Engineer carbohydrate functionality into foods.

Low-molecular-weight carbohydrates and plant and microbial polysaccharides have an impact on product quality because of their influence on processability, stability, texture and flavor release. Food polysaccharides also have health implications for the gastrointestinal tract.

It's possible to modify how carbohydrates behave in foods, and hence their functionality, by making alterations in molecular structure and assembly, food composition, and physical and enzymatic processing. There is a growing potential of technology that can be used to modify both the food raw material and its functional components.

At the U.K.'s Institute of Food Research, scientists have examined starch and its maltodextrins; low molecular weight carbohydrates, such as trehalose; the plant cell wall and its constituent polysaccharides; and microbial polysaccharides. This research could lead to improved food materials and can help in structurally engineering food to improve its quality.

Part of this research effort involves determining the structure and composition of polysaccharides. This entails using techniques for the extraction and isolation of polysaccharides and their structural characterization. Researchers also want to determine polysaccharide molecular weight and polydispersity using a combination of total intensity light scattering and quasielastic light scattering techniques. Researchers will characterize interactions in multicomponent aqueous mixtures using various forms of calorimetry; densimetric and dilatometric techniques; and vapor pressure measurements to describe the thermodynamics of the polysaccharides.

Investigators will use calorimetry to determine the glass transition behavior of food carbohydrates. They intend to characterize the rheological behavior of concentrated polysaccharide solutions and gels using mechanical spectroscopy. The research involves examining polysaccharide networks; concentrated carbohydrates, including low moisture glasses and frozen products in which the carbohydrate is concentrated by freezing; particulate dispersions, such as starch pastes; and cellular solids, such as starch foams plant tissue.

Scientists are looking at new approaches to texturizing foods and determining how polysaccharide interactions affect rheological behavior in complex food systems.

Patents. 5,294,448--Delayed release formulations. Issued: March 15, 1994. Inventors: Stephen Ring, et al. Assigned to the British Technology Group Ltd., London, England. This patent covers delayed release compositions. These compositions have an active compound, amorphous amylose and an outer coating comprising a film-forming cellulose or acrylic polymer material.

5,108,758--Delayed release formulations. Issued: April 28, 1992. Inventors: Michael Allwood, et al. Assigned to National Research Development Corp., London, England. Delayed release compositions comprise an active compound and glassy amylose. A variety of different active compounds may be employed in the compositions. The compositions can be adapted for achieving the selective release of medicaments into the colon.

Also see GB 2 223 503A: Gel forming materials; and GB 900 5051 9: Delayed release formulations.

Further information. Vic Morris, Institute of Food Research, Norwich Research Park, Colney, Norwich NR4 7UA, England, U.K.; phone: [phone]; fax: [phone]; email: [e-mail].