Effect of beet flour on films made from biological macromolecules: Native and modified plantain flour

Abstract

Biological macromolecules such as starches of different amylaceous sources have been used in the for-mulation of edible films. However, there are few studies aimed at evaluating edible and intelligent filmswith response to pH changes from natural pigments, this despite the importance of these materials. Inthis context, films from native and modified plantain flour, plasticized with glycerol, with or withoutthe addition of beet flour were developed. The chemical and structural composition of the flours, and itsincidence on thickness, water solubility, contact angle, and mechanical and microstructural propertieswere evaluated, thus as its response to pH changes of the developed films. The observations showed thatthe incorporation of beet flour allowed to obtain intelligent films front to pH changes alkaline. Likewise,the betalains that were found in beet flour interacted more efficiently with the phosphated plantainflour, limiting well its immediate response to pH changes. In the same way, proteins and sugars of beetflour allowed to obtain more flexible films, due to the hydrogen bond interactions between these con-stituents and the plantain flours. This latter could justify the decrease of contact angle, and the increaseon thickness and solubility of these films.