50 research outputs found
Influence of Pectin Structural Properties on Interactions with Divalent Cations and Its Associated Functionalities
© 2018 Institute of Food Technologists® Pectin is an anionic cell wall polysaccharide which is known to interact with divalent cations via its nonmethylesterified galacturonic acid units. Due to its cation-binding capacity, extracted pectin is frequently used for several purposes, such as a gelling agent in food products or as a biosorbent to remove toxic metals from waste water. Pectin can, however, possess a large variability in molecular structure, which influences its cation-binding capacity. Besides the pectin structure, several extrinsic factors, such as cation type or pH, have been shown to define the cation binding of pectin. This review paper focuses on the research progress in the field of pectin-divalent cation interactions and associated functional properties. In addition, it addresses the main research gaps and challenges in order to clearly understand the influence of pectin structural properties on its divalent cation-binding capacity and associated functionalities. This review reveals that many factors, including pectin molecular structure and extrinsic factors, influence pectin–cation interactions and its associated functionalities, which makes it difficult to predict the pectin–cation-binding capacity. Despite the limited information available, determination of the cation-binding capacity of pectins with distinct structural properties using equilibrium adsorption experiments or isothermal titration calorimetry is a promising tool to gain fundamental insights into pectin–cation interactions. These insights can then be used in targeted pectin structural modification, in order to optimize the cation-binding capacity and to promote pectin–cation interactions, for instance for a structure build-up in food products without compromising the mineral nutrition value.status: publishe
The potential of microalgae and their biopolymers as structuring ingredients in food: A review
Microalgae are considered promising functional food ingredients due to their balanced composition, containing multiple nutritional and health-beneficial components. However, their functionality in food products is not limited to health aspects, since microalgae can also play a structuring role in food, for instance as a texturizing ingredient. Photoautotrophic microalgae are actually rich in structural biopolymers such as proteins, storage polysaccharides, and cell wall related polysaccharides, and their presence might possibly alter the rheological properties of the enriched food product. A first approach to benefit from these structural biopolymers consists of isolating the cell wall related polysaccharides for use as food hydrocolloids. The potential of extracted cell wall polysaccharides as food hydrocolloids has only been shown for a few microalgae species, mainly due to an enormous diversity in molecular structure and composition. Nevertheless, with intrinsic viscosities comparable or higher than those of commercial thickening agents, extracellular polysaccharides of red microalgae and cyanobacteria could be a promising source of novel food hydrocolloids. A more sustainable approach would be to incorporate the whole microalgal biomass into food products, to combine health benefits with potential structuring benefits, i.e. providing desired rheological properties of the enriched food product. If microalgal biomass would act as a thickening agent, this would actually reduce the need for additional texturizing ingredients. Even though only limitedly studied so far, food processing operations have been proven successful in establishing desired microstructural and rheological properties. In fact, the use of cell disruption techniques allows the release of intracellular compounds, which become available to create strong particle aggregates resulting in an improved viscosity and network structure. Food processing operations might not only be favorable in terms of rheological properties, but also for enhancing the bioaccessibility of several bioactive compounds. However, this research area is only very scarcely explored, and there is a demand for more standardized research studies to draw conclusions on the effect of processing on the nutritional quality of food products enriched with microalgae. Even though considered as promising food ingredients, some major scientific challenges have been pointed out throughout this review paper for the successful design of microalgal based food products.status: publishe