Quality Changes and Browning Developments During Storage of Dried-Seasoned Squid (Dosidicus gigasandOmmastrephes bartrami)

The physicochemical changes—moisture, water activity, crude protein, total volatile basic nitrogen (TVB-N), trimethylamine oxide (TMAO), dimethylamine (DMA) and formaldehyde, reducing sugar and amino acid; microbiological changes—aerobic plate count (APC) and coliforms; and browning development (browning intensity and color) in dried-seasoned squids (Dosidicus gigas and Ommastrephes bartrami) during storage at 25°C were investigated. After the storage, the moisture and water activity decreased significantly. The content of crude protein decreased, accompanied by progressive accumulation of TVB-N and slow increase of APC. The high level of TMAO in dried-seasoned squid gradually decreased, whereas DMA and formaldehyde increased significantly during the whole period of storage. The browning intensity and b* value significantly increased, which revealed the occurrence of browning in two squid products. The dominant reducing sugar, lactose, and glucose, and the total amino acid including lysine and proline, decreased remarkably, which were well-correlated with the browning development. The quality deterioration in jumbo squid was more rapid than in neon flying squid partially due to the high level of reducing sugar in the former product. To improve quality and resist browning reaction of dried squid product during storage, the addition of extrinsic reducing sugar became a control factor.