Synergistic Effect of Oleic Acid and Glycerol on Zein Film Plasticization

Abstract

Oleic acid and glycerol are two different molecules with different plasticization mechanisms, and their effects on the mechanical properties of zein film were investigated. The mechanical parameters of tensile strength (TS) and elongation to break (E) were improved by either oleic acid or glycerol in a dose-dependent manner up to 20%. When a combination of the two plasticizers in different ratios was used to make zein films, the highest TS was observed at a ratio of 3:1 of oleic acid to glycerol, and a synergy between them was revealed through a statistical analysis. A significant decrease of glass transition temperature (Tg) and different microscopic patterns examined by scanning electronic microscopy (SEM) indicate the supramolecular structure was changed by the plasticizers. A combination of plasticizers with different plasticization mechanisms might be a better way to synergistically improve the mechanical properties of biopolymer-based films for practical applications.

Zein-based films and their usage for controlled delivery: Origin, classes and current landscape

“…The ideal plasticizer should be miscible and compatible with zein, and can reduce the T g of zein without negative effects on film barrier properties. In some cases, the combination of several plasticizers, such as oleic acid/glycerol and glycerol/poly(propylene glycol), is required to improve zein film properties through their synergistic effects [25,34,35]. In addition, plasticizers should satisfy regulations for pharmaceutical additives, and toxic and non-biodegradable plasticizers should be avoided.…”

Preparation of robust polyamide microcapsules by interfacial polycondensation ofp-phenylenediamine and sebacoyl chloride and plasticization with oleic acid

“…This fact can potentiate its positioning at the water/oil interface, and facilitate incorporation of the aliphatic chain in the capsule wall during polymerization. Use of fatty acids, namely oleic acid and fatty acid derivatives as plasticizers for zein, chitosan and PVC has been discussed before in the literature (Srinivasa et al, 2007;Xu et al, 2012;Fenollar et al, 2013). Figure 9 shows representative SEM images of microcapsules obtained when oleic acid was added to the organic phase at different percentages.…”

Extração de zeína e sua aplicação na conservação dos alimentos

“…Colaborando com sua potencialidade, a adição de nanopartículas aos filmes exibe propriedades superiores, como maior resistência, maior estabilidade térmica e oxidativa, melhor barreira a gases e à água (TAVARES et al, 2012). A incorporação de ácidos graxos, a exemplo do ácido oleico, como plastificante, produz filmes flexíveis, homogêneos, transparentes e de boa aceitação (XU et al, 2012;FORATO et al, 2013). Resultados desta aplicação apresentaram diminuição da perda de massa em maçãs, devido à menor perda de água e trocas gasosas (SCRAMIN et al, 2007).…”