Phytic acid in Rhamdia quelen nutrition: Antioxidant or antinutrient?

The study aimed to evaluate phytic acid supplementation at different levels in diets for juveniles of silver catfish (Rhamdia quelen). Five isonitrogenous and isolipidic diets were prepared with different phytic acid concentrations (0; 5.00; 10.00; 15.00 and 20.00 g/kg). A 50-day biological test was performed in a recirculating aquaculture system composed of 20 tanks (15 fish/tank), where the animals were fed three times a day, until apparent satiety with experimental diets. After the experimental period, the fish underwent biometric measurements to collect data, blood and tissues, which were later used to determine performance, plasma and liver metabolism, digestive enzyme activity, body composition, digestive indices and activity of pro and antioxidant enzymes. Our results show that the consumption of phytic acid at a low concentration (10.00 g/kg) promotes greater performance of fish and better body composition, and it does not negatively affect digestive enzyme activity. In addition, it has reduced the activity of prooxidant enzymes and increased that of antioxidants. Thus, we can conclude that when correctly administered and directed (10.00 g/kg, in this case), phytic acid acts as an antioxidant and performance promoter for silver catfish.

Automated summary

In this study, it was found that supplementation of phytic acid at a low concentration (10.00 g/kg) promoted better performance and body composition of silver catfish, without negatively affecting digestive enzyme activity. Furthermore, phytic acid reduced prooxidant enzyme activity and increased antioxidant activity in the fish.