Alginates in Foods - Practical Food Rheology - page 126

Alginate immobilisation technologies in food processing can enhance
productivity in continuous operations by entrapping cells or enzymes
used in the production and reusing them. Immobilisation technology
is used to produce a wide range of bacterial metabolites, including
enzymes, amino acids, organic acids (e.g. acetic acid) and alcohols
(Brownlee et al. , 2009). For example, alginate immobilisation technol-
ogy can be used in the production of fermented beverages to entrap
and reuse various cell yeast cultures (Navratil et al. , 2002) or in the
dairy industry, where various lactic acid producing bacteria are used as
a starter culture (Champagne et al. , 1994).
The addition of bioactive ingredients to foods is a challenging process
which is on the forefront of food research and development. Difficulties
particularly arise with respect to the stability of the bioactive compounds
during processing, storage and preventing interactions with other ingre-
dients. Alginate encapsulation may have use in the development of such
functional foods. The mild encapsulation process and acid insolubility
of alginate gels offer protection to the encapsulated contents from the
physiological extremes of pH once ingested, thus presenting the po-
tential to deliver fully functional enzymes or live probiotic bacteria to
the intestine. The enteric properties of alginate, in particular, provide
a great advantage when attempting to deliver live bacteria (Lee and
Heo, 2000; Hansen et al. , 2002; Krasaekoopt et al. , 2003; Clark et al. ,
2008) or fully functioning bioactive proteins and peptides (George and
Abraham, 2006) to the intestine.

6.6.5 Texturisation of vegetative materials

Many processed foods contain hydrocolloids, including alginates, which
govern the product's functionality and acceptability (Aguilera, 2005).
Novel structured fruit products are made from pulp and alginate, in
which particulates are embedded in the alginate gel matrix. Sodium
alginate is also used in the production of artificial fruits from sodium
alginate solutions (Nussinovitch, 2003).
Restructured food based on Ca-alginate gels seems to be a steadily
growing application of alginates. The restructuring process is based
on binding together a flaked, sectioned, chunked or milled foodstuff to
make it resemble the original, such as onion rings, pimento olive fillings,
crabsticks and cocktail berries (Draget et al. , 2006b).

6.6.6 Stabiliser

Alginates produce stable gels both at high or low temperatures and at
low pH (Draget, 2000). Therefore, they can be used for a number of
food processing applications as food stabilisers. Ice cream was the first