Ultrasound-Assisted Extraction and Microencapsulation of Durvillaea incurvata Polyphenols: Toward a Stable Anti-Inflammatory Ingredient for Functional Foods

Seaweed represents a rich and underexploited source of bioactive compounds with potential applications in nutraceuticals, pharmaceuticals, and functional foods. Among marine macroalgae, brown seaweeds (Phaeophyceae) are particularly notable due to their high content of polyphenols—mainly phlorotannins—alongside complex polysaccharides and minerals [1].

Despite this, most bioactivity-focused studies have concentrated on a limited number of genera, and significant gaps persist in early-stage evaluations of potential anti-inflammatory properties, as well as in the technological development of functional ingredients, particularly from endemic species such as Durvillaea incurvata, which remains underexplored despite its promising bioactive profile.

Durvillaea incurvata, commonly known as “cochayuyo” in Chile, is a brown seaweed endemic to the southeastern Pacific and traditionally consumed along the Chilean coast. Its documented antioxidant, anti-inflammatory, lipid-lowering, and anti-obesity properties highlight its potential as a source of bioactive compounds for functional applications [2].

However, translating these biological effects into viable, functional food ingredients requires the development of scalable extraction and stabilization strategies [3]. Among these, ultrasound-assisted extraction (UAE) has emerged as a green and efficient technique that enhances the recovery of thermolabile compounds by promoting cell disruption and solvent penetration, thereby reducing both solvent consumption and processing time [4]. Previous work by our group demonstrated that UAE applied to Durvillaea incurvata produces extracts with superior antioxidant capacity and enzyme-inhibitory activity compared to conventional extraction methods [5].

To complement these extraction advances, reliable bioactivity screening methods are also essential. Given the high cost and complexity of in vivo assays, in vitro enzymatic tests—such as hyaluronidase inhibition—offer a practical and informative approach for early-stage evaluation of anti-inflammatory potential. This method facilitates the identification of promising candidates prior to engaging in more resource-intensive mechanistic or clinical assessments. While additional assays will be necessary to confirm efficacy under physiological conditions, hyaluronidase inhibition provides a valuable first-line indicator of anti-inflammatory activity at the laboratory scale.

Building on this initial screening, further formulation steps are required to ensure the stability and functionality of the extract in real food systems. Although polyphenolic extracts exhibit promising biological properties, their susceptibility to heat, light, oxygen, and gastrointestinal conditions poses significant challenges for incorporation into food matrices [6]. To address this limitation, microencapsulation—particularly through spray drying—has been extensively employed in the food industry to improve compound stability, protect bioactivity, and enable controlled release [7]. Maltodextrin is frequently selected as a wall material due to its high water solubility, low viscosity, and compatibility with food-grade applications [8]. Moreover, encapsulation enhances dispersibility and can mitigate sensory drawbacks commonly associated with phenolic-rich ingredients.

To optimize the encapsulation process and ensure efficient use of materials and energy, Response Surface Methodology (RSM) offers a powerful statistical tool. RSM allows for the simultaneous evaluation of multiple variables and their interactions, enabling the identification of optimal conditions with a reduced number of experimental trials. It is widely applied in food engineering to model complex processes, such as encapsulation efficiency, antioxidant retention, and bioactive protection [9]. In this study, we aimed to (1) obtain a polyphenol-rich extract of Durvillaea incurvata using UAE and evaluate its anti-hyaluronidase activity and cytotoxicity in gastrointestinal cell models and (2) encapsulate the extract using spray drying with maltodextrin as the wall material, optimizing the process via RSM. This study provides foundational evidence supporting the stabilization and in vitro evaluation of bioactive compounds from seaweed, offering a relevant basis for their potential incorporation into food systems. The insights generated here are expected to guide future work focused on in vivo validation and food matrix integration, facilitating the development of functional ingredients for health-promoting applications.