In the present investigation, emulsifying potential of galactan exopolysaccharide (EPS) extracted from Weissella confusa KR780676 has been evaluated with various food grade flavours (vanilla, cardamom and pineapple). Concentration of EPS was optimized as 1% with these flavours, in addition to the effect of salinity (NaCl), monovalent ion (KCl) and temperature on emulsion activity (EA), and emulsion stability (ES) was also inspected. Filter paper wetting test exhibited water-in-oil-in-water (w/o/w) and oil-in-water (o/w) type emulsions. The extent in granule disintegration and the retrogradation process of flavour emulsions were studied with pasting properties. Electron micrography and particle size analysis revealed the morphology and the size of emulsion droplets. Thermal stability of emulsions has found 100% at various temperatures (−20 to 60 °C) for vanilla and pineapple flavour, whereas, it was varying for cardamom as per the temperature disparity. Emulsion stability of vanilla and pineapple flavour was retained as such for various concentrations of NaCl whereas decreased for cardamom in direct proportion. In case of KCl all the three flavours showed greater stability. These emulsifying properties indicate that galactan EPS can be a prospective alternative to commercial biopolymers in food and pharmaceuticals industries.

Most fossil fuel-derived polymers used for food packaging are non-biodegradable and induce pollution by microplastic, calling for safer material. Here we review microbial production and applications of pullulan, a unique biopolymer produced by fermentation of agro-residues, using a strain named Aureobasidium pullulan. Chemically modified pullulan is widely used in food, pharmaceuticals, biomedical, and cosmetics. Compared to conventional polymers, pullulan increases the tensile strength 6–37-folds and increases the bioadhesion time 72–120-folds. Pullulan has been recently produced from agro-based waste with yields as high as 58-69 g/L.

Hordein electrospun ultra-thin fibers are unstable in an aqueous environment. Chitosan was added to improve their water resistance. With increasing chitosan concentration, the viscosity and conductivity of the biopolymer blends increased, and the surface tensions remained almost constant. The structure and morphology of composite biopolymer fiber membranes showed that the average fiber diameter varied with chitosan concentration. ATR-FTIR spectra showed that the C–H stretching band changed or disappeared with increased chitosan. X-ray diffraction showed that chitosan was distributed in hordein fibers without crystallites. Compared with the hordein nanofibers, thermogravimetric analysis and derivative thermogravimetry curves showed that hordein/chitosan electrospun fibers had slightly decreased thermal stability. In conclusion, a low chitosan content improved the water resistance and other properties of hordein fibers, without changing their morphology or structure.

In this paper we are concerned with adsorption, structure, topography, and dynamic properties (relaxation phenomena and surface dilatational rheology) of food dairy proteins (beta-casein, caseinate, and whey protein isolate, WPI), water-insoluble lipids (monopalmitin, monoolein, and monolaurin) and phospholipids (dipalmitoyl-phosphatidyl-choline, DPPC, and dioleoyl-phosphatidyl-choline, DOPC) at the air-water interface. Combined surface chemistry (surface film balance and static and dynamic tensiometry) and microscopy (Brewster angle microscopy, BAM) techniques have been used to determine the static and dynamic characteristics of these emulsifiers and their mixtures at the air-water interface. The derived information shows that biopolymer (proteins) and low-molecular-weight-emulsifier (LMWE, monoglycerides and phospholipids) type and their mixtures affect the interfacial characteristics of adsorbed and spread films. Important functional differences have been established between proteins, lipids and phospholipids. The static and dynamic characteristics of mixed films depend on the interfacial composition and the surface pressure (pi). At higher surface pressures, collapsed protein residues may be displaced from the interface by LMWE molecules with important repercussions on the interfacial characteristics of the mixed films.

Natural biopolymers have become key players in the preparation of biodegradable food packaging. However, biopolymers are typically highly hydrophilic, which imposes limitations in terms of barrier properties that are associated with water interactions. Here, we enhance the barrier properties of biobased packaging using multilayer designs, in which each layer displays a complementary barrier function. Oxygen, water vapor, and UV barriers were achieved using a stepwise assembly of cellulose nanofibers, biobased wax, and lignin particles supported by chitin nanofibers. We first engineered several designs containing CNFs and carnauba wax. Among them, we obtained low water vapor permeabilities in an assembly containing three layers, i.e., CNF/wax/CNF, in which wax was present as a continuous layer. We then incorporated a layer of lignin nanoparticles nucleated on chitin nanofibrils (LPChNF) to introduce a complete barrier against UV light, while maintaining film translucency. Our multilayer design which comprised CNF/wax/LPChNF enabled high oxygen (OTR of 3 ± 1 cm³/m²·day) and water vapor (WVTR of 6 ± 1 g/m²·day) barriers at 50% relative humidity. It was also effective against oil penetration. Oxygen permeability was controlled by the presence of tight networks of cellulose and chitin nanofibers, while water vapor diffusion through the assembly was regulated by the continuous wax layer. Lastly, we showcased our fully renewable packaging material for preservation of the texture of a commercial cracker (dry food). Our material showed functionality similar to that of the original packaging, which was composed of synthetic polymers.

