Bioactive films based on babassu mesocarp flour and starch

Bioactive compounds and benefits of by-products of Amazon babassu oil production: potential for dietary supplement, biomedical and food applications

Babassu coconut (Attalea speciosa syn. Orbignya phalerata) contains an oil-rich nut and is primarily found in South America's Amazon region. Future market researchers predict an increase in the babassu oil market from USD 227.7 million in 2022 to USD 347.0 million by 2032, and the yield of babassu oil from babassu-processed waste could reach 90%. Of these, mesocarp flour is an underrated by-product used only for animal feed purposes by local producers. This comprehensive review focuses on advances in knowledge and understanding of phytochemicals from babassu oil by-products considering the mechanisms of action - covering antioxidant, antimicrobial, antiparasitic, anti-inflammatory, antithrombotic, immunomodulatory, and anticancer effects. Babassu coconut fruit contains free fatty acids, (poly)phenols, phytosterols, and triterpenes. Pytochemicals, antiparasitic and antibacterial activities of babassu mesocarp flour were shown, but fungi and viruses can get more attention. Beyond its antioxidant capacity, babassu mesocarp flour showed potential as a dietary food supplement. Aqueous suspensions of mesocarp flour with a higher preference for cancer cells than normal cells and an antithrombotic effect were also identified, probably related to the antioxidant capacity of its secondary metabolites. Mesocarp flour, a starch-rich fraction, is promising for application as biodegradable packaging to improve the oxidative stability of foods. Finally, low-added value fractions can be considered bio-waste/co-products, and their phytochemicals may attract interest for applications in medicine and nutrition. Toxicological concerns, trends, and gaps are discussed for the future of foods and related sciences.

Nanocomposite Films of Babassu Coconut Mesocarp and Green ZnO Nanoparticles for Application in Antimicrobial Food Packaging

In this work, novel nanocomposite films based on babassu coconut mesocarp and zinc oxide nanoparticles (ZnO NPs), synthesized by a green route, were produced for application as food packaging films. The films were prepared using the casting method containing different contents of ZnO NPs (0 wt%, 0.1 wt%, 0.5 wt%, and 1.0 wt%). The films were characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), instrumental color analysis, and optical properties. The water vapor permeability (WVP) and tensile strength of films were also determined. The antimicrobial activity of the films against cooked turkey ham samples contaminated with Staphylococcus aureus was investigated. The results showed that incorporating ZnO NPs into babassu mesocarp matrices influenced the structure of the biopolymer chains and the color of the films. The BM/ZnO-0.5 film (0.5 wt% ZnO NPs) showed better thermal, mechanical, and WVP properties. Furthermore, the synergistic effect of babassu mesocarp and ZnO NPs in the BM/ZnO-0.5 film improved the antimicrobial properties of the material, reducing the microbial count of S. aureus in cooked turkey ham samples stored under refrigeration for 7 days. Thus, the films produced in this study showed promising antimicrobial packaging materials for processed foods.

Spray dried acerola (Malpighia emarginata DC) juice particles to produce phytochemical-rich starch-based edible films

This study aimed to produce spray dried acerola juice microparticles with different protein carriers to be incorporated into edible starch films. The microparticles were evaluated for solids recovery, polyphenol retention, solubility, hygroscopicity, particle size distribution, X-ray diffraction, phytochemical compounds and antioxidant activity. Acerola microparticles produced with WPI/hydrolysed collagen carriers (AWC) with higher solids recovery (53.5 ± 0.34% w/w), polyphenol retention (74.4 ± 0.44% w/w), high solubility in water (85.2 ± 0.4% w/w), total polyphenol content (128.45 ± 2.44 mg GAE/g) and good storage stability were selected to produce starch-based films by casting. As a result, cassava films with water vapour permeability of 0.29 ± 0.07 g mm/m2 h KPa, polyphenol content of 10.15 ± 0.22 mg GAE/g film and DPPH radical scavenging activity of 6.57 ± 0.13 μM TE/g film, with greater migration of polyphenol to water (6.30 ± 0.52 mg GAE/g film) were obtained. Our results show that the incorporation of phytochemical-rich fruit microparticles is a promising strategy to create biodegradable edible films.

