The influence of whey protein concentrate on growth and survival of probiotic bacteria in whey

This research examines the influence of whey protein concentrate addition (WPC) on growth and activity of probiotic species Lactobacilus acidophilus La-5 and Bifidobacterium animalis subsp. lactis BB-12 in sweet reconstituted whey and their survival during 28 days of fermented whey cold storage (4 °C). The fermentation of whey at 37º C with and without 1.5 and 3% of WPC addition has been observed. Fermentation of whey with Lactobacillus acidophilus La-5 to which 3% WPC was added, was about an hour shorter (∼ 14 hours ) compared to the fermentation of whey without WPC addition (∼ 15 hours). The viable cells count of Lactobacilus acidophilus La-5 was better in whey with 3% of WPC addition (Δlog CFU/mL = 2.1 ) compared to whey without WPC addition (Δlog CFU/mL = 1.7 ). Addition of whey protein concentrate did not influence significantly on growth of Bifidobacterium animalis subsp. lactis BB-12 in whey, and also it did not influence the survival of both probiotic species during 28 days of cool storage (at 4 °C). Whey enriched with WPC had slightly higher titratable acidity during fermentation and storage compared to whey without WPC addition