Lentils enhance probiotic growth in yogurt and provide added benefit of antioxidant protection

We evaluated the antioxidant potential of lentil polysaccharides in stimulating the growth of probiotic bacteria in yogurt. Microbial counts, pH and total titratable acidity (TTA) were measured in yogurt samples containing starter cultures with or without probiotic bacteria, supplemented with whole ground green lentils. Additionally, the antioxidant potential of polysaccharides extracted from green, red, and dehulled red lentils were measured by oxygen radical absorbance capacity (ORAC) assay. Results demonstrate that green lentils selectively enhanced the number of probiotic bacteria in yogurt in the initial stages of storage and maintained overall microbial counts (starter cultures and probiotics) over a 28-day storage period. Furthermore, the overall reduction in pH and increase in TTA in lentil containing yogurt samples after the 28-day storage period at 4 degrees C, suggest that starter cultures preferentially utilize lentils toward the end of this storage period. Polysaccharide extracts exhibited strong antioxidant potential no significant difference between extracts from red and green whole lentil extracts (46.1 +/- 2.8 and 43.1 +/- 4.2 mu mol trolox equivalents (TE)/g of lentil respectively). However, the antioxidant capacity of dehulled red lentil extracts was significantly lower at 24.2 +/- 1.7 mu mol TE/g, suggesting that the hull has bioactive components, which play an important role in free radical scavenging. (C) 2012 Elsevier Ltd. All rights reserved.