Thermo-mechanical behaviors of thermoplastic starch derived from sugar palm tree (Arenga pinnata)

The application of starch-based edible film in food preservation: a comprehensive review

Using renewable resources for food packaging not only helps reduce our dependence on fossil fuels but also minimizes the environmental impact associated with traditional plastics. Starch has been a hot topic in the field of current research because of its low cost, wide source and good film forming property. However, a comprehensive review in this field is still lacking. Starch-based films offer a promising alternative for sustainable packaging in the food industry. The present paper covers various aspects such as raw material sources, modification methods, and film formation mechanisms. Understanding the physicochemical properties and potential commercial applications is crucial for bridging the gap between research and practical implementation. Finally, the application of starch-based films in the food industry is discussed in detail. Different modifications of starch can improve the mechanical and barrier properties of the films. The addition of active substances to starch-based films can endow them with more functions. Therefore, these factors should be better investigated and optimized in future studies to improve the physicochemical properties and functionality of starch-based films. In summary, this review provides comprehensive information and the latest research progress of starch-based films in the food industry.

Preparation and characterization of Arenga pinnata thermoplastic starch/bacterial cellulose nanofiber biocomposites via in-situ twin screw extrusion

Thermoplastic starch (TPS) is considered as alternative material for substitute petroleum-based materials for single-use packaging material applications. The main weakness of TPS is sensitive to water and humidity which causes low mechanical properties and low thermal resistance. To address this limitation, one can enhance the strength is by incorporating cellulose nanofiber as a reinforcing agent. Cellulose nanofiber used in this study is bacterial cellulose, synthesized from tapioca liquid waste media, namely Nata de Cassava (NDCass). The effect of NDCass addition to TPS on chemical characteristics, physical properties, crystallinity, mechanical properties, and thermal properties was investigated. As the results, NDCass incorporation has no significant effect on the chemical structure and crystal structure of composites as observed by FTIR and XRD analysis. Incorporating of NDCass improved the mechanical properties by 37.3 %, the thermal stability, and the viscosity, however reduced the elongation at break by 65.6 %, the density, the melt flow and shear rate of TPS biocomposite. This study evidently that starch from Arenga pinnata trunk and bacterial cellulose from tapioca liquid waste can be manufactured into biocomposites using in-situ twin screw extrusion which beneficial for large-scale applications.

Effects of polyols with different hydroxyl numbers on the structure and properties of starch straws

To study the relationship between the number of hydroxyl groups of polyols and the plasticizing effect, the effects of different polyols including ethylene glycol, glycerol, erythritol, xylitol and sorbitol on the structure and properties of corn starch straws were analyzed and compared. The results showed that the addition of plasticizer significantly improved the performance of starch straws, which greatly improved the mechanical properties, water absorption rate (WAR) and thermal stability. However, there was no linear relationship between the plasticizing effect on starch straws and the number of hydroxyl groups in plasticizers. Fourier transform infrared (FTIR) results showed that erythritol formed the strongest intermolecular interaction with starch. Starch straws with erythritol (S-ERY) had the highest bending force (Fb = 25.78 N) and the lowest WAR. Starch straws with glycerol (S-GLY) showed the lowest relative crystallinity (RC = 12.87 %) and the highest temperature of the maximum degradation (Tdmax = 302.1 °C). In addition, after storing for 180 days, S-GLY showed higher modulus of elasticity in bending (Eb = 4.26 N/cm) and a uniform surface.

Modification of palm fiber with chitosan-AESO blend coating

Natural fibers are available as an essential substitute for synthetic fiber in many applications. However, the sensitivity of Chinese Windmill Palm or Trachycarpus Fortune Fiber (TFF) to water causes low interfacial bonding between the matrix and the fiber and at the end reduces the mechanical properties of the composite product. Alkaline treatment improves mechanical properties and does not affect water absorption. Hence, additional treatment in the coating is required. This study uses alkaline treatment and coating modification using blended chitosan and Acrylated Epoxidized Soybean Oil (AESO). Blend coating between AESO and chitosan is performed to increase water absorption and mechanical properties. TFF water resistance improved significantly after the coating, with water absorption of the alkaline/blend coating-TFF of 3.98 % ± 0.52 and swell ability of 3.156 % ± 0.17. This indicated that blend coating had formed a cross-link of fiber and matrix after alkalization. Thus, the single fiber tensile strength increased due to the alkaline treatment, and water absorption decreased due to the coating. The combination of alkaline treatment and blend coating on TFF brings excellent properties, as shown by the increase in tensile strength in both single fiber test and composite.

