Sustainable Bioactive Packaging Based on Thermoplastic Starch and Microalgae

Abstract

This study combines the use of corn starch and Tetradesmus obliquus microalgae for the production of antioxidant starch films as flexible packaging material. Starch was plasticized with glycerol and blended with 1 w% polyallylamine chosen as an agent to modify the film physical properties. The addition of polyallylamine improved film water stability and water vapor transmission rate as well as mechanical stiffness and tenacity. The dried Tetradesmus obliquus microalgae, which showed an EC50 value of 2.8 mg/mg DPPH (2.2-Diphenyl-1-picrylhydrazyl radical), was then used as antioxidant filler. The addition of microalgae provided the films with good antioxidant activity, which increased with microalgae content increasing. To our knowledge, this is the first study reporting the development of sustainable bioactive packaging films composed of almost 100% starch, and follows the European union’s goals on plastics strategy concerning the promotion of bio-based, compostable plastics and the setting up of approaches to prevent food waste with a simple plastic packaging.

Microalgae Biorefinery: Optimization of Starch Recovery for Bioplastic Production

“…To determine surface wettability of the film, the static contact angle was evaluated by depositing a drop of water onto the film surface, and a picture was captured. The resulting image was processed by Software Motic Image Plus 2.0 ML to determine the contact angle as previously described . Mechanical properties like tensile strength (σ), Young’s modulus ( E ), and elongation at break (ε) of films were determined by tensile tests by using an ISTRON 4502 instrument (Instron Inc., Norwood, MA).…”

“…The resulting image was processed by Software Motic Image Plus 2.0 ML to determine the contact angle as previously described. 36 Mechanical properties like tensile strength (σ), Young's modulus (E), and elongation at break (ε) of films were determined by tensile tests by using an ISTRON 4502 instrument (Instron Inc., Norwood, MA). For analysis, films were cut into rectangular specimens with a known size and were fixed between two Instron flat plates.…”

Ion-Modified Starch Film Enables Rapid Detection of Spoiled Fruit Juices

“…The distorted vibrational absorption peak of -OH appeared at 1333 cm −1 [ 30 ]. The stretching vibration absorption peak of C-O appeared at 992 cm −1 , and the vibration absorption peak of the C-C skeleton appeared at 850 cm −1 [ 31 ]. As observed in Figure 5 b, the addition of AgNO 3 solution enhanced the -OH peak intensity but did not change the functional group type of the starch film.…”

Short-Term Stability of Electrochemical Properties of Layer-by-Layer Coated Heterogeneous Ion Exchange Membranes

“…The third component was a single layer of polyamine adsorbed from the dispersion— in one case this was polyallylamine (purchased from Merck KGaA, Darmstadt, Germany; the resulting membrane is denoted as MK-40-M-PAH) and in the other case it was polyethylenimine (purchased from Merck KGaA, Darmstadt, Germany; the resulting membrane is denoted as MK-40-M-PEI). Polyallylamine is used for layer-by-layer assembly [ 39 ] as a component of new promising materials (such as thermo-responsive polymers with cleavage-induced phase transition [ 40 ] or coatings decomposing by application of electric potential [ 41 ]), including biomedical applications such as creation of nano-capsules for drug delivery [ 42 ] and food packaging [ 43 ]. Polyethylenimine is frequently used as a polymer carrier [ 44 ] and basis for loading of nanoparticles [ 45 ] or coating for medical applications [ 46 ].…”