Encapsulation of colorants by natural polymers for food applications

Abstract

Product appearance is an important factor for consumers when determining the quality of a product, and colour is one of the most important factors which contribute to product appearance. Currently, the safety and consumer acceptance of some colorants used in food products, such as titanium dioxide and some synthetic colorants, are under discussion. Therefore, new ways to use natural colorants as alternatives to these suspect colorants for future applications are being investigated. A promising method for increasing the applicability of the often sensitive natural colorants is the encapsulation of these colorants in colloidal particles by natural polymers such as carbohydrates, lipids and proteins. In recent years, micro-and nano-encapsulation have increasingly been used for various purposes concerning several food properties such as colour, flavour and micronutrient content. This technique results in improved stability for the often sensitive natural colorants and presents the possibility of entrapping water-insoluble colorants for improved use in an aqueous system. This paper reviews the main methods that are used for encapsulation by natural polymers, discusses the different types thereof that are used for encapsulation of colorants, and provides a short overview of natural colorants successfully encapsulated in these natural polymers.

Photo-stability of lutein in surfactant-free lutein-zein composite colloidal particles

“…1a and b). This effect on the particle size was found to be statistically significant and was possible to obtain similar sizes when the same synthesis parameters were used, which corresponds to earlier findings (de Boer et al, 2019a, de Boer et al, 2019b, de Boer et al, 2018). Note that due to the relatively small particle sizes and low concentration of zein, the dispersions are nearly transparent but colored (see Section 3.4 for an example).…”

“…A natural colorant must be stabilized using methods that are recognized as natural, such as encapsulation, if it is to continue to be termed natural (Wissgott & Bortlik, 1996). Encapsulation of sensitive natural pigments can offer a solution by embedding it in a protective matrix or by creating a barrier between the pigment and the environment (de Boer et al, 2019a, de Boer et al, 2019b, Steiner et al, 2018). Additional benefits of encapsulation are that potential off-flavors may be masked by the biopolymer encapsulant (Yousuf et al, 2016) and that other ingredients such as stabilizers (examples include: sodium caseinate, Tween 80, Pluronic F68, Pluronic F127, Span 80 and lecithin) (Cheng and Jones, 2017, Farris et al, 2017, Paliwal and Palakurthi, 2014, Podaralla and Perumal, 2012) can be co-encapsulated.…”

The Realm of Microbial Pigments in the Food Color Market

“…Stability against light, pH, temperature, UV radiation, and food matrices is an important issue with regard to the suitability of a microbial pigment for industrial applications and strategies like microencapsulation, nanoemulsion, and nanoformulations have been suggested for this purpose (Sen et al, 2019). In encapsulation solids, liquids, or gaseous materials are packaged in matrices (encapsulants) which sustain and release their contents under specific conditions (de Boer et al, 2019). The technique offer multiple advantages such as protection against light, moisture, or heat and also increase the brightness of the natural colorants and enhance their stability for many industrial applications (de Boer et al, 2019).…”

“…In encapsulation solids, liquids, or gaseous materials are packaged in matrices (encapsulants) which sustain and release their contents under specific conditions (de Boer et al, 2019). The technique offer multiple advantages such as protection against light, moisture, or heat and also increase the brightness of the natural colorants and enhance their stability for many industrial applications (de Boer et al, 2019). The commonly used techniques for encapsulating colorants are spray-drying, electrospraying and anti-solvent precipitation (de Boer et al, 2019).…”

“…The technique offer multiple advantages such as protection against light, moisture, or heat and also increase the brightness of the natural colorants and enhance their stability for many industrial applications (de Boer et al, 2019). The commonly used techniques for encapsulating colorants are spray-drying, electrospraying and anti-solvent precipitation (de Boer et al, 2019). A number of reports are available on the microencapsulation of microbial pigments and their enhanced applicabilities.…”