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Carbon dioxide as a novel indicator for bacterial growth in milk
Author(s) -
Cranz Séverine,
Valster Sanne,
Vulders Roland,
Dellimore Kiran
Publication year - 2020
Publication title -
journal of food safety
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.427
H-Index - 43
eISSN - 1745-4565
pISSN - 0149-6085
DOI - 10.1111/jfs.12780
Subject(s) - food spoilage , food science , staphylococcus epidermidis , bacteria , contamination , meat spoilage , bacterial growth , shelf life , carbon dioxide , chemistry , biology , staphylococcus aureus , ecology , genetics , organic chemistry
Human milk spoils due to bacterial, yeast, or mold contamination. Current domestic methods of assessing milk spoilage are subjective or rely on time and temperature‐based guidelines. A key unmet food safety need remains the objective assessment of human milk spoilage. Experiments were conducted using a simplified human milk spoilage model based on goat's milk as a human milk surrogate, spiked with a single bacterial strain ( Staphylococcus epidermidis ), in which pH and carbon dioxide (CO 2 ) concentration were measured along with bacteria count over 160 hr. Bacteria count correlated highly with CO 2 but not with pH. A 0.21% CO 2 concentration threshold could be defined for milk spoilage (correlating to a bacteria count threshold of 10 5 CFU/ml), with sensitivity and specificity above 84%. These findings suggest that CO 2 measurement is a promising method to detect S. epidermidis growth in milk which merits further investigation for the objective and quantitative assessment of milk spoilage.