title: Pressure shift freezing of pork muscle: effect on color, drip loss, texture, and protein stability.
abstract: Cylindrical specimens (50 mm diameter and 160 mm length) of fresh pork muscle (boneless rib portions) packed in plastic bags were frozen by pressure shift freezing (PSF) at 100, 150, and 200 MPa, air blast freezing (ABF), and liquid immersion freezing (LIF). Temperature and phase transformations of the muscle tissue were monitored during the freezing process at three locations: center, midway between the center and the surface, and near the surface. Pork muscle quality changes [color, drip loss (both thawing and cooking), texture (shear force), and protein stability (DSC thermal profiles)] were evaluated after thawing the frozen samples at room temperature (20 degrees C). Employing pressures above 150 MPa caused very significant (P < 0.01) color changes in pork muscle during the PSF process. The PSF process reduced thawing drip loss of pork muscle but did not cause obvious changes in total drip loss following thawing and subsequent cooking. PSF at 150 and 200 MPa resulted in considerable denaturation of myofibrillar proteins of pork muscle. The PSF process also caused an increase in the pork muscle toughness as compared with that of unfrozen, ABF, and LIF samples.
authors.affiliation: Department of Food Science and Agricultural Chemistry, McGill University, 21111 Lakeshore Road, Ste Anne de Bellevue, Quebec H9X 3V9, Canada.
authors.forename: Songming
authors.initials: S
authors.lastname: Zhu
authors.forename: Alain
authors.initials: A
authors.lastname: Le Bail
authors.forename: Nicolas
authors.initials: N
authors.lastname: Chapleau
authors.forename: Hosahalli S
authors.initials: HS
authors.lastname: Ramaswamy
authors.forename: Marie
authors.initials: M
authors.lastname: De Lamballerie-Anton
mesh_terms: D000818:Animals; D015925:Cryopreservation / Q000379:methods; D005504:Food Analysis / Q000379:methods*; D005519:Food Preservation / Q000379:methods*; D005615:Freezing; D066298:In Vitro Techniques; D008460:Meat / Q000032:analysis*; D009124:Muscle Proteins / Q000032:analysis / Q000737:chemistry; D018482:Muscle, Skeletal / Q000737:chemistry* / Q000502:physiology*; D011312:Pressure; D011487:Protein Conformation; D013552:Swine; D013696:Temperature
chemical_list: D009124:Muscle Proteins