Vedecký časopis

45 2006

Journal of Food and Nutrition Research
Súhrny čísla 4 / 2006

Effect of protective culture on the growth of Candida maltosa YP1 in yoghurt
Journal of Food and Nutrition Research, 45, 2006, č. 4, s. 147-151

Ľubomír Valík, Department of Nutrition and Food Assessment, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, SK-812 37 Bratislava, Slovakia. Tel.: +421 2 59325 515, e-mail: lubomir.valik@stuba.sk

Súhrn: Effect of commercial protective cultures consisting of Lactobacillus rhamnosus and Propionibacterium freudenreichii subsp. shermanii on growth of resistant yeast contaminants C. maltosa YP1 was examined in fresh yoghurt products. The partial inhibition of growth of C. maltosa and its temperature dependence were observed. Adding of protective culture has no relevant effect on the lag time, however the temperature effect was significant. Growth rate of C. maltosa was significantly influenced by both factors protective culture and temperature of incubation as was described by the following Ratkowsky model ÖGrPc = 0.0112T + 0.0373 (R2 = 0.9569) for the trials with protective culture and ÖGrc = 0.0126T + 0.0489 (R2 = 0.9696) for the control samples, respectively. Furthermore, the equations resulting from secondary models were used for predicting the time yeast contaminants need to reach the count of 1.106 CFU.ml-1 in yoghurts at different storage temperatures. Predictions of this time were on the order of 8 d and 6 d longer in yoghurt containing protective culture at 6 and 8 °C, respectively. However our results confirmed the effects of protective culture on growth of yoghurt yeast contaminant, the application of protective culture in fermented dairy products cannot be considered a substitution for good hygiene or good manufacturing practice.

Kľúčové slová: Candida maltosa; protective cultures; yoghurt; growth modelling

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