"Effect of heat treatment on folate concentration in bio-enriched yogurts"

LAIÑO, JONATHAN; JUAREZ DEL VALLE, MARIANELA; SAVOY DE GIORI, GRACIELA; LEBLANC, JEAN GUY

Horco Molle-Tucumán

Congreso; XXIX Jornadas Científicas; 2012

Asociación de Biología de Tucumán

EFFECT OF HEAT TREATMENT ON  FOLATE CONCENTRATION IN BIO-ENRICHED YOGURTS Laiño, J*1, Juarez del Valle, M1, Savoy de Giori, G1,2 y LeBlanc, JG. 1- CERELA –CONICET – Chacabuco145 – S. M. de Tucumán – Argentina (CP 4000) 2-  Cát.  de Microbiología Superior  –  Fac.  Bioq., Qca.  y Fcia.  –U.N.T  -  *E-mail: lainoje@cerela.org.ar  The aim was to study the effect of heat treatment on folate (vit. B9) concentration and its stability in bio-enriched yogurts.  Three different  yogurts were elaborated  combining    B9  producing strains:  L. bulgaricus  CRL863  & CRL871 and  S. thermophilus  CRL803  & CRL415. These were then  heated 3 times at 80ºC for 30 min. After  heat  treatment, they were stored at 4ºC  for 28 days  and  a)  folate production;  b)  acidity  (pH);  c)  protein concentration  &  d)  cellular  viability  (Log CFU/mL)  were evaluated.  Results:  One yogurt (Yogurt B, prepared with the  mixture  of strains  CRL871+CRL803+CRL415)  showed the highest folate levels (224±3 µg/L). Generally, pH was about 4.75 and protein concentration ranged 0.17 to  0.24 g/dL  and did not vary after heat treatment.  Only yogurt  made with mixture B had the same folate values before and after heat treatment. Conclusion: from 3 yogurts, only one was not affected by heat treatment, whereas others showed decreases of up to 40% in the concentration of folates. The adequate selection of strains is essential if heat treatments are to be applied in order to increase product shelf life or their microbiological safety, the combination  of  CRL871+CRL803+CRL415  seems to be ideal for this objective.