Toward a Circular Bioeconomy: Exploring Pineapple Stem Starch Film as a Plastic Substitute in Single Use Applications

Ecotoxicological evaluation of chitosan biopolymer films particles in adult zebrafish (Danio rerio): A comparative study with polystyrene microplastics

To mitigate the environmental impact of microplastics (MPs), the scientific community has innovated sustainable and biodegradable polymers as viable alternatives to traditional plastics. Chitosan, the deacetylated form of chitin, stands as one of the most thoroughly investigated biopolymers and has garnered significant interest due to its versatile applications in both medical and cosmetic fields. Nevertheless, there is still a knowledge gap regarding the impact that chitosan biopolymer films (CBPF) may generate in aquatic organisms. In light of the foregoing, this study aimed to assess and compare the potential effects of CBPF on the gastrointestinal tract, gills, brain, and liver of Danio rerio against those induced by MPs. The findings revealed that both CBPF and MPs induced changes in the levels of oxidative stress biomarkers across all organs. However, it is essential to note that our star plots illustrate a tendency for CBPF to activate antioxidant enzymes and for MPs to produce oxidative damage. Regarding gene expression, our findings indicate that MPs led to an up-regulation in the expression of genes associated with apoptotic response (p53, casp3, cas9, bax, and bcl2) in all fish organs. Meanwhile, CBPF produced the same effect in genes related to antioxidant response (nrf1 and nrf2). Overall, our histological observations substantiated these effects, revealing the presence of plastic particles and tissue alterations in the gills and gastrointestinal tract of fish subjected to MPs. From these results, it can be concluded that CBPF does not represent a risk to fish after long exposure.

Sustainable Materials with Improved Biodegradability and Toughness from Blends of Poly(Lactic Acid), Pineapple Stem Starch and Modified Natural Rubber

Poly(lactic acid) (PLA), derived from renewable resources, plays a significant role in the global biodegradable plastic market. However, its widespread adoption faces challenges, including high brittleness, hydrophobicity, limited biodegradability, and higher costs compared to traditional petroleum-based plastics. This study addresses these challenges by incorporating thermoplastic pineapple stem starch (TPSS) and modified natural rubber (MNR) into PLA blends. TPSS, derived from pineapple stem waste, is employed to enhance hydrophilicity, biodegradability, and reduce costs. While the addition of TPSS (10 to 40 wt.%) marginally lowered mechanical properties due to poor interfacial interaction with PLA, the inclusion of MNR (1 to 10 wt.%) in the PLA/20TPSS blend significantly improved stretchability and impact strength, resulting in suitable modulus (1.3 to 1.7 GPa) and mechanical strength (32 to 52 MPa) for diverse applications. The presence of 7 wt.% MNR increased impact strength by 90% compared to neat PLA. The ternary blend exhibited a heterogeneous morphology with enhanced interfacial adhesion, confirmed by microfibrils and a rough texture on the fracture surface. Additionally, a downward shift in PLA's glass transition temperature (Tg) by 5-6 °C indicated improved compatibility between components. Remarkably, the PLA ternary blends demonstrated superior water resistance and proper biodegradability compared to binary blends. These findings highlight the potential of bio-based plastics, such as PLA blends with TPSS and MNR, to contribute to sustainable economic models and reduce environmental impact for using in plastic packaging applications.

Innovations in Food Packaging for a Sustainable and Circular Economy

Packaging is fundamental to maintaining the quality of food, but its contribution with a negative footprint to the environment must be completely changed worldwide to reduce pollution and climate change. Innovative and sustainable packaging and new strategies of reutilization are necessary to reduce plastic waste accumulation, maintain food quality and safety, and reduce food losses and waste. The purpose of this chapter is to present innovations in food packaging for a sustainable and circular economy. First, to present the eco-design packaging approach as well as new strategies for recycled or recyclable materials in food packaging. Second, to show current trends in new packaging materials developed from the use of agro-industrial wastes as well as new methods of production, including 3D/4D printing, electrostatic spinning, and the use of nanomaterials.

Development of Biodegradable Thermosetting Plastic Using Dialdehyde Pineapple Stem Starch

