To obtain a further understanding of the nature of the multiexponential T L
relaxation seen in muscle tissue water (myowater), relaxation measurements
were carried out on whole, minced, and homogenized pork of three different
qualities with regard to water-holding capacity (normal, red soft exudativ
e, and dark firm dry). Whole, minced, and homogenized pork all resulted in
multiexponential T-2 relaxation (three components) independently of the qua
lity, even though microscopic studies on homogenized meat revealed consider
able disruption of the macroscopic structure. This states that the relaxati
on behavior in meat cannot be explained by intra-/extracellular compartment
alization of the water as suggested in earlier studies. Subsequent studies
of T-2 relaxation in either whole meat, where the structure integrity was c
hanged by the introduction of dimethyl sulfoxide (membrane disruption) or u
rea (protein denaturation), or minced meat with added NaCl (inter-/intrapro
tein interactions) lead to the suggestion that in whole meat (i) the fastes
t relaxation component reflects water tightly associated with macromolecule
s, (ii) the intermediate relaxation component reflects water located within
highly organized protein structures, for example, water in tertiary and/or
quaternary protein structures and spatials with high myofibrillar protein
densities including actin and myosin filament structures, and (iii) the slo
west relaxation component reflects the extra-myofibrillar water containing
the sarcoplasmatic protein fraction. Finally, relaxation patterns in heat-s
et gels of superprecipitated actomyosin and bovine serum albumin similar to
that identified in whole meat support the proposed nature of T-2 relaxatio
n in muscle myowater.