Determination of honey varietal’s impact on Bifidobacterium animalis ssp lactis survivability in commercial yogurt through simulated in vitro digestion

Alvarado, David Anthony

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https://hdl.handle.net/2142/113340 Copy

Description

Title

Determination of honey varietal’s impact on Bifidobacterium animalis ssp lactis survivability in commercial yogurt through simulated in vitro digestion

Author(s)

Alvarado, David Anthony

Issue Date

2021-07-21

Director of Research (if dissertation) or Advisor (if thesis)

Holscher, Hannah D

Committee Member(s)

• Miller, Michael J
• Lee, Youngsoo

Department of Study

Food Science & Human Nutrition

Discipline

Food Science & Human Nutrition

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Bifidobacteria
• Honey
• Probiotic
• In vitro digestion
• B. animalis
• Yogurt

Abstract

Consumption of yogurt containing the probiotic strain Bifidobacterium animalis lactis DN-173 010/CNCM I-2494 (B. animalis) improves digestive health and quality of life in adults. While numerous studies have evaluated the probiotic properties of B. animalis, however, there are a limited number of studies on how this probiotic bacterium interacts with honey in a yogurt matrix through the digestive process. The objective of this study was to evaluate the effects of different honey varietals on B. animalis survivability in low-fat commercial yogurt through in vitro gastrointestinal digestion. Phase 1 tested four honey varietals (alfalfa, buckwheat, clover, and orange) at a final concentration of 20% weight by weight (w/w) in yogurt containing B. animalis. Yogurt samples started with an average of 8.6 log CFU/g per sample. Undiluted yogurt and yogurt with added sucrose or water (20% w/w) were included as control treatments. Phase 2 examined clover honey at final concentrations 20, 14, 10, 9, 8, 6, and 4% w/w. These samples were then subjected to in vitro simulated oral, gastric, and intestinal digestion using simulated salivary, gastric, and intestinal fluids, respectively. At four time points – baseline and after each phase of digestion (oral, gastric, intestinal) – probiotic cells were enumerated by spread plating on De Man Rogosa Sharpe (MRS) agar under anaerobic conditions for 5 hours(h) at 37º C. Plates were then overlaid with MRS supplemented with lithium chloride and sodium propionate for an additional 67 h at 37º C. There was comparable probiotic survivability observed in yogurt with alfalfa, buckwheat, and orange varietals relative to controls in all phases of in vitro digestion. Yogurt with clover honey revealed a significantly increased probiotic survivability after exposure to intestinal fluids (~3.5 Log CFU/g reduction) compared to all control treatments. Furthermore, clover honey significantly increased probiotic survivability after simulated intestinal digestion with doses 10, 14, and 20% w/w. In conclusion, our results support the addition of clover honey to improve the survival of probiotic bacteria in yogurt.

Graduation Semester

2021-08

Type of Resource

Thesis

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http://hdl.handle.net/2142/113340

Copyright and License Information

Copyright 2021 David Alvarado

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