EFFECT OF HEAT TREATMENT ON FOLATE CONCENTRATION IN BIO-ENRICHED YOGURTS

LAIÑO, J; JUAREZ DEL VALLE, M; SAVOY DE GIORI, G; LEBLANC, JG

Horco Molle, San Miguel de Tucumán

Jornada; XXIX Jornadas Científicas de la Asociación de Biología de Tucumán; 2012

Asociación de Biología de Tucumán

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.