Different crosslinking as a strategy to improve films produced from external mesocarp of pequi (Caryocar brasiliense)

The pequi (Caryocar brasiliense) external mesocarp is rich in phenolic compounds and pectin and demonstrates the potential to produce active and biodegradable films. Thus, the present study aimed to produce films with pequi mesocarp as a polymer matrix and evaluate the influence of crosslinking agents (calcium chloride and citric acid) on the film's properties. The films obtained from pequi mesocarp (MF), showed in general, complete biodegradation in 33 days, good antioxidant capacity, and inhibition against S. aureus (24.7 mm) and E. coli (23.0 mm). The crosslinking agents reduced solubility by up to 35% and increased the elongation of the films by up to 3.5-fold. Calcium chloride promoted a higher reduction in solubility, and both agents increase the antioxidant and antimicrobial activities, compared to MF. Citric acid proved to be the best agent to modify the properties of pequi mesocarp films. In addition to the crosslinking action, it presented plasticizing effect.

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.

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

In this study, biodegradable starch film was developed from pineapple stem waste as a substitute for non-biodegradable petroleum-based films for single-use applications where strength is not too demanding. High amylose starch from a pineapple stem was used as the matrix. Glycerol and citric acid were used as additives to adjust the ductility of the material. Glycerol content was fixed at 25% while that of citric acid varied from 0 to 15% by weight of starch. Films with a wide range of mechanical properties can be prepared. As more citric acid is added, the film becomes softer and weaker, and has greater elongation at the break. Properties range from a strength of about 21.5 MPa and 2.9% elongation to a strength of about 6.8 MPa and 35.7% elongation. An X-ray diffraction study showed that the films were semi-crystalline. The films were also found to be water-resistant and can be heat-sealed. An example of a single-use package was demonstrated. A soil burial test confirmed that the material was biodegradable and completely disintegrated into sizes smaller than 1 mm within one month.

Evaluating how avocado residue addition affects the properties of cassava starch-based foam trays

Avocado seed (AS) is an interesting residue for biopackaging because it has high starch content (41 %). We have prepared composite foam trays based on cassava starch containing different AS concentrations (0, 5, 10 and 15 % w/w) by thermopressing. Composite foam trays with AS were colorful because this residue contains phenolic compounds. The composite foam trays 10AS and 15AS were thicker (2.1-2.3 mm) and denser (0.8-0.9 g/cm³), but less porous (25.6-35.2 %) than cassava starch foam (Control). High AS concentrations yielded composite foam tray less puncture resistant (~40.4 N) and less flexible (0.7-0.9 %), but with tensile strength values (2.1 MPa) almost similar to the Control. The composite foam trays were less hydrophilic and more water resistant than control due to the presence of protein, lipid, and fibers and starch with more amylose content in AS. High AS concentration in composite foam tray decreases the temperature of thermal decomposition peak corresponding to starch. At temperatures >320 °C the foam trays with AS were more resistant to the thermal degradation due to the presence of fibers in AS. High AS concentrations delayed the degradation time of the composite foam trays by 15 days.

Development of a Halochromic, Antimicrobial, and Antioxidant Starch-Based Film Containing Phenolic Extract from Jaboticaba Peel

In this study, the antioxidant, antimicrobial, mechanical, optical, and barrier attributes of Solanum lycocarpum starch bio-based edible films incorporated with a phenolic extract from jaboticaba peel were investigated. Aiming to determine the effect of the polymers and the phenolic extract on the properties of the films, a three-factor simplex-lattice design was employed, and the formulation optimization was based on the produced films' antioxidant potential. The optimized formulation of the starch-PEJP film showed a reddish-pink color with no cracks or bubbles and 91% antioxidant activity against DPPH radical. The optimized starch-PEJP film showed good transparency properties and a potent UV-blocking action, presenting color variation as a function of the pH values. The optimized film was also considerably resistant and highly flexible, showing a water vapor permeability of 3.28 × 10-6 g m-1 h-1 Pa-1. The microbial permeation test and antimicrobial evaluation demonstrated that the optimized starch-PEJP film avoided microbial contamination and was potent in reducing the growth of Escherichia coli, Staphylococcus aureus, and Salmonella spp. In summary, the active starch-PEJP film showed great potential as an environmentally friendly and halochromic material, presenting antioxidant and antimicrobial properties and high UV-protecting activity.