Effects of different ratios of mannitol to sorbitol on the functional properties of sweet potato starch films

Sorbitol as a plasticizer is easily crystallized from starch film, resulting in the reduction in plasticizing effect. To improve the plasticizing performance of sorbitol in starch films, mannitol, an acyclic hexahydroxy sugar alcohol, was used to cooperate with sorbitol. The effects of different ratios of mannitol (M) to sorbitol (S) as a plasticizer on mechanical properties, thermal properties, water resistance and surface roughness of sweet potato starch films were investigated. The results showed that the surface roughness of starch film with M:S (60:40) was the smallest. The number of hydrogen bonds between plasticizer and starch molecule was proportional to the mannitol content starch film. With the decrease of mannitol contents, the tensile strength of starch films gradually decreased except for M:S (60:40). Moreover, the transverse relaxation time value of starch film with M:S (100:0) was the lowest, indicating that it had the lowest degree of freedom of water molecules. Starch film with M:S (60:40) is the most effective in delaying the retrogradation of starch film. This study offered a new theoretical basis that different ratios of mannitol to sorbitol improve different performances of starch films.

Combining pulsed electric field and cross-linking to enhance the structural and physicochemical properties of corn porous starch

In this study, corn porous starch (CPS) was firstly prepared using enzymatic hydrolysis, followed by pore formation enhancement using the treatment of a pulsed electric field (PEF). Subsequently, the PEF treated porous starch (CPS-PEF) was cross-linked with sodium trimetaphosphate (STMP) to investigate its structural and functional properties. The results showed PEF treatment increased the oil absorption of CPS by 26.92% and improved its specific surface area, total pore volume value, solubility and swelling power. After cross-linking of the CPS-PEF, C-O-P covalent bonds were formed between CPS-PEF molecules, resulting in a further increase in oil absorption and specific surface area properties. Moreover, the covalent bonds enhanced the intermolecular forces, resulting in increased thermal stability of the cross-linked porous starch (ScPS). The double modification resulted in significantly improved adsorption properties and better thermal stability of the ScPS, indicating that the double modification is an effective method for the preparation of porous starches.

The Glass Transition Temperature of Heterogeneous Biopolymer Systems

Biopolymers are abundant, renewable, and biodegradable resources. However, bio-based materials often require toughening additives, like (co)polymers or small plasticizing molecules. Plasticization is monitored via the glass transition temperature versus diluent content. To describe this, several thermodynamic models exist; nevertheless, most expressions are phenomenological and lead to over-parametrization. They also fail to describe the influence of sample history and the degree of miscibility via structure-property relationships. We propose a new model to deal with semi-compatible systems: the generalized mean model, which can classify diluent segregation or partitioning. When the constant k_GM is below unity, the addition of plasticizers has hardly any effect, and in some cases, even anti-plasticization is observed. On the other hand, when the k_GM is above unity, the system is highly plasticized even for a small addition of the plasticizer compound, which indicates that the plasticizer locally has a higher concentration. To showcase the model, we studied Na-alginate films with increasing sizes of sugar alcohols. Our k_GM analysis showed that blends have properties that depend on specific polymer interactions and morphological size effects. Finally, we also modeled other plasticized (bio)polymer systems from the literature, concluding that they all tend to have a heterogeneous nature.

Effect of Agar on the Mechanical, Thermal, and Moisture Absorption Properties of Thermoplastic Sago Starch Composites

Thermoplastic starch is a material that has the potential to be environmentally friendly and biodegradable. However, it has certain drawbacks concerning its mechanical performance and is sensitive to the presence of moisture. The current study assessed agar-containing thermoplastic sago starch (TPSS) properties at various loadings. Variable proportions of agar (5%, 10%, and 15% wt%) were used to produce TPSS by the hot-pressing method. Then, the samples were subjected to characterisation using scanning electron microscopy (SEM), mechanical analysis, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), and moisture absorption tests. The results demonstrated that adding agar to starch-based thermoplastic blends significantly improved their tensile, flexural, and impact properties. The samples' morphology showed that the fracture had become more erratic and uneven after adding agar. FT-IR revealed that intermolecular hydrogen bonds formed between TPSS and agar. Moreover, with an increase in agar content, TPSS's thermal stability was also increased. However, the moisture absorption values among the samples increased slightly as the amount of agar increased. Overall, the proposed TPSS/agar blend has the potential to be employed as biodegradable material due to its improved mechanical characteristics.

