Influência de processos de cocção no perfil de ácidos graxos dos filés de merluza (Merluccius hubbsi) e pescadabranca (Cynoscion leiarchus)

Abstract

It was determined the fatty acid profile in raw hake fillet (Merluccius hubbsi) and smooth weakfish (Cynoscion leiachurs) and subjected to different cooking methods: stewed, grilled and baked in conventional oven and using combined oven and microwave oven. In the raw fish, twenty-six fatty acids were identified. It is generally noticed that the cooking methods that best preserved most of the MUFA and PUFA are related to treatments that used wet heat specially the oleic acids, DHA and EPA. Concerning the EPA acid, it is perceived that the lower contents were for GRI, MIW and GCO methods and for DHA were the GRI, BEO and MIW treatments, that is, using both dry heat and microwaves. The treatments promoted a significant reduction (p <0.05) lower when compared to the crude samples in the majority of the fatty acids, being the ones that more preserved the fatty acids, including the 3 acids, were those that used humid heat, independent of the species of fish studied. For the indexes of atherogenicity (IA) and thrombogenicity (IT) and the ratio between the hypocholesterolemic and hypocholesterolemic acids (HIPO/HIPER), it is noticed that as the values in the ration H/H increase there is a decrease of the values of IA and IT, being desirable under the nutritional aspect. The HIPO/HIPER ratios were better for the BCO and SCO methods, which differed from RAW (p < 0.05). In the multivariate analysis, it can be perceived that the fatty acids profiles resulted from the different conditions of the thermal treatments, such as time and cooking temperature. Taking the importance of fatty acids to health into account, the results of this study indicate the necessity of identifying thermal treatments that best preserve the nutritional characteristics of food, being essential to highlight that the ideal thermal treatments for this study were steam combined oven.