Abstract

Title

Impact of Commercial Inactivated Yeast Derivatives on the Growth of Lactobacillus Rhamnosus HN001 and Other Probiotic Bacteria in Milk

Type
Poster Presentation
Theme
Probiotics and Prebiotics: Excellence in Science and Clinical Translation
Topic
Development of Probiotic and Prebiotic Foods, Medical Foods, Supplements and Drugs

Authors

Main Author
Mingzhan Toh1
Presenting Author
Mingzhan Toh1
Co-Author
Lin Qin Lim1
Shao-Quan Liu1

Authors' Institution

Department / Institution / Country
Department of Chemistry, National University of Singapore / Food Science and Technology Programme / Singapore1
Content
Background and Rationale
Fermented dairy products are popular carriers of probiotics. Nevertheless, the low levels of free amino acids and assimilable peptides, coupled with the weak proteolytic activity of certain probiotic bacteria strains, impede the growth of these microorganisms in milk. Previously, inactivated yeast derivatives (IYDs) used in winemaking have been shown to stimulate the growth of oenological lactic acid bacteria. Therefore, it is hypothesised that IYDs could be utilised to enhance the growth of probiotic bacteria during milk fermentation.
Objectives: Indicates the purpose of the study

The objective of this study was to evaluate the effect of IYD supplementation on the growth of probiotic bacteria in milk.

Methodology: Describe pertinent experimental procedures
UHT skim milk was supplemented with 3 g/L of commercial IYD (OptiRed®, OptiWhite® and Noblesse®) and fermented with Lactobacillus rhamnosus HN001 at 37 °C for 24 h. The growth of the probiotic was evaluated by enumerating its viable cell count and measuring the pH of the milk prior to and after fermentation. Milk fermentation was also carried out with L. acidophilus NCFM, L. paracasei LPC-37, B. animalis subsp. lactis HN019 and B. longum BB46. Chemical analyses of the milks and IYDs were performed using HPLC.
Results: Summarize the results of the research
Significantly higher L. rhamnosus counts and lower pH were observed in milks supplemented with IYD as compared to the control after fermentation. OptiWhite® was the most effective IYD tested, and its growth-stimulating effect also extended to other probiotic lactobacilli and bifidobacteria. IYD supplementation increased the free amino acid content of the milk by 3.3 to 3.7-fold, as well as introduced mannooligosaccharides and β-glucans. In addition, glutathione was detected in OptiWhite® and Noblesse®, which could have contributed to improved viability of probiotic bacteria in milk.
Conclusions: State the main conclusions

Based on the findings of this study, IYDs could potentially be applied to foods fermented with probiotic bacteria to increase the viable cell count of the microorganisms and shorten fermentation time.

Keywords: Probiotics; Dairy; Fermentation; Inactivated yeast derivatives
Requires Audio or Video system for Presentation?: No