Development of food packaging bioactive aerogels through the valorization of Gelidium sesquipedale seaweed

Current progress in functionalization of cellulose nanofibers (CNFs) for active food packaging

There is a growing interest in utilizing renewable biomass resources to manufacture environmentally friendly active food packaging, against the petroleum-based polymers. Cellulose nanofibers (CNFs) have received significant attention recently due to their sustainability, biodegradability, and widely available sources. CNFs are generally obtained through chemical or physical treatment, wherein the original surface chemistry and interfacial interactions can be changed if the functionalization process is applied. This review focuses on promising and sustainable methods of functionalization to broaden the potential uses of CNFs in active food packaging. Novel aspects, including functionalization before, during and after cellulose isolation, and functionalization during and after material processing are addressed. The CNF-involved structural construction including films, membranes, hydrogels, aerogels, foams, and microcapsules, is illustrated, which enables to explore the correlations between structure and performance in active food packaging. Additionally, the enhancement of CNFs on multiple properties of active food packaging are discussed, in which the interaction between active packaging systems and encapsulated food or the internal environment are highlighted. This review emphasizes novel approaches and emerging trends that have the potential to revolutionize the field, paving the way for advancements in the properties and applications of CNF-involved active food packaging.

Order matters: Methods for extracting cellulose from rice straw by coupling alkaline, ozone and enzymatic treatments

Rice straw is a widely produced residue that can be converted into value-added products. This work aimed at using greener processes combining mild alkali (A), ozone (O) and enzymatic (engineered xylanase) (E) treatments to extract cellulose and other value-added compounds from rice straw and to evaluate the effects of the order of the treatments. Solid (S) and liquid (L) fractions from the process were collected for physicochemical characterization. AOE treatment showed the best capacity to extract high purity cellulose and other valuable compounds. The lignin content was significantly decreased independently of the order of the treatments and, its content in the extract obtained after the AOE process was lower than the one obtained after the OAE process. Moreover, thermal stability of the samples increased after the enzymatic process, being higher in SAOE. The alkaline treatment increased the hemicellulose and polyphenol content (antioxidant activity) in the liquid fractions (LA and LOA). In contrast, the ozonized liquid fractions had lower polyphenol content. Therefore, alkali was fundamental in the process. In conclusion, the AOE strategy could be a more environmentally friendly method for extracting cellulose and other valuable compounds, which could be used to develop active materials in the future.

Superabsorbent whey protein isolates/chitosan-based antibacterial aerogels: Preparation, characterization and application in chicken meat preservation

Traditional absorbent pads are composed of hard-to-degrade polyethylene film and non-woven bottom layer, which have the characteristic of low absorption rate, without antibacterial effect. The objective of this study is to fabricate a novel superabsorbent and antibacterial aerogel, which consists of whey protein isolate (WPI) and chitosan (CS). The citric acid (CA) and ε-polylysine hydrochloride (ε-PLH) are incorporated into WPI/CS-based aerogel as cross-linking and antibacterial agent, respectively. The application in meat preservation as an absorbent pad is investigated. Results of water absorption, water vapor absorption and stress-strain show that aerogel comprised of 6 % WPI, 1.2 % CS, 2.0 % CA, and 2.0 % ε-PLH have the best water absorption capacity and stress. The density of WPI/CS/CA/ε-PLH aerogel is 82.7 ± 6.4 mg/cm3, and has a uniform and polyporous microstructure, resulting in superabsorbent capacity. Antibacterial rate of WPI/CS/CA/ε-PLH aerogel against Staphylococcus aureus, Escherichia coli, Salmonella and Listeria monocytogenes reach around 80 %. The WPI/CS/CA/ε-PLH aerogel significantly reduces increased velocity of b⁎, pH, total volatile base nitrogen, and total viable counts and decreased velocity of L⁎ and b⁎ of chicken meat (P < 0.05). Results indicate WPI/CS/CA/ε-PLH aerogel effectively extends shelf-life of chicken meat to 7 days, and could be used as an absorbent pad in meat preservation.

