pure polyurethane. Integration of natural pineapple fibres into composite represents a step toward a more sustainable future, combining economic benefits with environmental care. The mechanical characteristics of composite materials were enhanced by modified fibres, compared to their unmodified counterparts. This improvement comes from the unique structural properties of the modified fibres. When polyurethane (PU) is used as the matrix material, it effectively fills the interfibrillar voids, creating a more cohesive bond between the components.

Characterization and evaluation of the adsorption of uremic toxins through the pyrolysis of pineapple leaves and peels and by forming a bio-complex with sodium alginate

This study was performed to develop an optimal process for manufacturing activated carbon (AC) from pineapples' off-cuts (leaves and peels; PL and PP) by pyrolysis and for forming a bio-complex with sodium alginate (CA). In addition, the physicochemical properties were also explored under different preparation conditions, and the effects of adsorbed uremic toxins in three simulated gastrointestinal conditions (in vitro) were evaluated. This study showed that pyrolysis at 800 °C and activation by CO2 (30 min) resulted in satisfactory porous profiles with high specific surface areas of 388.79 and 536.84 m2/g for PLAC and PPAC, respectively. Regarding appearance and microstructures, there are still discernible disparities compared to the AST in regular service, while it exhibits a similar peak shape to that of the AC under the Raman spectrometer. Remarkably, the adsorption capacity of PLAC and PPAC for uremic toxins was best for indole adsorption while providing a consistent effect with AST. Indole-3-acetic acid (3-IAA) and p-cresol (p-C) adsorption capacities were the second highest. Nevertheless, AST also exhibited varying degrees of reduced adsorption capacity under different gastrointestinal simulation conditions. Therefore, this study conditions the development of cost-effective adsorbent products targeting uremic toxins, which could generate novel synergistic systems based on pineapple by-products within the circular economy framework.

Valorisation of pineapple peel waste as natural surimi gel enhancer and its optimization in Nile tilapia (Oreochromis niloticus) surimi gels

This investigation explored the preparation of surimi gel enhancer from pineapple peel waste, hugely generated by industries and spreading serious environment pollutions. The peel extracted with 100% ethanol had higher bioactive and antioxidant attributes, which was subsequently fortified in tilapia surimi at levels of 0.20%-1.20%, w/w to improve its physiochemical, textural, protein structural and sensorial properties. Our finding demonstrated that surimi gels enriched with 0.80% ethanolic pineapple peel extract (PAPE) exhibited significant (p<0.05) improvement in water holding capacity, breaking force, gel strength, and other textural properties and sensory attributes. Furthermore, the surimi gels fortified with 0.80% PAPE exhibited the elevated levels of hydrogen and hydrophobic interactions, while sulfhydryl and free amino acid contents demonstrated a contrasting trend. The FTIR spectra displayed that the incorporation of PAPE influenced the secondary structure of the protein, as evidenced by shifts in the α-helix to β-sheet peaks. In addition, 0.80% PAPE added gels displayed a compact, uniform, and organized microstructure, featuring small cavities. In summary, the fortification of tilapia surimi gels with 0.80% PAPE could improve gelling and other technological properties with higher sensory scores. This study offers an effective approach to utilize the pineapple peel as a gel enhancer additive for the development of functional surimi and surimi-based products enriched with bioactive compounds.

Production of biodegradable food packaging from mango peel via enzymatic hydrolysis and polyhydroxyalkanoates synthesis: A review on microbial intervention

The rising environmental problem of plastic packaging waste has led to the development of sustainable alternatives, particularly for food packaging. Polyhydroxyalkanoates (PHAs) are biodegradable, thermoplastic polyesters. They are employed in the production of various products, including packaging films. The bio-based nature and appropriate features of PHAs, similar to conventional synthetic plastics, have garnered significant attention from researchers and industries. The current study aimed to produce biodegradable food packaging using mango peel (a major agricultural waste) with enzymatic hydrolysis and PHAs synthesis. Mango peel is the hub for macro-and micronutrients, including phytochemicals. The process includes an enzymatic hydrolysis step that converts complex carbohydrates into simple sugars using mango peel as a substrate. The produced sugars are used as raw materials for bacteria to synthesize PHAs, which are a class of biodegradable polymers produced by these microorganisms that can serve as packaging materials in the food industry. To solve environmental problems and increase the utilization of agricultural by-products, this review presents a practical method for producing food packaging that is environmentally friendly.

