Dairy Chemistry And Biochemistry

CONTENTS vii

4 Milk proteins

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Introduction

Heterogeneity of milk proteins

4.2.1 Other protein fractions

Preparation of casein and whey proteins

4.3.1 Acid (isoelectric) precipitation

4.3.2 Centrifugation

4.3.3 Centrifugation of calcium-supplemented milk

4.3.4 Salting-out methods

4.3.5 Ultrafiltration

4.3.

4.3.7 Precipitation with ethanol

4.3.8 Cryoprecipitation

4.3.9 Rennet coagulation

4.3.10 Other methods for the preparation of whey proteins

Heterogeneity and fractionation of casein

4.4.

4.4.2 Microheterogeneity of the caseins

4.4.3 Nomenclature of the caseins

Some important properties of the caseins

4.5.1 Chemical composition

4.5.2 Secondary and tertiary structures

4.5.3 Molecular size

4.5.4 Hydrophobicity

4.5.5 Influence of Ca2+ on caseins

4.5.6 Action of rennets on casein

4.5.7 Casein association

4.5.8 Casein micelle structure

Whey proteins

4.6.1 Preparation

4.6.2 Heterogentity of whey proteins

P-Lactoglobulin

4.7.1 Occurrence and microheterogeneity

4.7.2 Amino acid composition

4.7.3 Primary structure

4.7.4 Secondary structure

4.7.5 Tertiary structure

4.7.6 Quaternary structure

4.7.7 Physiological function

4.7.8 Denaturation

a-Lactal bumin

4.8.1 Amino acid composition

4.8.2 Genetic variants

4.8.3 Primary structure

4.8.4 Secondary and tertiary structure

4.8.5 Quaternary structure

4.8.6 Other species

4.8.7 Biological function

4.8.

Blood serum albumin

Immunoglobulins (Ig)

Minor milk proteins

Non-protein nitrogen

Comparison of human and bovine milks

Gel filtration (gel permeation chromatography)

Resolution of caseins by electrophoresis

Metal binding and heat stability

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