Study into oxidative changes of butter with protective coat

Abstract

The contribution deals with employing starch-protein hydrolysate of amaranth flour to produce protective edible coatings on butter. Tests were run on 3 types of coating solutions. The first was made in such manner that to hydrolysate of 40-% dry matter content, 30-% (w/w) plasticiser (glycerol) was added and also 3-% (w/w) emulsifying agent (lecithin). The second and third contained an extra 2-% (w/w) antioxidant (ascorbic acid) and the third an extra 2-% (w/w) cross-linking agent (dialdehyde starch). Protective layers on butter were produced by coating with coat solutions. Butters were stored for a total of 96 days in refrigerator at a temperature of 7±1.5°C and relative humidity of 36±3%. The objective was to investigate the oxidation course of butter with protective coatings, butter wrapped in original wrapping and butter without wrapping/coat. Determined values were peroxide value, acid value and anisidine value. Results of butters with protective and edible polymer coatings displayed a similar oxidation course to that of butter in standard wrapping. Butter with a coat containing antioxidant exhibited slightly lower levels of peroxide value during storage than butter in original wrapping, which confirms good barrier properties to oxygen of the coating thus prepared.