Avaliação da influência do pH da matéria-prima in natura no ponto isoelétrico do produto final

Abstract

Gelatin is obtained by the partial hydrolysis of collagen present in tissues and bones of bovine, fish, and swine origin. A versatile product used since Ancient Egypt, gelatin has had diverse applications and uses over time, with emphasis on the food and pharmaceutical industries. Among the physical and chemical characteristics of gelatin, in addition to the traditional gel strength (bloom) and viscosity, the isoelectric point is of fundamental importance in various applications, especially in the development of hard capsules by the pharmaceutical industry. The reduction of the isoelectric point of collagen occurs through the conversion of asparagine and glutamine into aspartic acid and glutamic acid, respectively, by replacing the amide increasing the number of groups carboxyl in the molecule, a process that begins during the hair removal stage of leather tanning using alkaline solutions. The present study consists of evaluating the behavior of the isoelectric point of gelatin in different batches, raw materials, and processing stages, observing the effects of time and concentration applied in the alkaline treatment, in addition to verifying whether there is variation during processing after purification. Through the standard processing of Type B gelatin production, similar isoelectric point values are obtained in two different productions, demonstrating the significance of optimizing the treatment stage according to the material worked and its conditions. However, it is also observed that physicochemical characteristics such as bloom and viscosity are increased with greater treatment intensity, reiterating the importance of defining the process according to the desired profile. Thus, the pH of the raw material directly influences the isoelectric point of the final product, reflecting the alkaline residue from the depilation of the hide and directly associated with the onset and extent of the conversion of the amino acids evaluated, in addition to being an important indicator of the integrity and conditions of the raw material, especially regarding the effects of residual alkaline solution from depilation.