Starch-integrated alginate-based ternary hydrogel beads-loaded with mace extract-arils of<i> Myristica</i><i> fragrans:</i> Composition-dependent Hertzian elasticity, swelling and adsorptive properties

Integrating natural extracts derived from plants into gel-systems offers an environmentally friendly alternative to synthesis methods. Factors affecting the Hertzian elasticity and structure of starch-filled hydrocolloid beads were investigated to offer insights into design of hybrids with well-defined topology, particularly those obtained synthetically by combining polymerization pathways. In synthesis of plant extract-mediated mm-sized hybrids via ionotropic gelation, starch integrated alginate beads (ST/ALG-Mace) were prepared using phytocompound; mace extract from Myristica fragrans. The hypothesis of the study is to investigate mechanical behavior of alginate-based ternary beads by evaluating their swelling and adsorption for cationic safranin-O dye as a function of ST/ALG ratio. Elasticity data revealed by compression tests were analyzed with Hertz's contact mechanics theory to investigate the change in modulus with starch integration. ST/ALG-Mace beads showed different degree of swelling and stability depending on ST/ALG ratio and pH of environment, with lower swelling in acidic conditions. Addition of both alginate and mace improved the adsorption of safranin-O within the range of 75-84 %. Adsorption obeys pseudo-second order kinetics while isotherm results fit Langmuir model. A perspective is presented that composition-controlled elasticity can be used in design of new plant-engineered gel systems by green biosynthesis of hybrid beads obtained from Myristica fragrans.