Exploring the Versatility of Aerogels: Broad Applications in Biomedical Engineering, Astronautics, Energy Storage, Biosensing, and Current Progress

Aerogels are unique and extremely porous substances with fascinating characteristics such as ultra-low density, extraordinary surface area, and excellent thermal insulation capabilities. Due to their exceptional features, aerogels have attracted significant interest from various fields, including energy, environment, aerospace, and biomedical engineering. This review paper presents an overview of the trailblazing research on aerogels, aiming at their preparation, characterization, and applications. Various methods of aerogel synthesis, such as sol-gel, supercritical drying, are discussed. Additionally, recent progress in the characterization of aerogel structures, including their morphology, porosity, and thermal properties, are extensively reviewed. Finally, aerogel's utilizations in numerous disciplines, for instance, energy storage, thermal insulation, catalysis, environmental remedy, and biomedical applications, are summarized. This review paper provides a comprehensive understanding of aerogels and their prospective uses in diverse fields, highlighting their unique properties for future research and development.

Hybrid Materials of Bio-Based Aerogels for Sustainable Packaging Solutions

This review explores the field of hybrid materials in the context of bio-based aerogels for the development of sustainable packaging solutions. Increasing global concern over environmental degradation and the growing demand for environmentally friendly alternatives to conventional packaging materials have led to a growing interest in the synthesis and application of bio-based aerogels. These aerogels, which are derived from renewable resources such as biopolymers and biomass, have unique properties such as a lightweight structure, excellent thermal insulation, and biodegradability. The manuscript addresses the innovative integration of bio-based aerogels with various other materials such as nanoparticles, polymers, and additives to improve their mechanical, barrier, and functional properties for packaging applications. It critically analyzes recent advances in hybridization strategies and highlights their impact on the overall performance and sustainability of packaging materials. In addition, the article identifies the key challenges and future prospects associated with the development and commercialization of hybrid bio-based aerogel packaging materials. The synthesis of this knowledge is intended to contribute to ongoing efforts to create environmentally friendly alternatives that address the current problems associated with conventional packaging while promoting a deeper understanding of the potential of hybrid materials for sustainable packaging solutions.

Absorbent bioactive aerogels based on germinated wheat starch and grape skin extract

This study aimed to produce water-absorbent bioactive aerogels using biodegradable raw materials, wheat starch and poly ethylene oxide (PEO), and derived from agro-industrial residues (grape skin) obtained in the wine industry. The aerogels were produced using germinated wheat starch (GWS), with and without PEO, and incorporating grape skin extract (GSE) at concentrations of 5 and 10 % (w/w). The GSE was evaluated for total and individual phenolic compounds, anthocyanins, and antioxidant activity. The starch aerogels were characterized for morphology, density, porosity, functional groups by FT-IR, relative crystallinity and diffraction pattern, water absorption capacity, antioxidant activity, and in vitro release profile of phenolic compounds in food simulant medium. The total phenolic compounds in GSE was 226.25 ± 0.01 mg equivalent of gallic acid/g GSE. The aerogels showed low density and high porosity. All aerogels demonstrated high water absorption capacity (581.4 to 997.5 %). The antioxidant activity of the aerogels increased with increasing GSE concentration and the addition of PEO. The aerogels could release GSE gradually for up to 120 days in the hydrophilic simulant medium and 240 h for the hydrophobic medium. Starch-based aerogels with GSE showed potential to be applied as exudate absorbers with antioxidant activity to develop active food packaging.

Synthesis of cellulosic and nano-cellulosic aerogel from lignocellulosic materials for diverse sustainable applications: a review

Cellulosic aerogels are sustainable, biodegradable, and ultra-light porous materials with three-dimensional networks having high specific surface area. Depending on the source of precursor materials, they are categorized into plant-based aerogel, bacterial cellulosic aerogel. Different types of aerogels are also produced from microcrystalline cellulose (MCC), nanocrystalline cellulose (NCC), cellulose microfibril (CMF) and cellulose nanofibril (CNF). Furthermore, inorganic and organic substances are embedded to produce hybrid aerogel or composite aerogel for the enhancement of its performance in various fields. Mixing, gelation, solvent exchange, and drying (e.g., super critical carbon dioxide or freeze drying) are the basic steps involved in cellulosic aerogel synthesis. Based on the composition of precursors during aerogel synthesis, cellulosic aerogels have broad applications in various fields such as adsorbents, electrodes, sensors, captive deionization materials, catalysts, drug delivery, thermal and sound insulating materials. This review provided consolidated information on: (i) classification of cellulosic aerogels based on the sources of raw materials, (ii) processes involved to produce the cellulosic aerogel, (iii) cellulosic aerogel synthesized from MCC, NCC, CMF and CNF, (iv) nano particle doped cellulosic aerogel, and (v) its application in various field with future perspectives.

