Capability lignin from Acacia crassicarpa black liquor as an environmentally benign antibacterial agent to produce antibacterial and hydrophobic textiles.

Recently, the growing health awareness of society on the utilization of fabrics has led to an increasing demand for natural-based antibacterial textiles. Lignin, a generous polyphenol compound in nature, is capable of preventing bacterial growth; in particular, it dwells bacteria closely together on human skin, such as Staphylococcus epidermidis, Bacillus subtilis, Propionibacterium acnes, and Staphylococcus aureus. However, the antibacterial properties of lignin are limited by factors such as the lignin concentration, source, and type of bacteria. This study aimed to evaluate the potency of lignin as an antibacterial agent for textiles. Moreover, the thermal properties and wettability of the textile after lignin coating were also investigated. This study showed that lignin isolation methods significantly contributed to the inhibition of bacterial growth in the clear zone diameter. In addition, the lignin structure, lignin concentration, and type of bacteria had notably different antibacterial effects. SEM images showed that lignin was successfully coated on the fiber, and the antibacterial textile was successfully fabricated with clear zones in the range of 0.1-0.5 cm against four different bacteria. Lignin did not significantly improve the thermal stability of the textile, as proven by the TGA results. After the HDTMS coating by dispersion method, the wettability of the lignin-textile improved to that of the hydrophobic material, with a contact angle greater than 119.05° with excellent antibacterial properties (clear zone of 0.1-0.43 cm).

Development of a Lignin-Based Carrier - Citronella Oil Nanoemulsion and Its Utilization as an Herbicide against Specific Weed Species.

This research aims to create an emulsion formulation utilizing lignin as a carrier and citronella oil for its application as a herbicide. The formulation composition includes lignin solution 55-62 %v/v, Tween 80 25 %w/v, propylene glycol 10 %w/v, and citronella oil 3-10 %w/v. The preparation steps involve preparing the oil phase by mixing tween 80 surfactant, propylene glycol, and citronella oil; preparing the aqueous phase by mixing lignin into distilled water at pH 12 with stirring; mixing the oil phase and the water phase accompanied by stirring at 5000-10000 rpm for 1-5 minutes until a stable solution is formed as a natural herbicide. The application outcomes revealed that the formulation successfully eliminated specific weeds within two to three days at the maximum concentration of 10 %, leaving no detectable herbicide residue after 7 and 15 days of treatment. The result demonstrates how green technology has the capacity to replace herbicides derived from chemicals, especially in the agricultural sector.

Optimization of areca leaf sheath nanolignin synthesis by a mechanical method for in situ modification of ultra-low molar ratio urea-formaldehyde adhesives.

This study addresses the optimization of the nanolignin preparation method from the areca leaf sheath (ALS) by a mechanical process using a high shear homogenizer at 13,000-16,000 rpm for 1-4 h and its application in enhancing the performance of ultralow molar ratio urea-formaldehyde (UF) adhesive. Response surface methodology (RSM) with a central composite design (CCD) model was used to determine the optimum nanolignin preparation method. The mathematical model obtained was quadratic for the particle size response and linear for the zeta potential response. Under the optimum conditions, a speed of 16,000 rpm for 4 h resulted in a particle size of 227.7 nm and a zeta potential of -18.57 mV with a high desirability value of 0.970. FE-SEM revealed that the characteristic changes of lignin to nanolignin occur from an irregular or nonuniform shape to an oval shape with uniform particles. Nanolignin was introduced during the addition reaction of UF resin synthesis. UF modified with nanolignin (UF-NL) was analyzed for its adhesive characteristics, functional groups, crystallinity, and thermomechanical properties. The UF-NL adhesive had a slightly greater solid content (73.23 %) than the UF adhesive, a gelation time of 4.10 min, and a viscosity of 1066 mPa.s. The UF-NL adhesive had similar functional groups as the UF adhesive, with a lower crystallinity of 59.73 %. Compared with the control plywood which has a tensile shear strength value of 0.79 MPa, the plywood bonded with UF-NL had a greater tensile shear strength of 1.07 MPa, with a lower formaldehyde emission of 0.065 mg/L.

Valorization of Rejected Macroalgae Kappaphycopsis cottonii for Bio-Oil and Bio-Char Production via Slow Pyrolysis.

