Crosslinked electrospun zein-based food packaging coatings containing bioactive chilto fruit extracts

peer-reviewedIn this work, zein fibers loaded with phenolic-enriched extracts from pulp, seed and skin of orange chilto were collected on polyhydroxyalkanoate (PHA) films through the electrospinning technique, for their potential use as bioactive internal coatings for food packaging applications. The zein fibers were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA). The water stability of the zein fibers was improved by crosslinking with glutaraldehyde vapors. The encapsulation efficiency of all bioactive phenolic-enriched extracts was greater than 90%. Encapsulation in the zein fibers improved the thermostability of the extracts. Two food simulants (50% ethanol and 3% acetic acid) were used to evaluate the release of the extracts from the crosslinked zein fibers. It was observed that crosslinking delayed the release of phenolic compounds (rosmarinic acid, caffeic acid and its derivates) in both solvents (80% released after 7 days of contact in 50% ethanol and 23 days in 3% acetic acid) and their antioxidant properties were kept. Therefore, this work demonstrates the potential of the developed zein-based encapsulation structures containing chilto extracts to be applied as antioxidant coatings in food packaging structures to contribute to the preservation of both hydrophilic and lipophilic food products

Dietary polyphenols bind to potato cells and cellular components

The ability of phenolic compounds to bind to dietary polysaccharides such as starch and plant cell wall components impacts their nutritional value. Here, we report interactions between potato cells and three different phenolic compounds (+)-catechin, phloridzin and vanillic acid. The binding interactions of the phenolic compounds with intact potato cells, as well as disrupted cells, cooked cells, isolated cell walls and starch granules was explored varying polyphenol concentration, pH and incubation time. Results showed that binding capacity depends on the type of phenolic compound ((+)-catechin > phloridzin > vanillic acid) as well as the type of substrate, to a maximum of similar to 50 mu molig (dry weight). The observed differences (p < 0.05) were ascribed to the amount and accessibility of potential binding sites in both the phenolic compounds and the polysaccharides. Remarkably, polyphenols could penetrate intact cells and bind the starch within them, suggesting their potential as delivery vehicles, whose loading capacity more than doubled after cooking. (C) 2017 Elsevier Ltd. All rights reserved

The type of gum arabic affects interactions with soluble pea protein in complex coacervation

peer-reviewedComplex coacervation is an encapsulation process involving two oppositely charged biopolymers. Since different compositions of gum arabic may affect its interaction with protein, we studied the complex coacervation of two types of gum arabic (GA) (Acacia senegal-GA1 and Acacia seyal-GA2) with soluble pea protein (SPP) through Zeta potential, turbidity, morphology, the secondary structure of SPP, UV/vis absorbance and thermodynamic parameters. The maximum formation of coacervates occurred at SPP:GA 3:1 (w/w) and pH 3.5–4.0 with changes in the secondary structure of SPP. GA1 combination resulted in higher binding constant, implying a stronger affinity between SPP and GA1. Entropy of 0.7 and 0.5 kJ/mol.K, and enthalpy of −151 and −95.5 kJ/mol were obtained for SPP:GA1 and SPP:GA2. The complex coacervation was spontaneous as proved by the negative values of the Gibbs free energy. GA1 resulted in stronger interactions with SPP, offering new alternatives for encapsulation of bioactive compounds.TEAGAS