Abstract:
Fishbones are one of the main sources of Calcium and other minerals. During fish processing,
nearly 30-60% of fish body weight discard as head, skin, viscera, backbones, and fins. The
objective of the present study was to the extraction of bone powder from Yellowfin Tuna (Thunnus
albacares) and Swordfish (Xiphias gladius) bones & analysis their mineral contents. Yellowfin
Tuna and Swordfish bones were collected from a local fish processing company. Frozen bones
were thawed for 16 hours at 20°C to remove ice. Large flesh parts were removed from bones and
cut into 10cm size pieces and the remaining minor flesh particles were removed by soaking in 2M
NaOH for 24 hours at room temperature. Bones were first washed with tap water to remove fat,
dissolved protein, aroma, and to remove microorganisms bones were kept in 0.1% citric acid (bone
material to citric acid ratio of 1:5 (w/v) for 0.5 h) and 5% H2O2 (bone material to H2O2 ratio of 1:5
(w/v), twice for 1 h) respectively. Further washed with tap water, dried, and grounded. Moisture
and ash contents were analyzed by moisture meter (KERN, DBS60-3) at 105°C and Muffle
Furnace (Labtech, LEP-P Type) at 550 °C for 16 hours respectively. Yellowfin tuna bone powder
has 1.44% ash and 6.57% moisture content and Swordfish bone powder have 1.59% ash content
and 6.35% moisture content respectively. P percentage was measured by Spectrophotometric
Vanado Molybolate Method and Ca and other minerals were analyzed by Atomic Absorption
Spectrophotometry after dry ashing. Dried Yellowfin tuna bone powder has Ca-15.5±0.45%, P-
8.0±0.36%, Zn-8.3±0.4mg/kg, Fe-46.0±0.20mg/kg, Mn -7.3±0.46 mg/kg, Na-1.5±0.06%, Mg-
0.25±0.03%, K-357±1.73mg/kg. Further, dried Swordfish bone powder has Ca-13.2±0.25%, P-
7.8±0.25%, Zn-8.0±0.15mg/kg, Fe-10.7±0.25mg/kg,Mn-2.0±0.17mg/kg,Na-1.25±0.02%,Mg-
0.25±0.03%,K-454±2.65mg/kg. The results of the present study shows Ca:P of the yellowfin tuna
and sword fishbone powder nearly similar to the Ca:P of the human bones(2:1). The present study
concludes that Yellowfin tuna and Swordfish bone powder are rich in Ca, P, and other
microelements and can be used for the preparation of inexpensive and environmentally friendly
value-added products such as Calcium tablets and diet supplements.
Keywords: Fish waste; Value-added products; Bone powder; Economy
