Samples of fresh, frozen and heat- treated skipjack tuna muscle were observed by scanning electron mieros copy. The photomicrographs were used to assess changes in the microstructure of fish muscle during frozen storage and thermal processing . Differences noted in frozen tissue could be related to the formation of gaps between fibers and the deformation of muscle fibers . No freeze mediated damage to the cell wall was observed at the lower limits, 20,000x, of high resolution scanning electron microscopy. The degree of muscle fiber shrinkage and erosion and the behavior of certain protein fractions was found to be affected by thermal processing. Granular material presumed to be primarily sarcoplasmic proteins aggregated at the surface of the muscle fiber and in the interstices between the sarcolerrwna and the muscle fiber . The sarcomere was disrupted upon precooking. The I-band and the A-band have congea ed to form a single band which constitutes the majority of the sarcomere.
Lampila, L. E. and Brown, W. D.
"Changes in the Microstructure of Skipjack Tuna During Frozen Storage and Heat Treatment,"
Food Structure: Vol. 5
, Article 4.
Available at: http://digitalcommons.usu.edu/foodmicrostructure/vol5/iss1/4