Abstract. Rainbow hologram may be applied on the candies made from isomalt, fructose, sugar and molasses. The composition of caramel affects on its optical properties and the ability to save the diffraction grating.
IntroductionEveryone knows from childhood what caramel is. This amazing candy has various shapes, it is transparent and colored like glass. We assumed that the new aesthetic appearance of a traditional confectionery product can be decorated with a rainbow hologram. The rainbow hologram allows to create bright images with a color that depends on the viewing angle, due to the diffraction relief. Researches on the application of rainbow holograms on the surface of confectionery products were carried out earlier, but received wide practical application not yet [1][2][3][4]. The goal of this research was the creation of a diffraction grating on caramel. Caramel can be made from different materials -sugar, molasses, fructose, isomalt. Isomalt is a substitute for sugar, which has become popular to confectioners last time. Sugar is a food product of sweet taste, made from sugar cane or sugar beet. Sugar exists in the form of colorless monoclinic crystal blocks, has a melting point t= 185 ° C, is soluble in water and easily crystallizes in supersaturated solutions. Sugar is stable in the air, but hygroscopic, it is able to absorb the moisture of the air [4,5]. Molasses is a sugary product made by hydrolysis of starch with enzymes or dilute acids followed by filtration and boiling syrup. Molasses is a mixture of glucose, oligosaccharides and dextrins in water. The content of solids in molasses is about 80%. Molasses is transparent and colorless in pure form. It increases the solubility of sucrose and blocks crystallization, that is why it is used in caramel production [6]. Fructose is a monosaccharide, found in many fruits in a free form, and as a part of oligosaccharides and polysaccharides. Fructose is extracted from fruits by hydrolysis of sucrose and inulin, as well as the action of alkalis on glucose. Fructose has a melting point t = 102 ° C, is highly soluble in water, hygroscopic to a large extent [7]. Isomalt is a sugar substitute in the form of white crystals, flavourless with a sweet taste, its sweetness is 42% of the sweetness of sucrose. It is a mixture of hydrogenated monosaccharides and disaccharides. Isomalt has a melting point t = 150 ° C, it is readily soluble in water, hygroscopic to a small extent [8,9].