Biodegradable Films Prepared from Pulp Lignocellulose Adhesives of Urea Formaldehyde Resin Modified by Biosulfonate

Traditional low-density polyethylene (LDPE) film causes environmental pollution; there is a pressing need to make new bio-based polymers for alternative products, to meet agricultural production needs and for sustainable ecological development. In this study, urea-formaldehyde resin (UF) was modified with polyvinyl alcohol (PVA) and 1-2.5% bio-based sulfonate (BBS). The influence of BBS inducing on the functional groups, microstructure, and thermal behavior was evaluated by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). A biodegradable film was prepared with modified UF resin as adhesive and pulp lignocellulose as raw material. The biodegradable mulch film samples were tested for biodegradability, water retention, and cooling soil temperature characters using LDPE and no mulching (NM) as a control. The results showed that with the increase of BBS content, the viscosity and reactivity of modified PUF resin increased, and the free formaldehyde content decreased. A 2%BBS modified PUF resin (2.0BBS/PUF) accelerated the curing process of the PUF resin, formed a flexible macromolecular network structure, and enhanced the toughness of the resin. The biodegradable mulch prepared with PUF, BBS, and 2.0BBS/PUF as adhesives had good water retention. BBS modification increased the degradation rate of mulch by 17.53% compared to the PUF. Three biodegradable films compared with LDPE and NM significantly reduced the soil temperature under summer cucumber cultivation, and the 2.0BBS/PUF coating had the lowest diurnal temperature difference, which provided a suitable soil environment for crop growth.

Bioactive Films Based on Starch from White, Red, and Black Rice to Food Application

Packages from renewable sources have been the focus of many studies, due to the consumer needs for high-quality food, environmental concern related to the inadequate discard of packaging, low percentage of packaging recycling, and starch application by a viable method. Thus, this work aimed to develop bioactive packages based on white, red, and black rice starch and analyze the influence of macromolecule and plasticizer type, even its blends, on the characteristics of films. Films were characterized by color, opacity, thickness, water solubility, water vapor permeability, and bioactive properties. The use of rice starch in the development of edible and/or biodegradable films was feasible, with all the formulations tested presenting a homogeneous matrix and the films obtained varying in hue, to the naked eye, as a function of the starch used. Variation of the type of starch and plasticizer, as well as the concentrations of the same, resulted in films with differences in all studied properties. Films prepared with 5% of starch and 30% of sorbitol showed phenolic compounds and antioxidant capacity, using the DPPH and ABTS methods, indicating that these can be considered bioactive packages and also suitable for food application.

Starch isolation from turmeric dye extraction residue and its application in active film production

In this study, we have isolated starch from turmeric dye extraction residue by steeping in acid medium (AS), steeping in water (WS), or steeping in alkaline medium (KS) and assessed the filmogenic capacity of the resulting starches. We have also characterized the chemical composition, morphology, swelling power, solubility, crystallinity, and active properties of the AS, WS, and KS starches and investigated the mechanical, functional, antioxidant, and antimicrobial properties of the corresponding films. The AS and KS starches showed lower apparent amylose content and higher purity, relative crystallinity, swelling power, and solubility than the WS starch. All the starches retained phenolic compounds and curcuminoids; their phenolic and curcuminoid contents were higher than the contents in the residue, especially in the case of the AS starch, which yielded films with the best antioxidant and antimicrobial activities. The AS and KS starches yielded films that were more resistant at break, less soluble in water, and less hydrophilic than the film obtained from the WS starch. Thus, submitting turmeric dye extraction residue to AS in ascorbic acid yielded a starch that resulted in films with good mechanical properties and better antioxidant and antimicrobial properties, to ensure safe and prolonged food shelf life.

