Microstructure design in mixed biopolymer composites

Abstract:The present study sought to understand how the structure of protein gels impacts lipolysis of gelled emulsions. The selected system consisted of an o/w emulsion embedded within gelatine gels. The gelatine gelled emulsions consisted of a discontinuous network of aggregated emulsion droplets, dispersed within a continuous network of gelatine. The rheology of the gelled emulsions was dominated by the rheological behaviour of the gelatine, at no point was yielding or brittle fracture observed suggesting a gelatine continuous structure rather than a bi-continuous gel. A direct relationship between the speed of fat digestion and gel average mesh size was found, indicating that the digestion of fat within gelatine gelled emulsions is controlled by the gels ability to slow lipase diffusion to the interface of fat droplets. Digestion of fat was facilitated by deposition of the gelatine network, which mainly occurred via surface erosion catalysed by proteases. Overall this work has demonstrated that protein gels can considerably slow the kinetics of lipolysis of gelled emulsions, key for the future development of structures to control fat digestion and or the delivery of nutrients to different parts of the gastrointestinal tract.Introduction:

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“…alginate, agar, agarose) and proteins (e.g. gelatine) are used to design the properties of hydrogel network (45)(46)(47)(48).…”

Section: Introductionmentioning

confidence: 99%

Impact of Protein Gel Porosity on the Digestion of Lipid Emulsions

Sarkar

Juan

Kolodziejczyk

et al. 2015

J. Agric. Food Chem.

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“…Proteins, polysaccharides, and their mixtures are widely used in food products (33) and are known to show phase separation in a certain range of conditions, e.g., at high ionic strength (34). The process of phase separation and the resulting heterogeneous microstructures have extensively been discussed in the literature (see, for example, references 34 and 35).…”

mentioning

confidence: 99%

Effect of Microstructure on Population Growth Parameters of Escherichia coli in Gelatin-Dextran Systems

Boons

Noriega

Broeck

et al. 2014

Appl Environ Microbiol

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Current literature acknowledges the effect of food structure on bacterial dynamics. Most studies introduce this "structure" factor using a single gelling agent, resulting in a homogeneous environment, whereas in practice most food products are heterogeneous. Therefore, this study focuses on heterogeneous protein-polysaccharide mixtures, based on gelatin and dextran. These mixtures show phase separation, leading to a range of heterogeneous microstructures by adjusting relative concentrations of both gelling agents. Based on confocal microscope observations, the growth of Escherichia coli in gelatin-dextran systems was observed to occur in the dextran phase. To find a relation between microscopic and population behavior, growth experiments were performed in binary and singular gelatin-dextran systems and culture broth at 23.5°C, with or without adding 2.9% (wt/ vol) NaCl. The Baranyi and Roberts growth model was fitted to the experimental data and parameter estimates were statistically compared. For salted binary mixtures, a decrease in the population maximum cell density was observed with increasing gelatin concentration. In this series, for one type of microstructure, i.e., a gelatin matrix phase with a disperse dextran phase, the maximum cell density decreased with decreasing percentage of dextran phase. However, this relation no longer held when other types of microstructure were observed. Compared to singular systems, adding a second gelling agent in the presence of NaCl had an effect on population lag phases and maximum cell densities. For unsalted media, the growth parameters of singular and binary mixtures were comparable. Introducing this information into mathematical models leads to more reliable growth predictions and enhanced food safety.

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“…6). Once a particular microstructure has been formed, it is often possible to trap the system in a kinetically stable state, and thus create novel food microstructures and rheological properties (Norton & Frith, 2001). For example, kinetic trapping can be achieved by changing solution or environmental conditions so that one or both of the phases thickens or gels.…”

Section: Biopolymer Particles: Mixed Biopolymer Typementioning

confidence: 99%

“…For example, non-spherical biopolymer particles can be produced by extrusion or molding methods, or by application of shear forces during particle formation (Norton & Frith, 2001;Norton, Frith, & Ablett, 2006). The appearance, rheology, mouthfeel, and release characteristics of colloidal dispersions containing non-spherical particles are often quite different from those containing a similar amount of spherical ones.…”

Section: Biopolymer Particle Propertiesmentioning

confidence: 99%

“…These systems should be prepared from food-grade ingredients using economical and reliable processing operations. One of the most promising approaches to create food-grade colloidal particles is to use biopolymers, such as proteins and polysaccharides, as building blocks (Benichou, Aserin, & Garti, 2002;Burey, Bhandari, Howes, & Gidley, 2008;Chen, Remondetto, & Subirade, 2005;Dickinson, 2003;Malone & Appelqvist, 2003;Norton & Frith, 2001;Sundar, Kundu, & Kundu, 2010). Biopolymer colloidal particles can be assembled from proteins and polysaccharides using various bottom-up and top-down methods, including controlled biopolymer aggregation, segregation, and/or disruption (Aguilera & Stanley, 1999;Benichou et al, 2002;Tolstoguvoz, 2007;van der Goot & Manski, 2007).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Structured biopolymer-based delivery systems for encapsulation, protection, and release of lipophilic compounds

2011

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Available at: https://works.bepress.com/djulian_mcclements/160/ This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. such as u-3 rich oils, conjugated linoleic acid (CLA), oil-soluble vitamins, flavors, colors, and nutraceuticals. This article provides an overview of a number of different approaches that can be used to create structured delivery systems based on biopolymers, including molecular complexation, coacervation, thermodynamic incompatibility, moulding, and extrusion methods. These delivery systems can be produced from food-grade ingredients using simple processing operations (e.g., mixing, homogenizing, and thermal processing). The structure, production, performance, and potential applications of each type of structured delivery system are discussed.

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Microstructure design in mixed biopolymer composites

Cited by 253 publications

References 34 publications

Impact of Protein Gel Porosity on the Digestion of Lipid Emulsions

Impact of Protein Gel Porosity on the Digestion of Lipid Emulsions

Effect of Microstructure on Population Growth Parameters of Escherichia coli in Gelatin-Dextran Systems

Structured biopolymer-based delivery systems for encapsulation, protection, and release of lipophilic compounds

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