Gels as Precursors of Porous Matrices for Use in Foods: a Review

Gelation is a structuring mechanism commonly used in foods to produce soft and homogeneous structures. Techniques applied in other areas of science (e.g., bioengineering, biotechnology and electronics) aims at producing wet and dried porous gel matrices and they may find applications in foods. This review describes several processes to manufacture porous structures such as scaffolding, ice templating, use of porogens, oleogelation, incorporation and entrapment of bubbles, enzymatic modifications, microfluidics and microfabrication techniques, among others. Several examples are also presented. Beyond textural properties, porous gels and sponges may be tailored in their mass transfer characteristics to achieve specific rates of release of bioactive molecules, nutrients and flavors.