Effect of temperature on chitin and astaxanthin recoveries from shrimp waste using lactic acid bacteria

The chitin and astaxanthin recoveries by lactic acid fermentation of shrimp wastes (Litopenaeus sp) were conducted in bed-column reactors at 15, 20, 25, 30, 35, 40 and 45 degrees C. The response surface methodology showed that the fermentations carried out in the 27-36 degrees C temperature range with lactic acid above 0.319 mmol/g resulted in the highest demineralization. The maximal deproteinizations were attained from 30 to 40 degrees C. The extraction of free-astaxanthin did not present significant differences between 20 and 35 degrees C and the proportion of cis-stereoisomer forms increased with temperature. The growth rates of Lactobacillus plantarum were estimated in the 15-45 degrees C range and analyzed by Arrhenius and square root models. The cardinal values were 3.94 and 51.7 degrees C for minimum and maximum temperatures, respectively, with activation energy of 43.38 Jmol(-1).