Anais do Simpósio Latino Americano de Ciências de Alimentos
Proceedings of 14 SLACA - Latin American Symposium on Food Science

The objective of this study was to develop an oral antioxidant additive based on grape marc extract microparticles for salmonids. Red grape marc extract (GME) was prepared at a ratio of 5 g of dry GM:100 mL of distilled water, stirred at 60°C/1 h. GME was microencapsulated (GMEM) by spray drying using maltodextrin at 12 (GMEM-12), 24 and 36g/100mL of extract. GME showed high phenol content (20.7±1.5 mgGAE/g) and ORAC (1,133±352 µmolesTE/g). GMEM were light-purple, rounded microparticles, sizes ranging from 10-15 µm. The yield was high and decreased as maltodextrin increases, ranging from 68-77%. Total phenol content and ORAC decreased with increasing amount of maltodextrin, being higher for GMEM-12 with 8.5 mgGAE/g and 334 µmolesTE/g, respectively. The encapsulation efficiency was high and similar for all the GMEM (93-94%). Then, GMEM-12 was used to formulate three experimental plant-based extruded diets: control (0%-GMEM), and two diets with 1% and 2% GMEM. Rainbow trout, weighing 90 g (N=450, 3 replicates) were distributed to the diets. Blood samples were taken from 9 fish/diet at 0, 6, 12, and 24 hours (short term), and at 30, 60 and 90 days (long term). In the short-term study, it was observed that plasma from fish fed the 2%-GMEM diet presented higher ORAC values compared to the 0%-GMEM diet, at all sampling points. In the long term, fish fed the 1%-GMEM diet have a significant better plasma ORAC at days 30 and 60. At day 90 this effect disappears. In conclusion, simple processes of aqueous extraction and encapsulation by atomization allow to convert a waste into an feed additive with high antioxidant activity, in the form of micropowder, which could be easily included in diets for productive animals or fish. This additive significantly improves the antioxidant capacity of trout plasma in the short and long term.