In the present study, a well-defined set of chitosans, with different degrees of acetylation (DA) and degrees of polymerization (DP), were processed by solution electrospraying from a water-based solvent. The solution properties, in terms of surface tension, conductivity, viscosity, and pH, were characterized and related to the physico-chemical properties of the chitosans. It was observed that both DA and DP values of a given chitosan, in combination with biopolymer concentration, mainly determined solution viscosity. This was, in turn, the major driving factor that defined the electrosprayability of chitosan. In addition, the physico-chemical properties of chitosans highly influenced solution conductivity and results indicated that the chitosan solutions with low or low-to-medium values of conductivity were the most optimal for electrospraying. The results obtained here also demonstrate that a good process control can be achieved by adjusting the working conditions, i.e . applied voltage, flow-rate, and tip-to-collector distance. Finally, it was also shown that electrosprayability of chitosan with inadequate physico-chemical properties can be improved by solution mixing of very different kinds of this polysaccharide. The resultant electrosprayed submicron chitosan capsules can be applied for encapsulation of food additives and to develop bioactive coatings of interest in food packaging, where these particles alone or containing functional ingredients can be released from the package into the food to promote a health benefit.

This review article demonstrates fundamentals regarding the manufacturing of multilayer oil-in-water (M-O/W) emulsions and factors affecting stability of these systems. Moreover, characteristics of major bioactive lipophilic components and ingredients mostly applied to form multilayered membranes as well analytical methods used to examine properties of M-O/W emulsions are specified. It has been shown that production of M-O/W systems is based on the layer-by-layer (LbL) electrostatic deposition technique which makes use of the electrostatic attraction of oppositely charged surfactants and biopolymers to form multicomposite protective layers around emulsion droplets. Finally, limitations regarding studies of M-O/W systems which should be developed are specified.

This review article demonstrates fundamentals regarding the manufacturing of multilayer oil-in-water (M-O/W) emulsions and factors affecting stability of these systems. Moreover, characteristics of major bioactive lipophilic components and ingredients mostly applied to form multilayered membranes as well analytical methods used to examine properties of M-O/W emulsions are specified. It has been shown that production of M-O/W systems is based on the layer-by-layer (LbL) electrostatic deposition technique which makes use of the electrostatic attraction of oppositely charged surfactants and biopolymers to form multicomposite protective layers around emulsion droplets. Finally, limitations regarding studies of M-O/W systems which should be developed are specified.

Biopolymers of gellan gum (G), 2-hydroxyethyl cellulose (HEC), and lignin (L)-based binary and ternary sustainable composites were prepared for food packaging and biomedical application. The composite films were flexible and transparent or translucent with slight brown in color. The incorporation of lignin considerably improved the thermal and mechanical and hydrophobic properties of the composite films. The addition of 10 wt% of lignin to the composites increased the tensile strength by 54.3% and 59.2% respectively. The prepared lignin-based composite films showed high ultraviolet (UV) protection, with almost 100% protection against UVB (280–320 nm) and 90% against UVA (320–400 nm). The surface hydrophobicity of the composite films increased with the addition of lignin. The binary and ternary composites containing 1, 5, and 10 wt% lignin exhibited excellent radical scavenging activities. The gellan gum/HEC/lignin based composite films achieved the best biocompatibility. The obtained composites showed efficient antioxidant and non-cytotoxic activities, although there was no remarkable antimicrobial activity.

Green chemistry or in other words “green world” is referred to a sustainable environment using biocompatible, biodegradable, renewable, economical, and simple materials, and methods. Without any exaggeration, the exceptional chemical and physical properties of ZnO bionanocomposites beside various utilizations, make it vital materials in research and green chemistry field. Biocompatible ZnO nanoparticles with fascinating antimicrobial, physicochemical, as well as photocatalytic performance could be applied as a prominent candidate to reinforce diverse biopolymer matrixes, for instance, chitosan, starch, cellulose, gelatin, alginate, poly(hydroxyalkanoates), carrageenan, and so on. With a combination of advantageous properties of these materials, they could be illustrated specific utilizations in different areas. In this regard, the following context focuses on highlighting the recent achievements of this category of material on three important and widely used scopes: eco-friendly food packaging, biomedical specially wound dressings, and water remediation technologies.