The use of radiolabelled milk proteins to study thermally-induced interactions in milk systems

Thesis/Dissertation · Fri Jan 01 00:00:00 EST 1988

OSTI ID:7255506

Noh, B

Heat induced complexes between milk proteins are of considerable importance in determining the heat stability and rennin clottability of milk products. Thiol-disulfide interchange reactions have been suggested as the principal reaction mechanism for complex formation. Studies to data have not adequately established the mechanism and stoichiometry of complex formation in situ in total milk system. Tracer amounts of {sup 14}C-{beta}-lactoglobulin and {alpha}-lactalbumin were heated under various conditions. After clotting with rennet, radioactivity retained in the curd was counted to estimate extent of interaction of {beta}-lactoglobulin with casein. {sup 14}C- and {sup 3}H-Methyl labelled proteins were used for the preparation of radiolabelled artificial casein micelles. These micelles with radiolabelled whey proteins were heated and heat-induced complexes were separated on Sephacryl S-300 eluting with 6 M guanidine hydrochloride to break all non-covalent bonds. Further separation of the protein complexes was obtained using CPG-10 or Sephacryl S-1000. The ratios of {sup 3}H to {sup 14}C labelled proteins in the protein complexes suggested that the stoichiometries of k-, {alpha}{sub s2}-casein, {beta}-lactoglobulin and {alpha}-lactalbumin in the heat-induced complexes varied as a function of the heat treatment.

• Research Organization: California Univ., Davis, CA (USA)
• OSTI ID: 7255506
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ALBUMINS
BIOCHEMICAL REACTION KINETICS
CASEIN
GLOBULINS
MILK
TEMPERATURE EFFECTS
CARBON 14 COMPOUNDS
COMPLEXES
HEAT
ISOTOPE RATIO
STABILITY
STOICHIOMETRY
TRACER TECHNIQUES
TRITIUM COMPOUNDS
BIOLOGICAL MATERIALS
BODY FLUIDS
ENERGY
FOOD
HYDROGEN COMPOUNDS
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
MATERIALS
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
PROTEINS
REACTION KINETICS
550201* - Biochemistry- Tracer Techniques