Kappaphycopsis cottonii, a prominent macroalgae species cultivated in an Indonesian marine culture, yields significant biomass, a portion of which is often rejected by industry. This study explores the potential valorization of rejected K. cottonii biomass through slow pyrolysis for bio-oil and biochar production, presenting an alternative and sustainable utilization pathway. The study utilizes a batch reactor setup for the thermal decomposition of K. cottonii, conducted at temperatures between 400 and 600 °C and varying time intervals between 10 and 50 min. The study elucidates the temperature-dependent behavior of K. cottonii during slow pyrolysis, emphasizing its impact on product distributions. The results suggest that there is a rise in bio-oil production when the pyrolysis temperature is raised from 400 to 500 °C. This uptick is believed to be due to improved dehydration and greater thermal breakdown of the algal biomass. Conversely, at 600 °C, bio-oil yield diminishes, indicating secondary cracking of liquid products and the generation of noncondensable gases. Chemical analysis of bio-oils reveals substantial quantities of furan derivatives, aliphatic hydrocarbons, and carboxylic acids. Biochar exhibits calorific values within the range of 17.52-19.46 MJ kg-1, and slow pyrolysis enhances its specific surface area, accompanied by the observation of carbon nanostructures. The study not only investigates product yields but also deduces plausible reaction routes for the generation of certain substances throughout the process of slow pyrolysis. Overall, the slow pyrolysis of rejected K. cottonii presents an opportunity to obtain valuable chemicals and biochar. These products hold promise for applications such as biofuels and diverse uses in wastewater treatment, catalysis, and adsorption, contributing to both environmental mitigation and the circular economy.

Characteristics and Quality of Flame-Retarded Ramie Fabrics for the Development of Functional Textiles.

Cellulose fabric testing for flame-retardant studies is frequently necessary in various textile applications. Natural cellulose material from ramie (Boehmeria nivea) is being promoted as an alternative raw material for the development of fire-resistant fabrics. This research aims to optimize the coating process of ramie fabric using a phosphorus-based flame retardant (FR) to enhance its flame-retardant characteristics. The FR treatment involves bleaching the fabric with H2O2; followed by fabric finishing using a formula comprising 3% (v/v) hydroxymethyl resin; phosphoric acid (2%); and two formulations of the flammable agent Flamatic DM-3072N: 40% (v/v) and 50% (v/v), applied using the pad-dry-cure method. The flame-retardant properties of the treated fabric are evaluated through flammability testing based on the ASTM D6413-08 standard, limiting oxygen index (LOI) analysis, and micrograph surface structure analysis with SEM. The results indicate that ramie fabric treated with the FR-50% material exhibits superior fire resistance, preventing fire spread on the fabric with a char length of 15-30 mm and a LOI value of 29. These findings highlight the potential of FR-treated ramie fabrics for various industries, including the automotive and protective clothing industries.

Kappaphycus alvarezii as a renewable source of kappa-carrageenan and other cosmetic ingredients.

Kappa-carrageenan is one of the most traded marine-derived hydrocolloids used in the food-and-beverage, pharmaceuticals, and personal care/cosmetics industries. K. alvarezii (previously known as Kappaphycus alvarezii) is arguably the most important natural producer based on annual production size and near-homogeneity of the product (i.e., primarily being the kappa-type). The anticipated expansion of the kappa-carrageenan market in the coming years could easily generate >100,000 MT of residual K. alvarezii biomass per year, which, if left untreated, can severely affect the environment and economy of the surrounding area. Among several possible valorization routes, turning the biomass residue into anti-photoaging cosmetic ingredients could potentially be the most sustainable one. Not only optimizing the profit (thus better ensuring economic sustainability) relative to the biofuels- and animal feed-routes, the action could also promote environmental sustainability. It could reduce the dependency of the current cosmetic industry on both petrochemicals and terrestrial plant-derived bioactive compounds. Note how, in contrast to terrestrial agriculture, industrial cultivation of seaweeds does not require arable land, freshwater, fertilizers, and pesticides. The valorization mode could also facilitate the sequestration of more greenhouse gas CO2 as daily-used chemicals, since the aerial productivity of seaweeds is much higher than that of terrestrial plants. This review first summarizes any scientific evidence that K. alvarezii extracts possess anti-photoaging properties. Next, realizing that conventional extraction methods may prevent the use of such extracts in cosmetic formulations, this review discusses the feasibility of obtaining various K. alvarezii compounds using green methods. Lastly, a perspective on several potential challenges to the proposed valorization scheme, as well as the potential solutions, is offered.

Antioxidant and UV-blocking activity of PVA/tannin-based bioplastics in food packaging application.

