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Electron microscopy of normal and defective cottage cheese curd
Author(s) -
BROOKER B. E.
Publication year - 1986
Publication title -
international journal of dairy technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.061
H-Index - 53
eISSN - 1471-0307
pISSN - 1364-727X
DOI - 10.1111/j.1471-0307.1986.tb02377.x
Subject(s) - starter , ultrastructure , food science , chemistry , electron microscope , bacteria , biology , botany , physics , genetics , optics
Defects in cottage cheese curd were examined by electron microscopy and the structure of defective curd was compared with that of normal curd at cutting. The formation of the minor sludge frequently found as a thin layer at the bottom of vats was attributed to the very low p H produced by the sedimentation of agglutinated starter bacteria. In contrast, the ultrastructural appearance of curd from incidents of major sludging, in which whole vats were lost, suggested that a slowing down of acid production had caused the defect by allowing aggregated micelles to sediment. It is suggested that in such cases loss of acid production is the result of starter destruction by low initial numbers of bacteriophages.