Fermentación Láctica de la cáscara de camarón con Lactobacillus delbrueckii para obtención de quitina

Abstract

The aim of this study was to define the process to obtain chitin by lactic fermentation of shell shrimp with Lactobacillus delbrueckii. First, the effect of three different culture medium to generation of inoculum was studied It was selected the media that allow a concentration to 108 in the shortest time. Then, the effect of substrate (0, 5 and 10% sucrose), pH (no control, control) and temperature (37 and 45 ºC) was determined for the lactic fermentation process. For each treatment, 150 g of shell (85% moisture) were placed in a bioreactor (Bigtron Smart GX) and stir by 144 h. Upon completion of the fermentation process depigmentation and a treatment with 0.8% NaOH were conducted. The percentage reduction of the soluble protein, total protein and ash in the shell were calculated for each process (fermentation, depigmentation and alkalization). The best results were shown by treatments: S3 (without pH control at 37 and 10% sucrose) and S2 (without pH control at 37 and 5% sucrose) with 98.45% ash, 98.73% soluble protein and 99.89% total protein; and 83.07% ash, 55.26% soluble protein and 40.30% total protein, respectively. Infrared analysis suggests that chitin was obtained, and the widening of the band between the 2 000 and 3 000 is due to an uncomplete deproteinization or demineralization. The molecular weight of the chitin obtained is between 1,52x106 and 2.66 x106 (g / mol).