Data on antimicrobial, barrier, and mechanical properties of biocomposites prepared from carrot pomace and wheat gluten with varied eugenol content.

This article presents analyzed data on the antimicrobial, barrier, and mechanical properties inherent to films created by blending carrot pomace with wheat gluten and polyglycerol-3 plasticizer and combined with varying contents (0 wt.%, 3 wt.%, and 5 wt.%) of eugenol, a natural antimicrobial compound derived from essential oils. The integration of carrot pomace, wheat gluten, plasticizer, and eugenol involved meticulous mortar and pestle processing, ensuring a homogenous blend. Subsequently, the mixture was compression-molded in a hydraulic press to fabricate the films. Standard bacteria strains-Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 6538-are used in the antimicrobial evaluation, and antimicrobial efficacy is measured using OD600 measurements. Water vapor permeability (WVP) measurement effectively defines the films' potential to prevent water vapor infiltration. Mechanical properties are assessed by determining elastic modulus, tensile strength, and elongation at break, which together reveal the films' adaptive flexibility and durability. The dataset presented herein holds substantial promise for food packaging applications. Researchers in the food packaging industry can leverage the antimicrobial and barrier property data to design novel packaging materials, potentially enhancing shelf-life and food safety. Engineers and material scientists can utilize the mechanical properties data to develop structurally robust and flexible materials.

A Green Conformable Thermoformed Printed Circuit Board Sourced from Renewable Materials.

Printed circuit boards (PCBs) physically support and connect electronic components to the implementation of complex circuits. The most widespread insulating substrate that also acts as a mechanical support in PCBs is commercially known as FR4, and it is a glass-fiber-reinforced epoxy resin laminate. FR4 has exceptional dielectric, mechanical, and thermal properties. However, it was designed without considering sustainability and end-of-life aspects, heavily contributing to the accumulation of electronic waste in the environment. Thus, greener alternatives that can be reprocessed, reused, biodegraded, or composted at the end of their function are needed. This work presents the development and characterization of a PCB substrate based on poly(lactic acid) and cotton fabric, a compostable alternative to the conventional FR4. The substrate has been developed by compression molding, a process compatible with the polymer industry. We demonstrate that conductive silver ink can be additively printed on the substrate's surface, as its morphology and wettability are similar to those of FR4. For example, the compostable PCB's water contact angle is 72°, close to FR4's contact angle of 64°. The developed substrate can be thermoformed to curved surfaces at low temperatures while preserving the conductivity of the silver tracks. The green substrate has a dielectric constant comparable to that of the standard FR4, showing a value of 5.6 and 4.6 at 10 and 100 kHz, respectively, which is close to the constant value of 4.6 of FR4. The substrate is suitable for microdrilling, a fundamental process for integrating electronic components to the PCB. We implemented a proof-of-principle circuit to control the blinking of LEDs on top of the PCB, comprising resistors, capacitors, LEDs, and a dual in-line package circuit timer. The developed PCB substrate represents a sustainable alternative to standard FR4 and could contribute to the reduction of the overwhelming load of electronic waste in landfills.

Biodegradable and Biobased Mulch Films: Highly Stretchable PLA Composites with Different Industrial Vegetable Waste.

Highly stretchable biobased and biodegradable agricultural mulch films based on polylactic acid (PLA) and 10, 20, or 30 wt % various nonedible vegetable wastes such as spinach stems (SS), tomato pomace (TP), and cocoa shells (CS) are prepared and characterized in this work. The results demonstrate that appropriate PLA plasticization and vegetable waste addition allow for obtaining films suitable for mulching with tensile strengths in the 10-24 MPa range and elongations at break up to 460%, depending on the kind and amount of vegetable waste incorporated. Additionally, the developed mulches show low water solubility (1-15 wt %) and moisture content (1-3 wt %) with a water vapor permeability of up to 3 × 10-10 g s-1 m-1 Pa-1, similar to that of Mater-Bi. In addition, the type of vegetable waste added as filler were demonstrated to significantly affect not only the films' mentioned properties but also their biodegradability. For instance, films prepared with 20 wt % SS were demonstrated to improve PLA soil biodegradability, which increased from 0 to 38 wt % for PLA composites after 6 months of a soil burial experiment. Lastly, the developed composites contain different amounts of plant micro- and macronutrients, indicating their potential as fertilizers. The results found in this work represent a sustainable, fully biobased alternative to other mulches already in the market.

Avocado Peels and Seeds: Processing Strategies for the Development of Highly Antioxidant Bioplastic Films.

The industrial processing of avocados annually generates more than 1.2 million tons of avocado peels (APs) and avocado seeds (ASs) that have great potential in the production of active bioplastics, although they have never been considered for this aim until now. Separately, the APs and ASs, as well as a combination of avocado peels and seeds (APSs), were evaluated here for the first time for the preparation of antioxidant films, with application in food packaging. Films were prepared by casting, after their processing by three different methods: (1) hydrolysis in acid media, (2) hydrolysis followed by plasticization, and (3) hydrolysis and plasticization followed by blending with pectin polymers in different proportions (25 and 50 wt %). The results indicate that the combination of hydrolysis, plasticization, and pectin blending is essential to obtain materials with competitive mechanical properties, optical clarity, excellent oxygen barrier properties, high antioxidant activity, biodegradability, and migration of components in TENAX suitable for food contact applications. In addition, the materials prepared with APSs are advantageous from the point of view of the industrial waste valorization, since the entire avocado wastes are used for the production of bioplastics, avoiding further separation processes for their valorization.

Preparation, Characterization, and In Vitro Testing of Nanoclay Antimicrobial Activities and Elicitor Capacity.

Clay-based nanocomposites (nanoclays) are interesting systems to hold a wide type of active substances with a wide field of industrial applications. Bentonite-chitosan nanoclay was obtained via cationic exchange of natural bentonite (Bent) with an aqueous solution of chitosan (CS). Their physicochemical and morphological properties were discussed under the light of Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy. Bent-CS characterization indicated that CS was intercalated in 10% (w/w). This polycationic polymer was oriented mostly in a monolayer arrangement, interacting by electrostatic forces between Bent sheets. The antimicrobial action of Bent-CS nanoclay was assayed onto phytopathogens, the bacterium model Pseudomonas syringe pv. tomato DC3000 ( Psy) and the necrotrophic fungus Fusarium solani f. sp. eumartii ( F. eumartii). In addition to demonstrating cell death on both microorganisms, Bent-CS exerted elicitor property on tomato plantlets. The biological actions of this natural nanomaterial might make it proper to be used in crops.