Baroinactivation of Staphylococcus epidermidis - mathematical model and its verification using human and cow milks

• Published in: Czech Journal of Food Sciences Vol. 27; no. 2; pp. 118 - 126
• Main Authors: Schlemmerova, L.,Statni Zdravotni Ustav, Prague (Czech Republic), Houska, M.,Vyzkumny Ustav Potravinarsky, Prague (Czech Republic), Spelina, V.,Statni Zdravotni Ustav, Prague (Czech Republic), Strohalm, J.,Vyzkumny Ustav Potravinarsky, Prague (Czech Republic), Landfeld, A.,Vyzkumny Ustav Potravinarsky, Prague (Czech Republic), Smuharova, H.,Statni Zdravotni Ustav, Prague (Czech Republic), Nemcova, I.,Statni Zdravotni Ustav, Prague (Czech Republic), Kyhos, K.,Vyzkumny Ustav Potravinarsky, Prague (Czech Republic), Pruchova, J.,Vyzkumny Ustav Potravinarsky, Prague (Czech Republic), Novotna, P.,Vyzkumny Ustav Potravinarsky, Prague (Czech Republic), Mericka, P.,Fakultni Nemocnice, Hradec Kralove (Czech Republic)
• Format: Journal Article
• Language: English
• Published: 01-01-2009
• Subjects: ANALISIS MICROBIOLOGICO; ANALYSE MICROBIOLOGIQUE; BIOLOGICAL CONTAMINATION; CONTAMINACION BIOLOGICA; CONTAMINATION BIOLOGIQUE; COW MILK; HIGH PRESSURE TECHNOLOGY; http://www.fao.org/aos/agrovoc#c_15068; http://www.fao.org/aos/agrovoc#c_16080; http://www.fao.org/aos/agrovoc#c_16085; http://www.fao.org/aos/agrovoc#c_24199; http://www.fao.org/aos/agrovoc#c_25302; http://www.fao.org/aos/agrovoc#c_28318; http://www.fao.org/aos/agrovoc#c_34406; http://www.fao.org/aos/agrovoc#c_36742; http://www.fao.org/aos/agrovoc#c_5623; HUMAN MILK; LAIT DE VACHE; LAIT HUMAIN; LAIT UHT; LECHE DE VACA; LECHE HUMANA; LECHE UHT; MATHEMATICAL MODELS; MICROBIOLOGICAL ANALYSIS; MODELE MATHEMATIQUE; MODELOS MATEMATICOS; PASTEURISATION; PASTEURIZACION; PASTEURIZATION; STAPHYLOCOCCUS EPIDERMIDIS; TECHNOLOGIE HAUTE PRESSION; TECNOLOGIA ALTA PRESION; UHT MILK
• ISSN: 1212-1800
• DOI: 10.17221/1051-cjfs

Staphylococcus epidermidis, commonly found on the human skin, may contaminate human milk. High-pressure pasteurisation of human milk under normal temperature preserves the majority of its protective agents. The objective of this study was to acquire baroinactivation data and develop a model for model solutions of pH = 6.4 to 7.2 and water activity aw = 0.99 in which baroinactivation of Staphylococcus epidermidis takes place. Decontamination data manifested exponential kinetics and the resulting model was described by the following equations: Dp = Dp, ref x 10 (Pref - P)/Z, Z = -123.90 pH2 + 1635.54 pH - 5210.49; Dp, ref = -8.89 pH2 + 121.02 pH - 408.34. The developed model was verified using pasteurised human milk and UHT-treated skimmed cow milk. The agreement between the experimental data and model-based prediction was very good for human milk. The application of a pressure of 350 MPa for 10 min decreased the concentration of the working suspension of S. epidermidis in the model substrate by a minimum of five orders of magnitude.