EVALUATION OF POLYSACCHARIDE EXTRACTS FROM TWO BROWN ALGAE AS FUNCTIONAL ADDITIVE IN THE DIET OF SHRIMP Artemesia longinaris

ARZOZ, N.S.; FENUCCI, J.L.; DÍAZ, A.C.; VELURTAS, S.M.; ESPINO, M.L.; MARCOVAL, M.A,

Lima

Congreso; LAQUA 2016; 2016

WORLD AQUACULTURE SOCIETY

Use of extracts of brown algae as shrimp functional additive can be beneficial due to the antioxidant activity of the polysaccharides contained in them. A first tool to select potential compounds that prevent oxidative damage and for the future development of functional food is to measure total antioxidant activity (AT) in vitro. However, it is necessary to ensure that these additives do not interfere with the absorption of nutrients, for example by determining in vivo digestibility, these parameter is used to measure nutritional value of diets. The aims of this study were to determine the AT in hepatopancreas of A. longinaris in diets added with polysaccharide extracts of algae Undaria pinnatifida and Macrocystis pyrifera and assess apparent protein digestibility of these diets. A feeding trial was performed for 4 weeks. Shrimps (5.94 ± 1.30g) were fed diets with addition 0.5% of an inert marker Cr2O3, and with 1 or 2g of polysaccharide extracts of M. U. pinnatifida or pyrifera (U1, U2, M1 and M2, respectively) and without extract as control (C). Hepatopancreas were removed to determine the AT; estimation was based on the radical scavenging activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH). For determining digestibility, feces were collected during the last two weeks of the trial. In all hepatopancreas, the AT was observed, evidenced by the decreased concentration of DPPH (Fig. 1). However, the AT in U1, U2 and M2 treatments was significantly higher than control. For M1 the AT was not significantly different from the control treatment. In comparison, it can be seen that shrimp fed U diets showed greater AT than those fed with M. Apparent digestibility decreases significantly with the addition of 2g of both extracts, although this effect was lower in those animals fed U1 and U2 (Table 1). According to the results, the addition of 1g extract of U. pinnatifia in the diet of A. longinaris, is recommended to optimize the AT with minimal interference in the absorption of nutrients.