Optimization of wheat flour by product films: A technological and sustainable approach for bio-based packaging material

This study aimed to evaluate the feasibility of the production of sustainable and biodegradable packages made from a little-explored by product of wheat-milling, the glue flour (GF). Films were produced by the casting method and the effect of the incorporation of glycerol, sorbitol, and GF in the properties of the films was investigated following the central composite rotational design (CCRD) approach. The results have been statistically analyzed by the response surface methodology and the desirability function. Due to the rich composition in amylaceous reserve (64.81%; 26% of amylose content), considerable protein content (11.23%), and fibers (8.28%), the GF proved to be suitable for use as a matrix in biopolymer films. All the properties were mainly influenced by the plasticizer type and GF concentration. Film plasticized with glycerol (run 13) was more flexible, had higher moisture (28.39%) content, and was more adhesive than the formulation made with sorbitol (run 11). Film elongation (ELO) ranged from 25.84% to 56.71%, and tensile strength (TS) from 0.10 to 2.8 MPa. The optimized process conditions were 8% for Cf, 0% for Cg, and 4% for Cs. Under these conditions, the films presented low moisture (12.1%), moderate solubility (35.5%) and TS (1.64 MPa), and high ELO (72.06%). This study showed that GF is a promising source for the development of biodegradable films. PRACTICAL APPLICATION: Films made from a by product of wheat flour (glue flour) have technological potential to be used as packaging for food products. The valorization of a by product of the agribusiness without pre-treatment for the production of biodegradable films was made possible. The study by casting technique is a previous for scale-up production.

Development and Characterization of Novel Composite Films Based on Soy Protein Isolate and Oilseed Flours

The possibility of using oilseed flours as a waste source for film-forming materials with a combination of soy protein isolate in preparation of edible films was evaluated. Physical, mechanical and barrier properties were determined as a function of the oilseed type: hemp, evening primrose, flax, pumpkin, sesame and sunflower. It was observed that the addition of oilseed flours increased the refraction and thus the opacity of the obtained films from 1.27 to 9.57 A mm⁻¹. Depending on the type of flours used, the edible films took on various colors. Lightness (L*) was lowest for the evening primrose film (L* = 34.91) and highest for the soy protein film (L* = 91.84). Parameter a* was lowest for the sunflower film (a* = −5.13) and highest for the flax film (a* = 13.62). Edible films made of pumpkin seed flour had the highest value of the b* color parameter (b* = 34.40), while films made of evening primrose flour had the lowest value (b* = 1.35). All analyzed films had relatively low mechanical resistance, with tensile strength from 0.60 to 3.09 MPa. Films made of flour containing the highest amount of protein, pumpkin and sesame, had the highest water vapor permeability, 2.41 and 2.70 × 10⁻⁹ g·m⁻¹ s⁻¹ Pa⁻¹, respectively. All the edible films obtained had high water swelling values from 131.10 to 362.16%, and the microstructure of the films changed after adding the flour, from homogeneous and smooth to rough. All blended soy protein isolate–oilseed flour films showed lower thermal stability which was better observed at the first and second stages of thermogravimetric analysis when degradation occurred at lower temperatures. The oilseed flours blended with soy protein isolate show the possibility of using them in the development of biodegradable films which can find practical application in the food industry.

An overview on plasticized biodegradable corn starch-based films: the physicochemical properties and gelatinization process

With increasing awareness of environmental protection, petroleum-based raw materials are continuously decreasing, which in turn necessitated the development of eco-friendly sustainable biomaterials, as alternative strategy. Starch could be an ideal substitute. Corn starch has been used as a renewable material for development of biodegradable packaging, owing to great varieties, low cost, large-scale industrial production, and good films forming properties. Unfortunately, its poor mechanical and barrier properties have limited the application of starch-based films. Thence, plasticizers were added to overcome the aforementioned pitfalls and improve the films elongation, distribution, flexibility, elasticity, and rigidity. Addition of plasticizers can change the continuity and therefore would enhance the properties of corn starch-based films. While plasticization can improve the tensile strength and percent elongation, it can reduce the water resistance in prepared films. Herein, we focused on changes of starch granules during gelatinization process, types of biodegradable films, as well as the types of modified starch with plasticizers. Furthermore, the influence of plasticizers on corn starch-based films and the physicochemical properties of various types of corn starch-based films were also addressed.

