Caroteno protein, containing astaxanthin a s the prosthetic group was extracted from the carapace shells of the
lo bste r, Jasus lalandii. The materi al , with a molecular mass of a ro und 4 0 0 0 0 0 Da an d λma x 525 nm (α-c ru st a c ya n i n) ,
was re ad ily co nverte d under the c ondit ions used for ex traction and on s tanding to the subunit (β-c rust acya nin)
of molecular mass a ro und 4 0 0 0 0 Da and λmax 560 n m. The latte r complex wa s s ta ble up to 6 5 ° C a nd between pH 5
and 8 . Both the large mole cul e a nd t he su b unit showed the reversible b athochro mic s hi ft (λma x ~480 nm)
af ter be ing subjected to c ondit ions o f h eat a bove 65 ° C and b elow 85 °C and pH be tween 3 a nd 10, w hich alter
th e n at ural protein o ri entation . Above 85 °C and out side of th e pH range, the shif t was irreversibl e. Crus-
tac yanin fro m J. lalandii d i f f e re d f ro m t h e b l u e c r u s t a c ya n i n o f t h e Homarus species with respect to visible spectra
(λmax 632 nm and λmax 585 n m) an d by d isp lay ing a hy pso chro mic shif t b et ween t he α-and β-crustacyanin.
St a b i l i t y o f t h e α-crustacyanin and affinity to DE 52 also differed. Ye llow prote in, wit h a λmax 409/410 n m as
des c rib e d f o r the Homarus species was not de tected i n this J. lalandii s tud y, altho ugh it may h ave b een co -el ute d. The
prope rties of the ext racted comp lex show pote ntial fo r its use as a natural water sol uble food c olourant or
temp eratu re s ensit ive indicator.