Biochemical and physicochemical properties of thermally treated natural actomyosin extracted from normal and PSE pork Longissimus muscle

• Published in: Food chemistry Vol. 113; no. 1; pp. 21 - 27
• Main Authors: Wang, Haihong, Pato, Mary, Pietrasik, Zeb, Shand, Phyllis
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-03-2009; [Amsterdam]: Elsevier Science
• Subjects: Actomyosin; animal tissue extracts; biochemical compounds; Circular dichroism; color; cooking quality; Differential scanning calorimetry; Disulphide; Dynamic rheology; food analysis; food composition; Gelation; hardness; heat treatment; hydrophobicity; longissimus dorsi; meat quality; myofibrils; natural additives; pork; PSE pork; rheological properties; Surface hydrophobicity; Differential scanning calorimetry; Actomyosin; Dynamic rheology; Gelation; Disulphide; Surface hydrophobicity; PSE pork; Circular dichroism
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2008.06.084

Biochemical and physicochemical properties of thermally treated natural actomyosin (NAM) from normal and pale, soft and exudative (PSE) pork were studied. About 37% and 25% of available sulphydryl groups formed disulphide bonds or other permanent chemical bonds at 70
°C in NAM from normal and PSE pork, respectively. Surface hydrophobicities of NAM from normal and PSE pork at 70
°C were 3.6 and 2.4 times greater than that at 40
°C. About 90% of the α-helical structure of NAM was lost by heating to 70
°C. The temperature at maximum α-helical content decline of NAM was in accordance with the peak 3 thermal transition obtained by differential scanning calorimetry and the lowest storage modulus (
G′) during thermal rheology. NAM from normal pork underwent aggregation with a higher extent of hydrophobic interaction and disulphide bonds, higher temperatures at maximum velocity for conformational change and unfolding than that from PSE pork. As a consequence, NAM from normal pork had superior rheological properties.