Deposition of Pectin/Poly-l-lysine Multilayers with Pectins of Varying Degrees of Esterification

Abstract

The effect of pectin esterification on the assembly of multilayers consisting of poly-L-lysine (PLL) and pectin was studied using surface plasmon resonance (SPR), Fourier transform infrared-attenuated total reflection spectroscopy (FTIR-ATR), and a quartz crystal microbalance with dissipation monitoring (QCMD). With each layer deposited, there was a progressive increase in mass. The net charge of the multilayers was positive and increased with increasing degree of esterification of the pectin. Multilayer fabrication involved a limited fractionation of the pectin preparations, with the more highly esterified pectins having a weaker affinity for PLL. The multilayers were relatively hydrated structures with estimates of solids content in the range 10-32% w/w. The more highly esterified pectins had a tendency to form more hydrated structures, which showed a strong deswelling when PLL was added to a freshly deposited pectin layer.

Polysaccharide-based polyelectrolyte multilayers

“…This was indeed the case for amide modified HA [16] and for quaternized chitosan [17]. Plant derivatives such as carboxymethyl cellulose [18], pectin [19] and its derivatives polygalacturinic acid and furcelan [20] have been successfully used. Animal-derived polysaccharides such as HA [21], CS [22], HEP [23] and mucin [24] are also increasingly investigated for their ability to form PEM films with specific properties.…”

“…For such films, hydration is usually probed by comparing hydrated adsorbed masses measured by Quartz Cristal Microbalance with Dissipation monitoring (QCM-D) and dried masses measured by optical methods such as Surface Plasmon Resonance (SPR), ellipsometry or Fourier Transform Infrared Spectroscopy in Attenuated Total Reflection mode (ATR-FTIR). Water content is reported to be very high, ranging from 70 to 90% in (PLL/ pectin) films [19,37], 60% in (PLL/CSA), ∼90% in (PLL/HA) films [38], 80% for (CHI/HA) [39] and for starch based films [40], 93% for (PLL/ furcellaran) [20] and over 90% for (CHI/mucin) films [41]. In relation to this high hydration, film refractive indices are usually low (∼ 1.38-1.40) for polysaccharide-based films [42].…”

“…Film hydration can vary during film buildup. Indeed, when two oppositely charged polymers complex together, the counterion-polymer and water-polymer bonds are disrupted, which can lead to dehydration of the multilayer film [19]. Several chemical side groups appear to interact with water molecules via hydrogen bonds.…”

Coberturas e Filmes Comestíveis Aditivados de Compostos Bioativos para Conservação de Frutas

“…Esta tecnologia consiste na preparação de coberturas estruturas através da imersão consecutiva do substrato em duas ou mais soluções de revestimento que contêm espécies de carga oposta [58]. Os biopolímeros mais utilizados para formar estas estruturas multicamadas são as poli -l-lisinas, pectinas, alginatos e quitosana [59], [60].…”

Exploiting Plant Innate Immunity to Protect Crops Against Biotic Stress: Chitosaccharides as Natural and Suitable Candidates for this Purpose

“…Many PAMPs fulfill a critical function to the lifestyle of the organism or for penetration and invasion of a host cell and are therefore broadly conserved among diverse microbial pathogens, and are not normally present in the host (Krzeminski et al, 2006). These include lipopolysaccharides of Gram-negative bacteria, peptidoglycans from Gram-positive bacteria, flagellin, protein subunit of the flagellum, glucans, and proteins derived from fungal cell walls (Nurnberger et al, 2004).…”