Acetic acid mediates pectin structural remodeling to enhance cellulose binding in potato cell wall.

This study investigates how acetic acid pretreatment modifies pectin structure and its interaction mechanism with cellulose to regulate textural integrity of potato slices (Solanum tuberosum L.) during thermal processing. Potato slices were pretreated with distilled water and acetic acid, and changes in firmness, sugar composition and cell wall architecture were evaluated. Chelate soluble pectin was extracted, purified and characterized by galacturonic acid content, monosaccharide composition and UV-vis analysis. Acetic acid treated samples retained higher firmness and mitigated heat induced degradation of RG-I side chains compared with distilled water treatment. Cellulose purification reflected total solid yield reduction from 89.7% (starch free residue) to 27.53% in final cellulose fraction, with glucan content up to 84% confirming effective cellulose purification. SEM and XRD revealed progressive removal of amorphous components and crystalline integrity of cellulose. An in vitro pectin-cellulose composite was designed to elucidate binding behavior. Langmuir model, XRD, DSC demonstrated that acetic acid strengthens the pectin binding capacity, increases celluloses crystallinity (to 75%) and enhances thermal stability with decomposition temperature increasing to 358.7 °C, with FTIR confirming no alteration in cellulose functional groups. Overall, pretreatment with acetic acid strengthens pectin-cellulose interactions, stabilizes cell wall architecture, and further improves texture retention in cooked potatoes.