Development of highly reusable, mechanically stablecorn starch-based aerogel using glycerol for potential application in the storage of fresh spinach leaves

Impact of glycerol on the physico-functional, morphological, mechanical, and rehydration properties ofcorn starch-based aerogel has been investigated. The aerogel was prepared from hydrogel (sol-gel method) using solvent exchange and supercritical CO₂ drying. Glycerol-infused aerogel had a more connected, denser structure (0.38-0.45 g/cm³), enhanced hygroscopic behavior, and was reusable up to eight times in terms of its capacity to absorb water after being drawn from the soaked sample. However, the inclusion of glycerol reduced the aerogel's porosity (75.89-69.91 %) and water absorption rate (WAR; 118.53-84.64 %) but enhanced its percentage shrinkage (75.03-77.99 %) and compressive strength (26.01-295.06 N). The most effective models for describing the rehydration behavior of aerogel were determined to be the Page, Weibull, and Modified Peleg models. Glycerol addition improved the internal strength of the aerogel so could be recycled without significant change in the physical characteristics of the aerogel. By effectively eliminating the condensed moisture that was developed inside the packing owing to the transpiration of fresh spinach leaves, the aerogel extended the storage life of the leaves by up to eight days. The glycerol-based aerogel has the potential to be employed as a carrier matrix for various chemicals and a moisture scavenger.

Emerging Trends in Nanotechnology: Aerogel-Based Materials for Biomedical Applications

At present, aerogel is one of the most interesting materials globally. The network of aerogel consists of pores with nanometer widths, which leads to a variety of functional properties and broad applications. Aerogel is categorized as inorganic, organic, carbon, and biopolymers, and can be modified by the addition of advanced materials and nanofillers. Herein, this review critically discusses the basic preparation of aerogel from the sol-gel reaction with derivation and modification of a standard method to produce various aerogels for diverse functionalities. In addition, the biocompatibility of various types of aerogels were elaborated. Then, biomedical applications of aerogel were focused on this review as a drug delivery carrier, wound healing agent, antioxidant, anti-toxicity, bone regenerative, cartilage tissue activities and in dental fields. The clinical status of aerogel in the biomedical sector is shown to be similarly far from adequate. Moreover, due to their remarkable properties, aerogels are found to be preferably used as tissue scaffolds and drug delivery systems. The advanced studies in areas including self-healing, additive manufacturing (AM) technology, toxicity, and fluorescent-based aerogel are crucially important and are further addressed.

Research Progress in Hemicellulose-Based Nanocomposite Film as Food Packaging

As the main component of agricultural and forestry biomass, hemicellulose has the advantages of having an abundant source, biodegradability, nontoxicity and good biocompatibility. Its application in food packaging has thus become the focus of efficient utilization of biomass resources. However, due to its special molecular structure and physical and chemical characteristics, the mechanical properties and barrier properties of hemicellulose films are not sufficient, and modification for performance enhancement is still a challenge. In the field of food packaging materials preparation, modification of hemicellulose through blending with nanofibers or nanoparticles, both inorganic and organic, has attracted research attention because this approach offers the advantages of efficient improvement in the expected properties and better cost efficiency. In this paper, the composition of hemicellulose, the classification of nanofillers and the research status of hemicellulose-based nanocomposite films are reviewed. The research progress in modification of hemicellulose by using layered silicate, inorganic nanoparticles and organic nanoparticles in food packaging is described. Challenges and outlook of research in hemicellulose-based nanocomposite film in food packaging is discussed.

