No abstract

Nanotechnology applied to food and beverage packaging has created enormous interest in recent years, but in the same time there are many controversial issues surrounding nanotechnology and food. The benefits of engineered nanoparticles (ENPs) in food-contact applications are accompanied by safety concerns due to gaps in understanding the toxicology. In case of incorporation in food contact polymers, the first step to consumer exposure is the transfer of ENPs from the polymer to the food. Hence, to improve understanding of risk and benefit, the key questions are whether nanoparticles can be released from food contact polymers and under which conditions. This review has two main goals. Firstly, it will be presented the current advancements in the application of ENPs in food and beverage packaging sector to grant active and intelligent properties. A particular focus will be placed on current demands in terms of risk assessment strategies associated with the use ENPs in food contact materials (FCMs), i.e. upto-date migration / cytotoxicity studies of ENPs which are partly contradictory. Secondly, the review provide an extensive analysis of present market dynamics on ENPs in food/beverage packaging moving beyond concept to current industrial applications.

No abstract

This research reports about the development by electrospinning of fiber-based films made of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) derived from fermented fruit waste, so-called bio-papers, with enhanced antimicrobial performance. To this end, different combinations of oregano essential oil (OEO) and zinc oxide nanoparticles (ZnONPs) were added to PHBV solutions and electrospun into mats that were, thereafter, converted into homogeneous and continuous films of 130 µm. The morphology, optical, thermal, mechanical properties, crystallinity, and migration into food simulants of the resultant PHBV-based bio-papers were evaluated and their antimicrobial properties were assessed against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) in both open and closed systems. It was observed that the antimicrobial activity decreased after 15 days due to the release of the volatile compounds, whereas the bio-papers filled with ZnONPs showed high antimicrobial activity for up to 48 days. The electrospun PHBV biopapers containing 2.5 wt% OEO + 2.25 wt% ZnONPs successfully provided the most optimal activity for short and long periods against both bacteria. Nanomaterials 2020, 10, 506 2 of 26 studied, including the poly(3-hydroxybutyrate) (PHB or P3HB) homopolyester and its copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). The latter shows lower crystallinity and melting point as well as greater flexibility, which broadens its industrial applicability [4,5]. In order to confer active properties to PHAs, several substances can be incorporated into the biopolymers such as essential oils (EOs) and inorganic or metal nanoparticles (MNPs) [6,7].EOs are the product of the secondary metabolism of plants, separated from the aqueous phase, which is formed by various volatile components such as terpenes, alcohols, acids, esters, epoxies, aldehydes, ketones, amines, and sulphides, among others [8]. This wide range of compounds are responsible for the strong biological activity and also the antioxidant, antimicrobial, antifungal, and antiviral properties of plants [9]. In addition, EOs are biologically safe and have a low risk of causing resistance in pathogens [10]. In addition, they are classified as Generally Recognized as Safe (GRAS) by the U.S. Food and Drug Administration (FDA) [11]. Among them, oregano essential oil (OEO) is one of the most important and it is widely used in the pharmaceutical, food, and cosmetics industries [12]. It comes from the genus Origanum that belongs to the Lamiaceae family [13], which is constituted by more than 38 monoterpenoids [14]. Their main active compounds are carvacrol, thymol, p-cymene, and γ-terpinene, which are responsible for its high antimicrobial and antioxidant activities [15,16]. These active compounds have been particularly related to the inhibition of G− bacteria such as Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), and Salmonella typhimurium (S. typhimurium) and G+ bacteria including Staphylococcus aureus (S. aureus), Listeria mo...

No abstract

Oregano essential oil (OEO) has good antioxidant and antimicrobial activity and its incorporation into food packaging is challenging because of its intense flavor, high volatility and instability, and insolubility in aqueous systems. Additionally, the sensory perception of EO can be changed as a consequence of oxidation, heating, volatilization or chemical interactions. Cyclodextrins (CDs) can be used to avoid these inconveniences because they are able, due to their peculiar chemical structure, to encapsulate hydrophobic molecules such as OEO improving its aqueous solubility and reducing its volatility. In this work, kneading (KM) and freeze-drying (FDM) methods were evaluated to encapsulate OEO in two cyclodextrins types (α-CD and γ-CD). After, the α-CD:OEO and γ-CD:OEO inclusion complexes (ICs) were included in poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) electrospun fibers by electrospinning and annealed for film formation. Results showed that the encapsulation efficiency of oregano essential oil is influenced by both the encapsulation methods and the cyclodextrin type. The antimicrobial and antioxidant activity of the α-CD:OEO and γ-CD:OEO inclusion complexes were higher compared with pure OEO. The optimal concentration of α-CD:OEO inclusion complexes and γ-CD:OEO inclusion complexes for homogeneous and continues films formation was 15 and 25 wt%, respectively. At these concentrations, the films showed a strong antimicrobial and antioxidant activity, up to 15 days. In addition, the mechanical properties of the films were also improved (Young's modulus + 35%). In conclusion, this work shows that the encapsulation of CD:OEO inclusion complexes by electrospinning into PHBV polymeric matrix opens a new path in the development of bioactive packaging materials using EOs.

ABSTRACT:The influence of new types of additives, such as halogen-and antimony-free flame-retardant master batches based on phosphorus, a-zirconium dihydrogen phosphate, and b-cyclodextrin nanosponges, on the flame retardancy of polyamide 6,6 (PA6,6) by means of cone calorimetry and limiting oxygen index (LOI) tests was investigated. A significant decrease of the heat release rate, depending by the type of additive used, was observed. Furthermore, with the consideration that the life safety during the fire could be improved by a decrease in the fire hazard, a decrease in the quantity of the smoke and its toxicity, depending also on the type of additive, was revealed. With regard to the LOI test, neat PA6,6 showed a slight increase in the LOI value in comparison with the PA6,6 composites. However, all of the PA6,6/composites showed a slower burning velocity and antidripping effects at oxygen concentrations corresponding to the LOI value. To understand the flame-retardancy mechanism of these novel PA6,6 composites, we thoroughly investigated their thermal decomposition behavior and microstructure/ elemental analysis by scanning electron microscopy/ energy-dispersive X-ray spectroscopy. Furthermore, the combustion behavior of these novel PA6,6 composites was compared with that of conventional nanofillers (e.g., modified montmorillonite clay and carbon nanotubes). V C 2011Wiley Periodicals, Inc. J Appl Polym Sci 123: [3545][3546][3547][3548][3549][3550][3551][3552][3553][3554][3555] 2012

No abstract