Bio-inspired rapid green chemical pretreatment for astaxanthin extraction utilizing shrimp waste: a Taguchi optimized scalable approach

Lactic acid fermentation is a widely used, eco-friendly approach for the pretreatment of shrimp waste to extract astaxanthin, owing to its ability to disrupt the native chitin-calcium-carotenoprotein complex without harsh chemicals. However, its time-intensive nature limits its scalability for industrial applications. To overcome this challenge, the present study explores organic acid ensilation as a green, rapid, and industrially viable alternative pretreatment method. Process parameters were optimized using the Taguchi design of experiments applying 'larger the better' signal-to-noise ratio criteria. Five independent variables such as acid strength, acid treatment time, acid treatment temperature, buffer treatment time, and buffer treatment temperature were studied at three levels using L27 orthogonal array. The model successfully identified significant main and interaction effects influencing astaxanthin yield. Under optimized conditions, a maximum yield of 53.61 ± 2.10 µg/g was achieved. The predicted yield demonstrated 88.33% resemblance to the best experimental result, validating the robustness of the model, and representing an 11.83% improvement over the overall average yield. The extracted pigment was identified via HPTLC, HPLC and quantified using UV-Visible spectrophotometry. This study highlights organic acid ensilation as a promising scalable alternative to lactic fermentation for industrial astaxanthin recovery, with significant improvements in time efficiency and extraction performance.