Controllable Construction of Temperature-Sensitive Supramolecular Hydrogel Based on Cellulose and Cyclodextrin

In temperature sensitive hydrogels, the swelling degree or light transmittance of the gel itself changes with variations in ambient temperature, prompting its wide application in controlled drug release, tissue engineering, and material separation. Considering the amphiphilic structure of β-cyclodextrin (β-CD), a cellulose-based supramolecular hydrogel with superior temperature sensitivity was synthesized based on a combination of cellulose and β-CD as well as the host–guest interaction between β-CD and polypropylene glycol (PPG). In the one-pot tandem reaction process, chemical grafting of β-CD on cellulose and the inclusion complexation of β-CD with PPG were performed simultaneously in a NaOH/urea/water system. The obtained supramolecular hydrogel had a lower critical solution temperature (LCST) of 34 °C. There existed covalent bonding between the cellulose and β-CD, host–guest complexation between the β-CD and PPG, and hydrogen bonding and hydrophobic interactions between the components in the network structure of the supramolecular hydrogel. The combination of various covalent and non-covalent bonds endowed the resulting supramolecular hydrogel with good internal network structure stability and thermal stability, as well as sensitive temperature responsiveness within a certain range—implying its potential as a smart material in the fields of medicine, biology, and textiles. This work is expected to bring new strategies for the fabrication of cellulose-based thermosensitive materials, benefitting the high-value utilization of cellulose.

Enteromorpha cellulose micro-nanofibrils/poly(vinyl alcohol) based composite films with excellent hydrophilic, mechanical properties and improved thermal stability

This study presents the preparation of cellulose micro-nanofibrils (CMNFs) from Enteromorpha (EP) and the application in PVA/acetylated distarch phosphate (ADSP)/CMNFs composite films. The Micro-nano scale, hydrophilicity, and strong hydrogen bond characteristics of CMNFs prepared form EP by acid hydrolysis were confirmed through the granular statistics, XRD analysis and chemical structure analysis. With the addition of CMNFs, the ultimate tensile strength and elongation at break of composite films are increased by 42.4 % and 90.3 %. An original Weibull statistical analysis shows the impact of CMNFs' added amount on strength distribution and ultimate stress. SEM and polarizing microscope images show the CMNFs' dispersion state in that films is optimal, when their addition was to be 2 %-3 % of total dry weight of PVA/ADSP matrix， which is consistent with the results of Weibull modulus analysis. The main thermal weight-loss process of the composite film is divided into four stages, CMNFs can significantly increase the thermostability at 280 °C to 400 °C. The experiment of water contact angle and water vapor transmission rate of the composite films confirmed that CMNFs can improve films' hydrophilicity. This study provides basis for the preparation of hydrophilic CMNFs and mechanism of modification study PVA-based composites.

Antibacterial aerogels with nano‑silver reduced in situ by carboxymethyl cellulose for fresh meat preservation

Bacterial cellulose (BC) was used as a reinforcing agent, citric acid (CA) as a cross-linking agent, and CMC@AgNPs as antibacterial nanomaterials, in which CMC@AgNPs were reduced from AgNO₃ in situ by carboxymethyl cellulose (CMC) as a reducing agent and stabilizer to fight microbial corruption. Its potential application in packaging fresh meat has been investigated. Results showed that the antibacterial CMC@AgNPs/BC/CA aerogels with excellent structural integrity and outstanding water absorption were developed by adding 0.3% BC and 0.25% CA. The CMC@AgNPs/BC/CA aerogel significantly reduced the color change and the total viable bacterial counts (TVC) in fresh meat after 7 days of refrigerated storage. The results indicated that CMC@AgNPs/BC/CA aerogels can effectively extend the shelf life of fresh meat, and can be used for meat packaging as a biologically active absorption pad.

Contributions of Women in Recent Research on Biopolymer Science

Nowadays, biopolymers are playing a fundamental role in our society because of the environmental issues and concerns associated with synthetic polymers. The aim of this Special Issue entitled ‘Women in Polymer Science and Technology: Biopolymers’ is highlighting the work designed and developed by women on biopolymer science and technology. In this context, this short review aims to provide an introduction to this Special Issue by highlighting some recent contributions of women around the world on the particular topic of biopolymer science and technology during the last 20 years. In the first place, it highlights a selection of important works performed on a number of well-studied natural polymers, namely, agar, chitin, chitosan, cellulose, and collagen. Secondly, it gives an insight into the discovery of new polysaccharides and enzymes that have a role in their synthesis and in their degradation. These contributions will be paving the way for the next generation of female and male scientists on this topic.

