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Effect of Irradiation and Pre‐Irradiation Treatments on Beef Muscle Proteins
Author(s) -
ANGLEMIER A. F.,
ELBADAWI A. A.,
CAIN R. F.
Publication year - 1964
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1365-2621.1964.tb00457.x
Subject(s) - chemistry , food science , irradiation , sterilization (economics) , cooked meat , isoelectric point , distilled water , denaturation (fissile materials) , muscle protein , isoelectric focusing , biochemistry , chromatography , enzyme , nuclear chemistry , biology , anatomy , skeletal muscle , physics , nuclear physics , monetary economics , economics , foreign exchange market , foreign exchange
SUMMARY Changes in texture resulting from soaking beef steaks in an equal weight of distilled water for 72 hrs at 38°F, heating to an internal temperature of 160°F, and irradiating to a level of 4.5 Mrads are not due to the loss of the acidic and basic groups of the muscle proteins. The pH‐hydration curves of the soaked samples indicate that soaking causes a shift of the isoelectric region of the meat to a pH higher than that of the control samples. Severe precipitation of the meat proteins occurs when the soaked meat is cooked, resulting in a firmer texture than that possessed by the cooked unsoaked meat. The shift in the pH‐WHC curve of the meat by soaking appears to be caused by diminution of the muscle anions and/or partial denaturation of some of the muscle proteins. Thermal inactivation of the enzymes also tends to increase the firmness of meat, by causing a tightening of the meat structure, whereas irradiation‐sterilization may exert only a slight tightening of muscle structure, by increasing the number of the relatively weak hydrogen or electrostatic bonds. When meat was heated and then irradiated, however, the effect of cooking was dominant. The electrophoretic data suggest that the reported fragmentary action of irradiation upon meat proteins may be on the fractions not extracted by the glycine‐NaOH buffer.