Comparison of Gidyea gum, gum Arabic, and maltodextrin in the microencapsulation and colour stabilisation of anthocyanin-rich powders using freeze-drying and spray-drying techniques

Traditional foods in Australia have been under-explored as both food colourants and microencapsulates. Many of these native foods are high in anthocyanins. Anthocyanins, known for their vibrant colours and health benefits, face stability challenges in food applications due to sensitivity to environmental factors. Microencapsulation is a common technique used to preserve the stability of anthocyanins. This study investigates the microencapsulation of anthocyanins extracted from Antidesma erostre. The native Gidyea gum, as compared to gum Arabic and maltodextrin, is used as wall material, employing both freeze-drying and spray-drying techniques. The encapsulated powders were evaluated for colour stability, encapsulation efficiency, and morphological characteristics over a 30-day storage period. Results demonstrated that spray-drying was more effective than freeze-drying in preserving colour stability, with minimal changes observed in CIELAB metrics. Among the wall materials, maltodextrin combined with either gum Arabic or Gidyea gum exhibited superior encapsulation efficiency and anthocyanin retention. Gidyea gum was a reliable microencapsulation material with comparable performance to gum Arabic. The study provides valuable insights for food manufacturers seeking to enhance anthocyanin-rich products' nutritional and aesthetic qualities while highlighting the importance of selecting appropriate wall materials and drying techniques. The findings support the development of natural, sustainable, and consumerfriendly solutions for colour stabilisation in food products.