Seaweed Polysaccharide in Food Contact Materials (Active Packaging, Intelligent Packaging, Edible Films, and Coatings)

Food contact materials (FCMs) are materials that come in contact with food products such as food packaging which play a significant role in the food quality and safety. Plastic, which is a major food packaging material, harms the eco-system, wildlife, and the environment. As a result, numerous researches have been in progress on alternative polymers, which has similar properties as plastic but is also environmentally friendly (biodegradable). In recent years, the utilization of seaweed polysaccharides has piqued interest due to its biodegradability, non-toxicity, antioxidant capabilities, and excellent film formation ability. However, it has a number of drawbacks such as low tensile strength, water solubility, and moderate antibacterial characteristics, among others. The addition of other biopolymers, nanoparticles, or natural active agents improves these features. In this review article, we have summarized the current state of seaweed polysaccharide research in active packaging, intelligent packaging, edible films, and coatings. It also highlights the physical, thermal, antioxidant, and other properties of these materials. Finally, the article discusses the relevant legislation as well as the field’s future prospects. Research shows that seaweeds polysaccharide looks promising as a sustainable food contact material, but there is always a potential for development to make it market feasible.

Nanocelluloses: Sources, Pretreatment, Isolations, Modification, and Its Application as the Drug Carriers

The 'Back-to-nature' concept has currently been adopted intensively in various industries, especially the pharmaceutical industry. In the past few decades, the overuse of synthetic chemicals has caused severe damage to the environment and ecosystem. One class of natural materials developed to substitute artificial chemicals in the pharmaceutical industries is the natural polymers, including cellulose and its derivatives. The development of nanocelluloses as nanocarriers in drug delivery systems has reached an advanced stage. Cellulose nanofiber (CNF), nanocrystal cellulose (NCC), and bacterial nanocellulose (BC) are the most common nanocellulose used as nanocarriers in drug delivery systems. Modification and functionalization using various processes and chemicals have been carried out to increase the adsorption and drug delivery performance of nanocellulose. Nanocellulose may be attached to the drug by physical interaction or chemical functionalization for covalent drug binding. Current development of nanocarrier formulations such as surfactant nanocellulose, ultra-lightweight porous materials, hydrogel, polyelectrolytes, and inorganic hybridizations has advanced to enable the construction of stimuli-responsive and specific recognition characteristics. Thus, an opportunity has emerged to develop a new generation of nanocellulose-based carriers that can modulate the drug conveyance for diverse drug characteristics. This review provides insights into selecting appropriate nanocellulose-based hybrid materials and the available modification routes to achieve satisfactory carrier performance and briefly discusses the essential criteria to achieve high-quality nanocellulose.

Enhanced physical and antimicrobial properties of alginate/chitosan composite aerogels based on electrostatic interactions and noncovalent crosslinking

In this study, the alginate/chitosan composite aerogels based on electrostatic interactions and noncovalent crosslinking were fabricated using sol-gel method followed by freeze-drying process. The solution property results showed that with the addition of chitosan in alginate solution, a tighter network was induced by the more entangled molecular chains. The aerogel morphology observations showed that the pore diameter decreased with the increasing weight ratio of chitosan in the aerogels, but was even much lower after the crosslinking of excess alginate with calcium ions. After crosslinking, the aerogels presented the improved thermal stability and higher mechanical properties, as well as stronger antibacterial activities against Staphylococcus aureus and Escherichia coli. Therefore, the enhanced physical and antimicrobial properties of the alginate/chitosan aerogels may be achieved by modulation of electrostatic interactions and noncovalent crosslinking, suggesting the promising applications of these composite aerogels as active food packaging materials for antimicrobial purpose.

Nanocellulose from various biomass wastes: Its preparation and potential usages towards the high value-added products

Biomass waste comes from a wide range of sources, such as forest, agricultural, algae wastes, as well as other relevant industrial by-products. It is an important alternative energy source as well as a unique source for various bioproducts applied in many fields. For the past two decades, how to reuse, recycle and best recover various biomass wastes for high value-added bioproducts has received significant attention, which has not only come from various academia communities but also from many civil and medical industries. To summarize one of the cutting-edge technologies applied with nanocellulose biomaterials, this review focused on various preparation methods and strategies to make nanocellulose from diverse biomass wastes and their potential applications in biomedical areas and other promising new fields.

