food packaging with antimicrobial action against foodborne pathogens and spoilage microorganisms. The authors introduce the concept of active packaging, its different categories, and specific actions, with a dedicated section on the antimicrobial active packaging, its classes, research advances, and regulations. Then, they analyze separately the most studied natural antimicrobial agents, i.e. essential oils and phenolic compounds; organic acids, their salts and anhydrides; bacteriocins and enzymes; and the antimicrobial polymer chitosan, with references of their use as active additives in packaging of food systems. The authors conclude their chapter with the strategies needed for a successful and rapid introduction of active sustainable antibacterial packaging in the food packaging industry. Chapter 13 “Active Antioxidant Additives in Sustainable Food Packaging,” by Thi Nga Tran, deals also with active packaging but in this case with antioxidant activity. The author starts with an introduction to the urgent need of a significant reduction of food losses and wastes, and how protection from oxidation, using packaging systems of biopolymers combined with natural antioxidant substances, could help. The chapter continues with a detailed analysis of the various antioxidant molecules extracted by plants, their combination with biopolymers into active food packaging, and the properties of the obtained packaging systems, including, of course, their antioxidant activity. A particular mention is made to the possibility of using raw dried plants powders, even from agricultural by‐products, as antioxidant fillers into biopolymers for the development of active sustainable food packaging, avoiding the extraction costs. Part IV of the book ends with Chapter 14 “Natural and Biocompatible Optical Indicators for Food Spoilage Detection,” by Maria E. Genovese et al., which presents another very interesting approach in food waste prevention. The authors describe packaging materials with incorporated natural or biocompatible molecules that change their molecular structure, and thus their optical properties, in the presence of food spoilage. Consequently, when a specific food spoilage by‐product is present, the active packaging changes one or more optical properties (i.e. color, spectral absorption, fluorescence) enabling a real‐time and direct naked eye spoilage detection. The authors introduce the factors determining food spoilage, and analyze thoroughly the conventional methods, as well as the most recent portable technologies for on‐site and on‐package detection of the spoilage, together with the functioning principles of these technologies. Then, the authors focus on the description of the various functional components used for the optical and colorimetric spoilage indication usually embedded in a polymeric, most of times natural renewable, support, as well as the specific spoilage by‐product they can detect. A particular emphasis is given on the sensing potential of natural dyes and pigments extracted from plants, i.e. curcumin and anthocyanins, as well as their synthetic counterparts, due to their eco‐friendly nature.
The book closes with Part V “Technological Developments in the Engineering of Biocomposite Materials for Food Packaging Applications,” where Chapter 15 “Biopolymers in Multilayer Films for Long Lasting Protective Food Packaging: A Review,” by Ilker S. Bayer, presents the possibilities that technology provides to take advantage of the various biopolymers and composites combining them in unique solutions for food packaging. Apart from melt extrusion, injection molding, blow molding, and thermoforming, all techniques used broadly in the plastic industry and mentioned in the various chapters of this book, Chapter 15 describes the ways of making multilayer films that can combine the unique properties of the various biopolymer layers into one material. The chapter reviews both multilayer laminates of biopolymers with conventional oil‐derived polymers and all sustainable laminates, based on proteins, polysaccharides, or biopolyesters. The author concludes that multilayer laminates of carefully chosen biopolymers and biocomposites could be the ideal materials for food packaging since they combine sustainability with optimized desired properties due to their unique construction.
Athanassia Athanassiou
Genova, Italy
29 September 2020
References
1 1 Jambeck, J.R., Geyer, R., Wilcox, C. et al. (2015). Plastic waste inputs from land into the ocean. Science: 768–771.
2 2 Data for the year 2018 From ING Economics Department and https://www.statista.com/statistics/282732/global-production-of-plastics-since-1950.
1 Emerging Trends in Biopolymers for Food Packaging
Sergio Torres‐Giner, Kelly J. Figueroa‐Lopez, Beatriz Melendez‐Rodriguez, Cristina Prieto, Maria Pardo‐Figuerez, and Jose M. Lagaron
Novel Materials and Nanotechnology Group, Food Safety and Preservation Department, Institute of Agrochemistry and Food Technology (IATA), Spanish Council for Scientific Research (CSIC), Calle Catedrático Agustín Escardino Benlloch 7, 46980, Paterna, Spain
1.1 Introduction to Polymers in Packaging
According to the Food and Agriculture Organization of the United Nations (FAO), approximately one‐third of all food produced globally is lost or wasted [1]. Food waste is produced throughout the whole food value chain, from the household to manufacturing, distribution, retail, and food service activities. Taking into consideration the limited natural resources available, it is more effective to reduce food waste than to increase food production. For this reason, several efforts have been put for the development of more effective food packaging strategies [2, 3]. Packaging items have become essential to protect food from different environmental conditions. Depending on the type of food, the packaging article can be customized to prevent or inhibit microbial growth, avoid food decomposition by removing the entrance of light, oxygen, and moisture, or even to prevent spoilage from small insects. Additionally, novel packaging items can be monitored to give information about the quality of the packaged food, ultimately diminishing food waste during distribution and transport [4].
Common materials utilized for food packaging include glass, paper, metal, and plastic. The latter are nowadays more frequently used since they have a large availability at a relatively low cost and can display good characteristics for packaging items, such as mechanical strength, barrier properties, and transparency [4, 5]. The most commonly used petrochemical materials for packaging applications can be divided into various families:
Polyolefins and substitutes of olefins, such as low‐density polyethylene (LDPE) and linear low‐density polyethylene (LLDPE), polypropylene (PP), polystyrene (PS), oriented polystyrene (OPS), polyvinyl alcohol (PVOH), polyvinyl chloride (PVC), and polyvinylidene chloride (PVDC). Polyolefins are frequently used in reusable bags, paper cups, and stand‐up pouches, while substitutes of olefins such as PVC are popularly used in cling films and in some prepackaged meals.
Copolymers of ethylene, such as ethylene‐vinyl acetate (EVA) and ethylene‐vinyl alcohol (EVOH), are typically used to make lid films for trays and barrier interlayers.
Polyesters, such as polyethylene terephthalate (PET) and other aliphatic and aromatic polyesters, are mainly used to make water bottles.
Polyamides (PAs) are commonly employed in films or trays for food products that are very sensitive to oxygen.
Most of these materials are made by condensation or addition polymerization of monomers of hydrocarbon or hydrocarbon‐like raw materials, which means that due to their fossil‐based nature and high chemical stability, they are not biodegradable and will accumulate in landfills over the years,