TY - JOUR
T1 - The influence of lactoperoxidase, heat and low pH on survival of acid-adapted and non-adapted Escherichia coli O157:H7 in goat milk
AU - Parry-Hanson, Angela
AU - Jooste, Piet J.
AU - Buys, Elna M.
PY - 2009/6
Y1 - 2009/6
N2 - In hot climates where quality of milk is difficult to control, a lactoperoxidase (LP) system can be applied in combination with conventional preservation treatments at sub-lethal levels to inhibit pathogenic microbes. This study investigated the effect of combined heat treatments (55 °C, 60 °C and 72 °C) and milk acidification (pH 5.0) on survival of acid-adapted and non-adapted Escherichia coli O157:H7 strains UP10 and 1062 in activated LP goat milk. Heat treatment at 72 °C eliminated E. coli O157:H7. Acid-adapted strains UP10 and 1062 cells showed resistance to combined LP and heat at 60 °C in fresh milk. The inhibition of acid-adapted and non-adapted E. coli O157:H7 in milk following combined LP-activation, heat (60 °C) and milk acidification (pH 5.0) suggests that these treatments can be applied to reduce E. coli O157:H7 cells in milk when they occur at low numbers (<5 log10 cfu mL-1) but does not eliminate E. coli O157:H7 to produce a safe product.
AB - In hot climates where quality of milk is difficult to control, a lactoperoxidase (LP) system can be applied in combination with conventional preservation treatments at sub-lethal levels to inhibit pathogenic microbes. This study investigated the effect of combined heat treatments (55 °C, 60 °C and 72 °C) and milk acidification (pH 5.0) on survival of acid-adapted and non-adapted Escherichia coli O157:H7 strains UP10 and 1062 in activated LP goat milk. Heat treatment at 72 °C eliminated E. coli O157:H7. Acid-adapted strains UP10 and 1062 cells showed resistance to combined LP and heat at 60 °C in fresh milk. The inhibition of acid-adapted and non-adapted E. coli O157:H7 in milk following combined LP-activation, heat (60 °C) and milk acidification (pH 5.0) suggests that these treatments can be applied to reduce E. coli O157:H7 cells in milk when they occur at low numbers (<5 log10 cfu mL-1) but does not eliminate E. coli O157:H7 to produce a safe product.
UR - http://www.scopus.com/inward/record.url?scp=64449084824&partnerID=8YFLogxK
U2 - 10.1016/j.idairyj.2009.02.005
DO - 10.1016/j.idairyj.2009.02.005
M3 - Article
AN - SCOPUS:64449084824
SN - 0958-6946
VL - 19
SP - 417
EP - 421
JO - International Dairy Journal
JF - International Dairy Journal
IS - 6-7
ER -