Ohmic heating-assisted pretreatment of agave bagasse to increase bioactive compounds bioaccessibility

abstract

Agave bagasse, a byproduct of mezcal production, represents an abundant yet underutilized biomass. In this study, ohmic heating was applied as a pretreatment strategy to disrupt the bagasse's recalcitrant fiber structure and enhance the release of bioactive compounds. A central composite response surface design (20 runs) was used to evaluate the effects of three independent variables, moisture content (50¿70 %), voltage (100¿120 V), and time (5¿15 min), on the extraction of total phenolic content, soluble dietary fiber, and insoluble dietary fiber. The optimal conditions for maximizing phenolic yield and soluble fiber were 76.33 % moisture, 107.53 V, and 7.77 min of treatment. Under these conditions, ohmic heating significantly increased the extraction of phenolic compounds and the proportion of soluble dietary fiber, while reducing the content of insoluble fiber. To evaluate the nutritional relevance of these changes, the bioaccessibility of phenolics and sugars was assessed using the standardized INFOGEST digestion model. Ohmic heating increased the release of simple sugars up to 222 %, indicating effective breakdown of structural carbohydrates. Phenolic bioaccessibility increased up to 252 %, a substantial increase compared with the control sample without ohmic treatment. Although the bioaccessibility of phenolic compounds improved for certain processing conditions, a significant fraction remained undigested, suggesting potential prebiotic activity in the colon. Overall, this study demonstrates that ohmic heating is a promising green technology for the valorization of agave bagasse, enhancing its functionality as a source of bioaccessible compounds and supporting its incorporation into sustainable, health-oriented food applications. © 2025 Elsevier Ltd