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Improving calcium bioavailability from fish bone waste: the role of sodium hydroxide in bio‑calcium extraction from tilapia (Oreochromis niloticus) bones
Author(s)
Senphan, Theeraphol
Mungmueang, Natthapong
Choommongkol, Vachira
Kishimura, Hideki
Kittiphattanabawon, Phanat
Benjakul, Soottawat
Date Issued
October 1, 2025
Type
Article
Abstract
Calcium deficiency is a global health issue motivating the search for sustainable calcium sources from aquaculture waste. This study investigated sodium hydroxide (NaOH) concentration effects on bio‑calcium quality and bioavailability extracted from tilapia (Oreochromis niloticus) bones. Tilapia bones were treated with 0.5 M, 1 M, and 2 M NaOH solutions for 30 min compared to untreated controls. Increasing NaOH concentrations decreased yield while improving brightness, ash content, and calcium bioavailability. The 2 M NaOH treatment produced bio‑calcium with highest calcium bioavailability (8.57 %), surpassing both control (7.26 %) and commercial calcium carbonate (0.72 %) by 12-fold. Higher NaOH concentrations reduced moisture, protein, and fat contents while increasing hydroxyproline and decreasing lipid oxidation. SEM showed smoother surfaces with homogeneous pores in 2 M NaOH-treated samples. ATR-FTIR and EDS confirmed consistent hydroxyapatite structure. This optimization provides a sustainable approach for converting fish waste into high-bioavailability calcium supplements, supporting circular economy in aquaculture while addressing global calcium deficiency.
Citation
Food Chemistry X, 31, 2025