Ethno-pharmacological and industrial attributes on the underutilized Arenga species in India

The genus Arenga belongs to the Arecaceae family, which has a significant economic value. Several species of this genus have a decent potential of becoming an industrial crop. In India, four species of the genus, namely Arenga pinnata, A. obtusifolia, A. micranta, and A. wightii have been reported. These species have not been cultivated on a commercial scale in most of the growing regions. People use this plant directly from the forest or those produced in their backyard, even though productivity is minimal. To date, several studies from throughout the world have reported numerous beneficial roles of such species. Proper use of such plants or their products has immense significance in the food, fiber, and pharmaceutical industry. These plants are also recognized as ecologically significant plants. In this article, we have presented an up-to-date review on the species of Arenga reported from India along with their potential utility as industrial crops. This review is motivated by the desire to produce many eco-friendly resources from A. pinnata and other species of Arenga, which can contribute to an increase in the standard of living and economy of many nations, including India. PRACTICAL APPLICATIONS: Arenga has a lot of potential as medicinal as well as industrial raw materials. Despite this, these plants are somehow underutilized and have not gained much attention in international trade. In this communication, we have presented some aspects of these plants by reviewing many research articles and conference proceedings. The utilization of these plants as traditional medicine serves an important part in basic health care for many people in developing nations. Gradual study and clinical trial of different formulations of these plants can explore novel drugs for some critical disorders. We also highlighted the industrial uses of these species. Biofuel and fiber obtained from A. pinnata have been appreciated by the researchers. This article points out some attributes of these plants that required further improvement. Botanists and phytochemists will appreciate the description of the medicinal properties of these plants and the biological data provided in the article.

Effect of Chemical Treatment of Sugar Palm Fibre on Rheological and Thermal Properties of the PLA Composites Filament for FDM 3D Printing

The thermal and rheological properties of bio-composite filament materials are crucial characteristics in the development of a bio-composite Fused Deposition Modeling (FDM) filament since the printing mechanism of FDM strongly depends on the heating and extrusion process. The effect of chemical treatment on the thermal and rheological properties was investigated to develop composite filaments for FDM using natural fibres such as sugar palm fibre (SPF). SPF underwent alkaline and silane treatment processes before being reinforced with PLA for improving adhesion and removing impurities. Thermogravimetric Analysis (TGA), Differential Scanning Calorimetric (DSC), and Melt Flow Index (MFI) analyses were conducted to identify the differences in thermal properties. Meanwhile, a rheological test was conducted to investigate the shear stress and its viscosity. The TGA test shows that the SPF/PLA composite treated with NaOH and silane showed good thermal stability at 789.5 °C with 0.4% final residue. The DSC results indicate that the melting temperature of all samples is slightly the same at 155 °C (in the range of 1 °C), showing that the treatment does not interfere with the melting temperature of the SPF/PLA composite. Thus, the untreated SPF/PLA composite showed the highest degradation temperature, which was 383.2 °C. The SPF/PLA composite treated with NaOH and silane demonstrated the highest melt flow index of 17.6 g/min. In conclusion, these findings offer a reference point for determining the filament extrusion and printability of SPF/PLA composite filaments.

Novel In Situ Modification for Thermoplastic Starch Preparation based on Arenga pinnata Palm Starch

Thermoplastic starch (TPS) has three main disadvantages, i.e., poor mechanical properties, low thermal stability and water sensibility. To overcome these disadvantages, TPS properties can be improved by starch modification, adding reinforcements and blending with other polymers. In this research, to prepare modified TPS, starch modification was carried out by in situ modification. The modified TPS was prepared by adding Arenga pinnata palm starch (APPS), glycerol and benzoyl peroxide simultaneously in the twin-screw extruder. Morphology analysis of TPS revealed that the starch granules were damaged and gelatinized in the extrusion process. No phase separation is observed in TPS, which exhibits that starch granules with and without benzoyl peroxide were uniformly dispersed in the matrix. The addition of benzoyl peroxide resulted in increased density of TPS from 1.37 to 1.39 g·cm^-3, tensile strength from 7.19 to 8.61 MPa and viscosity from 2482.19 to 2604.60 Pa.s. However, it decreased the elongation at break of TPS from 33.95 to 30.16%, melt flow rate from 7.13 to 5.73 gr/10 min and glass transition temperature from 65 to 52 °C. In addition, the thermal analysis showed that the addition of benzoyl peroxide increased the thermal stability of TPS and extended the temperature range of thermal degradation.

Corn: Its Structure, Polymer, Fiber, Composite, Properties, and Applications

Biocomposite materials have a significant function in saving the environment by replacing artificial plastic materials with natural substances. They have been enrolled in many applications, such as housing, automotive engine components, aerospace and military products, electronic and circuit board components, and oil and gas equipment. Therefore, continuous studies have been employed to improve their mechanical, thermal, physical properties. In this research, we conduct a comprehensive review about corn fiber and corn starch-based biocomposite. The results gained from previous studies were compared and discussed. Firstly, the chemical, thermal, and mechanical properties of cornstarch-based composite were discussed. Then, the effects of various types of plasticizers on the flexibility of the cornstarch-based composite were addressed. The effects of chemical treatments on the properties of biocomposite using different cross-linking agents were discussed. The corn fiber surface treatment to enhance interfacial adhesion between natural fiber and polymeric matrix also were addressed. Finally, morphological characterization, crystallinity degree, and measurement of vapor permeability, degradation, and uptake of water were discussed. The mechanical, thermal, and water resistance properties of corn starch and fibers-based biopolymers show a significant improvement through plasticizing, chemical treatment, grafting, and cross-linker agent procedures, which expands their potential applications.

