Abstract:
The mineral spectrum of five species of tuna namely; skipjack
(Balaya, Katsuwonus pelamisi ,Yellow fin tuna (Kellawalla, Thunnus
albacares), Bullet tuna( Ragoduwa, Auxis rochei), Frigate tuna
(Alagoduwa, Auxis thazard) and kawakawa (Attawalla, Euthynnus
affinis'[ were detected in skin, red muscle, white muscle, head muscle
and belly flap using an Atomic Absorption Spectrophotometer (GBC
932 plus). Both macro and micro elements were detected in all tunas
studied. Accordingly from the recorded minerals K was the most
abundant macro element as its mean concentration among the tunas
studied ranged from 246.94±62.27 to 293.84±77.78mgIlOOg and the
highest K level among the different body parts, was recorded in the
skin (p<O.05). The second most abundant macro element was Na and
its mean concentration among all tunas varied from 135.19 ±41.04to
155.47±38.92mgIlOOg.The ratio between Na:K was 1:2 to 1:3. Skin
was five times (l03.36±67.43- 512.72±88.23mg/l00g) as rich in Ca as
Karuuarathna and Attygal/e
other body parts (9.84±2.43 - 19.32±14.47 mgllOOg) in tunas studied
except yellow fin tuna (p<0.05). Mg concentration varied from
52.95±11.68 mgllOCg t079.66±15.02mg/100g in all tunas studied and
highest values were recorded in the skin samples except for skipjack
tuna .. Fe was the most abundant micro element (2.52±1.78 -3.29±1.88
mgllOOg) followed by Zn (1.03 ±0.53mg/100g -1.70±0.88mg/lOOg).
Red muscles of all tunas were significantly rich in Fe than the other
body parts. The recorded mean values for Mn were always less than
0.2 mg/iOOg. Cu, Ni and Cr were the other trace elements studied and
those were recorded occasionally in trace amounts, and were well
below the permissible limits.
