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TEMPERATURE COMPENSATED TESTS FOR RAW MILK SUPPLIES II. THE METHYLENE BLUE TEST
Author(s) -
Clegg L. F. L.
Publication year - 1949
Publication title -
proceedings of the society for applied bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 0370-1778
DOI - 10.1111/j.1365-2672.1949.tb03881.x
Subject(s) - methylene blue , boiling , methylene , chromatography , raw milk , chemistry , analytical chemistry (journal) , materials science , zoology , food science , biology , organic chemistry , photocatalysis , catalysis
Summary. To determine whether a time‐temperature compensation scale can be applied to the methylene blue test samples of fresh raw milk from nearby farms and local creameries were examined at regular intervals throughout a twelve‐month period. Each sample was divided into seven sub‐samples which were stored for approximately 24 hr. in water baths controlled at 37.5°, 42.5°, 47.5°, 52.5°, 57.5°, 62.5° and 67.5° F.; decolourisation of methylene blue at 37°C. was observed at regular intervals. Average times of reduction of methylene blue following storage at different temperatures are given saparetely for the various keeping quality groups (time to endpoint with clot‐on‐boiling at 15.5°C.). The mean times for samples of all keeping quality groups to reduce methylene blue at all pre‐test storage temperatures are found to lie on a straight line.