Thermal, flammability, and antimicrobial properties of arrowroot (Maranta arundinacea) fiber reinforced arrowroot starch biopolymer composites for food packaging applications

Using the solution casting method, a novel biodegradable thermoplastic arrowroot (Maranta arundinacea) starch (TPAS) films containing arrowroot fiber (AF) at different concentrations (0, 2, 4, 6, 8, and 10 wt%) were developed and characterized in terms of thermal, antibacterial activity, water vapor permeability (WVP), biodegradability, and light transmittance properties. The TPAS/AF-10 biocomposite film revealed a higher degradation temperature (313.02 °C) than other biocomposite films, indicating better thermal stability. Furthermore, increasing AF concentration led to a significant (p < 0.05) reduction in the linear burning rate and WVP of the biocomposite films from 248.9 to 115.2 mm/min and 8.18 × 10^-10 ×g. s^-1.m^-1. Pa^-1 to 5.20 × 10^-10 ×g. s^-1.m^-1. Pa^-1, respectively. The addition of fibers in the surface structure had a significant impact on remarkable drop in opacity (91.1 to 74.1%). In addition, the incorporation of AF and control film showed an insignificant effect against three pathogenic bacteria, including Staphylococcus aureus (ATCC 43300), Escherichia coli (ATCC 25922), and Bacillus subtilis (B29). The soil burial findings demonstrated that the weight loss of TPAS/AF biocomposite films was significantly higher than TPAS film. Overall, the reinforcement of arrowroot fiber with TPAS film improved the properties of biocomposites for environmentally friendly food packaging applications.

Physical, Mechanical, and Morphological Performances of Arrowroot (Maranta arundinacea) Fiber Reinforced Arrowroot Starch Biopolymer Composites

This research is driven by stringent environmental legislation requiring the consumption and use of environmentally friendly materials. In this context, this paper is concerned with the development and characterization of thermoplastic arrowroot starch (TPAS) based biocomposite films by incorporating arrowroot fiber (AF) (0–10%) into a glycerol plasticized matrix by using the solution casting method. Developed TPAS/AF composite films were investigated, such as physical, morphological (FESEM), tensile, and tear strength characteristics. The tensile and tear strengths of TPAS/AF composites were increased significantly from 4.77 to 15.22 MPa and 0.87 to 1.28 MPa, respectively, as compared to the control TPAS films, which were 2.42 MPa and 0.83 MPa, respectively, while elongation was significantly decreased from 25.57 to 6.21% compared to control TPAS film, which was 46.62%. The findings revealed that after the fiber was reinforced, the mechanical properties were enhanced, and the optimum filler content was 10%. Regardless of fiber loadings, the results of water absorption testing revealed that the composite films immersed in seawater and rainwater absorbed more water than distilled water. Overall, the results of this research focus on providing information on biopolymer composite film and revealing the great potential it has for the food packaging industry.

Thermal Stability and Dynamic Mechanical Analysis of Benzoylation Treated Sugar Palm/Kenaf Fiber Reinforced Polypropylene Hybrid Composites

This research was performed to evaluate the mechanical and thermal properties of sugar palm fiber (SPF)- and kenaf fiber (KF)-reinforced polypropylene (PP) composites. Sugar palm/kenaf was successfully treated by benzoylation treatment. The hybridized bio-composites (PP/SPF/KF) were fabricated with overall 10 weight percentage (wt%) relatively with three different fibers ratios between sugar palm-treated and kenaf-treated (7:3, 5:5, 3:7) and vice versa. The investigations of thermal stability were then carried out by using diffraction scanning calorimetry (DSC) and thermogravimetry analysis (TGA). The result of a flammability test showed that the treated hybrid composite (PP/SPF/KF) was the specimen that exhibited the best flammability properties, having the lowest average burning rate of 28 mm/min. The stiffness storage modulus (E’), loss modulus (E”), and damping factor (Tan δ) were examined by using dynamic mechanical analysis (DMA). The hybrid composite with the best ratio (PP/SPF/KF), T-SP5K5, showed a loss modulus (E”) of 86.2 MPa and a damping factor of 0.058. In addition, thermomechanical analysis (TMA) of the studies of the dimension coefficient (µm) against temperature were successfully recorded, with T-SP5K5 achieving the highest dimensional coefficient of 30.11 µm at 105 °C.

