Abstract:The interest for the development of new active packaging materials has rapidly increased in the last few years. Antimicrobial active packaging is a potential alternative to protect perishable products during their preparation, storage and distribution to increase their shelf-life by reducing bacterial and fungal growth. This review underlines the most recent trends in the use of new edible coatings enriched with antimicrobial agents to reduce the growth of different microorganisms, such as Gram-negative and Gram-positive bacteria, molds and yeasts. The application of edible biopolymers directly extracted from biomass (proteins, lipids and polysaccharides) or their combinations, by themselves or enriched with natural extracts, essential oils, bacteriocins, metals or enzyme systems, such as lactoperoxidase, have shown interesting properties to reduce the contamination and decomposition of perishable food products, mainly fish, meat, fruits and vegetables. These formulations can be also applied to food products to control gas exchange, moisture permeation and oxidation processes.

This review discusses the latest advances in the composition of gelatin-based edible films and coatings, including nanoparticle addition, and their properties are reviewed along their potential for application in the food packaging industry. Gelatin is an important biopolymer derived from collagen and is extensively used by various industries because of its technological and functional properties. Nowadays, a very wide range of components are available to be included as additives to improve its properties, as well as its applications and future potential. Antimicrobials, antioxidants and other agents are detailed due to the fact that an increasing awareness among consumers regarding healthy lifestyle has promoted research into novel techniques and additives to prolong the shelf life of food products. Thanks to its ability to improve global food quality, gelatin has been particularly considered in food preservation of meat and fish products, among others.

Abstract:The most fashionable trends in food packaging research are targeted towards improvements in food quality and safety by increasing the use of environmentally-friendly materials, ideally those able to be obtained from bio-based resources and presenting biodegradable characteristics. Edible films represent a key area of development in new multifunctional materials by their character and properties to effectively protect food with no waste production. The use of edible films should be considered as a clean and elegant solution to problems related with waste disposal in packaging materials. In particular, pectin has been reported as one of the main raw materials to obtain edible films by its natural abundance, low cost and renewable character. The latest innovations in food packaging by the use of pectin-based edible films are reviewed in this paper, with special focus on the use of pectin as base material for edible coatings. The structure, properties related to the intended use in food packaging and main applications of pectins are herein reported.

On the use of tris(nonylphenyl) phosphite as a chain extender in melt-blended poly(hydroxybutyrate-co-hydroxyvalerate)/ clay nanocomposites: Morphology, thermal stability, and mechanical properties J. González-Ausejo, E. Sánchez-Safont, J. Gámez-Pérez and L. Cabedo, J. Appl. Polym. Sci. 2015, DOI: 10.1002 Characterization of polyhydroxyalkanoate blends incorporating unpurified biosustainably produced poly(3-hydroxybutyrate-co-3-hydroxyvalerate) A. Martínez-Abad, L. Cabedo, C. S. S. Oliveira, L. Hilliou, M. Reis and J. M. Lagarón, J. Appl. Polym. Sci. 2015, DOI: 10.1002 Modification of poly (3-hydroxybutyrate-co-3-hydroxyvalerate) ABSTRACT: Active edible films represent one of the current and future trends in the development of new polymers for selected applications, particularly food packaging. Some biopolymers show excellent performance as carriers for active compounds extracted from natural sources and are able to be released at a controlled rate to packaged food. In this review we aim to present, in a comprehensive way, the most recent advances and updates in this subject, where much research is currently ongoing and new studies are reported very often. This review focuses on innovative biopolymer matrices, their processing to obtain edible active films, and present and future applications.