Production of natural cellulose-based microfibres, from oil palm mesocarp fibres and pineapple leaf wastes, as porous supports for further applications

Natural cellulose-based microfibers were obtained through an economical and environmentally sustainable process called alkaline-peroxide purification, from the waste products of oil palm mesocarp fibres (OPMF) and pineapple leaves (PL), with the intention of creating porous, biodegradable, biocompatible, and non-toxic solid supports for use in future processes. The extracted microfibres were then taken through microscopic, spectroscopic and thermal characterisation to establish their cellulosic nature. The scanning electron microscopic (SEM) images of the bleached microfibres (B-OPMF and B-PLF) were cleaner, smoother and porous as compared with that of the unrefined fibres (Ur-OPMF and Ur-PLF). The bleached fibres (B-OPMF and B-PLF) exhibited peaks of C and O, which are indicative of pure cellulose, in the energy-dispersive X-ray spectroscopy (EDS) analysis. The FTIR spectral analysis of the extracted cellulose-based fibres (B-OPMF and B-PLF) exhibited peaks that were similar in composition to the reference cellulose (P-GB). For the thermogravimetric analysis (TGA) analysis, the maximum weight degradation in the reference cellulose (P-GB), occurred at 363.11 °C, in the bleached palm fibres (B-OPMF) at 334.55 °C and in the bleached pineapple leaf fibres (B-PLF) at 375.68 °C which, corresponds to cellulose decomposition. The differential scanning calorimetry (DSC) test verified the microfibers' thermally induced transitions. Therefore, these cellulose-based microfibres could be applied as functionalised microfibre supports for future applications.

Circular Bioeconomy in Action: Transforming Food Wastes into Renewable Food Resources

The growing challenge of food waste management presents a critical opportunity for advancing the circular bioeconomy, aiming to transform waste into valuable resources. This paper explores innovative strategies for converting food wastes into renewable food resources, emphasizing the integration of sustainable technologies and zero-waste principles. The main objective is to demonstrate how these approaches can contribute to a more sustainable food system by reducing environmental impacts and enhancing resource efficiency. Novel contributions of this study include the development of bioproducts from various food waste streams, highlighting the potential of underutilized resources like bread and jackfruit waste. Through case studies and experimental findings, the paper illustrates the successful application of green techniques, such as microbial fermentation and bioprocessing, in valorizing food wastes. The implications of this research extend to policy frameworks, encouraging the adoption of circular bioeconomy models that not only address waste management challenges but also foster economic growth and sustainability. These findings underscore the potential for food waste to serve as a cornerstone in the transition to a circular, regenerative economy.

Recovery of green phenolic compounds from lignin-based source: Role of ferulic acid esterase towards waste valorization and bioeconomic perspectives

The production of chemicals/products so far relies on fossil-based resources with the creation of several environmental problems at the global level. In this situation, a sustainable and circular economy model is necessitated to mitigate global environmental issues. Production of biowaste from various processing industries also creates environmental issues which would be valorized for the production of industrially important reactive and bioactive compounds. Lignin acts as a vital part in biowaste composition which can be converted into a wide range of phenolic compounds. The phenolic compounds have attracted much attention, owing to their influence on diverse not only organoleptic parameters, such as taste or color, but also active agents for active packaging systems. Crop residues of varied groups, which are an affluent source of lignocellulosic biomass could serve as a renewable resource for the biosynthesis of ferulic acid (FA). FA is obtained by the FA esterase enzyme action, and it can be further converted into various tail end phenolic flavor green compounds like vanillin, vanillic acid and hydroxycinnamic acid. Lignin being renewable in nature, processing and management of biowastes towards sustainability is the need as far as the global industrial point is concerned. This review explores all the approaches for conversion of lignin into value-added phenolic compounds that could be included to packaging applications. These valorized products can exhibit the antioxidant, antimicrobial, cardioprotective, anti-inflammatory and anticancer properties, and due to these features can emerge to incorporate them into production of functional foods and be utilization of them at active food packaging application. These approaches would be an important step for utilization of the recovered bioactive compounds at the nutraceutical and food industrial sectors.