Effect of plasticizers on physical, thermal, and tensile properties of thermoplastic films based on Dioscorea hispida starch

This study examines the effects of varying the concentrations of sorbitol (S) and glycerol (G) on the physical, morphological, thermal, and mechanical properties of Dioscorea hispida, starch-based films. In this context, the films of Dioscorea hispida starch were developed using solution casting technique with glycerol (G), sorbitol (S), and a mixture of sorbitol-glycerol (SG) as plasticizers at the ratios of 0, 30, 45, and 60 wt%. The films' moisture contents were increased when increasing the plasticizer contents. The tensile strengths were decreased, but elongations at break were increased; 7.38%-11.54% for G-plasticized films, 10.17%-15.76% for S-plasticized films, and 14.41%- 16.10% for SG-plasticized films with increasing plasticizer concentrations of the film samples. Varying plasticizer concentrations exhibited a minor effect on the S-plasticized film's thermal properties. Significant decrement in the glass transition temperatures of Dioscorea hispida starch films was observed when the plasticizer contents were raised from 30% to 60%. Significantly, the present work has shown that plasticized Dioscorea hispida starch can be considered a promising biopolymer for the applications of biodegradable films.

Physical Properties of Thermoplastic Starch Derived from Natural Resources and Its Blends: A Review

Thermoplastic starch composites have attracted significant attention due to the rise of environmental pollutions induced by the use of synthetic petroleum-based polymer materials. The degradation of traditional plastics requires an unusually long time, which may lead to high cost and secondary pollution. To solve these difficulties, more petroleum-based plastics should be substituted with sustainable bio-based plastics. Renewable and natural materials that are abundant in nature are potential candidates for a wide range of polymers, which can be used to replace their synthetic counterparts. This paper focuses on some aspects of biopolymers and their classes, providing a description of starch as a main component of biopolymers, composites, and potential applications of thermoplastics starch-based in packaging application. Currently, biopolymer composites blended with other components have exhibited several enhanced qualities. The same behavior is also observed when natural fibre is incorporated with biopolymers. However, it should be noted that the degree of compatibility between starch and other biopolymers extensively varies depending on the specific biopolymer. Although their efficacy is yet to reach the level of their fossil fuel counterparts, biopolymers have made a distinguishing mark, which will continue to inspire the creation of novel substances for many years to come.

Effects of ultrasonication on the properties of maize starch/stearic acid/ sodium carboxymethyl cellulose composite film

Ultrasonic treatment can improve the compatibility between a hydrophobic material and a hydrophilic polymer. The light transmittance, crystalline structure, microstructure, surface morphology, moisture barrier, and mechanical properties of a composite film with or without ultrasonication were investigated. Ultrasound increases the film's light transmittance, resulting in a film that has good transparency. Ultrasonication did not change the crystalline structure of the polymer film, but promoted V-type complex formation. The surface of the film became smooth and homogeneous after the film-form suspension underwent ultrasonic treatment. Compared to the control film, after ultrasonication at 70% amplitude with a duration of 30 min, the average roughness and maximum roughness declined from 212 nm to 17.6 nm and from 768.7 nm to 86.5 nm, respectively. The composite film with ultrasonication exhibited better tensile and moisture barrier properties than the nonsonicated film. However, long-term and strong ultrasonication will destroy the polymer structure to some extent.

Molar mass effect in food and health

It is demanded to supply foods with good quality for all the humans. With the advent of aging society, palatable and healthy foods are required to improve the quality of life and reduce the burden of finance for medical expenditure. Food hydrocolloids can contribute to this demand by versatile functions such as thickening, gelling, stabilising, and emulsifying, controlling texture and flavour release in food processing. Molar mass effects on viscosity and diffusion in liquid foods, and on mechanical and other physical properties of solid and semi-solid foods and films are overviewed. In these functions, the molar mass is one of the key factors, and therefore, the effects of molar mass on various health problems related to noncommunicable diseases or symptoms such as cancer, hyperlipidemia, hyperglycemia, constipation, high blood pressure, knee pain, osteoporosis, cystic fibrosis and dysphagia are described. Understanding these problems only from the viewpoint of molar mass is limited since other structural characteristics, conformation, branching, blockiness in copolymers such as pectin and alginate, degree of substitution as well as the position of the substituents are sometimes the determining factor rather than the molar mass. Nevertheless, comparison of different behaviours and functions in different polymers from the viewpoint of molar mass is expected to be useful to find a common characteristics, which may be helpful to understand the mechanism in other problems.

