eng Enviro Research Publishers Current Research in Nutrition and Food Science Journal 2347-467X 2322-0007 2026-08-31 14 2 1005 1017 10.12944/CRNFSJ.14.2.20 26774 article Nguyen Duy Linh 1 Do Thi Hong Tuoi 3 Nguyen Ngoc Hoa 4 Huynh Hoang Nhu Khanh 5 Vo Thanh Trung 6 Dang Xuan Cuong 7 Institute of Biotechnology and Food Technology, Industrial University of Ho Chi Minh City, Ho Chi Minh City, Viet Nam Innovation Department, Department of Science and Technology of Lam Dong Province, Lam Dong Province, Viet Nam Personnel organization at Ho Chi Minh City University of Medicine and Pharmacy, Ho Chi Minh City, Viet Nam International Analysis Center, Ho Chi Minh City University of Industry and Trade, Ho Chi Minh City, Viet Nam Department of Marine Biochemistry and Biotechnology, Institute of Oceanography, VAST, KhanhHoa Province, Viet Nam Department of Aquaculture and Processing Technology, Institute of Oceanography, VAST, KhanhHoa Province, Viet Nam The study focused on comparing the chemical composition and antioxidant and anti-aging activities of marine- and terrestrial-derived biomaterials. Six species of brown seaweeds (Sargassumspp. and Turbinariaornata) and three dragon fruit varieties (red-fleshed, white-fleshed, and yellow-peel white-fleshed) were investigated. Phenolic and phlorotannin fractions were extracted using 70% aqueous ethanol, whereas polysaccharide fractions were obtained by hot-water extraction followed by ethanol precipitation. The contents of fucoidan, alginate, soluble polysaccharides, polyphenols, phlorotannins, vitamin C, and total minerals were determined using standard chemical methods. Antioxidant activity was determined using DPPH, ABTS, and FRAP method, while anti-aging activity was assessed based on the inhibitory effects against tyrosinase, elastase, and hyaluronidase using UV–Vis spectrophotometric methods. The results showed that brown seaweeds contained high levels of structural polysaccharides and minerals (fucoidan 0.59–2.36% DW; alginate 18.62–30.67% DW) and exhibited moderate antioxidant and enzyme inhibitory activities. In contrast, red-fleshed dragon fruit (Hylocereuspolyrhizus) demonstrated the strongest antioxidant and anti-aging activities, which were closely associated with its high contents of polyphenols, betalains, and vitamin C. The study highlights distinct bioactivity mechanisms between marine polysaccharide-based systems and fruit-derived low-molecular-weight antioxidant systems. https://www.foodandnutritionjournal.org/volume14number2/seaweed-and-dragon-fruit-in-lam-dong-province-vietnam-chemical-composition-and-antioxidant-and-anti-aging-activities/ Antioxidant activity Anti-aging enzymes Brown seaweeds Dragon fruit Functional materials Polysaccharides