Nanoscale properties of biopolymer multilayers

Abstract

Layer by Layer (LbL) deposition is a simple and inexpensive method of multilayer self-assembly, that relies on the electrostatic interactions of oppositely charged polyelectrolytes. Functional biopolymers used to build such nanostructured multilayers can keep serving their inherent functions in food systems. A good example is chitosan, a positively charged biopolymer which has antimicrobial properties and forms stable complexes with negatively charged polymers. This study investigates the potential of commercially available food grade biopolymers to substitute synthetic polyelectrolytes when building nanostructured multilayers. Chitosan molecular weight, carrageenan charge density and pectin degree of esterification and amidation was varied to investigate their respective effects on the nanoscale morphology and wettability of these surfaces. Extracellular Ice Nucleators (ECINs), functional lipoglycoproteins of negative charge known to increase ice nucleation temperatures in food systems, were used to confirm the suitability of biopolymer multilayers for fabricating functional food grade nano-thin films. High molecular weight chitosan and iota-carrageenan created the most appropriate biopolymer pair to serve this purpose, as demonstrated by the nanoscale evaluation of these ultra-thin layers. ECINs successfully adsorbed onto the multilayer system, and ice nucleation activity of the nano-thin film was confirmed via the cooling bath experiments.

Development of bionanocomposites of pectin and nanoemulsions of carnauba wax and neem oil pectin/carnauba wax/neem oil composites

“…In addition, pectin is easily available and cheap due to it is a byproduct or waste product of fruit juice manufacture . Gezgin et al reported that pectin properties vary with the degree of methyl esterification, being classified as high methyl esterification pectin (HDM) or low methyl esterification pectin. Thus, it has several applications due to its gelling agent capacity, besides to be biocompatible, biodegradable, and nontoxic.…”

Effect of whey protein isolate addition on thermoplasticized pectin packaging properties

“…Its main commercial sources are peel and pulp of citrus fruits and apples, due to the fact that it is a byproduct of the production of juices and jams (Chakravartula et al, 2019;de Castro e Silva et al, 2020;Kadzi nska, Janowicz, Kalisz, Bry s, & Lenart, 2019;Naik, Rawson, & Rangarajan, 2020;Syarifuddin, Manggala, Dirpan, & Laga, 2019). Gezgin, Lee, and Huang (2017) reported that pectin has several properties according to the degree of methyl esterification, being classified as low methylesterification pectin (LMP) or high methylesterification pectin (HMP). The various properties provide various applications as a gelling, thickener, and stabilizer in the food and pharmaceutical industries (Assadpour, Jafari, & Maghsoudlou, 2017;de Castro e Silva et al, 2020;Lin et al, 2020).…”

AFM imaging of extracellular ice nucleators

“…A similar work on ice propagation had been conducted using the layer by layer (LbL) deposition of polyelectrolyte pairs PSS/poly(allylamine hydrochloride) (PAH) and PSS/PDDA without using ECINs, where authors concluded that ice propagation can be tuned by modifying the outermost polymer layer (Jin, He, Guo, & Wang, 2017), which in fact was performed in our above cited work by adding a single layer of ECINs on the PSS/PDDA multilayers. We have also demonstrated the potential to fabricate the same using food grade charged biopolymers such as chitosan, carrageenan, and pectin (Gezgin, Lee, & Huang, 2017). Tuning of ice nucleation using ionic polyelectrolyte multilayers such as poly[2‐(methacryloyloxy)‐ethyltrimethylammonium] (PMETA) and anionic poly(3‐sulfopropylmethacrylate) (PSPMA) brush surfaces (He et al., 2016), as well as polyvinyl alcohol (PVA) layers (Wu et al., 2019) have also been reported.…”