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Chitosan and its derivatives regulate lactic acid synthesis during milk fermentation
Vladimir Kurchenko1,2, Tatsiana Halavach1, Alexey Yantsevich3
1Department of Biology, Belarusian State University, Minsk, Belarus.
Frontiers in Nutrition
|October 1, 2024
Summary
Oligochitosans significantly enhance lactic acid production and bacterial growth in fermented milk. Chitosan derivatives can extend shelf life by slowing fermentation while maintaining high bacterial counts.
Area of Science:
- Food Science
- Microbiology
- Biochemistry
Background:
- Chitosan's impact on lactic acid bacteria (LAB) and lactic acid (LA) production is poorly understood, with conflicting research.
- Previous studies show varied effects of chitosan and its derivatives on Lactobacillus spp. growth.
Purpose of the Study:
- To investigate the effect of chitosan and its derivatives on the growth and productivity of *L. bulgaricus*.
- To clarify the influence of chitosan's physicochemical properties on LAB functionality.
Main Methods:
- Fermentation of low-fat skim milk using *L. bulgaricus* with varying concentrations of high molecular weight chitosan (350 kDa) and oligochitosans (25.4 and 45.3 kDa).
- Analysis of dynamic viscosity, titratable acidity, pH, LA content, colony-forming units (CFUs), and metabolite profiles (GC-MS, SDS-PAGE, microscopy).
Main Results:
- Oligochitosans (25.4 and 45.3 kDa) significantly increased LA synthesis rates compared to controls.
- High molecular weight chitosan (350 kDa) did not affect LA synthesis but increased *L. bulgaricus* counts by over 1700 times.
- Chitosan derivatives altered fatty acid profiles, reduced propanol synthesis, and extended fermented milk shelf life from 5 to 17 days.
Conclusions:
- Oligochitosans are effective stimulators of lactic acid production by *L. bulgaricus*.
- Chitosan can enhance the viability of *L. bulgaricus* and prolong the shelf life of fermented dairy products.
- Chitosan's molecular weight is critical in determining its effect on LAB fermentation and metabolite production.
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