From Classical to Advanced Use of Polymers in Food and Beverage Applications

Abstract

Polymers are extensively used in food and beverage packaging to shield against contaminants and external damage due to their barrier properties, protecting the goods inside and reducing waste. However, current trends in polymers for food, water, and beverage applications are moving forward into the design and preparation of advanced polymers, which can act as active packaging, bearing active ingredients in their formulation, or controlling the head-space composition to extend the shelf-life of the goods inside. In addition, polymers can serve as sensory polymers to detect and indicate the presence of target species, including contaminants of food quality indicators, or even to remove or separate target species for later quantification. Polymers are nowadays essential materials for both food safety and the extension of food shelf-life, which are key goals of the food industry, and the irruption of smart materials is opening new opportunities for going even further in these goals. This review describes the state of the art following the last 10 years of research within the field of food and beverage polymer’s applications, covering present applications, perspectives, and concerns related to waste generation and the circular economy.

Natural and Synthetic Polymers for Biomedical and Environmental Applications

“…These polymers protect against chemical, biological, and physical damage and prevent the loss of flavor, aroma, and antioxidants. They also ensure an adequate balance of gases and humidity inside the packaged food, increasing its shelf life and facilitating its handling [ 41 ].…”

“…Some of the main reviews for natural polymers for biomedical and environmental applications are [ 1 , 6 , 7 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 ] and for synthetic polymers [ 8 , 12 , 22 , 30 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 ].…”

Optical Anisotropy of Polyethylene Terephthalate Films Characterized by Spectral Means

“…Polyethylene terephthalate (PET) is a thermoplastic polymer, a polyester with a partially aliphatic and aromatic structure, that can be amorphous or semi-crystalline [ 1 ], made starting from ethylene and paraxylene, whose derivatives, i.e., ethylene glycol (a diol) and terephthalic acid (a dicarboxylic acid) react in the presence of a catalyst to obtain the PET resin in the shape of long polymer chains. They can be subsequently further stretched by means of several techniques, which improve their crystallinity by accentuating the reciprocal orientation of the molecules, and thus change their properties, not only the optical ones but also others, e.g., the thermal stability improves, but the transparency decreases [ 2 , 3 ].…”

“…Other key features of PET are its low production cost and recyclability [ 3 , 4 ]. Various preparation methods are available for PET films: casting, blowing, and extrusion.…”

“…Commercial PET has a density of 1.41 g/cm 3 , a breaking strength of 50 MPa, a Young's modulus of 1700 MPa, a melting temperature of 265 • C, and a glass transition temperature between 69 and 115 • C, above which PET is highly stiff [4].…”