Utilization of carrot (Daucus carota L.) fiber as a filler for chitosan based films

A review of starch-based biocomposites reinforced with plant fibers

Renewable and biodegradable resources have gained increasing attention as promising alternatives to synthetic plastics. Among the diverse raw materials employed in bioplastics production, starch emerges as an attractive, low-cost, and largely available source. However, the inherent properties of starch-based materials often limit their utility across various applications, necessitating strategic modifications to enhance their performance. A common approach to boost these materials involves incorporating natural fillers into biopolymer matrices. Incorporating natural fibers within starch matrices enables the development of biocomposites with improved properties while retaining their renewable and biodegradable characteristics. This review briefly addresses fundamental aspects of starch structure, obtention, and processing, as well as the main pre-treatments of natural fibers and processing methods currently applied to produce starch-based composites. It also highlights the most recent advances in this field, elucidates the effect of the incorporation of fibers on the biocomposite properties, and discusses the critical parameters affecting the synergic combination between starch and fibers.

Biobased Films Based on Chitosan and Microcrystalline Cellulose for Sustainable Packaging Applications

The transition to a more sustainable lifestyle requires a move away from petroleum-based sources and the investigation and funding of renewable and waste feedstocks to provide biobased sustainable materials. The formulation of films based on chitosan and microcrystalline cellulose with potential applications in the packaging sector has been demonstrated. Glycerol is also used as a plasticizer in the formulation of flexible films, while mucic acid is used as a valid alternative to acetic acid in such films. The film based on chitosan, microcrystalline cellulose, glycerol, and mucic acid shows properties and a performance similar to those of the film formulated with acetic acid, and, in addition, it seems that the photo-oxidation resistance of the film based on mucic acid is better than that of the material containing acetic acid. The films were characterized using spectroscopy (FTIR and UV-vis), tensile testing, water contact angle measurements, surface observations, and photo-oxidation resistance measurements. The presence of microcrystalline cellulose enhances the mechanical behavior, UV barrier properties, and surface hydrophobicity of the film. The feasibility of formulating chitosan-based films, with or without microcrystalline cellulose, which exhibit good properties and performances is demonstrated. Mucic acid instead of acetic acid is used in the formulation of these film.

A novel high water-soluble antibacterial films-based guar gum incorporated with Aloe vera gel and ε-polylysine

The high water-soluble films are commonly used in food coating and food encapsulation. In this study, the effect of Aloe vera gel (AV) and ε-polylysine (ε-PL) on the comprehensive properties of films based on guar gum (GG) were investigated. When GG to AV was 8:2, the GG:AV:ε-PL composite films (water solubility = 68.50%) had an 82.42% higher water solubility than pure guar gum (PGG) films (water solubility = 37.55%). Compared with PGG films, the composite films more transparent, better thermal stability and elongation at break. X-ray diffraction and SEM analysis showed the composite films were amorphous structures and the AV and ε-PL did not change the structure of PGG. FITR analysis confirmed the formation of hydrogen bonds within the composite films. Antibacterial properties showed the composite films had a good antibacterial effect against Escherichia coli and Staphylococcus aureus. Therefore, the composite films can be a new option of high water-soluble antibacterial food packaging materials.

A Review on the Challenges and Choices for Food Waste Valorization: Environmental and Economic Impacts

Valorization of food waste (FW) is instrumental for reducing the environmental and economic burden of FW and transitioning to a circular economy. The FW valorization process has widely been studied to produce various end-use products and summarize them; however, their economic, environmental, and social aspects are limited. This study synthesizes some of the valorization methods used for FW management and produces value-added products for various applications, and also discusses the technological advances and their environmental, economic, and social aspects. Globally, 1.3 billion tonnes of edible food is lost or wasted each year, during which about 3.3 billion tonnes of greenhouse gas is emitted. The environmental (-347 to 2969 kg CO₂ equiv/tonne FW) and economic (-100 to $138/tonne FW) impacts of FW depend on the multiple parameters of food chains and waste management systems. Although enormous efforts are underway to reduce FW as well as valorize unavoidable FW to reduce environmental and economic loss, it seems the transdisciplinary approach/initiative would be essential to minimize FW as well as abate the environmental impacts of FW. A joint effort from stakeholders is the key to reducing FW and the efficient and effective valorization of FW to improve its sustainability. However, any initiative in reducing food waste should consider a broader sustainability check to avoid risks to investment and the environment.

Utilization of chestnut shell lignin in alginate films

BACKGROUND

Lignocellulosic structures obtained from agricultural wastes can re-design sustainable packaging materials. The present study investigated the utilization of lignocellulose (LS), alkali lignin (L) and hydroxymethylated (modified) lignin (ML), separated from chestnut shells in alginate (AL) films at 100 and 200 mg g^-1 (10% and 20%, w/w based on AL), as reinforcing agents. Lignin modification and concentration effects on the AL films were characterized by water vapor permeability (WVP), as well as morphological, mechanical, optical, thermal and active properties.

