Physical Methods as Pretreatment of Prickly Pear and Pineapple Peels for Producing Enzymes and Chemical Precursors

Mexico produces 1.27 million tons of pineapple and prickly pear, whose wastes account about 40%. Therefore, effective utilization of this lignocellulosic biomass is crucial. Our research emphasizes the need for efficient pretreatment to optimize enzyme efficacy and enhance saccharification processes. Particle size significantly affects the microbial breakdown of these biomasses. Sun-dried prickly pear peels with 1.84 mm particles showed a remarkable increase in xylanase and laccase activities, achieving up to 1431 ± 190 U/mL and 1165 ± 19 U/mL, respectively, a stark contrast to the lower enzymatic activities recorded in oven-dried counterparts. Surprisingly, untreated pineapple peels yielded the highest saccharification rates, suggesting that some traditional pretreatment practices might be redundant. Despite employing an enzymatic cocktail with high hydrolase activities, the saccharification of pineapple peels peaked at a modest 0.16 g_RS/g_biomass, hinting at inefficiencies potentially due to high solid loading or inadequate enzyme cocktail components. Besides, this research proposes the sustainable use of the residual composites obtained after the biological processing of pretreated material. In this respect, a pathway to more cost-efficient and environmentally friendly industrial bioprocesses through valorizing lignocellulosic residues is suggested.