Integrated MADM of low-carbon structural design for high-end equipment based on attribute reduction considering incomplete interval uncertainties

With the increasingly severe energy supply and environmental pressures, high-end equipment is gradually adopted to reduce the carbon emissions of manufacturing industry which makes its low-carbon structural design a critical research hotspot. The best structural scheme can be got by multi-attribute decision-making (MADM) with design requirements. However, the decision-making attributes in the structural design of high-end equipment are too many at first and low-carbon attributes are seldom fully considered. Moreover, there are a large amount of related data with linguistic vagueness, interval uncertainty, and information incompleteness, which fail to be handled simultaneously. There, this paper proposes an integrated MADM method of low-carbon structural design for high-end equipment based on attribute reduction considering incomplete interval uncertainties. First, distribution reduction of low-carbon structural design is carried out to obtain the minimum attribute set and encompass low-carbon attributes comprehensively. Second, a collaborative filtering algorithm is utilized to complete the missing data in the subsequent design process. Third, interval rough numbers (IRNs) are integrated into DEMATEL-ANP (DANP) and multi-attribute border approximation area comparison (MABAC) to quickly rank the alternative schemes for high-end equipment and determine which is the best. The rationality and robustness of the proposed method are verified through the case study and comparative analysis of a hydraulic forming machine.

A critical assessment on scalable technologies using high solids loadings in lignocellulose biorefinery: challenges and solutions

The pretreatment and the enzymatic saccharification are the key steps in the extraction of fermentable sugars for further valorization of lignocellulosic biomass (LCB) to biofuels and value-added products via biochemical and/or chemical conversion routes. Due to low density and high-water absorption capacity of LCB, the large volume of water is required for its processing. Integration of pretreatment, saccharification, and co-fermentation has succeeded and well-reported in the literature. However, there are only few reports on extraction of fermentable sugars from LCB with high biomass loading (>10% Total solids-TS) feasible to industrial reality. Furthermore, the development of enzymatic cocktails can overcome technology hurdles with high biomass loading. Hence, a better understanding of constraints involved in the development of technology with high biomass loading can result in an economical and efficient yield of fermentable sugars for the production of biofuels and bio-chemicals with viable titer, rate, and yield (TRY) at industrial scale. The present review aims to provide a critical assessment on the production of fermentable sugars from lignocelluloses with high solid biomass loading. The impact of inhibitors produced during both pretreatment and saccharification has been elucidated. Moreover, the limitations imposed by high solid loading on efficient mass transfer during saccharification process have been elaborated.

Biotechnological innovations in nanocellulose production from waste biomass with a focus on pineapple waste

New materials' synthesis and utilization have shown many critical challenges in healthcare and other industrial sectors as most of these materials are directly or indirectly developed from fossil fuel resources. Environmental regulations and sustainability concepts have promoted the use of natural compounds with unique structures and properties that can be biodegradable, biocompatible, and eco-friendly. In this context, nanocellulose (NC) utility in different sectors and industries is reported due to their unique properties including biocompatibility and antimicrobial characteristics. The bacterial nanocellulose (BNC)-based materials have been synthesized by bacterial cells and extracted from plant waste materials including pineapple plant waste biomass. These materials have been utilized in the form of nanofibers and nanocrystals. These materials are found to have excellent surface properties, low density, and good transparency, and are rich in hydroxyl groups for their modifications to other useful products. These materials are well utilized in different sectors including biomedical or health care centres, nanocomposite materials, supercapacitors, and polymer matrix production. This review explores different approaches for NC production from pineapple waste residues using biotechnological interventions, approaches for their modification, and wider applications in different sectors. Recent technological developments in NC production by enzymatic treatment are critically discussed. The utilization of pineapple waste-derived NC from a bioeconomic perspective is summarized in the paper. The chemical composition and properties of nanocellulose extracted from pineapple waste may have unique characteristics compared to other sources. Pineapple waste for nanocellulose production aligns with the principles of sustainability, waste reduction, and innovation, making it a promising and novel approach in the field of nanocellulose materials.

