María Trinidad García Arias

Influence of Frozen Storage and Defrosting on the Chemical and Nutritional Quality of Sardine ((Clupea pilchardus)

Studies were carried out on the changes in solubility in SDS + β-mercaptoethanol, the -SH group content, the amino acid and the fatty acid compositions, and nutritional quality of the muscle protein following freezing, storage at -20°C and conventional defrosting of sardines (Clupea pilchardus). During the processes, 8% of the total SH- group content was lost and there was a slight drop in solubility in SDS + β-mercaptoethanol. The amino acids which dropped to the greatest extent were the S-amino acids, followed by histidine, tyrosine, leucine, lysine and phenylalanin. The C22 : 6/C16 : 0 ratio dropped and this was considered to be related to oxidation phenomena. The digestibility of protein, biological value and net protein utilization (NPU) also dropped as a result of the processes studied.