@article{jbph2026_pitoyo54,
  author    = {Ariel Maximillian Pitoyo and Amir Husni},
  title     = {Effect of Ultrasonic Amplitude on Extraction Yield, Phytochemical Indicators, and Antioxidant Capacity of Sargassum hystrix},
  journal   = {Journal of Biosciences and Public Health},
  year      = {2026},
  volume    = {2},
  number    = {4},
  pages     = {381-391},
  doi       = {10.5455/JBPH.2026.20},
  issn      = {3104-8749},
  publisher = {4Green Research Society},
  language  = {English},
  keywords  = {Amplitude; Antioxidant capacity; Brown macroalgae; Phytochemical indicators; Sargassum hystrix; Ultrasound-assisted extraction},
  abstract  = {Sargassum hystrix is a brown macroalga containing compounds with potential antioxidant activity. This study evaluated the effect of nominal ultrasound amplitude on extraction yield, Folin–Ciocalteu reducing capacity reported as total phenolic content-equivalents (TPC-equivalents), total flavonoid content (TFC), and antioxidant responses of S. hystrix extracts. A completely randomized design compared ultrasound-assisted extraction (UAE) at 50%, 60%, 70%, 80%, and 90% amplitude with 24-h maceration as a reference treatment. The solvent concentration, solid-to-liquid ratio, extraction time, pulse cycle, particle size, and other operating conditions were fixed. The 70% treatment gave the highest reported TPC-equivalents (76.79 ± 0.97 mg GAE/g), TFC (115.38 ± 1.09 mg QE/g), and FRAP response (81.15 ± 0.69 µmol Fe²⁺/g), and the lowest DPPH IC₅₀ (502.30 ± 6.89 ppm) among the tested settings. Maceration produced the highest gravimetric yield (1.85 ± 0.09%), whereas the 70% treatment produced 1.70 ± 0.22%. Exploratory quadratic fits to the five UAE treatment means showed curved amplitude-response patterns, but inferential regression requires the replicate-level dataset. GC–MS tentatively assigned 47 compounds in the 70% extract, with major relative peak areas for n-hexadecanoic acid (13.94%), oleic acid (13.17%), and cis-7-hexadecenoic acid (10.28%). The lower responses observed at 80–90% amplitude is reported as an association; compound degradation, heating, oxidation, and other mechanisms were not directly measured. Thus, 70% was the most effective amplitude among the tested settings under the selected extraction conditions, not a globally optimized UAE condition.},
  url       = {https://www.jbph.org/article/details/effect-of-ultrasonic-amplitude-on-extraction-yield-phytochemical-indicators-and-antioxidant-capacity-of-sargassum-hystrix}
}