Biomethanol production from renewable resources: a sustainable approach

The abundant availability of various kinds of biomass and their use as feedstock for the production of gaseous and liquid biofuels has been considered a viable, eco-friendly, and sustainable mode of energy generation. Gaseous fuels like biogas and liquid fuels, e.g., bioethanol, biodiesel, and biomethanol derived from biological sources, have been theorized to produce numerous industrially relevant organic compounds replacing the traditional practice of employing fossil fuels as a raw material. Among the biofuels explored, biomethanol has shown promising potential to be a future product addressing multifactorial issues concerning sustainable energy and associated process developments. The presented mini-review has explored the importance and application of biomethanol as a value-added product. The biomethanol production process was well reviewed by focusing on different thermochemical and biochemical conversion processes. Syngas and biogas have been acknowledged as potential resources for biomethanol synthesis. The emphasis on biochemical processes is laid on the principal metabolic pathways and enzymatic machinery involved or used by microbial physiology to convert feedstock into biomethanol under normal temperature and pressure conditions. The advantage of minimizing the cost of production by utilizing suggested modifications to the overall process of biomethanol production that involves metabolic and genetic engineering in microbial strains used in the production process has been delineated. The challenges that exist in our current knowledge domain, impeding large-scale commercial production potential of biomethanol at a cost-effective rate, and strategies to overcome them along with its future scenarios have also been pointed out.

Development and characterization of rigid packaging material using cellulose/sugarcane bagasse and natural resins

Composites developed from cellulose and natural resins have received much attention due to their low cost and positive environmental impact. Knowledge of the mechanical and degradation characteristics of cellulose based composite boards is essential to obtain indications of the strength and degradability of the resulting rigid packaging material. The composite was prepared with sugarcane bagasse and hybrid resin (a combination of epoxy and natural resin such as dammar, pine, and cashew nut shell liquid) with the mixing ratios (Bagasse fibers: Epoxy resin: Natural resin) 1:1:1.5, 1:1:1.75, and 1:1:2 using compression moulding method. Tensile strength, young's modulus, flexural strength, soil burial weight loss, microbial degradation, and CO2 evolution was determined. Cashew nut shell liquid (CNSL) resin-incorporated composite boards in the mixing ratio of 1:1:2 gave maximum flexural strength (5.10 MPa), tensile strength (3.10 MPa), and tensile modulus (0.97 MPa). The maximum degradation in soil burial test and CO2 evolution between the boards made using natural resin was found in the composite boards incorporated with CNSL resin with a mixing ratio of 1:1:1.5 were 8.30 % and 12.8 % respectively. The maximum weight loss percentage (3.49) in microbial degradation analysis was found in the composite board made using dammar resin in the mixing ratio of 1:1:1.5.

Pineapple peel waste valorization for extraction of bio-active compounds and protein: Microwave assisted method and Box Behnken design optimization

Pineapple peel waste (PPW) is obtained in huge quantities out of pineapple canning industries and it is found to be rich in bioactive compounds with antioxidant activity and an opulent source of bromelain protein having commercial importance. To fulfil the purpose, microwave assisted extraction was considered. Three parameters varied were solvent to substrate ratio, microwave power and extraction time. The independent variables were solvent to substrate ratio (10:1 mL/g to 20:1 mL/g), microwave power (300 W-600 W) and extraction time (40 min-50 min). Optimization was done with three factors and three level Box- Behnken Design (BBD). Each of the experiment has been analysed for Total phenolic content (TPC), Total flavonoid content (TFC), Total tannin content (TTC) as well as for protein content. The Folin- Ciocalteu method was utilized for analysing TPC, TTC and the colorimetric method (AlCl₃) was used for the analysis of TFC, protein content was analysed by lowry's method and antioxidant activity making use of 2,2-diphenyl-1-picrylhydrazyl (DPPH). The p values were less than 0.05 which showed all the four models were significant. The experimental values and the predicted values were harmonious for the optimum conditions. The optimum condition obtained out of BBD were solvent to substrate ratio of 20:1 mL/g, microwave power of 600 W and extraction time 40 min. Antioxidant activity for the extract was found out by DPPH assay under the optimized conditions was 75% along with proteolytic activity of bromelain as 1647.612 GDUg_concentrate^-1.

