Investigating Infrared Radiation on Peeling and Roasting Chestnut Seeds (<i>Castanea sativa Mill</i>.) and Its Effect on the Physical, Chemical, and Sensory Characteristics of the Product

The application of infrared radiation has proven effective for roasting, peeling, and inactivating microbes in food, leading to its increased use. This study explores its use for chestnut processing and its effects on storage. Response surface methodology (RSM) optimized conditions for both infrared roasting and peeling: Radiation power (490.5 W), duration (21.42 min), distance (5.55 cm), and initial moisture content (13.77% and 2.72%). Under these conditions, the physicochemical properties, antioxidant content, color, mold count, microstructure, and sensory characteristics of chestnut samples were evaluated during 60 days of storage in polyethylene bags. Storage generally increased hardness and decreased moisture across all chestnut samples, but those processed with infrared radiation exhibited superior outcomes. Hot air roasting yielded the highest phenolic content. Initial color analysis showed no significant difference between IR and control groups, except for manually peeled samples exhibiting lower lightness (<i>L</i>* index) and browning index. Notably, on day 30, IR-roasted chestnuts had the lowest mold count, while hand-peeled samples had the highest. Finally, after 60 days, sensory evaluation revealed the lowest overall acceptance scores for hand-peeled chestnuts, while IR-roasted samples received the highest ratings. These findings demonstrate that IR technology for both roasting and peeling significantly improves the quality and sensory attributes of chestnuts during storage, suggesting its potential for industrial application.