ศูนย์นวัตกรรมเทคโนโลยีหลังการเก็บเกี่ยว

Effects of feed diets on digestive proteases from the hepatopancreas of white shrimp (Penaeus vannamei).

Ezquerra, J. M.; Garcia-Carreno, F. L.;

Journal of Food Biochemistry Year: 1997 Vol: 21 Issue: 5 Pages: 401-419 Ref: 40 ref.

1997

บทคัดย่อ

Protease activities in the hepatopancreas extract (HP) from white shrimp, P. vannamei, fed on one of 7 test diets for 30 days were evaluated by several methods. The test diet contained 85% of a reference ration for shrimp and 15% of either anchovy meal, tuna waste meal, deboned white fish meal, langostilla meal, soyabean meal or 2 menhaden meals. One of the menhaden fish meals (B) tested had the lowest quality as a shrimp feed based on amino acid analysis. SDS-PAGE zymograms of HP from each of the 7 diet groups showed similar proteinase activity patterns with casein as substrate. The degree of hydrolysis of casein, measured by pH-stat, was also the same for HP from the 7 diet groups. However, total protease activity measured by azocasein hydrolysis (units/g HP) was higher for the diet group fed on the test ration containing tuna waste as a protein replacer. Trypsin and chymotrypsin activities measured with synthetic substrates (units/mg protein, units/g HP) from shrimps reared on the diet with m

enhaden meal B replacer were greater than in the other diet groups (P<0.05). The results show that a relatively small amount (15%) of a specific protein replacer in white shrimp rations can influence the protease activity of shrimp HP. Given that digestive proteases such as trypsin can leach into the muscle of postharvest shrimp and thereby cause softening of the meat, the impact of the rearing diet on postharvest shelf-life should be considered along with standard measures of feed quality that are used by the fish farmer, growth and health.