Food and fruit waste valorisation for pectin recovery: Recent process technologies and future prospects

Pectin possesses a dual property of resistance and flexibility and thus has diverse commercial value which has generated research interest on this versatile biopolymer. Formulated products using pectin could be useful in food, pharma, foam, plasticiser and paper substitute industries. Pectin is structurally tailor-made for greater bioactivity and diverse applications. Sustainable biorefinery leaves greener footprints while producing high-value bioproducts like pectin. The essential oils and polyphenols obtained as byproducts from a pectin-based biorefinery are useful in cosmetics, toiletries and fragrance industries. Pectin can be extracted from organic sources following eco-friendly strategies, and the extraction techniques, structural alterations and the applications are continually being upgraded and standardized. Pectin has great applications in diverse areas, and its green synthesis is a welcome development. In future, growing industrial application of pectin is anticipated as research orients on biopolymers, biotechnologies and renewable source-based processes. As the world is gradually adopting greener strategies in sync with the global sustainable development goal, active involvement of policy makers and public participation are prime. Governance and policy framing are essential in the transition of the world economy towards circularity since green circular bioeconomy is ill-understood among the public in general and within the administrative circles in particular. Concerted efforts by researchers, investors, innovators, and policy and decision makers to integrate biorefinery technologies as loops within loop of biological structures and bioprocesses is suggested. The review focusses on generation of the different nature of food wastes including fruits and vegetables with cauterization of their components. It discusses the innovative extraction and biotransformation approaches for these waste conversions into value-added products at cost-effective and eco-friendly way. This article compiles numerous effective and efficient and green way pectin extraction techniques with their advantages with varying success in an integrated manner.

Fruit peel crude enzymes for enhancement of biohydrogen production from synthetic swine wastewater by improving biohydrogen-formation processes of dark fermentation

Biohydrogen is a promising clean fuel but with a low yield. This study aims to enhance biohydrogen production from synthetic swine wastewater by employing crude enzymes obtained from different fruit peels (orange, mandarin, and banana) to improve the biohydrogen-formation processes of dark fermentation. Results indicated that dosing with crude enzymes affected volatile fatty acids (VFAs) and biogas composition insignificantly, while increased biohydrogen yield from 1.62 ± 0.00 (blank) to 1.90 ± 0.08 (orange peel), 2.01 ± 0.00 (mandarin peel), and 1.96 ± 0.01 (banana peel) mol H₂/mol glucose, respectively. Banana peel crude enzyme was the most effective additive, with 1 g/L protein improving 97.41 ± 3.72 % of biohydrogen yield. The crude enzymes wielded less influence on acetic acid and butyric acid pathways but enhanced other biohydrogen production pathways. These observations demonstrated that fruit peel-based crude enzymes as additives are advantageous to improving biohydrogen yield towards higher biohydrogen production.

Effective hydrolysis for waste plant biomass impacts sustainable fuel and reduced air pollution generation: A comprehensive review

Among various natural biowastes availability in the environment, agricultural residues showed great impacts. It is due to huge availability and cheap carbon source, creating big challenges for their utility and systematic reduction. Objective of this review is to address the waste biomass availability and huge quantities issues and also put effort to minimize this nutrient load via biotransforming into value-added products. Different wastes (organic/inorganic) generation with their negative issues are due to numbers of developmental and social activities, reported. Currently, various efforts are found for these wastes minimization via generation of different types of value-added products (biogas, bioH₂, alcoholic fuel, organic acids and others products) and these wastes in municipal cities are also reported with production of advanced biofuels as promising outcomes. For hydrolysis of complex organic resources including lignocellulosic biomasses, physicochemical, structural or compositional changes are needed that aid in conversion into sugar and organic compounds such as biofuels. So, efficient and effective pretreatment processes selection (physical, biological, chemical or combined one) is critical to achieve these hydrolysis goals and resultant cellulose or hemicellulose components can be accessible by biological catalysis. These can achieve final hydrolysis and fermentative or monomer sugars. And later, synthesis of fuels or value-added products during microbial fermentation or biotransformation processes can be achieved. This review discusses pretreatment techniques for improved hydrolysis for fermentative sugar with emphasis on reduced quantities of toxic compounds (furfural compound) in hydrolyzed biomasses. Minimum deterioration fuel economy also reported with production of different bioproducts including biofuels. Additionally, impacts of toxic products and gasses emission are also discussed with their minimization.

