Current+innovation+in+Gums+and+Stabilizers

__ The Challenges Ahead __

Leatherhead Food International, Surrey, U.K., recently conducted a survey in which its members identified key trends, technologies and issues impacting ingredient manufacturers and food processing companies over the next five years. New tastes and textures, shelf life extension, faster processing, functional foods and nutritional science are identified as important areas presenting challenges and opportunities for ingredient and food product innovation. Some of these issues are traditional. For example, the food industry always has had concerns about product quality, shelflife, convenience of use, and economics of manufacture.

More recent challenges reflect concerns consumers have in relation to religion and culture, health and nutrition, and safety. Religious and cultural concerns lead to an increased demand for non-animal products and, in particular, by-products with no pork in them. This generates a market for gelatin alternatives. Because of the nature of polysaccharide gelling agents, finding suitable replacements for gelatin seldom is easy.

Additionally, health and nutrition concerns generate new markets for low-fat and low-calorie foods, and for products containing nutritional supplements. These products have specific requirements for functional ingredients.

Gelling hydrocolloids have their own characteristic texture profiles. In some cases, these textures can be modified and extended by interaction with other hydrocolloids. The best-known example of a co-gelling polysaccharide is locust bean gum, which interacts by association with helical polysaccharides including agar-agar, carrageenans and xanthan gum. Such complex polysaccharide gelling systems improve structural stability and modify elastic properties that make them particularly useful and economical.

Gel structures and associated textures can further be improved and extended by controlling molecular weight distribution. Leatherhead Food International is pursuing this approach by investigating complex gels based on mixtures of locust bean gum with both agar and alginate.

Molecular weight distribution is controlled by partial hydrolysis. Interactions between locust bean gum and hydrolyzed agar fractions generate complex gels networks based on both agar galactan and locust bean galactomannan chains. For short-chain, non-gelling agars, these complex gels are based only on locust bean galactomannan chains. Generally, locust bean gum extends the elasticity and break strength of agar gels, while improving water-holding capacity.

Locust bean gum has the opposite effect on the properties of calcium alginate gels, elasticity being reduced with little change in break strength. This shortening of texture occurs with a range of hydrolyzed alginate fractions, indicating that locust bean gum interferes with the formation of the calcium alginate gel but does not form a part of the mixed gel network. Reduced elasticity is beneficial since calcium alginate gels tend to be elastic and rubbery in texture. Locust bean gum also improves the stability of calcium alginate gels and reduces syneresis.

Molecular weight control through partial hydrolysis can also assist in the processing of polysaccharide gelling agents. For agars, partial hydrolysis reduces dispersion temperatures resulting in easier, more economical processing. Sugar compatibility is improved and confectionery processing is facilitated. In the case of alginates, partial hydrolysis moderates the reactivity towards calcium ions and extends the setting time. This facilitates processing and helps to produce homogeneous gels without “fish-eyes.”