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INFLUENCE OF HARVEST SEASON ON THE PROTEOLYTIC ACTIVITY OF HEPATOPANCREAS AND MANTLE TISSUES FROM JUMBO SQUID ( DOSWICUS GIGAS )
Author(s) -
EZQUERRABRAUER JOSAFAT MARINA,
HAARD NORMAN F.,
RAMÍREZOLIVAS ROSALINA,
OLIVASBURROLA HERMENEGILDO,
VELAZQUEZSÁNCHEZ CARLOS J.
Publication year - 2002
Publication title -
journal of food biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.507
H-Index - 47
eISSN - 1745-4514
pISSN - 0145-8884
DOI - 10.1111/j.1745-4514.2002.tb00766.x
Subject(s) - hepatopancreas , protease , chemistry , food science , trypsin , biochemistry , biology , enzyme
ABSTRACT Jumbo squid (Dosidicus gigas) size and protease activities were evaluated after harvest in April (A) and November (N). A were smaller (560±120 g vs 6040±1130 g) and hepatopancreas was a larger percent of body weight (8.3±2.5 vs 4.6±2.1). Mantle from A had lower water (73.9±l.l vs 79.1± 1.2) and higher protein (29.0±1.1 vs 23.1±0.8). Lipid and protein contents of N and A hepatopancreas tissues did not differ (P < 0.05). Azocaseinolytic, trypsin‐like, chymotrypsin‐like, aminopeptidase, and carboxypeptidase activities were detected in mantle (ME) and hepatopancreas extracts (HPE). HPE and ME from N had higher activity than A for all substrates (P < 0.05). With azocasein substrate, HPE activity from A had a pH optimum of 5 ‐ 6 and a temperature optimum of 70C, whereas HPE from Nhad highest activity at pH 9 and 40–70C. ME from A had maximum proteolytic activity at pH 6 and 60C, whereas that from N had maximum activity at pH 10 and 40C. SDS‐PAGE zymograms of HPE from A and N revealed different patterns of activity and 1 and 2 major protease zones, respectively .