This is paper FSR-09-28 of the Journal Series of the Dept. of Food, Bioprocessing and Nutrition Sciences, North Carolina State Univ. (Raleigh, N.C., U.S.A.). The use of trade names in this publication does not imply endorsement by the North Carolina Agricultural Research Service of the products named or criticism of similar those not mentioned. This study was funded in part by North Carolina Sea Grant and the Starkist Co.
Autolytic Degradation of Skipjack Tuna during Heating As Affected by Initial Quality and Processing Conditions
Article first published online: 17 JAN 2012
© 2012 Institute of Food Technologists®
Journal of Food Science
Volume 77, Issue 2, pages C149–C155, February 2012
How to Cite
Stagg, N. J., Amato, P. M., Giesbrecht, F. and Lanier, T. C. (2012), Autolytic Degradation of Skipjack Tuna during Heating As Affected by Initial Quality and Processing Conditions. Journal of Food Science, 77: C149–C155. doi: 10.1111/j.1750-3841.2011.02543.x
- Issue published online: 17 FEB 2012
- Article first published online: 17 JAN 2012
- MS 20110550 Submitted 4/30/2011, Accepted 10/31/2011.
Abstract: Several factors were studied as affecting protein degradation and texture of skipjack tuna muscle following ambient pressure thermal processing (precooking). These included degree of mushy tuna syndrome (MTS) evidenced in the raw meat, raw meat pH, abusive thawing/holding, and precooking temperature/time. Slurries and intact pieces from frozen skipjack tuna, either tempered for 2 h or thawed and held at 25 °C for 22 h (abusive treatment) were heated at temperatures ranging from 40 to 80 °C for up to 2 h, and also at 90 °C for 1 h, with or without prior adjustment of pH to 5 or 7 to favor cathepsin or calpain activity, respectively. Proteolysis of precooked samples was monitored by Lowry assay and SDS–PAGE; cooked texture of intact meat was measured using a Kramer shear press and by sensory profile analysis. Proteolysis maximally occurred in slurries of skipjack tuna muscle that had been abusively stored (22 h at 25 °C) and adjusted to pH 5 prior to heating at 55 °C. Intact pieces of tuna abusively thawed/held for 22 h with subsequent heating at 55 °C also evidenced the most proteolysis and were the least firm in texture. Raw fish that evidenced higher severity of MTS when raw displayed higher levels of proteolysis prior to cooking, which were further increased after cooking at 55 °C.
Practical Application: The kinetic data presented here can be used to optimize processing conditions for skipjack tuna canning to minimize textural degradation and optimize quality.