Aerogels based on corn starch as carriers for pinhão coat extract (Araucaria angustifolia) rich in phenolic compounds for active packaging

The objective of this study was to produce renewable aerogels from native and anionic corn starches loaded with pinhão coat extract (PCE) with water absorbent capacity, antioxidant activity and controlled release of phenolic compounds in a hydrophilic food simulant media. Starch aerogels were produced with different concentrations of PCE, 5 and 10%, and evaluated for FT-IR spectra, relative crystallinity, thermal properties, water absorption capacity (WAC), density, antioxidant activity and in vitro release. Thermal stability of the compounds was improved by the incorporation of PCE. The aerogels presented high WAC of 541 to 731% and low-density values of 0.03 g.cm^-1. The highest inhibition of DPPH and ABTS radicals was presented to anionic starch aerogels with 10% PCE rendering 26% of inhibition of ABTS and 24% of DPPH. The maximum in vitro releases for native and anionic starch aerogels with 5% of PCE were 28.70 and 29.44%, respectively, and for aerogels with 10% of PCE they were 34.27 and 35.94%, respectively. The anionic starch aerogels had the highest amount of phenolic compounds released when compared to the native starch aerogels. The starch-based bioactive aerogels showed potential to be applied in food packaging as water absorbent and as a carrier of phenolic compounds.

Biorefinery Approach for Aerogels

According to the International Energy Agency, biorefinery is "the sustainable processing of biomass into a spectrum of marketable bio-based products (chemicals, materials) and bioenergy (fuels, power, heat)". In this review, we survey how the biorefinery approach can be applied to highly porous and nanostructured materials, namely aerogels. Historically, aerogels were first developed using inorganic matter. Subsequently, synthetic polymers were also employed. At the beginning of the 21st century, new aerogels were created based on biomass. Which sources of biomass can be used to make aerogels and how? This review answers these questions, paying special attention to bio-aerogels' environmental and biomedical applications. The article is a result of fruitful exchanges in the frame of the European project COST Action "CA 18125 AERoGELS: Advanced Engineering and Research of aeroGels for Environment and Life Sciences".

Amyloid Fibril-Templated High-Performance Conductive Aerogels with Sensing Properties

Amyloid fibrils have garnered increasing attention as viable building blocks for functional material design and synthesis, especially those derived from food and agricultural wastes. Here, amyloid fibrils generated from β-lactoglobulin, a by-product from cheese industries, have been successfully used as a template for the design of a new class of high-performance conductive aerogels with sensing properties. These mechanically stable aerogels with three-dimensional porous architecture have a large surface area (≈159 m2 g-1), low density (≈0.044 g cm-3), and high electrical conductivity (≈0.042 S cm-1). A pressure sensing device is developed from these aerogels based on their combined electrical conductivity and compressible properties. More interestingly, these aerogels can be employed to design novel enzyme sensors by exploiting the proteinaceous nature of amyloid fibrils. This study expands the scope of structured amyloid fibrils as scaffolds for in situ polymerization of conducting polymers, offering new opportunities to design materials with multiple functionalities.

Prospect of Polysaccharide-Based Materials as Advanced Food Packaging

The use of polysaccharide-based materials presents an eco-friendly technological solution, by reducing dependence on fossil resources while reducing a product's carbon footprint, when compared to conventional plastic packaging materials. This review discusses the potential of polysaccharides as a raw material to produce multifunctional materials for food packaging applications. The covered areas include the recent innovations and properties of the polysaccharide-based materials. Emphasis is given to hemicelluloses, marine polysaccharides, and bacterial exopolysaccharides and their potential application in the latest trends of food packaging materials, including edible coatings, intelligent films, and thermo-insulated aerogel packaging.

