Effect of oligofructose and type of microbial culture on conjugated linoleic acid content and viability of probiotic bacteria in probiotic yogurt

Subject Areas : Food Microbial Contamination

Motahareh Broughani ¹ (M.Sc. Student of Food Science and Technology, Islamic Azad University, Varamin-Pishva Branch)
Rezvan Pourahmad ² (Associate Professor, Department of Food Science and Technology, Faculty of Agriculture, Varamin-Pishva Branch, Islamic Azad University)
Ali Akbarian Moghari ³ (Department of Food Science, Technology and Engineering, Faculty of Agricultural Engineering and Technology, Tehran University, Karaj, Iran)

Received: 2017-11-02 Accepted : 2018-01-01 Published : 2018-10-23

Keywords: conjugated linoleic acid, microbial culture, Probiotic yogurt, oligofructose,

Abstract :

The purpose of this study was to investigate the effect of oligofructose and type of microbial culture on conjugated linoleic acid (CLA) and viability of probiotic bacteria in probiotic yogurt. The amounts of 3 and 5 percent of oligofructose were used in probiotic yogurt containing Lactobacillus acidophilus or Bifidobacterium lactis. (The control sample was considered without adding the prebiotic compound). The viability of probiotic bacteria, CLA content, pH, acidity and sensory properties of probiotic yogurt were investigated at intervals of 1, 11 and 21 days. During storage, the number of probiotics and pH of the samples decreased but acidity increased significantly (P<0.05). The amount of CLA increased significantly in the majority of samples during storage (P<0.05). However, the score of overall acceptance of the majority of the samples did not change significantly during storage. The highest population of probiotic bacteria was belonged to sample containing Lactobacillus acidophilus + 5% oligophroctase. After control 1 sample (sample containing L. acidophilus), sample containing L. acidophilus + 3% oligofructose had the highest concentration of CLA. After control 1 sample, sample containing L. acidophilus + 3% oligophroctase had the highest sensory score (overall acceptance) which also had a high population of probiotic bacteria (4.6 × 106 CFU/ml) at the end of the maintenance period. Therefore, it can be said that prebiotics have a positive effect on survival of probiotics and CLA content in probiotic yogurt so can improve health properties of probiotic products.