Food Waste Utilization for Reducing Carbon Footprints towards Sustainable and Cleaner Environment: A Review

There is world-wide generation of food waste daily in significant amounts, leading to depletion of natural resources and deteriorating air quality. One-third of global food produced is wasted laterally with the food value chain. Carbon footprint is an efficient way of communicating the issues related to climate change and the necessity of changing behavior. Valorization or utilization of food wastes helps in resolving issues related to environment pollution. Reduction in the carbon footprint throughout the chain of food supply makes the whole process eco-friendly. Prevailing food waste disposal systems focus on their economic and environmental viability and are putting efforts into using food waste as a resource input to agriculture. Effective and advanced waste management systems are adopted to deal with massive waste production so as to fill the gap between the production and management of waste disposal. Food waste biorefineries are a sustainable, eco-friendly, and cost-effective approach for the production of platform chemicals, biofuels, and other bio-based materials. These materials not only provide sustainable resources for producing various chemicals and materials but have the potential to reduce this huge environmental burden significantly. In this regard, technological advancement has occurred in past few years that has proven suitable for tackling this problem.

Utilization of agricultural waste biomass and recycling toward circular bioeconomy

The major global concern on energy is focused on conventional fossil resources. The burning of fossil fuels is an origin of greenhouse gas emissions resulting in the utmost threat to the environment and subsequently which leads to global climate changes. As far as sustainability is concerned, fuels and materials derived from organic or plant wastes overcome this downside establishing the solution to the fossil resource crisis. In this context, exploration of agricultural residue appears to be a suitable alternative of non-renewable resources to support the environmental feasibility and meet the high energy crisis. The use of agricultural waste as a feedstock for the biorefinery approach emerges to be an eco-friendly process for the production of biofuel and value-added chemicals, intensifying energy security. Therefore, a prospective choice of this renewable biomass for the synthesis of green fuel and other green biochemicals comes up with a favorable outcome in terms of cost-effectiveness and sustainability. Exploiting different agricultural biomass and exploring various biomass conversion techniques, biorefinery generates bioenergy in a strategic way which eventually fits in a circular bioeconomy. Sources and production of agricultural waste are critically explained in this paper, which provides a path for further value addition by various technologies. Biorefinery solutions, along with a life cycle assessment of agricultural waste biomass toward a wide array of value-added products aiding the bioeconomy, are summarized in this paper.

Valorization of pineapple processing residues through acetification to produce specialty vinegars enriched with red-Jambo extract of Syzygium malaccense leaf

The present study proposes the production of vinegars from pineapple processing residues as an eco-friendly strategy for adding value and economic strengthening of the production chain. Pineapple pulp and peel wines were produced and acetificated to vinegar by wild strains of acetic bacteria using Orlean's method (traditional system) followed by enrichment with leaf extract of Red-Jambo, Syzygium malaccense. Appreciable phenolic contents and antioxidant potential were found in pulp and peel vinegars with the added leaf extract. Catechin, epicatechin and caffeic, p-coumaric, ferulic, and gallic acids were the main phenolic compounds found in peel vinegar. The enrichment of the vinegar with the extract promoted an increase in the content of polyphenols (443.6-337.3 mg GAE/L) and antioxidant activity. Peel wines presented higher luminosity (L^*) and higher saturation index (C^*), and their color tended more toward yellow than pulp wines. Acetification reduced the saturation index (C^*) and led to the intensification of the hue angle in the peels vinegar. Each type of pineapple vinegar produced showed biocidal activity against different bacteria and yeast, and the addition of leaf extract potentiated the antimicrobial activity of peel vinegar, especially against Staphalococcus aureus. The vinegars developed could find an attractive market niche in the food sector.