Starch extracted from pineapple stem waste underwent an environmentally friendly modification process characterized by low-energy consumption. This process resulted in the creation of dialdehyde pineapple stem starch featuring varying aldehyde contents ranging from 10% to 90%. Leveraging these dialdehyde starches, thermosetting plastics were meticulously developed by incorporating glycerol as a plasticizer. Concurrently, unmodified pineapple stem starch was employed as a control to produce thermoplastic material under identical conditions. The objective of streamlining the processing steps was pursued by adopting a direct hot compression molding technique. This enabled the transformation of starch powders into plastic sheets without the need for water-based gelatinization. Consequently, the dialdehyde starch-based thermosetting plastics exhibited exceptional mechanical properties, boasting a modulus within the range of 1862 MPa to 2000 MPa and a strength of 15 MPa to 42 MPa. Notably, their stretchability remained relatively modest, spanning from 0.8% to 2.4%. Comparatively, these properties significantly outperformed the thermoplastic counterpart derived from unmodified starch. Tailoring the mechanical performance of the thermosetting plastics was achieved by manipulating the glycerol content, ranging from 30% to 50%. Phase morphologies of the thermoset starch unveiled a uniformly distributed microstructure without any observable starch particles. This stood in contrast to the heterogeneous structure exhibited by the thermoplastic derived from unmodified starch. X-ray diffraction patterns indicated the absence of a crystalline structure within the thermosets, likely attributed to the establishment of a crosslinked structure. The resultant network formation in the thermosets directly correlated with enhanced water resistance. Remarkably, the thermosetting starch originating from pineapple stem starch demonstrated continued biodegradability following a soil burial test, albeit at a notably slower rate when compared to its thermoplastic counterpart. These findings hold the potential to pave the way for the utilization of starch-based products, thereby replacing non-biodegradable petroleum-based materials and contributing to the creation of more enduring and sustainable commodities.

Development of Biodegradable Rigid Foams from Pineapple Field Waste

Pineapple materials sourced from agricultural waste have been employed to process novel bio-degradable rigid composite foams. The matrix for the foam consisted of starch extracted from pineapple stem, known for its high amylose content, while the filler comprised non-fibrous cellulosic materials sourced from pineapple leaf. In contrast to traditional methods that involve preparing a batter, this study adopted a unique approach where the starch gel containing glycerol were first formed using a household microwave oven, followed by blending the filler into the gel using a two-roll mill. The resulting mixture was then foamed at 160 °C using a compression molding machine. The foams displayed densities ranging from 0.43-0.51 g/cm³ and exhibited a highly amorphous structure. Notably, the foams demonstrated an equilibrium moisture content of approximately 8-10% and the ability to absorb 150-200% of their own weight without disintegration. Flexural strengths ranged from 1.5-4.5 MPa, varying with the filler and glycerol contents. Biodegradability tests using a soil burial method revealed complete disintegration of the foam into particles measuring 1 mm or smaller within 15 days. Moreover, to showcase practical applications, an environmentally friendly single-use foam tray was fabricated. This novel method, involving gel formation followed by filler blending, sets it apart from previous works. The findings highlight the potential of pineapple waste materials for producing sustainable bio-degradable foams with desirable properties and contribute to the field of sustainable materials.

Toward a Circular Bioeconomy: Exploring Pineapple Stem Starch Film as Protective Coating for Fruits and Vegetables

In order to reduce our dependence on nonrenewable plastics and solve the problem of non-biodegradable plastic waste, there has been much attention paid to the development of biodegradable plastics from natural resources. Starch-based materials have been widely studied and developed for commercial production, primarily from corn and tapioca. However, the use of these starches could generate food security problems. Therefore, the use of alternative starch sources, such as agricultural waste, would be of great interest. In this work, we investigated the properties of films prepared from pineapple stem starch, which has a high amylose content. Pineapple stem starch (PSS) films and glycerol-plasticized PSS films were prepared and characterized using X-ray diffraction and water contact angle measurements. All films exhibited some degree of crystallinity, making them water-resistant. The effect of glycerol content on mechanical properties and gas (oxygen, carbon dioxide and water vapor) transmission rates was also studied. The tensile modulus and tensile strength of the films decreased with increasing glycerol content, while gas transmission rates increased. Preliminary studies showed that coatings made from PSS films could slow down the ripening process of bananas and extend their shelf life.

Toward a Circular Bioeconomy: Development of Pineapple Stem Starch Composite as a Plastic-Sheet Substitute for Single-Use Applications

Plastic waste poses a significant challenge for the environment, particularly smaller plastic products that are often difficult to recycle or collect. In this study, we developed a fully biodegradable composite material from pineapple field waste that is suitable for small-sized plastic products that are difficult to recycle, such as bread clips. We utilized starch from waste pineapple stems, which is high in amylose content, as the matrix, and added glycerol and calcium carbonate as the plasticizer and filler, respectively, to improve the material's moldability and hardness. We varied the amounts of glycerol (20-50% by weight) and calcium carbonate (0-30 wt.%) to produce composite samples with a wide range of mechanical properties. The tensile moduli were in the range of 45-1100 MPa, with tensile strengths of 2-17 MPa and an elongation at break of 10-50%. The resulting materials exhibited good water resistance and had lower water absorption (~30-60%) than other types of starch-based materials. Soil burial tests showed that the material completely disintegrated into particles smaller than 1 mm within 14 days. We also created a bread clip prototype to test the material's ability to hold a filled bag tightly. The obtained results demonstrate the potential of using pineapple stem starch as a sustainable alternative to petroleum-based and biobased synthetic materials in small-sized plastic products while promoting a circular bioeconomy.