Life Sciences Commons^™

Investigation Of Solubilization, Cold Gelation, And Rennet Coagulation Properties Of Highly Concentrated Micellar Casein Concentrate For Use In Cheese Making, Ying Lu

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This work demonstrated potentials to use a microfiltrated, diafiltrated, and vacuum-evaporated milk protein concentrate-highly concentrated micellar casein
concentrate (HC-MCC) for use in cheese making. Previously, ultrafiltrated milk concentrate has been used for cheese making to improve cheese yield and increase milk processing ability. However, ultrafiltrated milk contains high level of serum protein, which negatively impact cheese quality during aging. Microfiltrated milk is more suitable for cheese making with most serum proteins removed.

The project evaluated the potential of cheese making using recombined concentrated milk (RCM) by mixing HC-MCC and cream. We identify the method to solubilize …

Casein Micelles And Their Properties: Polydispersity, Association With Vitamin A And Effect Of Ultra-High Pressure Homogenization, Maneesha Sheenu Mohan

Doctoral Dissertations

The internal structure of casein micelles is not fully understood. In the present work, we explore some of the basic questions about casein micelles in bovine milk including its size distribution, native binding properties and effect of ultra-high pressure homogenization (ultra-HPH) on technological properties of casein micelles. The size distribution of casein micelles was studied by cryo-TEM using skim milk from four cows. The degree of variation in casein micelle sizes (polydispersity) ranged between 0.39 and 0.47 for a size distribution ranging from 10 to 693 nm. These results indicated high polydispersity of casein micelles in milk from single cows. …

Activity And Nature Of Plasminogen Activators Associated With The Casein Micelle, B. Ismail, L. H. Choi, Lilian M. Were, S. S. Nielsen

Food Science Faculty Articles and Research

In fresh milk, plasminogen, the zymogen form of plasmin (PL), is the predominant form. Therefore, plasminogen activators (PA) can contribute significantly to PL activity in milk. Both tissue-type PA (tPA) and urokinase-type PA (uPA) exist in milk; however, contradictory findings have been reported for which type of PA is most closely associated with the casein micelles. Little is known about the factors that might lead to variations in the individual activities of the PA. The objective of this work was therefore to investigate possible factors that might affect the association of tPA and uPA with the casein micelle and their …

Observations On The Air-Serum Interface Of Milk Foams, B. E. Brooker

Food Structure

A new rapid method for the preparation of milk foams for transmission electron microscopy is described . The air-serum interface of foams made from skimmed milk consists of a uniform electron dense layer (5 nm thick) to which casein micelles become secondarily attached . Changes in bubble volume lead to the formation of folds of excess interfacial material which project into the aqueous phase. Using collapsed bubble ghosts to study the attachment of micelles to the airserum interface it was concluded that neither disulphide bridge formation nor hydrophobic interactions were of major importance. Similar preparations of interfacial material but without …

Structure Formation In Acid Milk Gels, I. Heertje, J. Visser, P. Smits

Food Structure

The structure formation in acid milk gels is influenced by many factors such as heat, salt system, pH, culture and thickening agents. Understanding of the mechanism of structure formation is important in order to be able to influence the final texture of these products.

In the present study the network formation in acid milk gels during acidification is monitored by freeze-fracture electron microscopy. Network formation appears to be a much more complex process than just an aggregation of the original milk casein micelles; it is accompanied by subtle dissociation and association phenomena of the milk caseins. The observed sequence of …

The Size Distribution Of Bovine Casein Micelles: A Review, C. Holt

Food Structure

This review considers the average size and size distribution of bovine casein micelles as measured by electron microscopy, light scattering and controlled pore glass chromatography, and the origin and biological function of the size distribution.

Recent work by electron microscopy has given average sizes in reasonable agreement with measurements on the same milk sample by light scattering . It is suggested that natural variations in averaqe micelle size and overestimation of micelle radii by light scattering methods as well as deficiencies in electron microscopical methodology were responsible for past discrepancies.

Electron microscopy and controlled pore glass chromatography provide evidence that …