RSM-based optimization of power and duration in microwave-assisted Lakadong soy milk turmeric extracts

The article presents the optimal characteristics of RSM-based microwave-assisted extraction (MAE) of Lakadong turmeric in the soy milk system. Either pepper or a combination of 6-herbs as adjuvants were considered for improved palatability of the in-situ prepared liquid soy milk-based turmeric extracts (SMTE). Microwave power (W) and heating time (min) were systematically varied. In these investigations, curcumin and anti-oxidant activity (AA) were evaluated as the response variables. Non-linear quadratic models were affirmed by RSM. Statistical analysis confirmed upon the adequacy of the models with higher R² values, significant model terms (p < 0.05), and lower errors. Pareto charts revealed the terms with significant influence on the response variables. The optimized process parameter combinations, as obtained from numerical optimization, were 450 W, 7.0 min for powder-based and 450 W and 10 min for paste-based liquid SMTEs. For these conditions, the highest combination of curcumin (14.755-17.154 mg/100 mL) and AA (119.820-135.011%) was achieved for the liquid SMTEs. The RSM-associated MAE-based turmeric milk products' development has been successful to infer upon the functional dairy products. However, the conducted study can only be utilized as a generic framework for the integration of plant-based bio-actives into the plant-based matrices and with the household appliances.