Protein breakdown during the preparation of frozen batter-coated squid rings.

摘要

This study investigated the main chemical and microstructural changes in squid proteins during processing as a frozen batter-coated product using different coatings. Protein bands of the squid and of the batters used for coating were studied using SDS-PAGE. Results indicated that it is not only the proteins in the batter layer, which are directly exposed both to the frying oil and to freezing temp., that deteriorate during the preparation process; the protein fraction of the squid substrate, mainly the myofibrillar proteins, is also degraded. At a microstructural level, big voids were generated during freezing as a consequence of the packing of the fibres, although the size of these voids decreased after final frying. After this step of the process, the central sarcoplasm was still visible, but was altered by coagulation of the sarcoplasmic proteins, and the sarcolemma was observed to be separate from the myofibrillar package.