Sustainable Bioactive Packaging Based on Thermoplastic Starch and Microalgae

This study combines the use of corn starch and Tetradesmus obliquus microalgae for the production of antioxidant starch films as flexible packaging material. Starch was plasticized with glycerol and blended with 1 w% polyallylamine chosen as an agent to modify the film physical properties. The addition of polyallylamine improved film water stability and water vapor transmission rate as well as mechanical stiffness and tenacity. The dried Tetradesmus obliquus microalgae, which showed an EC50 value of 2.8 mg/mg DPPH (2.2-Diphenyl-1-picrylhydrazyl radical), was then used as antioxidant filler. The addition of microalgae provided the films with good antioxidant activity, which increased with microalgae content increasing. To our knowledge, this is the first study reporting the development of sustainable bioactive packaging films composed of almost 100% starch, and follows the European union’s goals on plastics strategy concerning the promotion of bio-based, compostable plastics and the setting up of approaches to prevent food waste with a simple plastic packaging.

Rapid-deposited high-performance submicron encapsulation film with in-situ plasma oxidized Al layer inserted

High-performance submicron thin-film encapsulation deposited rapidly under low temperature plays an important role in Si-based organic micro-displays. In this letter, the formation mechanism of high-performance encapsulation films consisting of SiO2/in-situ plasma oxidized Al at 77°C is explained. We think that the reason why the performance of encapsulation films deposited by this method behave better than the simple stacking of SiO2/Al2O3 is the formation of Al-O-Si bonds. By further optimizing the process parameters, the water vapor transmission rate and the transmittance in the visible region have been improved, which reached 10-6 g∙m 2∙day 1 and 90%, respectively.

Effects of Geomaterial-Originated Fillers on Microstructure and Mechanical/Physical Properties of α- and β-Chitosan-Based Films

Edible films and coatings with good mechanical/physical properties are highly required for carrying medical substances and food packaging. So, solvent-cast films of α- or β-chitosan filled with palygorskite, montmorillonite or geopolymer-containing material (GCM), were prepared, and the effects of their clay contents (up to 50 wt.%) on the mechanical/physical properties were assessed. The microstructure of the films was investigated using FT-IR spectroscopy, SEM and thermal analysis. The results showed that, except for the films composed of GCM and β-chitosan, the mechanical properties of the films with limited (up to 5 wt.%) to moderate (5–25 wt.%) amounts of fillers increased as a result of the attractive electrostatic forces formed between the fillers and chitosan functional groups (–NH3+, CH2OH and NHCOCH3). However, due to the occurrence of coarse aggregates, the strength of filler-rich films declined. The addition of fillers led to an increase in porosity and water absorption of the films, but it had irregular effects on their wettability and water vapor transmission rate. These observations as well as the thermal stability of the films were discussed in relation to the characterization results.

Physico-chemical properties of gathot (fermented cassava) flour applied on edible film

The objective of this research is to examine the physicochemical properties of gathot and its potential as an edible film. The materials used included dried gathot, carrageenan, and glycerol with 4 levels of treatment and 5 repetitions. The treatment was in the form of variation of gathot flour’s concentration (0.00; 0.75; 1.00; 1.25 %). The test was conducted on gathot flour, covering scavenging ability, bulk density, water absorbency, color brightness, proximate analysis and crude fiber with descriptive analysis. Gathot flour-derived edible film’s characteristics were tested for tensile strength and water vapor transmission rate (WVTR) to examine whether gathot flour-derived edible film was able to compete with commercial bioplastics through quantitative statistical analysis and Completely Randomized Design (RAL) and processing with SPSS 23.0. The results of physicochemical test on gathot flour were scavenging ability 49.37%; bulk density 0.57 g/mL; water absorbency 2.37 g/g; color brightness 17.42; water content 9.32%; protein content 4.76%; fat content 0.13%; ash content 0.09%; carbohydrate 85.70%; and crude fiber 3.54%. The average results of edible film’s characteristics test with a variation of gathot flour’s concentration were tensile strength 1.41-3.00 N/mm2 and water vapor transmission rate (WVTR) 5.42-6.99%. From the perspective of physicochemical properties, it is concluded that gathot flour is almost equal to wheat flour and tapioca flour. In addition, gathot flour-derived edible film at up to concentration level 1.25% has met the criteria for the edible film with moderate properties and complied with the standard bioplastic packaging.