Preparation and Characterization of Starch/Empty Fruit Bunch-Based Bioplastic Composites Reinforced with Epoxidized Oils

This study examined the development of starch/oil palm empty fruit bunch-based bioplastic composites reinforced with either epoxidized palm oil (EPO) or epoxidized soybean oil (ESO), at various concentrations, in order to improve the mechanical and water-resistance properties of the bio-composites. The SEM micrographs showed that low content (0.75 wt%) of epoxidized oils (EOs), especially ESO, improved the compatibility of the composites, while high content (3 wt%) of EO induced many voids. The melting temperature of the composites was increased by the incorporation of both EOs. Thermal stability of the bioplastics was increased by the introduction of ESO. Low contents of EO led to a huge enhancement of tensile strength, while higher contents of EO showed a negative effect, due to the phase separation. The tensile strength increased from 0.83 MPa of the control sample to 3.92 and 5.42 MPa for the composites with 1.5 wt% EPO and 0.75 wt% ESO, respectively. EOs reduced the composites’ water uptake and solubility but increased the water vapor permeability. Overall, the reinforcing effect of ESO was better than EPO. These results suggested that both EOs can be utilized as modifiers to prepare starch/empty-fruit-bunch-based bioplastic composites with enhanced properties.

Sandwich panel biocomposite of thermoplastic corn starch and bacterial cellulose

Inadequate disposition and long period for degradation of Petroleum-derived polymers promote damages in the environment, which could be minimized by the use of biodegradable polymers such as starch and cellulose. Films of thermoplastic corn starch (TPS) and bacterial cellulose (BC) were used to produce sandwich panel biocomposite. RXD, SEM and FTIR were used to verify the transformation of TPS from native corn starch. TPS/BC is flexible and transparent, but it is less transparent that TPS and BC due to its multilayer format. TPS/BC presented similar thermal events to TPS and BC samples and thermal stability similar to TPS. The FTIR spectrum of the TPS/BC showed bands observed in the BC and TPS spectra. BC, TPS and TPS/BC showed faster water absorption in the initial stage reaching a stability at about 50 h and presenting Fickian behavior. TPS/BC showed lower water absorption and a good adhesion between the phases observed by SEM images, which can be associated to hydrogen interactions in the interface improving mechanical properties. TPS/BC showed an increase of about 3.6 times in the tensile strength compared to TPS, indicating that BC is a good reinforcement for TPS.

Life Cycle Assessment of Sugar Palm Fiber Reinforced-Sago Biopolymer Composite Takeout Food Container

In the development of packaging products, the considerations are not limited to the food shelf-life, safety, and practicality, but also environmental sustainability. This paper reports a life cycle assessment (LCA) analysis of a proposed natural fiber-reinforced biopolymer composite takeout food container. The study focuses on the damage assessment of the whole product system, including disposal scenarios of the thermoformed sugar palm fiber (SPF)-reinforced sago starch composite takeout food container. The analysis performed was to anticipate the environmental impact of the cradle-to-grave approach. The results exhibited the total human health damage of 2.63 × 10−5 DALY and ecosystem damage of 9.46 × 10−8 species.year per kg of containers. The main contributor was the carbon dioxide emission from fossil fuel combustion for energy generation that contributed to climate change and caused human health and the ecosystem damages with low-level metrics of 1.3 × 10−5 DALY and 7.39 × 10−8 species.yr per kg of containers, respectively. The most contributed substances in the ‘Particulate matter formation’ impact categories that caused respiratory diseases were from air/nitrogen oxides, air/particulates, <2.5 µm, and air/sulphur dioxide with the metrics of 2.93 × 10−6 DALY, 2.75 × 10−6 DALY, and 1.9 × 10−6 DALY per kg containers, correspondingly. Whereas, for the ‘Agricultural land occupation’, which contributed to ecosystem damage, almost the total contributions came from raw/occupation, forest, intensive with the metric of 1.93 × 10−9 species.yr per kg of containers. Nevertheless, from the results, all impact categories impacted below than 0.0001 DALY for the Human Health damage category and below 0.00001 species.yr for the ecosystem damage category. These results would provide important insights to companies and manufacturers in commercializing the fully biobased takeout food containers.

The Effects of Silver Nanoparticles Compositions on the Mechanical, Physiochemical, Antibacterial, and Morphology Properties of Sugar Palm Starch Biocomposites for Antibacterial Coating