Recent advances in biogas production using Agro-Industrial Waste: A comprehensive review outlook of Techno-Economic analysis

Agrowaste sources can be utilized to produce biogas by anaerobic digestion reaction. Fossil fuels have damaged the environment, while the biogas rectifies the issues related to the environment and climate change problems. Techno-economic analysis of biogas production is followed by nutrient recycling, reducing the greenhouse gas level, biorefinery purpose, and global warming effect. In addition, biogas production is mediated by different metabolic reactions, the usage of different microorganisms, purification process, upgrading process and removal of CO₂ from the gas mixture techniques. This review focuses on pre-treatment, usage of waste, production methods and application besides summarizing recent advancements in biogas production. Economical, technical, environmental properties and factors affecting biogas production as well as the future perspective of bioenergy are highlighted in the review. Among all agro-industrial wastes, sugarcane straw produced 94% of the biogas. In the future, to overcome all the problems related to biogas production and modify the production process.

Sustainable utilization of unavoidable food waste into nutritional media for the isolation of bacterial culture for the removal of heavy metals

This study aims to reuse food waste (FW) as growth media for bacterial cultures for bioremediation of heavy metal. The best natural medium was selected based on the carbon, nitrogen, and other elements. The batch culture of Comamonas terrae showed growth stability for 16 days in the pig bone medium. C. terrae showed the best growth at pH of 7.4, temperature of 35 °C, and medium concentration of 10 g/L. The C. terrae showed heavy metal (HM) removal efficiencies of Cd (52 %) Cr (63 %) Pb (62 %) and Zn (55 %). In addition, the Fourier transform infrared spectroscopy results revealed the bioadsorption of HM in C. terrae. The study suggests the C. terrae can efficiently remove HM and C. terrae may be used for bioremediation of HM. Therefore, pig bone waste is a cost-effective medium and a good solution for the valorization and reuse of FW in line with the circular economy.

Integrated system of anaerobic digestion and pyrolysis for valorization of agricultural and food waste towards circular bioeconomy: Review

Agricultural and food waste have become major issue affecting the environment and climate owing to growing population. However, such wastes have potential to produce renewable fuels which will help to meet energy demands. Numerous valorization pathways like anaerobic digestion, pyrolysis, composting and landfilling have been employed for treating such wastes. However, it requires integrated system that could utilize waste and promote circular bioeconomy. This review explores integration of anaerobic digestion and pyrolysis for treating agricultural and food waste. Proposed system examines the production of biochar and pyro-oil by pyrolysis of digestate. The use of this biochar for stabilizing anaerobic digestion process, biogas purification and soil amendment will promote the circular bioeconomy. Kinetic models and framework of techno-economic analysis of system were discussed and knowledge gaps have been identified for future research. This system will provide sustainable approach and offer carbon capture and storage in form of biochar in soil.

Microbial originated surfactants with multiple applications: a comprehensive review

Microbial synthesized surfactants are used in contaminated soil bioremediation processes and have multiple applications in various industries. These compounds minimize the negative influences in soil via absorption by detoxifying the toxic metals or compounds. Further, applications of biosurfactants are detected in treating chronic diseases or synthetic drugs alternatives in current periods. Various surfactant molecules can provide many benefits due to their diversities in structural and functional groups. These compounds showed a wide array of applications in multiple sectors such as biomedical or pharmaceutical fields. Agricultural, food processing, laundry, or other sectors. Many microbial systems or plant cells are utilized in biosurfactant production as confirmed by biochemical analysis of genome sequencing tools. Biosurfactant compounds can alter drug transport across the cell membrane. Different nature of biosurfactant compounds exhibited their antifungal, antibacterial, antiviral activities, or antiadhesive coating agents used in reduction of many hospital infections. These distinct properties of biosurfactants pushed their broad spectrum applications in biomedical, agriculture sectors and bioremediation tasks. Additionally, many strains of fungi or bacteria are utilized for biosurfactant synthesis involved in the detoxification of soil/other components of the environment. In these reviews, authors explained various biosurfactants molecules and their mode of actions. Also, applications of microbial originated biosurfactants along with their process technologies are described. Future perspectives of biosurfactants and their scope are also critically explained so that this review paper can be used as a showcase for production and application of biosurfactants.