Enhancement of Gas Barrier Properties and Durability of Poly(butylene succinate-co-butylene adipate)-Based Nanocomposites for Food Packaging Applications.

Poly(butylene succinate-co-butylene adipate) (PBSA)-based materials are receiving growing attention in the packaging industry for their promising biodegradability. However, poor gas barrier properties and low durability of biodegradable polymers, such as PBSA, have limited their wide-spread use in food packaging applications. Here we report a scalable solution to improve gas barrier properties and stabilize PBSA against photo-aging, with minimal modifications to the biodegradable polymer backbone by using a commercially available and biocompatible layered double hydroxide (LDH) filler. We investigate and compare the mechanical, gas barrier, and photoaging properties of PBSA and PBSA-LDH nanocomposite films produced on a pilot scale. An increase in rigidity in the nanocomposite was observed upon addition of LDH fillers to neat PBSA, which direct the application of neat PBSA and PBSA-LDH nanocomposite to different food packaging applications. The addition of LDH fillers into neat PBSA improves the oxygen and water vapour barriers for the PBSA based nanocomposites, which increases the attractiveness of PBSA material in food packaging applications. Through changes in the viscoelastic behaviour, we observe an improved photo-durability of photoaged PBSA-LDH nanocomposites compared to neat PBSA. It is clear from our studies that the presence of LDH enhances the lifetime durability and modulates the photodegradation rate of the elaborated biocomposites.

Current status of biobased and biodegradable food packaging materials: Impact on food quality and effect of innovative processing technologies.

Fossil-based plastic materials are an integral part of modern life. In food packaging, plastics have a highly important function in preserving food quality and safety, ensuring adequate shelf life, and thereby contributing to limiting food waste. Meanwhile, the global stream of plastics into the oceans is increasing exponentially, triggering worldwide concerns for the environment. There is an urgent need to reduce the environmental impacts of packaging waste, a matter raising increasing consumer awareness. Shifting part of the focus toward packaging materials from renewable resources is one promising strategy. This review provides an overview of the status and future of biobased and biodegradable films used for food packaging applications, highlighting the effects on food shelf life and quality. Potentials, limitations, and promising modifications of selected synthetic biopolymers; polylactic acid, polybutylene succinate, and polyhydroxyalkanoate; and natural biopolymers such as cellulose, starch, chitosan, alginate, gelatine, whey, and soy protein are discussed. Further, this review provides insight into the connection between biobased packaging materials and innovative technologies such as high pressure, cold plasma, microwave, ultrasound, and ultraviolet light. The potential for utilizing such technologies to improve biomaterial barrier and mechanical properties as well as to aid in improving overall shelf life for the packaging system by in-pack processing is elaborated on.

Active Packaging Applications for Food.

The traditional role of food packaging is continuing to evolve in response to changing market needs. Current drivers such as consumer's demand for safer, "healthier," and higher-quality foods, ideally with a long shelf-life; the demand for convenient and transparent packaging, and the preference for more sustainable packaging materials, have led to the development of new packaging technologies, such as active packaging (AP). As defined in the European regulation (EC) No 450/2009, AP systems are designed to "deliberately incorporate components that would release or absorb substances into or from the packaged food or the environment surrounding the food." Active packaging materials are thereby "intended to extend the shelf-life or to maintain or improve the condition of packaged food." Although extensive research on AP technologies is being undertaken, many of these technologies have not yet been implemented successfully in commercial food packaging systems. Broad communication of their benefits in food product applications will facilitate the successful development and market introduction. In this review, an overview of AP technologies, such as antimicrobial, antioxidant or carbon dioxide-releasing systems, and systems absorbing oxygen, moisture or ethylene, is provided, and, in particular, scientific publications illustrating the benefits of such technologies for specific food products are reviewed. Furthermore, the challenges in applying such AP technologies to food systems and the anticipated direction of future developments are discussed. This review will provide food and packaging scientists with a thorough understanding of the benefits of AP technologies when applied to specific foods and hence can assist in accelerating commercial adoption.

Antioxidant and Antiproliferative Potential of Fruiting Bodies of the Wild-Growing King Bolete Mushroom, Boletus edulis (Agaricomycetes), from Western Serbia.

The aim of this work was to study the bioactivity of crude aqueous and ethanolic extracts of Boletus edulis prepared from caps and stipes of wild-growing basidiocarps collected from the Prijepolje region (western Serbia). The bioactivity screening included antioxidant (2,2-diphenyl-l-picrylhydrazyl [DPPH], nitric oxide, super-oxide anion*, and hydroxyl radicals and ferric-reducing antioxidant power) and antiproliferative MTT assays (human breast MCF-7 cancer cell line). In addition, all extracts were primarily characterized by ultraviolet/visible spectrophotometry to determine total phenolic and flavonoid contents. The highest anti-DPPH and anti-hydroxyl radical activity were observed in aqueous B. edulis extract from the caps (half maximal inhibitory concentration [IC50] = 50.97 µg/ mL and 2.05 µg/mL, respectively), whereas the highest anti-nitric oxide radical activity was observed in aqueous B. edulis extract from the stipes (IC50 = 10.74 µg/mL). The ethanolic extract obtained from the mushroom stipe showed higher anti-superoxide anion radical activity (IC50 = 9.84 µg/mL) and ferric-reducing antioxidant power (22.14 mg ascorbic acid equivalents/g dry weight) compared with aqueous extracts. Total phenolic content for all extracts was similar but total flavonoid content was significantly higher in the aqueous B. edulis extract from the caps (4.5 mg quercetin equivalents/g dry weight). All crude extracts showed activity against the MCF-7 cell line, with the ethanolic extract of B. edulis prepared from stipes (IC50 = 56 µg/mL) being the most potent. This is, to our knowledge, the first report of the antiproliferative effects of crude aqueous and ethanolic extracts prepared from caps and stipes of wild-growing basidiocarps of B. edulis on the human breast MCF-7 cancer cell line.