Cp Kelco U.s., Inc.

Lucent Technologies Inc.

Monsanto Company

You-Lung Chen

Neil Argo Morrison

Todd A Talashek

Ross Clark

Sanjay Patel

Jorge L Valdes

John Flanagan

Helen L Anderson

Frank Miskiel

Dan Burgum

Graham Sworn

The invention relates to a modified gellan gum in which the total acyl content as well as the ratio of acyl substituent groups to glycerate substituent groups per linear saccharide repeat unit is altered to be higher than 1. The invention further relates to a process for the modification of a gellan gum to alter its acyl content in which the gum is treated with a weak base such as sodium or potassium carbonate or a suitable phosphate. The process enables &ldquo;tailor made&rdquo; gums having appropriate setting temperatures and theological properties to be made. Novel compositions containing them are also claimed.

Modified gellan gum composition process for preparation of same and use thereof

A seed coating comprising gellan gum is disclosed along with a process which comprises admixing gellan gum and water under effective shear conditions to prepare an aqueous gellan gum coating composition thereof whereby the aqueous gellan gum coating composition may be applied in an adherent fashion to a seed to form a gellan gum coated seed. A gellan gum seed coating composition may indicate one or more bioactive(s) and optionally one or more colors.

Gellan gum seed coating

This invention provides reduced molecular weight gellan gums. The reduced molecular weight gellan gums of this invention generally have a weight average molecular weight less than about 1.7&times;10,, and typically in a range of about 1.2&times;10,to about 9.3&times;10,. This invention also provides compositions, e.g., solutions and gels, comprising reduced molecular weight gellan gums. The reduced molecular weight gellan gums of this invention may be prepared by any method which reduces the molecular weight of polymers. Such methods include homogenization, sonication, radiation, oxidation and hydrolysis.

Reduced molecular weight native gellan gum

The invention provides an alternative to conventional sol-gel methods that utilize undesirably high amounts of a stabilizing agent such as TMAH and a gelling agent such as methyl formate. The method involves the steps of (a) providing a colloidal silica dispersion containing a stabilizing/gelling agent, where only a portion of the molecules of the agent ionize, and (b) subsequently adding to the silica dispersion a pH-reducing additive. The stabilizing/gelling agent has a dual function. The agent, e.g., an amine, initially acts as a stabilizer in the silica dispersion in that a portion of its molecules ionize, while an appreciable amount of the agent remains non-ionized. The agent later transforms in situ to a gelling agent upon addition of a pH-reducing additive. Specifically, as the pH-reducing additive lowers the pH to values at or around the pK.sub.a of the stabilizing/gelling agent, more of the agent's molecules are ionized, these cations contributing to charge neutralization, and thus gellation, of the colloidal silica particles.

Fabrication including sol-gel processing

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San Diego, CA, United States of America

You-Lung Chen