Aquaculture and by-products: Challenges and opportunities in the use of alternative protein sources and bioactive compounds

There is a growing concern about chronic diseases such as obesity, diabetes, hypertension, hypercholesterolemia, cancer and cardiovascular diseases resulting from profound changes in the western lifestyle. Aquaculture by-products are generated in large quantities and they can be profitably recycled through their bioactive compounds used for health or food supplements. Improving waste utilization in the field of aquaculture is essential for a sustainable industry to prevent or minimize the environmental impact. In this sense fish by-products are a great source of protein and omega-3 polyunsaturated fatty acids which are particularly studied on Atlantic salmon or rainbow trout. Fish protein hydrolysate (FPH) obtained from chemical, enzymatical and microbial hydrolysis of processing by-products are being used as a source of amino acids and peptides with high digestibility, fast absorption and important biological activities. Omega-3 polyunsaturated fatty acids, eicosapentaenoic (EPA) and docosahexaenoic (DHA) from fish discards have been reported to decrease postprandial triacylglycerol levels, reduction of blood pressure, platelet aggregation and the inflammatory response. Crustacean by-products can also be used to produce chitosan with antioxidant and antimicrobial activity for food and pharmaceutical industries and carotenoids with important biological activity. Seaweeds are rich in bioactive compounds such as alginate, carrageenan, agar, carotenoids and polyphenols with different biological activities such as antioxidant, anticancer, antidiabetic, antimicrobial or anti-inflammatory activity. Finally, regarding harvest microalgae, during the past decades, they were mainly used in the healthy food market, with >75% of the annual microalgal biomass production, used for the manufacture of powders, tablets, capsules or pills. We will report and discuss the present and future role of aquaculture by-products as sources of biomolecules for the design and development of functional foods/beverages. This chapter will focus on the main bioactive compounds from aquaculture by-products as functional compounds in food and their applications in biomedicine for the prevention and treatment of diseases.

In-Depth Characterization of Bioactive Extracts from Posidonia oceanica Waste Biomass

Posidonia oceanica waste biomass has been valorised to produce extracts by means of different methodologies and their bioactive properties have been evaluated. Water-based extracts were produced using ultrasound-assisted and hot water methods and classified according to their ethanol-affinity (E1: ethanol soluble; E2: non-soluble). Moreover, a conventional protocol with organic solvents was applied, yielding E3 extracts. Compositional and structural characterization confirmed that while E1 and E3 extracts were mainly composed of minerals and lipids, respectively, E2 extracts were a mixture of minerals, proteins and carbohydrates. All the extracts showed remarkably high antioxidant capacity, which was not only related to phenolic compounds but also to the presence of proteins and polysaccharides. All E2 and E3 extracts inhibited the growth of several foodborne fungi, while only E3 extracts decreased substantially the infectivity of feline calicivirus and murine norovirus. These results show the potential of P. oceanica waste biomass for the production of bioactive extracts.

Nanomaterials in Advanced, High-Performance Aerogel Composites: A Review

Aerogels are one of the most interesting materials of the 21st century owing to their high porosity, low density, and large available surface area. Historically, aerogels have been used for highly efficient insulation and niche applications, such as interstellar particle capture. Recently, aerogels have made their way into the composite universe. By coupling nanomaterial with a variety of matrix materials, lightweight, high-performance composite aerogels have been developed for applications ranging from lithium-ion batteries to tissue engineering materials. In this paper, the current status of aerogel composites based on nanomaterials is reviewed and their application in environmental remediation, energy storage, controlled drug delivery, tissue engineering, and biosensing are discussed.

Cellulose nanocrystals from rice and oat husks and their application in aerogels for food packaging

This study describes the valorization of rice and oat husks by obtaining cellulose nanocrystals for the production of aerogels for food packaging applications. Commercial cellulose was used as a control sample. Nanocrystals from cellulose were obtained by enzymatic hydrolysis and mechanical treatment at high pressure. The morphology, particle size, functional groups, crystallinity, and thermal properties of the cellulose nanocrystals were analyzed. The morphology, functional groups, crystallinity, water absorption capability, and zeta potential of aerogels were also analyzed. Cellulose nanocrystals show different structural properties and crystallinity depending on the source of the cellulose. The average diameter of the nanocrystals varied from 16.0 to 28.8 nm. The aerogels prepared with cellulose nanocrystals showed a porous and uniform structure with a water absorption capacity between 264.2% and 402.8% at 25 °C. The aerogel of oat cellulose nanocrystals showed a larger pore size than that of eucalyptus cellulose nanocrystals, and this may have influenced the lowest water absorption capacity of the aerogels of eucalyptus cellulose nanocrystals. These results show that agroindustrial residues have promising applications in various industrial fields and could be used as aerogel absorbers of water in food packaging.