In this study, bioplastics with antioxidant and UV protection properties based on tannin and PVA were created for packaging uses. Using a hot water extraction method at various extraction temperatures (60-100 °C), tannins were removed from the bark of Acacia mangium. Tannins with the best antioxidant activity were extracted at 80 °C. In order to create bioplastic formulations (PVA/Tannins), the extract is then employed. The non-heating bioplastic method's preparation (M3) stage produced the highest levels of antioxidant activity. Therefore, subsequent tests were conducted using the non-heating method (M3). On the opacity, UV protective activity, antioxidant capacity, mechanical strength, thermal stability, and water vapor permeability of the resultant bioplastics, the impact of tannin concentration (0.1-0.5 g) was examined. The findings of the experiments demonstrate that PVA/Tannin bioplastics are less transparent than pure PVA. The PVA/tannin bioplastics that are formed, on the whole, show strong antioxidant and UV protection action. Comparing PVA/Tannin bioplastics to pure PVA also revealed a small improvement in thermal stability and tensile strength. In PVA bioplastics with resistant tannins, moisture content was marginally greater even at low tannin concentrations (0.1 g). Based on the findings, bioplastics made from PVA and the tannin A. mangium have the potential to be used to create packaging that is UV and active antioxidant resistant. It can be applied as the second (inner) layer of the primary packaging to protect food freshness and nutrition due to their antioxidant activity.

Cytotoxicity evaluation of phytochemicals from stingless bee (Tetragonula biroi) propolis.

Three prenylated flavonoids (1-3) were isolated from Tetragonula biroi propolis. The structures of the isolated compounds were characterized by NMR, IR, and UV spectroscopic and mass spectrometric analyses. The cytotoxicity activity of the crude extracts, fractions and the isolated compounds were established against four cell lines such as Caco-2, HeLa, MCF-7, and OVK-18. Among the tested compounds, compound 1 showed cytotoxicity activity against MCF-7 cell lines, whereas compound 2 showed good activity against Caco-2 and OVK-18 cell lines with IC50 values of 14.73 and 14.44, respectively. Moreover, compound 3 exhibited strong activity against OVK-18 cell lines. These findings contribute to the phytochemical understanding of the T. biroi propolis, and their cytotoxicity effects for future pharmaceutical purposes.

Briquettes Made of Branches Wood of Three Mangrove Species Bonded by Starch Adhesive.

The development and utilization of wood briquettes is one of the efforts to reduce dependence on fossil fuels, including to fulfill overseas market need. This study aimed to evaluate the properties of wood briquettes made of the branches of three mangrove species and to analyze the effect of different wood species of mangrove branches, and the types of starch adhesive, on the quality of wood briquettes. The wood briquettes made in this study were 3 cm × 4 cm in a cylindrical shape using three wood species of mangrove branches, namely mata buaya (Bruguiera sexangula), buta-buta (Excoecaria agallocha), and bakau minyak (Rhizophora apiculata), while the adhesives used were tapioca starch, maize starch, and potato starch. The results showed that the moisture, ash content, and calorific value of the wood briquettes mostly met the ISO 17225-3:2-2020 class A2 standard and the specification and quality standards of wood briquettes for Grade A2 issued by the Korea Forest Research Institute, except the density. Wood briquettes made of mata buaya by using the three types of starch adhesives generally had better properties than all other types of wood briquettes. The interaction of mangrove wood species and the types of starch adhesive had a significant effect on the properties of wood briquettes, except for volatile matter and calorific value for which they had no significant effect. The use of wood briquettes from mangrove wood branches contributes to sustainable forest management and maintains the ecological function of mangrove forests while providing environmentally friendly alternative energy for households as a source of fuel/energy. Furthermore, future research is needed, such as investigating the optimal pressing pressure needed to achieve higher density of the wood briquettes.

Tensile Strength Improvements of Ramie Fiber Threads through Combination of Citric Acid and Sodium Hypophosphite Cross-Linking.

