Morphological, barrier, and mechanical properties of cassava starch films reinforced with cellulose and starch nanoparticles

Biodegradable film based on barley sprout powder/pectin modified with quercetin and V2O5 nanoparticles: Investigation of physicochemical and structural properties

In this study, barley sprout powder/pectin (BS/Pec) composite film was prepared. Quercetin (Qu) and vanadium oxide (V2O5) nanoparticles were used to improve the physicochemical and structural characteristics of the film. The structural, physicochemical and thermal properties of the films were investigated by various techniques such as TGA, SEM, XRD, FTIR, texture analysis, etc. The thickness and tensile strength of the films increased from 120 μm to 2.4 MPa to 220 μm and 6 MPa respectively with the increase of V2O5 nanoparticles and quercetin pigment. Nanoparticles of V2O5 and quercetin decreased the moisture content of the film from 50% to 20%. Quercetin had little effect in reducing water vapor permeability (WVP), but V2O5 nanoparticles had a significant effect in reducing WVP. The pure BS/Pec film had almost 30% antioxidant properties, which increased to 81% with the increase of quercetin. Adding quercetin and V2O5 nanoparticles to the film increased the antimicrobial properties of the film against both Escherichia coli and Staphylococcus aureus bacteria. The SEM images showed the inhomogeneous surface of the BS/Pec film caused by BS powder fibers. The interactions between the components of the films (electrostatic type) was confirmed by FTIR results. The degradation temperature of the overall structure of the film in the presence of nanoparticles indicated the positive effect of nanoparticles in increasing the thermal resistance of the film. Investigating the crystal structure of the film showed that the BS/Pec film has an amorphous/crystalline or semi-crystalline structure. Considering that the prepared film has good mechanical properties and as well as antioxidant/antimicrobial properties, this film as an active composite can be used in food products packaging.

Plant-based Biomass/Polyvinyl Alcohol Gels for Flexible Sensors

Flexible sensors show great application potential in wearable electronics, human-computer interaction, medical health, bionic electronic skin and other fields. Compared with rigid sensors, hydrogel-based devices are more flexible and biocompatible and can easily fit the skin or be implanted into the body, making them more advantageous in the field of flexible electronics. In all designs, polyvinyl alcohol (PVA) series hydrogels exhibit high mechanical strength, excellent sensitivity and fatigue resistance, which make them promising candidates for flexible electronic sensing devices. This paper has reviewed the latest progress of PVA/plant-based biomass hydrogels in the construction of flexible sensor applications. We first briefly introduced representative plant biomass materials, including sodium alginate, phytic acid, starch, cellulose and lignin, and summarized their unique physical and chemical properties. After that, the design principles and performance indicators of hydrogel sensors are highlighted, and representative examples of PVA/plant-based biomass hydrogel applications in wearable electronics are illustrated. Finally, the future research is briefly prospected. We hope it can promote the research of novel green flexible sensors based on PVA/biomass hydrogel.

Environmental Properties and Applications of Biodegradable Starch-Based Nanocomposites

In recent years, the demand for environmental sustainability has caused a great interest in finding novel polymer materials from natural resources that are both biodegradable and eco-friendly. Natural biodegradable polymers can displace the usage of petroleum-based synthetic polymers due to their renewability, low toxicity, low costs, biocompatibility, and biodegradability. The development of novel starch-based bionanocomposites with improved properties has drawn specific attention recently in many applications, including food, agriculture, packaging, environmental remediation, textile, cosmetic, pharmaceutical, and biomedical fields. This paper discusses starch-based nanocomposites, mainly with nanocellulose, chitin nanoparticles, nanoclay, and carbon-based materials, and their applications in the agriculture, packaging, biomedical, and environment fields. This paper also focused on the lifecycle analysis and degradation of various starch-based nanocomposites.

