Phan-Phuong-Trang Huynh1, Thanh-Tri Do2, Thanh-Cong Nguyen3, My-Ngoc Bui3, Tuan-Loc Le4, Thanh-Luu Pham5, Hoang-Dung Tran1*
1Faculty of Biology and Environment, Ho Chi Minh City University of Industry and Trade (HUIT), 140 Le Trong Tan Street, Tay Thanh ward, Ho Chi Minh City 72009, Vietnam
2Faculty of Biology, Ho Chi Minh City University of Education, 280 An Duong Vuong street, Cho Quan ward, Ho Chi Minh City 72820, Vietnam
3Institute of Applied Research and Technology Transfer HUFI, Ho Chi Minh City University of Industry and Trade, 93 Tan Ky Tan Quy Street, Tan Son Nhi ward, Ho Chi Minh City 72011, Vietnam
4Department of Biotechnology, Faculty of Applied Science and Technology, Nguyen Tat Thanh University, 1165 National Road 1A, Ho Chi Minh City, Vietnam
5Faculty of Environment and Labour Safety, Ton Duc Thang University, 19 Nguyen Huu Tho Street, Tan Hung ward, Ho Chi Minh City 700000, Vietnam
*Corresponding author’s email: dungth@huit.edu.vn
Received: 27 August 2025 / Revised: 13 November 2025 / Accepted: 21 November 2025 / Published Online: 29 November 2025
Abstract
Phycocyanin is a blue pigment–protein with antioxidant properties, but its use in foods is limited by poor stability. A cyanobacterium, Leptolyngbya sp. CCAH036/1, was isolated from the Can Gio Mangrove Biosphere Reserve, Vietnam, and identified by morphology and 16S rRNA sequencing (96.5% similarity to the closest reference). C-phycocyanin was extracted by freeze–thaw and lysozyme treatment and then encapsulated with maltodextrin using spray drying. The optimized powder contained 20.53 mg/g phycocyanin, 5.14% moisture, 79.43% encapsulation efficiency, and 56.66% antioxidant retention. After three weeks of storage at 4 °C, both pigment content and antioxidant activity remained above 80%. Heating at 50–70 °C preserved about half of the activity, but stronger heat caused rapid decline. Stability was also greatest at pH 5–7. The powder was added to sticky rice mooncakes at 5–20%. At 15% supplementation, the cakes contained 1.874 mg/g phycocyanin and 43.78% antioxidant activity, with no loss of texture or sensory quality. The results indicate that spray drying with maltodextrin is recommended as an effective approach to stabilize phycocyanin from the local Leptolyngbya strain for incorporation into functional foods processed at moderate temperatures and near-neutral pH.
Keywords: Phycocyanin, Leptolyngbya sp., Microencapsulation, Spray-drying, Antioxidant, Mooncake
