Zein coated or impregnated paper straws and related tublar article

A process for preparing a zein coated article, comprising:

• (a) Preparing a zein powder containing zein polymer (10-99.9% by wt.), water (0.1-10% by wt.), and starch particles (0.01-80% by wt.), wherein all percentages are based on the total weight of the zein powder;
• (b) Using the zein powder from step (a) in one or more of the following steps:
• (i) Grinding the zein powder with inorganic colloidal particles and sieving;
• (ii) Preparing a zein solution by mixing the zein powder with a solvent or plasticizer or both;
• (iii) Separating insoluble starch particles and contaminants using decantation or filtration;
• (iv) Performing adsorptive filtration to remove color or odor;
• (v) Adding soluble or insoluble active agents and/or crosslinking agents;
• and
• (vi) Homogenizing and aging the solution at a temperature between 30-80° C. for 0.1 hour to 48 hours;
• (c) Coating a pre-manufactured paper straw with the zein solution to create a zein-coated paper straw;
• or creating straws by spirally winding zein pre-impregnated paper strips;
• (e) Drying the zein-coated paper straw at a temperature between 20-200° C. for a duration of about 1-180 minutes;
• and
• (f) Cutting the zein-coated paper straw to a desired length as needed.