Rheological and structural characterization of carrageenan emulsion gels

Abstract

Carrageenan emulsion gels containing sunflower oil were prepared using three different commercial carrageenan grades (κ-C, ι-C and λ-C). The effect of the carrageenan and salt content, as well as the oil:water ratio, on the emulsion gel strength was evaluated through a response surface methodology. Moreover, the rheological properties and the micro-and nanostructure from the stronger emulsion gel formulations were investigated and compared to their analogous hydrogel formulations. Interestingly, emulsion gels formed stronger and more thermally stable networks than the hydrogels, being this effect more evident in ι-C and λ-C. The results indicate that this was mainly due to a polysaccharide concentration effect, as no evidence of interactions between the carrageenan and the oil phase was found. Consequently, the rheological behaviour of the emulsion gels was mostly determined by the type of carrageenan. The association of carrageenan molecular chains was favoured in κ-C and λ-C (due to the presence of κ-carrageenan in the latter) and promoted by the addition of KCl. In contrast, a lower degree of chain association, mostly driven by ionic cross-linking, took place in ι-C. These results evidence the relevance of the gelation mechanism on the properties of emulsion gels and provide the basis for the design of these systems for targeted applications within the food industry.

Rheology, Microstructure, and Storage Stability of Emulsion-Filled Gels Stabilized Solely by Maize Starch Modified with Octenyl Succinylation and Pregelatinization

“…Many researchers have recently striven to develop food emulsions stabilized by biopolymers, such as proteins, polysaccharides, and their complexes [ 2 , 3 ]. When biopolymers are applied as emulsion stabilizers, they act as emulsifiers, weighting agents, and reducing coalescence by coating oil droplets [ 4 , 5 , 6 ]. However, some fluid emulsions are thermodynamically unstable systems that tend to revert to separate water and oil phases over time via coalescence, flocculation, Ostwald ripening, and gravitational separation [ 7 ].…”

“…Fats play an important role in food processing; however, they also contain high amounts of saturated fatty acids, which have adverse effects in several health conditions, such as obesity, cancer, and cardiovascular diseases [ 12 ]. Consequently, the food industry is actively seeking alternatives to replace, at least partially, saturated and trans fats in products, such as dairy and processed meats, while preserving their original organoleptic attributes as much as possible to ensure consumer acceptance [ 4 ]. The use of synthetic polymers such as polyvinyl alcohol and polysiloxanes as oil structuring agents has been reported, but due to their synthetic nature, these compounds are not accepted as edible matrices [ 13 ].…”

“…The use of synthetic polymers such as polyvinyl alcohol and polysiloxanes as oil structuring agents has been reported, but due to their synthetic nature, these compounds are not accepted as edible matrices [ 13 ]. As an alternative, natural compounds such as proteins [ 3 , 14 , 15 , 16 , 17 ] and polysaccharides [ 4 , 18 , 19 ] are being studied as gelling agents for food-grade emulsion-filled gels. However, mimicking the rheological and textural properties of solid fats using emulsion-filled gels is not trivial, and many factors, such as the physicochemical properties of the gelling matrix, interactions between matrix and oil phases, and oil volume fraction, have an impact on the textural and rheological properties of the product [ 20 , 21 , 22 , 23 ].…”

Recent developments and prospects in the composition, extraction, stability, delivery system, digestion and food applications of plant oil bodies

“…Emulsion-gel is a typical semi-solid food system consisting of gel matrix filled with oil/fat droplets (Dickinson, 2012). Proteins such as gelatin, soy protein, casein and polysaccharides such as starch, carrageenan, pectins, alginate and flax gum are the most recently used as the matrix (Bi, Chi, Wang, Alkhatib, Huang & Liu, 2021;Dickinson, 2012;Fontes-Candia, Ström, Lopez-Sanchez, López-Rubio & Martínez-Sanz, 2020;Hu, Karthik & Chen, 2021;Li, Gong, Hou, Yang & Guo, 2020;Saavedra Isusi, Madlindl, Karbstein & van der Schaaf, 2020). Emulsion-gels have broad application prospects in food industry such as fat reduction, probiotics release and flavor control due to their diversity in structure and composition (Lin, Kelly & Miao, 2020).…”

Sensory and Physicochemical Characteristics of Manyung (Arius thalassinus) Kekian High Fiber with the Addition of Eucheuma cottonii Seaweed

“…The Eucheuma sp. contains carrageenan, which works as a gelling agent (Nur Fatin Nazurah and Nur Hanani, 2017;Fontes-Candia et al, 2020). Some researchers have used Eucheuma to be developed into noodles (Halimah et al, 2016), pasta (Firdaus et al, 2017) and jelly candy (Ismawati et al, 2019).…”