The effects of glycerol concentration and coating weight on biopolymer-coated paper properties were
investigated using response surface methodology. Tests were run on the coated papers to determine water
vapor barrier and mechanical properties. Coating weight was the most important parameter affecting
water vapor permeability (WVP). Conversely, increasing coating weight led to a decrease in WVP and
to an increase in tensile strength (TS) of the resulting coated papers. The papers coated with sodium
caseinate (NaCAS) exhibited lower WVP values than those coated with other biopolymers. The TS of the
papers coated with hydroxypropylmethylcellulose (HPMC) and chitosan was not affected by the glycerol
concentration. HPMC-coated papers were higher in TS and %E than the other coated papers. For all types
of coated paper, a maximum level of coating weight and level of glycerol concentration within range of
18.72–26.11% were found to be optimum for minimum WVP and maximum TS and %E.