RESULTS

Fourier transform infrared spectroscopy results showed that extracted L and LS had different structures, and the modification of L resulted in a peak shift and a decrease in peak intensities between 1250 and 800 cm^-1 . The antioxidant and antimicrobial activity tests showed that films containing L had higher activity values (P < 0.05). WVP of the films containing ML was the lowest (P < 0.05) and the results revealed that 20% (w/w) concentration had an adverse effect on the WVP of films. The addition of L, LS and ML increased the tensile strength, elastic modulus and thermal properties (P < 0.05) compared to AL control films. With an increasing concentration, films containing L-based structures showed higher opacity and relatively lower L* values (P < 0.05).

CONCLUSION

These results show that the addition of lignin to biopolymers is a promising method for improving the properties of biopolymers and providing functional attributes. LS had no or little effect on the film properties; however, the modification of L had the advantage of enhancing WVP and thermal properties at the same time as showing a decrease in functional properties compared to L. © 2022 Society of Chemical Industry.

Optimization of Cellulosic Fiber Extraction from Parsley Stalks and Utilization as Filler in Composite Biobased Films

Food waste is an abundant source of cellulose which can be extracted via mild alkali treatment. The extraction conditions of cellulose fibers can be optimized for reduced chemical and energy use and optimal functionality. This study focused on the optimization of alkali extraction of lignocellulosic fiber from parsley stalks by building an experimental design with the response surface method with alkali concentration (2, 6, and 10%, w/v), fiber:alkali ratio (0.02, 0.035, and 0.05; w/v) and extraction temperature (40, 70, and 100 °C) as independent variables, in order to evaluate the effects of extraction conditions on fiber yield and composition of parsley stalks extract (PSE). Following the optimization, PSE and untreated fibers (PF) were incorporated as filler into gum Arabic-sodium alginate-based films, and film properties such as water vapor permeability, optical and thermal properties, Fourier transform infrared spectra and surface morphology of the films were analyzed for evaluating the compatibility of these fillers with the composite film matrix. The optimal extraction conditions were determined as 2% alkali, sample:alkali ratio of 0.0276 and extraction temperature of 40 °C. PSE extracted at optimal conditions was added to the composite films, and water vapor permeability and optical properties were improved by up to 10% PSE compared to films with PF.

Antibacterial Gelidium amansii polysaccharide-based edible films containing cyclic adenosine monophosphate for bioactive packaging

A homogeneous polysaccharide (GAP), with a molecular weight of 51.8 kDa, was isolated from edible red seaweed Gelidium amansii. Composition analysis suggested GAP contained 5.31% sulfate and 17.33% 3,6-anhydro-galactose and was mainly composed of galactose. Furthermore, GAP, as a biopolymer matrix, was used to form the composite films with the small biological molecules cytidine-5'-monophosphate (CMP), adenosine-5'-monophosphate (AMP), and cyclic adenosine monophosphate (cAMP). Scanning electron microscope (SEM), Fourier transform infrared (FTIR) spectrum, and X-ray diffraction (XRD) results showed that CMP, AMP, and cAMP interacted with the film substrates and might made films more complex. Notably, the addition of CMP, AMP, and cAMP promoted the light, water vapor, and oxygen barrier ability, surface wettability, mechanical strength, and antimicrobial activity against Gram-negative and -positive bacteria. Finally, GAP-based films composited with cAMP (cAMPF) exhibited the best characteristics were applied to fish packaging and preservation at 4 °C and extended the fish shelf life. All these data suggested the potential value of cAMPF as a functional edible polysaccharide film applied in food industries.

O-ATRP synthesized poly(β-pinene) blended with chitosan for antimicrobial and antioxidant bio-based films production

Antioxidant and antimicrobial activities are important characteristics of active film packaging designed to extend food preservation. In this study, functional bio-based films were produced using different concentrations of antioxidant poly(β-pinene) bio-oligomer synthesized via organocatalyzed atom transfer radical polymerization (O-ATRP) and blended with chitosan of different molecular weights. The structural, mechanical, thermal, solubility, antioxidant, and antimicrobial properties of the films were investigated. The poly(β-pinene)-chitosan blends presented significant pores and irregularities with the increase of poly(β-pinene) concentration over 30%. Chitosan molecular weight did not show any important influence in the physical properties of the blends. Poly(β-pinene) load decreased the materials' tensile strength and melting temperature, exhibiting a plasticizing effect on chitosan chains. The antioxidant and antimicrobial activities of the films were improved by poly(β-pinene) incorporation and mainly depended on its concentration. Therefore, the incorporation of poly(β-pinene) in chitosan films can be an alternative for active packaging production.