No abstract

Unripe banana flour and starch were used to formulate plasticized banana-based films (flour film, PBF; starch film, PBS) with two types of plasticizers (glycerol, Gly; sorbitol, Sor) and a mixture of GlySor on film properties. PBS showed greater water barrier, elongation at break, toughness, and transparency, but lower efficiency in heat sealability than PBF. However, the easier and a higher yield in the preparation process of PBF lead to higher UV and visible light barrier than PBS which could be due to its protein content and the presence of phenolic compounds in PBF. Both banana films plasticized with Sor showed high glossiness, high efficiency in heat sealability, and mechanical and water barrier properties; however, the undesirable recrystallization of white crystals resulted in lower film flexibility. Thus, Gly-Sor was preferred without change of water barrier but strengthened heat sealability. Therefore, banana-based film might be considered as a green food packaging material. Practical applicationsBanana flour and starch from unripe bananas can be used as safe food ingredients for food products and as green biodegradable packaging materials. Banana flour film showed similar mechanical properties as banana starch film but involved easier processing and higher yield in the preparation of banana flour. Moreover, banana flour films had higher efficiency in heat sealability with the potential to protect the packed food from UV-visible light deterioration. Furthermore, an easier way to modify proper film properties is by the proper selection of the plasticizer. A mixture of plasticizers (glycerol and sorbitol) showed high potential to improve long-term physical stability such as through UV-visible light prevention, and improved mechanical properties and heat sealability of plasticized banana-based films. Briefly, plasticized banana flour film with a mixture of plasticizer will be potential, alternative biodegradable packaging material to reduce the use of nonbiodegradable synthetic plastic materials in food applications. | M A TE RI A L S A ND M E TH ODS | MaterialsGreen banana (Musa sapientum Linn cv. Kluai Namwa) was obtained at 112-116 days after petal fall from an orchard of Kasetsart University, Khamphaengsaen Campus, Nakhonpathom, Thailand. Banana flour and starch were prepared according to Sothornvit and Pitak (2007) and Orsuwan and Sothornvit (2015), respectively. The proximate composition of the banana flour powder was: 7.9 6 0.2% moisture content, 85.9 6 0.4% starch, 3.1 6 0.2% protein, 0.3 6 0.1% fat, 1.8 6 0.1% ash, 1.0 6 0.1% crude fiber, and 19.6 6 0.1% amylose content. The proximate composition of the banana starch powder was: 8.7 6 0.0% moisture content, 88.6 6 0.3% starch, 1.6 6 0.3% protein, 0.2 6 0.1% fat, 0.2 6 0.0% ash, 0.6 6 0.0% crude fiber, and 13.3 6 0.1% amylose content. Sodium chloride (NaCl) was purchased from WVR International Ltd. (Poole, England). Glycerol (Gly) and sorbitol (Sor) were purchased from Ajax Fine Chemicals (Sydney, NSW, Australia). | Plasticized banana-base...

No abstract

No abstract

Silver nanoparticles (Ag-NPs) were synthesized using banana powder as a reducing and stabilizing agent, and banana/Ag-NPs composite films with different concentration of Ag-NPs were prepared simultaneously. The composite films were yellowish brown and exhibited characteristic plasmon resonance peak of Ag-NPs at 430 nm. The optical, mechanical, water vapor barrier, thermal stability, and antimicrobial properties of the composite films were greatly influenced by the concentration of Ag-NPs. The composite film with a silver concentration of 1.0 mM demonstrated the highest tensile strength, thermal stability, transparency, and water contact angle with the lowest water vapor permeability (1.36 ± 0.10 9 10 -9 g m/m 2 Pa s). Also, the composite films incorporated with 1.0 mM of Ag-NPs exhibited a strong antibacterial activity against both Gram-positive (Listeria monocytogenes) and Gram-negative (Escherichia coli) food-borne pathogenic bacteria.