Impact of maltodextrin and gum arabic on the microencapsulation and antioxidant activity of Rumex crispus

Abstract

• MD–GA ratios were optimized to maximize encapsulation efficiency and protect Rumex crispus bioactive compounds. • SEM confirms smooth, low-porosity particles providing high thermal and oxidative stability with low permeability. • Best-fitting kinetic models were identified, confirming the matrix effectively governs bioactive release behavior. Rumex crispus L. is a potent, scented herb used in traditional as well as modern medicine due to its exceptional biological qualities. However, the bioactive compounds are liable to oxidation when exposed to oxygen, light, pH and heat and lead to a loss of antioxidant activity. The present study is aimed at evaluating the microencapsulation of bioactive compounds extracted from Rumex crispus by applying freeze drying methods with varying amounts of wall materials (maltodextrin and gum Arabic) and extract with 12 different treatments in order to optimize the encapsulation of bioactive extract using face centered central composite design using Design–Expert®11.0 from Stat-Ease Inc. Encapsulation efficiency was evaluated through total phenolic content (TPC), achieving maximal retention (86.69%) under optimal conditions: maltodextrin-to-gum arabic (15.2:4.8 g/g) and wall-to-core (6:1 g/g) ratios. This obtained optimal product also studied its release kinetics in order to see effective retention and controlled release of total phenolic and flavonoid content from encapsulated formulations. In addition, the thermal analysis carried out to observe the stability of microencapsulated and the result showed that the encapsulated powder is matrix-controlled which indicating that the extract is successfully embedded within the MD–GA matrix. Furthermore, the morphological properties of the optimal encapsulate were determined by scanning electron microscopy in order to see the inference of a smooth surface with low porosity is possibly an indication of the low oxygen permeability and a high oxidative stability. Hence, encapsulation of Rumex crispus bioactive results in rich total phenolic content, high antioxidant activity, thermally stable with controlled release in gastrointestinal media in vitro test.