View
26
Download
0
Category
Preview:
Citation preview
“EVALUATION OF THE EFFECT OF RECONSTITUTION AND
MAINTENANCE TEMPERATURES AT 20ºC AND 30ºC ON THE
GROWTH OF Salmonella Typhimurium AND Cronobacter
sakazakii IN POWDERED INFANT FORMULA.”
UNIVERSITY AUTONOMOUS OF BARCELONAVETERINARY FACULTY
DEPARTMENT OF ANIMAL AND FOOD SCIENCE
EVA MARÍA HERNÁNDEZ QUESADASEPTEMBER 2012
INTRODUCTION
• PIF not steriles: GHP preparation &use/utilization.
• A Category (FAO/OMS): Salmonella Typhimurium &Cronobacter sakazakii.
• Infective dose & level in PIF :Microb. Criteria ✔ RECONSTITUTION
• Public Health Advisories Safety+Hygiene:Controversy T reconstitution water 70ºC.
• FAO/OMS-ESPAGHAN-AFSSA… FABRICANTES
OBJECTIVE
Controversysafety measuresfor preparation
& use.
Controversysafety measuresfor preparation
& use.
Insufficientpractice atdomesticscenario
Insufficientpractice atdomesticscenario
Severity ofinfection
Severity ofinfection
Assessment of the effect on thedevelopment of microorganismsinvolved of:- Water reconstitution
temperature- Storage temperature- PIF composition
MATERIALS & METHODS
ENUMERATION / GROWTH MODELIZATIONSTATISTICAL ANALYSIS
INCUBATION 24-72 HRS / 37°C
MICROBIOLOGICAL ANALYSIS 2-4-6-8 HRS - SPECIFIC CHROMOGENIC MEDIA
Salmonella Typhimurium CECT 772: SM2 AGAR Cronobacter sakazakii DSM 4485: ESIA AGAR
RIF STORAGE TEMPERATURE
20°C 30°C
INOCULATION OF STRAINS AT CI = 50-100 CFU/ml
Salmonella Typhimurium CECT 772 Cronobacter sakazakii DSM 4485
PIF REHYDRATION: STERILE DISTILLED WATER TEMPERATURE
20°C 30°C 40°C 50°C 60°C 70°C
FOOD MATRIX
Milk-based formula without probiotics 150 ml Milk-based formula with probiotics 150ml Soy protein-based formula 90ml
CONCLUSIONS• Although no statistically significant difference was observed on
the growth of both bacterias due to the presence of probioticswhen comparing milk-based formulas, nutricional composition ofthe formula has definitely an effect on lag time and maximumgrowth rate for both bacteria, as for the differences observedbetween milk-based formulas and soy-based formulas, presentingboth strains higher growth rates in the former.
• The storage of the rehydrated formulas at a room temperaturesbenefits the development of both strains, especially if thereconstitution temperature is close to the optimal growth rangefor the strains studied.
CONCLUSIONS• Reconstitution at 70 °C (FAO / WHO) Major detrimental impact
on Cronobacter sakazakii and Salmonella Typhimurium,significantly reducing the risk of infection.
• Although an initial inactivation occurs with the reconstitution at60°C, depending on storage conditions, such inactivation can beexceeded by the growth, especially for Cronobacter sakazakiiDSM 4485, since it showed greater thermotolerance thanSalmonella Typhimurium CECT 722.
• Manufacturers recommendations for water T = 40-50 °C Basedon the results obtained, the risk of infection for any of the strains inany of the food matrices is not reduced.
CONCLUSIONSThus…This study indicates that long-term exposure of C. sakazakii tomild heat could enhance their survival during rehydration ofpowdered infant formula at high temperatures.
Furthermore…This study suggests that the prepared and the leftovers ofrehydrated infant formula must be stored at a refrigerationtemperature to inhibit the growth of C. sakazakii, minimizing therisk of possible outbreaks.
Recommended