Ramie (Boehmeria nivea) is believed to be one of the strongest natural fibers, but it still remains behind synthetic materials in terms of tensile strength. In this study, ramie materials were prepared to evaluate the modification crosslinking effect of natural fiber. The aim is to optimize various concentrations of citric acid (CA) crosslinking by adding Sodium hypophosphite (NaPO2H2), which is activated at different temperatures, to obtain the highest tensile mechanical strength. This crosslinking effect has been confirmed by FTIR to show the esterification process in the molecular structure of cellulose. The changes in the character of the fiber surface were analyzed by SEM. The tensile strength increased from 62.33 MPa for 0% CA to 124-172.86 MPa for decorticated fiber with a CA concentration of 0.75-1.875% (w/w). A significant increase in tensile strength was observed more than 19 times when CA/SHP 1% was treated at an activation temperature of 110 °C with a superior tensile strength of 1290.63. The fiber crosslinked with CA/SHP should be recommended for application of Natural Fiber Reinforced Polymer Composite (NFRPC), which has the potential to use in functional textile and industrial sector automotive or construction.

Current roles of lignin for the agroindustry: Applications, challenges, and opportunities.

Lignin has the potential to be used as an additive, coating agent, fertilizer, plant growth stimulator, and packaging material in the agroindustry due to its functional aromatic structure. The quantitative measurement of functional groups is a significant element of the research for lignin structure since they directly impact their optical, dispersion, and chemical properties. These physical and chemical properties of lignin strongly depend on its type and source and its isolation procedure. Thus, lignin provides numerous opportunities for the circular economy in the agroindustry; however, studying and resolving the challenges associated with its separation, purification, and modification is required. This review discusses the most recent findings on lignin use in agroindustry and historical facts about lignin. The properties of lignin and its roles as coating agents, pesticide carriers, plant growth stimulators, and soil-improving agents have been summarized. The emerging challenges in the field of lignin-based agroindustry are considered, and potential future steps to overcome these challenges are discussed.

The role of selected flavonoids from bajakah tampala (Spatholobus littoralis Hassk.) stem on cosmetic properties: A review.

Cosmetics made from natural ingredients are increasingly popular because they contain bioactive compounds which can provide many health benefits, more environmentally friendly and sustainable. The health benefits obtained from natural-based ingredients include anti-aging, photoprotective, antioxidant, and anti-inflammatory. This article reviewed the potential of selected flavonoids from bajakah tampala (Spatholobus littoralis Hassk.) as the native plant in Indonesia. We present in silico, in vitro, in vivo, and clinical research data on the use of selected flavonoids that have been reported in other extracts.

Antioxidant, anti-inflammatory and anti-acne activities of stingless bee (Tetragonula biroi) propolis.

We collected stingless bee propolis Tetragonula biroi in order to find materials for medicine and cosmetics applications from tropical rainforest resources. Even though this bee has some biological functions including a cancer cell line, hair growth promotion, asthma remedy, α-glucosidase enzyme inhibition, and antiviral action, the investigation on anti-acne has not been reported yet. This study was to focus on propolis Tetragonula biroi extracts and leads us to isolate active compounds for antioxidant, anti-inflammatory, and anti-acne. We used methanol to obtain the extract from this propolis and assayed it with antioxidants, anti-inflammation, and anti-acne. The extract showed strong activity in antioxidants by DPPH radical scavenging activity (82.31% in 6.25 µg/ml). Via a column chromatography and Reveleris PREP purification system, we isolated 3'-O-methyldiplacone, nymphaeol A, and 5,7,3',4'-tetrahydroxy-6-geranyl flavonol. These compounds showed potential biological activity with IC50 for antioxidant 6.33, 15.49, 17.32 µM; and antiinflammatory 121.54, 121.20, 117.31 µM. The isolated compounds showed anti-acne properties with properties 0.00, 14.11, and 13.78 mm for the inhibition zone (at a concentration of 1 µg/well), respectively. The results indicated that the propolis extract of Tetragonula biroi has the potential to be developed as a cosmetic agent; however, further work needs to be done to clarify its application.

Pretreatment with dilute maleic acid enhances the enzymatic digestibility of sugarcane bagasse and oil palm empty fruit bunch fiber.

Lignocellulose is resistant to degradation and requires pretreatment before hydrolytic enzymes can release fermentable sugars. Sulfuric acid has been widely used for biomass pretreatment, but high amount of degradation products usually occurred when using this method. To enhance accessibility to cellulose, we studied the performances of several dilute organic acid pretreatments of sugarcane bagasse and oil palm empty fruit bunch fiber. The results revealed that pretreatment with maleic acid yields the highest xylose and glucose release among other organic acids. The effects of concentration, duration of heating and heating temperature were further studied. Dilute maleic acid 1 % (w/w) pretreatment at 180 °C was the key to its viability as a substitute for sulfuric acid. Moreover, maleic acid did not seem to highly promote the formation of either furfural or 5-HMF in the liquid hydrolysate after pretreatment.