Methods of Incorporating Plant-Derived Bioactive Compounds into Films Made with Agro-Based Polymers for Application as Food Packaging: A Brief Review

Plastic, usually derived from non-renewable sources, is among the most used materials in food packaging. Despite its barrier properties, plastic packaging has a recycling rate below the ideal and its accumulation in the environment leads to environmental issues. One of the solutions approached to minimize this impact is the development of food packaging materials made from polymers from renewable sources that, in addition to being biodegradable, can also be edible. Different biopolymers from agricultural renewable sources such as gelatin, whey protein, starch, chitosan, alginate and pectin, among other, have been analyzed for the development of biodegradable films. Moreover, these films can serve as vehicles for transporting bioactive compounds, extending their applicability as bioactive, edible, compostable and biodegradable films. Biopolymer films incorporated with plant-derived bioactive compounds have become an interesting area of research. The interaction between environment-friendly biopolymers and bioactive compounds improves functionality. In addition to interfering with thermal, mechanical and barrier properties of films, depending on the properties of the bioactive compounds, new characteristics are attributed to films, such as antimicrobial and antioxidant properties, color and innovative flavors. This review compiles information on agro-based biopolymers and plant-derived bioactive compounds used in the production of bioactive films. Particular emphasis has been given to the methods used for incorporating bioactive compounds from plant-derived into films and their influence on the functional properties of biopolymer films. Some limitations to be overcome for future advances are also briefly summarized. This review will benefit future prospects for exploring innovative methods of incorporating plant-derived bioactive compounds into films made from agricultural polymers.

Active Edible Films Based on Arrowroot Starch with Microparticles of Blackberry Pulp Obtained by Freeze-Drying for Food Packaging

This research work evaluated the influence of the type of incorporation and variation in the concentration of blackberry pulp (BL) and microencapsulated blackberry pulp (ML) powders by freeze-drying on the chemical and physical properties of arrowroot starch films. Blackberry powders were added to the film-forming suspension in different concentrations, 0%, 20%, 30% and 40% (mass/mass of dry starch) and through two different techniques, directly (D) and by sprinkling (S). Scanning electron microscopy (SEM) images revealed that the incorporation of blackberry powder has rendered the surface of the film rough and irregular. Films incorporated with BL and ML powders showed an increase in thickness and water solubility and a decrease in tensile strength in comparison with the film containing 0% powder. The incorporation of blackberry BL and ML powders into films transferred colour, anthocyanins and antioxidant capacity to the resulting films. Films added with blackberry powder by sprinkling were more soluble in water and presented higher antioxidant capacity than films incorporated directly, suggesting great potential as a vehicle for releasing bioactive compounds into food.

Banana starch nanocomposite with cellulose nanofibers isolated from banana peel by enzymatic treatment: In vitro cytotoxicity assessment

The potential use of cellulose nanofibers (CNFs) as a reinforcing agent in banana starch-based nanocomposite films was investigated. CNFs were isolated from banana peel (Musa paradisiaca) by enzymatic hydrolysis. Banana starch-based nanocomposite films were prepared with CNFs using the casting method. CNFs effect on cell viability and on nanocomposite films properties' was investigated. The cytotoxicity of CNFs was assessed on Caco-2 cell line. CNFs were not cytotoxic at 50-2000 μg/mL. However, CNFs above 2000 μg/mL significantly decreased cell viability. Topography analysis showed that the incorporation of CNFs modified the film structure. The nanocomposites exhibited a complex structure due to strong interactions between CNFs and starch matrix, promoting a remarkable improvement on mechanical and water barrier properties, opacity and UV light barrier compared to the control film. CNFs can offer a great potential as reinforcing material for starch-based nanocomposite films, producing a value-added food packaging from a waste material.

Development and characterization of edible films based on eggplant flour and corn starch

In this study, biodegradable and edible films based on eggplant flour (EF) and corn starch (CS) were prepared using casting method at proportion of 0-100, 25-75, 50-50, 75-25 and 100-0%, w/w. The mechanical, barrier, physical, and biodegradability properties were evaluated. Tensile strength, elongation at break, Young's modulus, thickness, density and L^⁎ parameter of pure starch films were higher than those of other films. Solubility, water vapor permeability (WVP), moisture content and swelling index of films were augmented with the substitution of CS by EF. Color measurement of the edible films indicated that increasing the proportion of EF increased a^⁎, b^⁎ and opacity values. The highest amount of water sorption was obtained for pure EF films. Moreover, the incorporation of EF accelerated films biodegradability compared to ones with only starch. In general, EF is a promising material for the formulation of edible and biodegradable films with adequate physical properties for food applications by direct contact.