Effects of different wet heating methods on the water distribution, microstructure and protein denaturation of pork steaks

Abstract

This study aimed to investigate the influence of different wet heating methods (SC: steam cooking; BC: boiling cooking) on the water distribution, microstructure and protein denaturation of pork steaks. Results showed that SC increased the proton relaxation intensity (T1 and T2) and the amount of immobilized water, but decreased the amount of free water compared with BC treatment. Proton density images showed that the red area was more in SC treatment than BC treatment. Muscle volume contraction and microstructure destruction in SC treatments were lower than that of BC treatments. Meanwhile, SC had higher protein solubility, but lower surface hydrophobicity as compared with BC. Additionally, pork steaks containing salt cooked by the same heating method had higher water mobility than those of without salt. Moreover, salting process aggravated the swelling of muscle fibre structure and protein denaturation.

Role of Intramuscular Connective Tissue in Water Holding Capacity of Porcine Muscles

“…A shorter T 22 indicated lower mobility of entrapped protons and therefore reflected more protein denaturation. These results were accordant to Table 1 and Song [ 21 ].…”

“…Three populations can be divided into bound water ( T 21 , 0.1–10 ms), immobilized water ( T 22 , around 100 ms) and free water ( T 23 , 100–1000 ms) [ 16 , 20 , 21 ]. Their relative percentages are shown as A 21 , A 22 and A 23 in Table 1 .…”

“…The increment of T 22 and A 22 indicated that the mobility of immobilized water was enhanced [ 25 ], that is to say, the immobilized water mobility of ST was enhanced. The longer T 22 in the meat matrix is related to the higher mobility of entrapped protons [ 21 ]. H-proton has fewer degrees of freedom, which indicates that the hydrogen bond energy of retained immobilized water is higher [ 32 ].…”

“…The nuclear magnetic resonance spin–spin relaxation ( T 2 ) was measured by LF-NMR . Three populations can be classified as bound water ( T 21 , 0.1–10 ms), immobilized water ( T 22 , around 100 ms) and free water ( T 23 , 100–1000 ms) [ 16 , 20 , 21 ]. The relative percentages of the three fractions of water are showed as A 21 , A 22 and A 23 .…”

Insight into Antioxidant Activity and Peptide Profile of Jinhua Ham Broth Peptides at Different Cooking Times

“…Previous studies have shown that high-temperature heating can cause the fracture of myofibrils [ 23 ] and collagen fibers [ 24 ] in meat and give rise to significant changes in ultrastructure. The Z-lines of myofibrils were broken and the M-lines became blurred.…”