Chemical, Physical, and Mechanical Properties of Belangke Bamboo (Gigantochloa pruriens) and Its Application as a Reinforcing Material in Particleboard Manufacturing.

This study aimed to analyze the basic properties (chemical composition and physical and mechanical properties) of belangke bamboo (Gigantochloa pruriens) and its potential as a particleboard reinforcement material, aimed at increasing the mechanical properties of the boards. The chemical composition was determined by Fourier transform near infrared (NIR) analysis and X-ray diffraction (XRD) analysis. The physical and mechanical properties of bamboo were evaluated following the Japanese standard JIS A 5908 (2003) and the ISO 22157:2004 standard, respectively. The results showed that this bamboo had average lignin, holocellulose, and alpha-cellulose content of 29.78%, 65.13%, and 41.48%, respectively, with a degree of crystallinity of 33.54%. The physical properties of bamboo, including specific gravity, inner and outer diameter shrinkage, and linear shrinkage, were 0.59%, 2.18%, 2.26%, and 0.18%, respectively. Meanwhile, bamboo's mechanical properties, including compressive strength, shear strength, and tensile strength, were 42.19 MPa, 7.63 MPa, and 163.8 MPa, respectively. Markedly, the addition of belangke bamboo strands as a reinforcing material (surface coating) in particleboards significantly improved the mechanical properties of the boards, increasing the modulus of elasticity (MOE) and bending strength (MOR) values of the fabricated composites by 16 and 3 times.

Recent Advances in the Development of Fire-Resistant Biocomposites-A Review.

Biocomposites reinforced with natural fibers represent an eco-friendly and inexpensive alternative to conventional petroleum-based materials and have been increasingly utilized in a wide variety of industrial applications due to their numerous advantages, such as their good mechanical properties, low production costs, renewability, and biodegradability. However, these engineered composite materials have inherent downsides, such as their increased flammability when subjected to heat flux or flame initiators, which can limit their range of applications. As a result, certain attempts are still being made to reduce the flammability of biocomposites. The combustion of biobased composites can potentially create life-threatening conditions in buildings, resulting in substantial human and material losses. Additives known as flame-retardants (FRs) have been commonly used to improve the fire protection of wood and biocomposite materials, textiles, and other fields for the purpose of widening their application areas. At present, this practice is very common in the construction sector due to stringent fire safety regulations on residential and public buildings. The aim of this study was to present and discuss recent advances in the development of fire-resistant biocomposites. The flammability of wood and natural fibers as material resources to produce biocomposites was researched to build a holistic picture. Furthermore, the potential of lignin as an eco-friendly and low-cost FR additive to produce high-performance biocomposites with improved technological and fire properties was also discussed in detail. The development of sustainable FR systems, based on renewable raw materials, represents a viable and promising approach to manufacturing biocomposites with improved fire resistance, lower environmental footprint, and enhanced health and safety performance.

Physical and Chemical Properties of Acacia mangium Lignin Isolated from Pulp Mill Byproduct for Potential Application in Wood Composites.

The efficient isolation process and understanding of lignin properties are essential to determine key features and insights for more effective lignin valorization as a renewable feedstock for the production of bio-based chemicals including wood adhesives. This study successfully used dilute acid precipitation to recover lignin from black liquor (BL) through a single-step and ethanol-fractionated-step, with a lignin recovery of ~35% and ~16%, respectively. The physical characteristics of lignin, i.e., its morphological structure, were evaluated by scanning electron microscopy (SEM). The chemical properties of the isolated lignin were characterized using comprehensive analytical techniques such as chemical composition, solubility test, morphological structure, Fourier-transform infrared spectroscopy (FTIR), 1H and 13C Nuclear Magnetic Resonance (NMR), elucidation structure by pyrolysis-gas chromatography-mass spectroscopy (Py-GCMS), and gel permeation chromatography (GPC). The fingerprint analysis by FTIR detected the unique peaks corresponding to lignin, such as C=C and C-O in aromatic rings, but no significant differences in the fingerprint result between both lignin. The 1H and 13C NMR showed unique signals related to functional groups in lignin molecules such as methoxy, aromatic protons, aldehyde, and carboxylic acid. The lower insoluble acid content of lignin derived from fractionated-step (69.94%) than single-step (77.45%) correlated to lignin yield, total phenolic content, solubility, thermal stability, and molecular distribution. It contradicted the syringyl/guaiacyl (S/G) units' ratio where ethanol fractionation slightly increased syringyl unit content, increasing the S/G ratio. Hence, the fractionation step affected more rupture and pores on the lignin morphological surface than the ethanol-fractionated step. The interrelationships between these chemical and physicochemical as well as different isolation methods were investigated. The results obtained could enhance the wider industrial application of lignin in manufacturing wood-based composites with improved properties and lower environmental impact.

