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.
Selected fatty acid contents of cooked n-3 PUFA enriched trout fillets / BADIANI A.; TESTI S.; SILVI M.; ZIRONI E.; BONALDO A.; PECCHINI A.; GATTA P.P.. - STAMPA. - 1:(2004), pp. 69-72. (Intervento presentato al convegno 34th Annual Plenary Meeting of the West European Fish Technologists Association tenutosi a Lubeck, Germany nel September 12-15, 2004).
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.