Antibacterial sugar palm starch biopolymer composite films were developed and derived from renewable sources and inorganic silver nanoparticles (AgNPs) as main ingredients for antibacterial coatings. The composite films were produced by solution casting method and the mechanical and physicochemical properties were determined by tensile test, Fourier Transform Infrared (FTIR) analysis, thermal gravimetric analysis (TGA), antibacterial screening test and field emission scanning electron microscopy (FESEM) images. It was found that mechanical and antibacterial properties of biocomposite films were improved after the addition of AgNPs compared with the film without active metals. The weakness of neat biocomposite films was improved by incorporating inorganic AgNPs as a nanofiller in the films' matrix to avoid bacterial growth. The results showed that the tensile strength ranged between 8 kPa and 408 kPa and the elasticity modulus was between 5.72 kPa and 9.86 kPa. The addition of AgNPs in FTIR analysis decreased the transmittance value, caused small changes in the chemical structure, caused small differences in the intensity peaks, and produced longer wavelengths. These active films increased the degradation weight and decomposition temperature due to the more heat-stable AgNPs. Meanwhile, the average inhibited areas measured were between 7.66 and 7.83 mm (Escherichia coli), 7.5 and 8.0 mm (Salmonella cholerasuis), and 0.1 and 0.5 mm for Staphylococcus aureus. From the microscopic analysis, it was observed that the average size of all microbes for 1 wt% and 4 wt% AgNPs ranged from 0.57 to 2.90 mm. Overall, 3 wt% AgNP nanofiller was found to be the best composition that fulfilled all the mechanical properties and had better antimicrobial properties. Thus, the development of an organic-inorganic hybrid of antibacterial biopolymer composite films is suitable for antibacterial coatings.

Mechanical, Physical and Thermal Properties of Sugar Palm Nanocellulose Reinforced Thermoplastic Starch (TPS)/Poly (Lactic Acid) (PLA) Blend Bionanocomposites

In this paper, sugar palm nanocellulose fibre-reinforced thermoplastic starch (TPS)/poly (lactic acid) (PLA) blend bionanocomposites were prepared using melt blending and compression moulding with different TPS concentrations (20%, 30%, 40%, 60%, and 80%) and constant sugar palm nanocellulose fibres (0.5%). The physical, mechanical, thermal, and water barrier properties were investigated. The SEM images indicated different TPS loading effects with the morphology of the blend bionanocomposites due to their immiscibility. A high content of TPS led to agglomeration, while a lower content resulted in the presence of cracks and voids. The 20% TPS loading reduced the tensile strength from 49.08 to 19.45 MPa and flexural strength from 79.60 to 35.38 MPa. The thermal stability of the blend bionanocomposites was reduced as the TPS loading increased. The thickness swelling, which corresponded to the water absorption, demonstrated an increasing trend with the increased addition of TPS loading.

Stand-Level Transpiration Increases after Eastern Redcedar (Juniperus virginiana L.) Encroachment into the Midstory of Oak Forests

Eastern redcedar (Juniperus virginiana L., redcedar) encroachment is transitioning the oak-dominated Cross-Timbers of the southern Great Plain of the USA into mixed-species forests. However, it remains unknown how the re-assemblage of tree species in a semiarid to sub-humid climate affects species-specific water use and competition, and ultimately the ecosystem-level water budget. We selected three sites representative of oak, redcedar, and oak and redcedar mixed stands with a similar total basal area (BA) in a Cross-Timbers forest near Stillwater, Oklahoma. Sap flow sensors were installed in a subset of trees in each stand representing the distribution of diameter at breast height (DBH). Sap flow of each selected tree was continuously monitored over a period of 20 months, encompassing two growing seasons between May 2017 and December 2018. Results showed that the mean sap flow density (Sd) of redcedar was usually higher than post oaks (Quercus stellata Wangenh.). A structural equation model showed a significant correlation between Sd and shallow soil moisture for redcedar but not for post oak. At the stand level, the annual water use of the mixed species stand was greater than the redcedar or oak stand of similar total BA. The transition of oak-dominated Cross-Timbers to redcedar and oak mixed forest will increase stand-level transpiration, potentially reducing the water available for runoff or recharge to groundwater.

Characterization of Chickpea (Cicer arietinum L.) Flour Films: Effects of pH and Plasticizer Concentration

The use of flours as a material for biopolymer-based film preparation has gained interest due to the fact that they are a natural mixture of compatible macromolecules and due to their low cost. Chickpea flour shows a promising composition for the development of edible films. The aim of this study was to characterize and evaluate the properties of chickpea flour films as affected by pH (7 or 10) and plasticizer concentration (1% or 3% w/v) of film-forming solutions. Water vapor permeability, solubility, color, opacity, mechanical properties, thermal stability, structural changes by Fourier transform infrared analysis, and microstructure of the films were determined. Glycerol content and pH influenced chickpea flour film properties, microstructure and structural organization; interactions were also observed. The 1% glycerol films showed lower water vapor permeability, thickness, radical scavenging capacity, elongation at break and puncture deformation, and higher dry matter content, swelling, opacity, elastic modulus, and tensile and puncture strengths than 3% glycerol films. Film-forming solutions at pH 10 produced films with higher thickness and swelling, and were greener than those from solutions at neutral pH. The changes were more intense in 1% glycerol films. Glycerol concentration and pH could be combined in order to obtain chickpea flour films with different properties according to different food packaging requirements.