A recent advancement on preparation, characterization and application of nanolignin.

Each year, 50 to 70 million tonnes of lignin are produced worldwide as by-products from pulp industries and biorefineries through numerous processes. Nevertheless, about 98% of lignin is directly burnt to produce steam to generate energy for the pulp mills and only a handful of isolated lignin is used as a raw material for the chemical conversion and for the preparation of various substances as well as modification of lignin into nanomaterials. Thus, thanks to its complex structure, the conversion of lignin to nanolignin, attracting growing attention and generating considerable interest in the scientific community. The objective of this review is to provide a complete understanding and knowledge of the synthesis methods and functionalization of various lignin nanoparticles (LNP). The characterization of LNP such as structural, thermal, molecular weight properties together with macromolecule and quantification assessments are also reviewed. In particular, emerging applications in different areas such as UV barriers, antimicrobials, drug administration, agriculture, anticorrosives, the environment, wood protection, enzymatic immobilization and others were highlighted. In addition, future perspectives and challenges related to the development of LNP are discussed.

A Comprehensive Review on Natural Fibers: Technological and Socio-Economical Aspects.

Asian countries have abundant resources of natural fibers, but unfortunately, they have not been optimally utilized. The facts showed that from 2014 to 2020, there was a shortfall in meeting national demand of over USD 2.75 million per year. Therefore, in order to develop the utilization and improve the economic potential as well as the sustainability of natural fibers, a comprehensive review is required. The study aimed to demonstrate the availability, technological processing, and socio-economical aspects of natural fibers. Although many studies have been conducted on this material, it is necessary to revisit their potential from those perspectives to maximize their use. The renewability and biodegradability of natural fiber are part of the fascinating properties that lead to their prospective use in automotive, aerospace industries, structural and building constructions, bio packaging, textiles, biomedical applications, and military vehicles. To increase the range of applications, relevant technologies in conjunction with social approaches are very important. Hence, in the future, the utilization can be expanded in many fields by considering the basic characteristics and appropriate technologies of the natural fibers. Selecting the most prospective natural fiber for creating national products can be assisted by providing an integrated management system from a digitalized information on potential and related technological approaches. To make it happens, collaborations between stakeholders from the national R&D agency, the government as policy maker, and academic institutions to develop national bioproducts based on domestic innovation in order to move the circular economy forward are essential.

Novel antimicrobial bioplastic based on PLA-chitosan by addition of TiO2 and ZnO.

PURPOSE: The purpose of this study was to develop antimicrobial bioplastics based on Poly Lactic Acid (PLA) with the addition of chitosan-ZnO, and chitosan-TiO2 to improve antimicrobial properties. METHODS: For the preparation of the bioplastics, PLA with chitosan-ZnO or chitosan-TiO2 were used. The antimicrobial activity, mechanical and thermal properties, and water vapor permeability of bioplastics were evaluated. RESULTS: PLA-chitosan-ZnO indicated a robust antimicrobial activity against bacteria such as Salmonella typhi, Bacillus subtilis, Escherichia coli, Staphylococcus aureus, yeast such as Candida albicans, and fungus Aspergillus niger. No formation of new functional groups in PLA-chitosan-ZnO composites. In comparison to other PLA-based bioplastics, this bioplastic has medium tensile strength, tensile modulus, and elongation percentages with low barrier ability to water vapor. Chitosan-ZnO itself has a greater tensile strength compared to chitosan-TiO2. These two compounds undergo 2 stages of decomposition in a temperature range of 43 °C to 265 °C. The addition of PLA into chitosan-ZnO or chitosan TiO2 causes the bioplastics decomposed in a single stage. It also increases the decomposition temperature of bioplastic. However, compared to chitosan-ZnO or TiO2, the PLA-chitosan-ZnO or TiO2 bioplastics tend to produce a fragile composite indicating by decrease in their tensile strength. CONCLUSION: In general, the addition of chitosan-ZnO into in PLA-based bioplastic produces better antimicrobial properties compared to TiO2.