USANS and SANS investigations on the coagulation of commercial bovine milk: Microstructures induced by calf and fungal rennet
- Resource Type
- Authors
- David A. Pink; Alejandro G. Marangoni; Nukhalu Callaghan-Patrachar; Fernanda Peyronel; Carl Adams
- Source
- Food Hydrocolloids. 116:106622
- Subject
- chemistry.chemical_classification
Materials science
010304 chemical physics
Scattering
General Chemical Engineering
food and beverages
04 agricultural and veterinary sciences
General Chemistry
Polymer
Neutron scattering
040401 food science
01 natural sciences
Small-angle neutron scattering
Fractal dimension
0404 agricultural biotechnology
Fractal
chemistry
Chemical engineering
0103 physical sciences
Coagulation (water treatment)
Rennet
Food Science
- Language
- ISSN
- 0268-005X
Coagulation of milk is a fundamental process in the manufacture of dairy products. Under the enzymatic action of rennet, casein micelles form aggregates resulting in a fractal gel network. There are few studies of microstructures using scattering techniques resulting from rennet coagulation in commercial milk in its native state. Here we employ ultra-small angle neutron scattering (USANS) and small angle neutron scattering (SANS) covering the scattering q-vector range of 5 × 10 - 5 q 2 × 10 - 2 A - 1 and the fractal cylinder model to study fractal structures and sizes resulting from calf and fungal rennet-induced coagulation of commercial skim and whole milk. We report evidence of aggregation with fractal properties analogous to that of swollen, randomly-branched polymers. Calf rennet resulted in a larger fractal dimension in skim compared to whole milk. In milk coagulated by fungal M. miehei, the randomly-branched polymer-like structures had a slightly larger fractal dimension of 2.5 and the structural unit was smaller. These measurements provide an important foundation for continuing study of the structure of commercial cheese with scattering techniques.