Protective edible polymeric coatings on butter

Abstract

The contribution deals with employing starch-protein hydrolysate of amaranth flour, as by-product in manufacture of protein concentrate, to produce protective edible coats on butter. Tests were run on 2 coating solutions. The first was made in such manner that to hydrolysate containing 35 % (w/v) dry matter, 30 % (w/w) plasticiser (glycerol) was added and also 3 % (w/w) emulsifying agent (lecithin). The second furthermore contained 1% (w/w) antioxidant (tocopherol). Protective layers on butter were produced by coating with coat solutions. Butters were stored for a total of 126 days in refrigerator at 6±1.5 °C and relative humidity 43±3 °C. Tests examined the oxidation course of butter by determining its peroxide value (PV) and the difference between PV of butters with coatings, without coatings, of butter wrapped in original wrapper, butters wrapped in paper wrapper and of butters in paper wrappers impregnated with coating solutions. Lower PV levels were found with butter treated with our coats than with butters wrapped in original wrapper. Coating solutions were applied to prepare films by casting and to investigate their properties - water solubility, water vapour permeability, moisture absorption and thermal properties (DSC and TGA).