The main directions in food packaging research are targeted toward improvements in food quality and food safety. For this purpose, food packaging providing longer product shelf-life, as well as the monitoring of safety and quality based upon international standards, is desirable. New active packaging strategies represent a key area of development in new multifunctional materials where the use of natural additives and/or agricultural wastes is getting increasing interest. The development of new materials, and particularly innovative biopolymer formulations, can help to address these requirements and also with other packaging functions such as: food protection and preservation, marketing and smart communication to consumers. The use of biocomposites for active food packaging is one of the most studied approaches in the last years on materials in contact with food. Applications of these innovative biocomposites could help to provide new food packaging materials with improved mechanical, barrier, antioxidant, and antimicrobial properties. From the food industry standpoint, concerns such as the safety and risk associated with these new additives, migration properties and possible human ingestion and regulations need to be considered. The latest innovations in the use of these innovative formulations to obtain biocomposites are reported in this review. Legislative issues related to the use of natural additives and agricultural wastes in food packaging systems are also discussed.

26A microwave-assisted extraction (MAE) procedure to isolate phenolic compounds from 27 almond skin by-products was optimized. A three-level, three-factor Box-Behnken 28 design was used to evaluate the effect of almond skin weight, microwave power and 29 irradiation time on total phenolic content (TPC) and antioxidant activity (DPPH). 30Almond skin weight was the most important parameter on the studied responses. The 31 best extraction was achieved using 4 g, 60 s, 100 W and 60 mL of 70% (v/v) ethanol. 32 TPC, antioxidant activity (DPPH, FRAP) and chemical composition (HPLC-DAD-ESI-33MS/MS) were determined by using the optimized method from 7 different almond 34 cultivars. Successful discrimination was obtained for all cultivars by using multivariate 35 linear discriminant analysis (LDA) suggesting the influence of cultivar type on 36 polyphenols content and antioxidant activity. The results showed the potential of 37 almond skin as a natural source of phenolics and the effectiveness of MAE for the 38 reutilization of these by-products. 39

In this study, the effect of different cooking processes (blanching, roasting and frying) on the oxidative stability of almonds under normal storage and accelerated oxidation conditions were investigated. Fried almonds showed higher initial linoleic acid content due to oil frying medium migration to the samples. As oxidation time increased, a different trend in fatty acid composition was obtained depending on the oxidation conditions used. Samples processed at high temperatures presented an initial high PV, resulting in an advanced state of oxidation. A simultaneous formation of hydroperoxides and secondary oxidation compounds was observed in samples under normal storage, presenting raw samples of the lower PV and AV. Lower values of thermal parameters (DSC and TGA) were obtained with increasing oxidation time at 100°C. The most abundant volatile compounds (HS‐SPME‐GC‐MS) present in raw almonds were benzaldehyde, 1,3‐dimethyl‐benzene, 1,2‐dimethyl‐benzene, styrene, 3‐methyl‐1‐butanol, alpha‐pinene and limonene; whereas roasted almonds showed Maillard reaction volatiles such as pyrazines, pyrroles and furans; and fried almonds showed compounds derived from frying oil decomposition (trans,cis‐2,4‐decadienal and trans,trans‐2,4‐decadienal) and higher amounts of aldehydes (hexanal, octanal and nonanal). The generation of hydroperoxides, their degradation and the formation of secondary oxidation products were also investigated by FTIR analysis. Practical applications: Processing of almonds at high temperatures may result in quality deterioration, leading to oxidative rancidity. The studied techniques used in this paper can be useful for processors in order to monitor the oxidative degradation of nuts with storage time and to evaluate their acceptance on the market. In particular, the use of DSC, TGA and ATR‐FTIR could be suitable for studying the shelf life of processed almonds and saving time, which is very precious in quality control. The effect of different cooking processes (blanching, roasting and frying) on the oxidative stability of almonds under normal storage and accelerated oxidation conditions were investigated. Fatty acid composition, primary and secondary oxidation products, thermal parameters, volatiles and lipid degradation were assessed. Results indicate that processing and technological strategies should be used for almond production in order to obtain better oxidative stability and to assure preservation of their overall nutritional profile.

The increasing interest and society demand on the use of natural, biodegradable and renewable resources has increased in the last few years. In addition, food producers and consumers have improved their requirements in the quality of processed food, particularly in the field of increasing shelf-life while preserving organoleptic and nutritional properties. This review aims to present the last published work in this area.