Determinación del pH óptimo de acción del peróxido de hidrógeno en el blanqueamiento de la carnaza para la producción de gelatina pura elaborada en la empresa PRODEGEL S. A.

Abstract

In the pure gelatin industry, the bleaching process of the carnaza is vital for the quality of the finished product. Hydrogen peroxide is used as a bleaching agent for animal skins. This is ionized in the alkaline medium forming the perhydroxyl ion which is responsible for destroying the chromophoric (melanin) groups of the skin, producing the bleanching until its decomposition in gaseous oxygen and water. The objective of the present study was to obtain the optimal conditions of action of hydrogen peroxide in the whitewash of the carnaza (pelambre and descarne) by means of the response surface methodology (RSM), given in the washers-acidulators implemented in the production plant of pure gelatine PRODEGEL S.A. We used 11 treatments defined by the central composite design, taken as factors of analysis the pH of the solution and the time of the stir in the washer-acidulators; the response variable was the brightness (L*) of the carnaza measured with the Lovibond colorimeter model RM-200 and compared with the L * of the material bleached with the previous process (liming pools). The resulting equation determined by the RSM established that the optimum conditions for the bleaching of descarne material were pH 7 with 2.4 hours of stir obtained a value of L* equal to 91.73 compared to the process in pools that used a pH of 12-12.4 for four days, giving a luminosity of 70.41. On the other hand, for the pelambre material, the optimum conditions were pH 7.5 with 1 hour of stir, obtaining a value of L* equal to 85.16; comparing with the hair treated in pools of L* equal to 79.16 which was bleached in 6 days at a pH of 12-12.6; obtaining thus an optimization in the time of bleached of the carnaza.