BETACYANINS PIGMENTS AS PHOTOSENSITIZING AGENTS FOR HOLOGRAPHIC RECORDING MEDIUM. Author(s): Santa Toxqui-Lopez, Edgar Hernández-Hernández, Claudia Santacruz-Vázquez, Benemérita Univ. Autónoma de Puebla (Mexico); Arturo Olivares-Pérez, Instituto Nacional de Astrofísica, Óptica y Electrónica (Mexico); Veronica Santacruz-Vazquez, Benemérita Univ. Autónoma de Puebla (Mexico) 1. INTRODUCTION. One of the natural most employed within the food industry are pigments of betalains by their solubility in water to give desired colorations in processed foods such as beverages, dairy, meat. However, this research shows that this type of pigments can be used as photosensitizing agents in the field of holographic recording materials. Red Beet (Beta vulgaris) is a plant rich in fitocolorantes (pigments) of betalains, which are divided into two groups, the betacyanins (predominant in beets) responsible for granting a red hue, and betaxantins for yellow. The process for obtaining holographic films with implementing beet betacyanin pigment is carried out after obtaining the dried juice powder plant and determination of their physicochemical properties, to measuring the diffraction efficiency of the films obtained by an interferometric experimental arrangement for laser engraving in real time and time-dependent representation through graphs. IMAGE 1. Red Beet (Beta vulgaris) ready for juice extraction process. 2. OBJECTIVE. The objective of this study is the implementation of betacyanins pigments obtained from beets as photosensitizing agent, and polyvinyl alcohol as a medium of suspension on the process of holographic film obtaining for engraving in real time and replication information, which have been demonstrated in literature that betacyanins exhibits optical activity since they have two quiral centers in C-2 and C-15 and absorb light in the range of 400 to 600 nm. 3. METHODOLOGY. Beet plant is subjected to washing with distilled water to prevent absorption of unwanted impurities included in potable water, is then removed the shell and clean beet is cut into about 3 cm 3 pieces in order to be able to bring them to the removal in a juice extractor. The juice obtained is filtered with the aid of a vacuum pump to eliminate impurities from the juice and add a encapsulating in a concentration of 10% on the juice obtained, which helps us to protect it from the oxidation of the environment, temperature and other ingredients, in addition provides us with an effective protection and prolonged of the active ingredient (betacyanins) of the environment and helps to facilitate their transition from liquid to powder. A synthetic polymer soluble in water as polyvinyl alcohol (PVA) is presented in the form of granules or white powder that has the characteristics to be odorless, non-toxic, resistant to oxygen in addition to possess great flexibility and colorless in aqueous solution, in addition to form excellent movies, so it is the optimal choice for the role of the suspending medium for the pigment of beet . A mixture of all 3 components are used to form our movie: beet pigment, PVA and water, which forms a solution with good transparency reddish . This solution is uniformly spread on glass substrates that have been subjected to a sterilization and cleaning to remove any impurities, keeping in mind that the delivered quantity of solution into the substrate will influence the thickness of the film, and therefore in transparency and quality for engraving. The engraving is carried out by implementing an interferometric experimental arrangement, where a beam of laser light is diffracted through a splitter and focused to a point on the film at a certain distance by means of mirrors, which allows us the recorded diffraction gratings, and to determine if our film is high or low frequency. 4. RESULTS. The following figure (Figure 4), the UV absorption spectrum (200 to 900 nm) of the solution that forms the film layer with pH of 6.1 and density of 1.2 g/cm3 is shown, in which two absorbance peaks are observed corresponding to yellow pigments (betaxantinas; 485 nm) and red pigments (betacyanins; 537 nm) that are fully identified betalains pigments in beet. It was also noted a third peak at 276 nm in where it is suggested that the presence of proteins to accompany the betalains [ 6], however, at this same wavelength can be absorb other nitrogenous compounds or polyphenols because that is not reported in the literature any report on the interaction of proteins with the betalains of beetroot. IMAGE 2. Ultraviolet absorption spectrum. In the following figures can be seen the variation of diffraction efficiency as a function of exposure time of the film layer in the laser engraving (Figure 7), the diffraction efficiency of the energy versus time of exposure (Figure 8), and the second order intensity versus time of exposure (Figure 9) made iŶ Polymath 6.0 software. IMAGE 3. Diffraction efficiency VS Time. IMAGE 4. . Diffraction efficiency VS Time. IMAGE 5. Intensity VS Time. 5. CONCLUSION. Implementation as photosensitizer agent of betacyanin pigments obtained from dehydrated beetroot juice in holographic films is possible due to fitocolorantes absorb wavelength from the light spectrum on range of 400 to 600 nm as have been demonstrated on the analysis of UV spectrum light, using interferometric arrangements with laser light sources working in the same range of the light spectrum, showing good results in diffraction efficiency and recorded in short periods of time as is demonstrated in earlier graphs. 6. REFERENCES. • Marañón, V., De-La-Torre, L. , CaraĐterizaĐióŶ de las propiedades ópticas de Betacianinas y Betaxantinas por espectroscopia Uv-Vis y Barrido en Z, Sup. y Vacío. 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