Optimisation of laminar jet flow microencapsulation variables to enhance the anthocyanin retention and antioxidant function of sohiong

Abstract

Anthocyanins are valuable dietary elements with biological functions and health-promoting effects. However, there are technological barriers to their use in the food industry, primarily due to their poor stability and susceptibility to environmental factors, such as oxygen, temperature, pH, and light, which can significantly affect the physicochemical characteristics of the final food products. In this study, the microencapsulation of an anthocyanin extract from sohiong fruits was performed using a laminar jet flow vibration nozzle, with calcium chloride as a hardening agent and sodium alginate as a polymer. To produce calcium-alginate microbeads with a high anthocyanin content and favourable morphological characteristics, an RSM approach was used. Thus, with three nozzles of 150, 300, and 450 µm, the effects of pressure, frequency, voltage, and distance to the gelling bath were adjusted. Alginate-loaded anthocyanin microbeads produced with a 300 µm (SA-A300) nozzle had an average size of 588 ± 43 µm, with a consistent spherical shape and a smooth surface. Similarly, the encapsulated sample (SF-A300) exhibited greater resistance to digestion and higher overall anthocyanin retention (84.33% ± 0.33%). In the simulated in vitro digestion (SIVD) environment, photo-oxidative and osmotic stress showed that (SA-A300) substantially preserved a high level of anthocyanins and demonstrated increased antioxidant activity. This optimisation improved the anthocyanin retention of sohiong, with great potential for use in the functional and nutraceutical industries, as well as other beverage sectors.