Autolytic Degradation of Skipjack Tuna during Heating As Affected by Initial Quality and Processing Conditions

作者：Stagg Nicola J; Amato Penny M; Gie**recht Francis; Lanier Tyre C^*

来源：Journal of Food Science, 2012, 77(2): C149-C155.

DOI：10.1111/j.1750-3841.2011.02543.x

• fish
• meat
• myosin
• proteolysis
• texture

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 degrees C for 22 h (abusive treatment) were heated at temperatures ranging from 40 to 80 degrees C for up to 2 h, and also at 90 degrees 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 SDSPAGE; 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 degrees C) and adjusted to pH 5 prior to heating at 55 degrees C. Intact pieces of tuna abusively thawed/held for 22 h with subsequent heating at 55 degrees 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 degrees C.

• 出版日期2012-2