Development and Characterization of Alginate Based Biocomposite Films Reinforced by Gracilaria Powder

The edible film is a thin sheet that functions as a coating or packaging material on foods that may be eaten simultaneously as packaged products. The ingredient that is often used is alginate made from seaweed. The advantage of using seaweed as a bioplastic material is that it can be produced in a large quantity, low price, and is non-toxic; it can also produce bioplastic that resembles conventional plastic. The experimental method with two components of Completely Randomized Factorial Design was employed in this study (CRFD), the concentration of Gracilaria seaweed powder with four levels (0%, 0.5%, 1%, 1.5%, and 1%) and concentration of alginate with three levels (1%, 1.25%, dan 1.5%). The result showed that the concentration of seaweed powder and concentration of alginate that used in the making of the edible film had a significant effect on the quality of the edible film on all parameters, which is thickness, moisture content, tensile strength, elongation, water vapor transmission rate, water-solubility, color, opacity and surface morphology. There is an interaction between the concentration of seaweed powder and concentration of alginate at the significant effect on the quality of the edible film, which is a concentration of seaweed powder at the level of 1.5% and concentration of alginate at the level of 1.5%. The film has a the thickness of 0.25mm, moisture content of 6.94%, tensile strength of 54.29 Mpa, elongation of 3.26%, the water solubility of 64.41%, water vapor transmission rate of 3242 g/cm2/24 h, and opacity of 81.7%.

The role of gambeir filtrate and red palm oil in the formation of canna starch based-functional edible film

This study aims to analyze the role of gambier filtrate and red palm oil in the formation of functional edible film and to determine whether the gambier filtrate and red palm oil are synergistic or antagonistic in the formation of functional edible films. The study design used a factorial randomized block design with two treatment factors and each treatment consisted of three levels, namely: gambier filtrate concentration (A): 20, 30, and 40% (v/v) as well as red palm oil concentration (B): 1.2 and 3% (v/v). The observed parameters were thickness, elongation percentage, water vapor transmission rate, antioxidant activity, and antibacterial activity. Gambier filtrate and red palm oil were capable to improve the antioxidant and antibacterial properties of canna starch-based edible film. Gambier filtrate plays a role in increasing the elongation percentage, thickness, and water vapor transmission rate of edible film.

Structural Impact on Some Common Physical Properties of Single Jersey Weft Knit Fabric

Single jersey weft knit fabrics include a large portion of knitted products. These fabrics are made using different types of stitches. In this study, several single jersey weft knit fabric samples containing four courses and two wales in the repeating unit of the fabric structure were made by introducing and gradually increasing the number of tuck stitches in the structure, to find out the effect of this stitch on fabric properties. Results showed that tuck stitches could positively affect the areal density, width, and tensile properties of the fabric. For some comfort-related properties, tuck stitches were found to improve wicking and drying properties, reduce water vapor transmission rate, and affect fabric smoothness. The position of tuck stitches in the structure also had some effect, but was not as significant as when the number of tuck stitches was varied.

Eye-Movement-Controlled Wheelchair Based on Flexible Hydrogel Biosensor and WT-SVM

To assist patients with restricted mobility to control wheelchair freely, this paper presents an eye-movement-controlled wheelchair prototype based on a flexible hydrogel biosensor and Wavelet Transform-Support Vector Machine (WT-SVM) algorithm. Considering the poor deformability and biocompatibility of rigid metal electrodes, we propose a flexible hydrogel biosensor made of conductive HPC/PVA (Hydroxypropyl cellulose/Polyvinyl alcohol) hydrogel and flexible PDMS (Polydimethylsiloxane) substrate. The proposed biosensor is affixed to the wheelchair user’s forehead to collect electrooculogram (EOG) and strain signals, which are the basis to recognize eye movements. The low Young’s modulus (286 KPa) and exceptional breathability (18 g m−2 h−1 of water vapor transmission rate) of the biosensor ensures a conformal and unobtrusive adhesion between it and the epidermis. To improve the recognition accuracy of eye movements (straight, upward, downward, left, and right), the WT-SVM algorithm is introduced to classify EOG and strain signals according to different features (amplitude, duration, interval). The average recognition accuracy reaches 96.3%, thus the wheelchair can be manipulated precisely.

Functional Antibacterial Nanometer Zinc Ion Yarns: Manufacturing Technique and Antimicrobial Efficacy against Escherichia coli

People are no longer satisfied with only comfortable textile clothing with advanced technology and elevated standard of living and, thus, are gradually preferring functional textiles. In the meanwhile, the spread of medical knowledge has educated the public about the antimicrobial concept. In this study, composed of different twist coefficients and different numbers of plies, the zinc ion twisted yarns are made into knitted fabrics. Next, the knitted fabrics are examined for water vapor transmission rate and antimicrobial efficacy. The test results indicate that the water vapor transmission rate is 1013 g/m2/day for 2Zn-0C-K and 981 g/m2/day for 3Zn-0C-K. However, a rise in the twist coefficient adversely affects the water vapor transmission rate. The fabric 2Zn-3C-K exhibits the maximal air permeability of 265 cm3/cm2/s and 3Zn-3C-K 186 cm3/cm2/s. Regardless of whether it is at OD600, colony count observation, or antibacterial rate, 3Zn-5C-K exhibits the maximal antibacterial rate with the value being 0.45 at OD600 and the optimal antimicrobial efficacy being 85%. To sum up, based on the interest of the test results, production cost, and manufacturing process evaluation, 2Zn-5C-K is the optimal nonwoven fabric that achieved the maximal effects.