Cosmeceutical Effects of Galactomannan Fraction from Arenga pinnata Fruits In vitro

BACKGROUND

Cosmeceuticals refer to natural cosmetics with medical-like benefits due to their bioactive contents. Sugar palm fruit (Arenga pinnata) extract has been claimed for its anti-aging effect in vitro. However, its active compounds for cosmeceuticals is still unclear.

OBJECTIVE

This study was aimed to extract galactomannan from A. pinnata fruits and test its efficacy for tyrosinase inhibition, antioxidant, and anti-photoaging activities in vitro.

MATERIALS AND METHODS

Galactomannan from A. pinnata fruits was extracted by freeze drying and identified for its chemical compounds by using pyrolysis gas chromatography-mass spectrometry (py-GC/MS). Galactomannan was tested for its tyrosinase inhibition in both cell-based (melanocytes) and enzymatic assays, antioxidant activity using ferrous ion chelating assay (FCA) assay, and anti-photoaging activity for inhibiting the gene expression of matrix metalloproteinase-1 (MMP-1) and MMP-13 in macrophages using quantitative real-time polymerase chain reaction (qRT-PCR) analysis.

RESULTS

Identification of galactomannan fraction from A. pinnata fruits by py-GC/MS mainly consisted of oxonium ion and glucosides. For cellular assay, galactomannan at 5 μg/mL inhibited >50% of tyrosinase activity in melanocytes induced by phorbol myristate acetate. At the enzymatic level, galactomannan at similar concentration showed less tyrosinase activity inhibition (~20%). FCA results showed that galactomannan at 10 μg/mL exerted >50% of antioxidant activity. The qRT-PCR data indicated that galactomannan at 5 μg/mL inhibited >50% of MMP-1 and MMP-13 gene expressions in ultraviolet B-treated macrophages.

CONCLUSION

Galactomannan fraction from A. pinnata fruits has efficacy for enlightening effect, antioxidant, and anti-photoaging activity in the dose-independent pattern, indicating its cosmeceutical effects for skin healthcare.

SUMMARY

A. pinnata fruit containing galactomannan has cosmeceutical potentials through enlightening effect, antioxidant, and anti-photoaging activity in vitro.Galactomannan fraction has inhibitory effect on tyrosinase activity in both cellular melanocytes and enzymatic systems.Galactomannan fraction has strong protection against UVB-irradiation effect by inhibiting collagenase genes (MMP-1 and MMP-13) in macrophages. Abbreviations Used: Py-GC/MS: Pyrolysis-Gas Chromatography-Mass Spectrometry; FCA: Ferrous chelating activity; MMP: Matrix metalloproteinase; qRT-PCR: Quantitative Real-Time Polymerase Chain Reaction; PMA: Phorbol myristate acetate; UV: Ultraviolet; RPMI: Roswell Park Memorial Institute; DMEM: Dulbecco's modified eagle media; FBS: Fetal bovine serum; PBS: Phosphate buffered saline; MTT: 3-(4,5-diethylthiazol-2-yl)-2,5-dipheniltetrazolium bromide; L-DOPA: L-3,4-dihydroxyphenylalanine; EDTA: Ethylenediaminetetraacetic acid; GAPDH: Glyceraldehyde 3-phosphate dehydrogenase; DPPH: 1,1-diphenyl-2-picryl-hydrazyl; SPF: Sun protection factor.

Thermal, mechanical, and physical properties of seaweed/sugar palm fibre reinforced thermoplastic sugar palm Starch/Agar hybrid composites

The aim of this research is to investigate the effect of sugar palm fibre (SPF) on the mechanical, thermal and physical properties of seaweed/thermoplastic sugar palm starch agar (TPSA) composites. Hybridized seaweed/SPF filler at weight ratio of 25:75, 50:50 and 75:25 were prepared using TPSA as a matrix. Mechanical, thermal and physical properties of hybrid composites were carried out. Obtained results indicated that hybrid composites display improved tensile and flexural properties accompanied with lower impact resistance. The highest tensile (17.74MPa) and flexural strength (31.24MPa) was obtained from hybrid composite with 50:50 ratio of seaweed/SPF. Good fibre-matrix bonding was evident in the scanning electron microscopy (SEM) micrograph of the hybrid composites' tensile fracture. Fourier transform infrared spectroscopy (FT-IR) analysis showed increase in intermolecular hydrogen bonding following the addition of SPF. Thermal stability of hybrid composites was enhanced, indicated by a higher onset degradation temperature (259°C) for 25:75 seaweed/SPF composites than the individual seaweed composites (253°C). Water absorption, thickness swelling, water solubility, and soil burial tests showed higher water and biodegradation resistance of the hybrid composites. Overall, the hybridization of SPF with seaweed/TPSA composites enhances the properties of the biocomposites for short-life application; that is, disposable tray, plate, etc.