Food Science Commons^™

A Method For Separating Casein Micelles From Whey Proteins For Determining Casein In Milk, Robert N. Carpenter

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to determine if size exclusion chromatography could be used to separate casein micelles from whey proteins for a rapid, direct test to measure percent casein in milk. A size exclusion chromatography column was developed for the separation having dimensions 100 by .4 cm. Packing material selected was glycophase coated porous glass supports. A Beckman DU-8B spectrophotometer monitored the casein and whey protein peaks as they eluted and a Tektronix 4052 computer accepted data points every 4 sec, storing these on tape. Absorbances and areas of each peak were used in the evaluation of samples. …

Enzymic Milk Coagulation: Casein Micelle Aggregation And Curd Formation, Donald J. Mcmahon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Enzymic milk coagulation was monitored by measuring changes in curd firmness and apparent absorbance of undiluted milk. Detection of coagulation, visually or rheologically, occurred after the milk changes from a system of aggregating particles to an extended space network. This change was observed as a shoulder in apparent absorbance plots and coagulation time was defined as the critical point in the aggregation process analogously to non-linear condensation polymerization reactions. It corresponds to the inflexion point during the period when apparent absorbance was rapidly increasing and can be calculated by fitting curd firmness data to an exponential equation.

Addition of calcium …

Effects Of Heat Treatment And Post-Treatment Holding Time On Rennet-Clotting Properties Of Milk, Zeynep Ustunol

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Samples of raw whole milk were heated at L5, 50 and 75 C for 0, 30, 60, llU and 240 min. After heat treatment each sample was subdivided and portions held at 0 C for 0, 30, 60 and 120 min. In a second experiment samples of milk were heated at 25 and 50 C for the same lengths of time as before but this time at 75 C for only 5, 10, 15 and 20 min. A constant holding time of 30 min was used after the heat treatments. Following the various heat treatments pH of each sample was …