Scholarly record

EDIBLE GELATIN HOLOGRAMS

Alexandra Toropova

Abstract

A research of edible gelatin rainbow holograms is presented. Gelatin is an edible material with optical properties: it is transparent in the visible region of the spectrum and has refractive index close to refractive index of optical polymers. Gelatin is capable to transfer diffraction relief and save it for a long time. Gelatin holograms were prepared by nanoimprinting method from gelatin aqua solutions with different concentrations (1 part of gelatin per 5, 10, 15, 20, 25 parts of water). The samples were made of three types of gelatin: beef gelatin, pork gelatin, quick-dissolving pork gelatin. The diffraction efficiency and lifetime of gelatin holograms were analyzed. The best sample was obtained from solution with ratio of 1 gram of quick-dissolving pork gelatin per 15 grams of water. This sample has the greatest diffraction efficiency ? 17%. The samples were observed 6 months, low degradation of the gratings was noticed, diffraction efficiency decreased. This fact can be explained by the relaxation processes in the material and the influence of the environment. It should be noted, that rainbow effect preserved, and the diffraction grating did not disappear during this time Edible rainbow holograms are forming on product surface a color image due to the relief not using food dyes. These holograms can be used for marking products and improve the aesthetic properties of a products. Edible protective rainbow holograms can be applied to the surface of medicines and increase their protection.

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