This study was undertaken within the frame of an ongoing project directed at fortifying rainbow trout fillets with selected beneficial n-3 polyunsaturated fatty acids (PUFA), namely alpha-linolenic acid (LNA, C18:3 n-3), eicosapentaenoic acid (EPA, C20:5 n-3) and docosahexaenoic acid (DHA, C22:6 n-3). Triplicate groups of rainbow trout (Oncorhynchus mykiss Walbaum) weighing 150-160 g were fed 3 diets at 26% lipid, 15% of which was as follows: D1, linseed oil; D2, EPAX 4510 TG (a glyceride containing min. 44% EPA and max. 15% DHA; Pronova Biocare, Lysaker, Norway); D3, EPAX 1050 TG (a glyceride containing max. 17% EPA and min. 50% DHA; ditto). Fish were sampled and analysed every 15 days for lipid content and fatty acid composition of the fillets, special attention being paid here to examine selected PUFA concentrations (as % fatty acid methyl esters) obtained within the first 60 days of the trial. At the 60th day, lipid content (g/100 g edible portion) did not differ significantly among diets (D1=8.18; D2=8.41; D3=7.74). D1 fillets had the highest concentration of LNA (D1=7.30 x; D2=3.32 y; D3=3.35 y), which increased by 58.35% compared with the start of the trial. EPA concentration was significantly higher in D2 fillets (D1=3.34 z; D2=5.88 x; D3=4.16 y), marking a 44.12% increase. D3 fillets were found to have a significantly higher DHA concentration (D1=13.93 y; D2=15.35 y; D3=17.81 x), the increase being more modest in this case (9.40%). As to the response in term of the most important n-6 PUFA concentrations in the fillets, a small but significant difference emerged among diets for linoleic acid (LA, C18:2 n-6; D1=14.79 x; D2=14.15 y; D3=14.40 xy), whereas no difference was observed for arachidonic acid (AA, C20:4 n-6, range 2.21-2.34). At the 60th day, n-6/n-3 did not differ among diets (D1=0.64; D2=0.60; D3=0.61), whereas significant differences emerged as to LNA/n-3 PUFA, LNA/EPA+DHA, EPA/DHA, LA/LNA, EPA/AA. These preliminary results indicate there is considerable scope for producing rainbow trout fillets to attain different n-3 PUFA levels and pertaining health-related ratios.
Tailoring the fatty acid composition of trout fillets for health purposes - Preliminary results.
GATTA, PIER PAOLO;TESTI, SILVIA;SILVI, MARINA;PAGLIUCA, GIAMPIERO;BONALDO, ALESSIO;BADIANI, ANNA
2004
Abstract
This study was undertaken within the frame of an ongoing project directed at fortifying rainbow trout fillets with selected beneficial n-3 polyunsaturated fatty acids (PUFA), namely alpha-linolenic acid (LNA, C18:3 n-3), eicosapentaenoic acid (EPA, C20:5 n-3) and docosahexaenoic acid (DHA, C22:6 n-3). Triplicate groups of rainbow trout (Oncorhynchus mykiss Walbaum) weighing 150-160 g were fed 3 diets at 26% lipid, 15% of which was as follows: D1, linseed oil; D2, EPAX 4510 TG (a glyceride containing min. 44% EPA and max. 15% DHA; Pronova Biocare, Lysaker, Norway); D3, EPAX 1050 TG (a glyceride containing max. 17% EPA and min. 50% DHA; ditto). Fish were sampled and analysed every 15 days for lipid content and fatty acid composition of the fillets, special attention being paid here to examine selected PUFA concentrations (as % fatty acid methyl esters) obtained within the first 60 days of the trial. At the 60th day, lipid content (g/100 g edible portion) did not differ significantly among diets (D1=8.18; D2=8.41; D3=7.74). D1 fillets had the highest concentration of LNA (D1=7.30 x; D2=3.32 y; D3=3.35 y), which increased by 58.35% compared with the start of the trial. EPA concentration was significantly higher in D2 fillets (D1=3.34 z; D2=5.88 x; D3=4.16 y), marking a 44.12% increase. D3 fillets were found to have a significantly higher DHA concentration (D1=13.93 y; D2=15.35 y; D3=17.81 x), the increase being more modest in this case (9.40%). As to the response in term of the most important n-6 PUFA concentrations in the fillets, a small but significant difference emerged among diets for linoleic acid (LA, C18:2 n-6; D1=14.79 x; D2=14.15 y; D3=14.40 xy), whereas no difference was observed for arachidonic acid (AA, C20:4 n-6, range 2.21-2.34). At the 60th day, n-6/n-3 did not differ among diets (D1=0.64; D2=0.60; D3=0.61), whereas significant differences emerged as to LNA/n-3 PUFA, LNA/EPA+DHA, EPA/DHA, LA/LNA, EPA/AA. These preliminary results indicate there is considerable scope for producing rainbow trout fillets to attain different n-3 PUFA levels and pertaining health-related ratios.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
