Shrimp biowaste fermentation with Pediococcus acidolactici CFR2182: Optimization of fermentation conditions by response surface methodology and effect of optimized conditions on deproteination/demineralization and carotenoid recovery

Fermentation of shrimp biowaste was conducted using different lactic acid bacteria (LAB) to select the efficient starter culture based on pH reduction and acid production. Pediococcus acidolactici CFR2182 was found to be the efficient (P ≤ 0.05) among the five starter cultures tested. Fermentation conditions viz., inoculum level (X1), sugar level (X2) and incubation time (X3) were optimized using response surface methodology (RSM) to obtain the desirable pH of 4.3 ± 0.1. The optimized conditions were found to be 5% (v/w) inoculum (with 8.28 log cfu ml−1), 15% (w/w) glucose and 72 h of incubation time at 37 ± 1 °C to attain a pH of 4.30. The usefulness of the predicted model was further validated by considering random combinations of the independent factors. The high correlation (with regression coefficient close to 1.0) between the predicted and observed values during validation indicated the validity of the model. The effect of fermentation, by P. acidolactici CFR2182, on the production of chitin (as indicated by deproteination and demineralization efficiency) and recovery of carotenoids was also studied. Deproteination of 97.9 ± 0.3% and demineralization of 72.5 ± 1.5% was achieved by fermentation of shrimp biowaste with P. acidolactici. The carotenoid recovery in fermented shrimp biowaste, as compared to the wet waste, varied between 72.4 and 78.5% during fermentation.