716. Physical changes in milk caused by the action of rennet: I. Description of apparatus for measuring rigidity moduli and internal viscosities, tests of reliability and some observations on syneresis

Abstract

A method for measuring the increasing rigidity moduli and internal viscosities of milk during rennet setting is described. Curves are given showing the degree of reproducibility on replicate samples of dried and liquid milks, and of the effects of changes in calcium levels in the case of the former.A tentative interpretation of the shape of the main part of the setting curve is proposed. The upper part of the curve generally becomes erratic with the onset of syneresis, but some dried milks do not show this behaviour.Some curious phenomena concerning the production of syneretic liquid (whey) are described and methods for obviating the disturbing effects of syneresis are discussed.