Microencapsulation of okra mucilage: extraction, characterization, and potential application in jaggery processing

Okra ( Abelmoschus esculentus L.) mucilage is a polysaccharide-rich, natural bioactive compound known for its functional and therapeutic properties. This study aimed to microencapsulate okra mucilage using cassava starch as the wall material and to characterize the microcapsules, with a focus on their application as a natural clarifying agent in the processing of sugarcane juice/jaggery. The freeze-drying technique was used to microencapsulate the mucilage from okra fruit (without peduncle) and peduncle. The mucilage was extracted using three distinct methods: solvent precipitation, grinding-centrifugation-solvent, and ultrasonic-assisted solvent extraction. The ultrasonic-assisted solvent extraction method yielded the highest mucilage recovery of 11.67% for okra fruit and 10.03% for okra peduncle. The encapsulation efficiency reached 61% for fruit and 56% for peduncle. X-ray diffraction showed an enhanced crystallinity, from 33.52% for raw mucilage of okra fruit to 55.23% for the encapsulated fruit sample, and from 29.02% for raw mucilage of okra peduncle to 78.25% for the encapsulated peduncle sample. This improved microcapsule structural order alongside a high glass transition temperature ( Tg = 74.8 °C) verified by differential scanning calorimetry, significantly enhanced the stability of the cassava starch-encapsulated mucilage against thermal stress. This stabilzation enabled effective impurity removal during high-temperature sugarcane juice clarification. FTIR and LC–MS analyses revealed galacturonic acid, mannose, Quercetin-3-O-glucoside, and Rutin (quercetin-3-O-rutinoside) as the primary compounds driving clarification. The incorporation of encapsulated mucilage during jaggery processing significantly improved clarification efficiency by 45% and increased scum removal by 1.45-fold at a 1 g/L dosage compared to the control. Furthermore, the foaming capacity was significantly supressed to 250% and 130%, respectively, with the addition of encapsulated mucilage at concentrations of 1 g/L and 2 g/L, respectively.