Changes in physicochemical properties and microstructure of dried squid during softening treatment

Dried squid were prepared at 4 or 40 °C and softened first in water and then in alkaline solution. The physicochemical and structural changes in the dried squid during the softening treatment were examined. A significantly higher wet weight was observed for the 4 °C‐dried squid during the softening treatment compared with the 40 °C‐dried squid. The rupture stress and rupture energy of the 40 °C‐dried squid were significantly higher than those of the 4 °C‐dried squid during the softening treatment. The sodium dodecyl sulphate polyacrylamide slab gel electrophoresis (SDS‐PAGE) pattern of the 4 °C‐dried squid was almost the same as that of raw squid. The SDS‐PAGE pattern of the 40 °C‐dried squid showed many fragments of lower molecular weight. After soaking in distilled water the SDS‐PAGE pattern of the 40 °C‐dried squid did not change significantly; however, the SDS‐PAGE pattern of the 4 °C‐dried squid became the same as that of the 40 °C‐dried squid. Histological analysis by light microscopy showed the formation of muscle fibre bundles in the 40 °C‐dried squid. A higher water permeation was observed among the muscle fibres of the alkali‐softened 4 °C‐dried squid when compared with the alkali‐softened 40 °C‐dried squid. Copyright © 2003 Society of Chemical Industry