Morphological, structural and physicochemical properties of rice starch nanoparticles prepared via ultra-high pressure homogenization

Native rice starches were treated with five periods of ultra-high pressure homogenization (UHPH) under each of 60, 80, 100, 120, 140 and 160 MPa, respectively. The morphological, structural and physicochemical properties of starches treated with UHPH were examined. The mean particle diameter of starch nanoparticles ranged between 154.20 and 260.40 nm. SEM revealed that the granular amorphous region of starch granules was damaged under pressures between 60 and 80 MPa, and the crystalline region was further destroyed under pressures as high as 100–160 MPa. DSC demonstrated that the gelatinization temperatures and enthalpies of nanoparticles reduced. The relative crystallinity reduced from 22.90 to 13.61% as the pressure increased. FTIR showed that the absorbance ratio at 1047/1022 cm−1 decreased, and increased at 1022/995 cm−1. RVA results indicated that the viscosity of starch samples increased between 60 and 120 MPa, and the reverse effect was observed under 140 and 160 MPa.

Functionality and Applicability of Starch-Based Films: An Eco-Friendly Approach

The accumulation of high amounts of petro-based plastics is a growing environmental devastation issue, leading to the urgent need to innovate eco-safe packaging materials at an equivalent cost to save the environment. Among different substitutes, starch-based types and their blends with biopolymers are considered an innovative and smart material alternative for petrol-based polymers because of their abundance, low cost, biodegradability, high biocompatibility, and better-quality film-forming and improved mechanical characteristics. Furthermore, starch is a valuable, sustainable food packaging material. The rising and growing importance of designing starch-based films from various sources for sustainable food packaging purposes is ongoing research. Research on "starch food packaging" is still at the beginning, based on the few studies published in the last decade in Web of Science. Additionally, the functionality of starch-based biodegradable substances is technically a challenge. It can be improved by starch modification, blending starch with other biopolymers or additives, and using novel preparation techniques. Starch-based films have been applied to packaging various foods, such as fruits and vegetables, bakery goods, and meat, indicating good prospects for commercial utilization. The current review will give a critical snapshot of starch-based films' properties and potential applicability in the sustainable smart (active and intelligent) new packaging concepts and discuss new challenges and opportunities for starch bio composites.

Morphological, barrier, and mechanical properties of banana starch films reinforced with cellulose nanoparticles from plantain rachis

The main aim of the present study was to characterize banana starch films reinforced with nanoparticles from plantain rachis. Nanoparticles were obtained by acid hydrolysis and sonication, exhibiting a mean hydraulic diameter of about 60 nm. Scanning electron microscopy micrographs showed that the nanoparticle thickness ranged between 9.8 and 22.3 nm. The thermal gravimetric analysis showed that nanoparticles are thermally stable for temperatures up to 340 °C. Films were made for different fractions of nanoparticles (0.0, 1.75, 2.5, and 4.0%) relative to total solids, and glycerol was used as a plasticizer. The influence of the addition of nanoparticles to starch films on the morphology, water vapor permeability (WVP), and mechanical properties of the nanocomposites films was explored. Cellulose nanoparticles reduced the WVP, and increased the tensile strength and flexibility of the starch films. FTIR analysis of films was used to show that nanoparticles improved the molecular organization of starch chains. It was proposed that nanoparticles acted as a crosslinked for starch chains via hydrogen bonding effects.

Nanocellulose in food packaging: A review

The research in eco-friendly and sustainable materials for packaging applications with enhanced barrier, thermo-mechanical, rheological and anti-bacterial properties has accelerated in the last decade. Last decade has witnessed immense interest in employing nanocellulose (NC) as a sustainable and biodegradable alternative to the current synthetic packaging barrier films. This review article gathers the research information on NC as a choice for food packaging material. It reviews on the employment of NC and its various forms including its chemico-physical treatments into bio/polymers and its impact on the performance of nanocomposites for food packaging application. The review reveals the fact that the research trends towards NC based materials are quite promising for Active Packaging (AP) applications, including the Controlled Release Packaging (CRP) and Responsive Packaging (RP). Finally, it summarizes with the challenges of sustainable packaging, gray areas that need an improvement/focus in order to commercially exploit this wonderful material for packaging application.