Compositions and methods for preparing an edible film of lower water vapor permeability

An edible coating composition having a low water vapor permeability, comprising:

• a heat cured reaction product comprising
• A. unbleached, edible shellac, and
• B. a reactant member selected from the group consisting of hydroxypropyl cellulose and hydroxypropyl methyl cellulose and mixtures thereof,
• wherein the ratio of the reactant member and shellac ranges from 0.001 to 2:1,
• and wherein the product has an average molecular weight of at least 2,000.

An edible film having a low water vapor permeability, said film comprising:

• a heat cured reaction product comprising,
• A. unbleached, edible shellac, and
• B. a first reactant member selected from the group consisting of hydroxypropyl cellulose and hydroxypropyl methyl cellulose and mixtures thereof,
• wherein the ratio of first reactant member and shellac ranges from 0.001 to 2:1, and wherein the product has an average molecular weight of at least 2,000 and wherein the film ranges from 1 to 5 mil in thickness.

A method for preparing a heat sensitive substrate coated with an edible film of low moisture permeability comprising:

• A. heating in a dry state a mixture comprising:
• 1. unbleached edible shellac,
• 2. a first reactant member selected from the group consisting of hydroxypropyl cellulose, hydroxypropyl methyl cellulose and mixtures thereof, and
• wherein the weight ratio of shellac to member ranges from about 1:0.001 to 1:2,
• in a dry state to a temperature of about 130.degree. to 175.degree. C. for a period of about 2 to 15 minutes, to form a cross-linked reaction product coating composition;
• B. dissolving the coating composition while still molten in a food grade solvent with agitation to form a solution;
• C. applying the solution to a heat sensitive substrate to form a coated substrate;
• and
• D. drying the coated substrate.

A coated food article comprising:

• A. a food substrate having a surface,
• B. a film overlaying said surface, said film comprising a heat cured thermo-plastic resin product comprising
• 1. refined, unbleached, edible shellac, and
• 2. a first reactant member selected from the group consisting of hydroxypropyl cellulose and hydroxypropyl methyl cellulose and mixtures thereof,
• wherein the ratio of first reactant member and shellac ranges from 0.001 to 2:1 and wherein the resin product has an average molecular weight of at least 2,000.

A composite food article, resistant to degradation by species migration food phases, comprising:

• A. a first food phase;
• B. a second food phase;
• said composite food article having a gradient between the first and second food phases;
• and
• C. an interjacent barrier phase comprising a film formed from an edible thermoplastic, heat cured resin, said resin comprising:
• 1. about 0.1% to 85% by weight of edible unbleached, refined shellac,
• 2. about 25% to 99.9% by weight of a member selected from the group consisting of hydroxypropyl cellulose, hydroxypropyl methyl cellulose and mixtures thereof.