The aim of this study was to determine to what extent rainbow trout fillets fortifyied with selected n-3 polyunsaturated fatty acids (PUFA) and cooked by moist- or dry-heat cooking methods could meet the adequate intake of adults for alpha-linolenic acid (LNA, C18:3 n-3), eicosapentaenoic acid (EPA, C20:5 n-3) and docosahexaenoic acid (DHA, C22:6 n-3). n-3 PUFA enriched rainbow trout (Oncorhynchus mykiss Walbaum) were produced as described by Gatta et al. (2004, same proceedings). At the 75th day of the trial, 6 batches of fish (3 fish each) were randomly sampled for each diet. Fish were immersed in ice-cold water for slaughter, gutted, filleted and boned. Within batch, 3 skin-on fillets were destined for baking-in-foil in a preheated forced air convection oven, to exemplify “convection + moist-heating” (OB), while their counterparts were pan-fried in a Teflon-coated pan to exemplify “conduction + dry-heating” (PF). Cooking was discontinued upon reaching 65-70°C. All fillets from each subsample of fish (i.e. cooking method within batch) were skinned, ground together and thoroughly mixed to provide a homogeneous composite paste, which was analysed for lipid and fatty acid contents (g/100 g edible portion). Lipid content did not differ significantly among diets (mean  standard error: OB=7.390.30; PF=7.190.32). On the whole, PUFA contents of cooked fillets were not affected by cooking method. Linoleic acid (LA, C18:2n-6) and arachidonic acid (AA, C20:4 n-6) did not differ among diets (LA range=0.89-1.06; AA range=0.12-0.16). LNA content was significantly higher in D1 cooked fillets (D1=0.44 x; D2=0.23 y; D3=0.20 y). EPA content predominated in D2 cooked fillets (D1=0.19 z; D2=0.43 x; D3=0.27 y). DHA was significantly more represented in D3 cooked fillets (D1=0.79 y; D2=1.10 x; D3=1.13 x). n-6/n-3 did not differ among diets, ranging between 0.62 and 0.66. With reference to the adequate intake of adults recently issued for LNA, and DHA+EPA (2.22 and 0.65 grams/day, respectively, for a 2000 kcal diet), a 100-g serving of the cooked fillets were able to give the following average contribution: D1=20 and 151%; D2=10 and 235%; D3=9 and 215%, respectively. In conclusion, selective n-3 PUFA fortification generated trout fillets which, regardless of the cooking method used, could provide considerable amounts of the suggested adequate intake.
BADIANI A., TESTI S., SILVI M., ZIRONI E., BONALDO A., PECCHINI A., et al. (2004). Selected fatty acid contents of cooked n-3 PUFA enriched trout fillets.. HAMBURG : German Fed. Res. Centre for Nutrition and Food.
Selected fatty acid contents of cooked n-3 PUFA enriched trout fillets.
BADIANI, ANNA;TESTI, SILVIA;SILVI, MARINA;ZIRONI, ELISA;BONALDO, ALESSIO;GATTA, PIER PAOLO
2004
Abstract
The aim of this study was to determine to what extent rainbow trout fillets fortifyied with selected n-3 polyunsaturated fatty acids (PUFA) and cooked by moist- or dry-heat cooking methods could meet the adequate intake of adults for alpha-linolenic acid (LNA, C18:3 n-3), eicosapentaenoic acid (EPA, C20:5 n-3) and docosahexaenoic acid (DHA, C22:6 n-3). n-3 PUFA enriched rainbow trout (Oncorhynchus mykiss Walbaum) were produced as described by Gatta et al. (2004, same proceedings). At the 75th day of the trial, 6 batches of fish (3 fish each) were randomly sampled for each diet. Fish were immersed in ice-cold water for slaughter, gutted, filleted and boned. Within batch, 3 skin-on fillets were destined for baking-in-foil in a preheated forced air convection oven, to exemplify “convection + moist-heating” (OB), while their counterparts were pan-fried in a Teflon-coated pan to exemplify “conduction + dry-heating” (PF). Cooking was discontinued upon reaching 65-70°C. All fillets from each subsample of fish (i.e. cooking method within batch) were skinned, ground together and thoroughly mixed to provide a homogeneous composite paste, which was analysed for lipid and fatty acid contents (g/100 g edible portion). Lipid content did not differ significantly among diets (mean standard error: OB=7.390.30; PF=7.190.32). On the whole, PUFA contents of cooked fillets were not affected by cooking method. Linoleic acid (LA, C18:2n-6) and arachidonic acid (AA, C20:4 n-6) did not differ among diets (LA range=0.89-1.06; AA range=0.12-0.16). LNA content was significantly higher in D1 cooked fillets (D1=0.44 x; D2=0.23 y; D3=0.20 y). EPA content predominated in D2 cooked fillets (D1=0.19 z; D2=0.43 x; D3=0.27 y). DHA was significantly more represented in D3 cooked fillets (D1=0.79 y; D2=1.10 x; D3=1.13 x). n-6/n-3 did not differ among diets, ranging between 0.62 and 0.66. With reference to the adequate intake of adults recently issued for LNA, and DHA+EPA (2.22 and 0.65 grams/day, respectively, for a 2000 kcal diet), a 100-g serving of the cooked fillets were able to give the following average contribution: D1=20 and 151%; D2=10 and 235%; D3=9 and 215%, respectively. In conclusion, selective n-3 PUFA fortification generated trout fillets which, regardless of the cooking method used, could provide considerable amounts of the suggested adequate intake.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
