Optimization of medium composition for enhanced chitin extraction from Parapenaeus longirostris by Lactobacillus helveticus using response surface methodology

► Chitin was recovered by lactic acid fermentation from shrimp shell waste. ► Factors influencing demineralization and deproteinization were studied by RSM. ► The results showed that incubation time had the main effect on demineralization. ► Concentration of reducing sugars was the most significant on deproteinization.