Figure 1 - BFTV Cluster: News

Identification and Characterization of
Potential Prebiotic Oligosaccharides in Coffee
Tian Tian1, Samara Freeman2, Guy Shani1 , David Mills1,2, Bruce German1,2, Daniela Barile1,2
1Department of Food Science & Technology, University of California, Davis, CA
2 Foods for Health Institute, Department of Food Science & Technology, University of California, Davis, CA
Ground Coffee
Gas Chromatography
and Anion Exchange
chromatography
Total
Carbohydrate
Assay
Coffee
• Details about
OS structure
• Degree of
polymerization
• Basic info about
possible OS presence
• Free Monosaccharides
• Monosaccharides fingerprint in
oligosaccharide
• Rough quantification of
total carbohydrates in
coffee
bc
bc
4
bc
Rhamnose
Mannose
Glucose
2
1.5
bc
2
1
0.5
1
0
R1
R2
R3
R4
R5
R6
Processing Conditions
R7
R1
R8
R2
R3
R4
R5
R6
Processing Conditions
R7
R8
(a)
(b)
Figure 3: Abundance of (a) oligosaccharides and (b) their structural monosaccharides in coffee with different processing conditions
(Note: due to the proprietary nature of this work, the detailed information of processing conditions are not shown here)
0.8
1.8
1.6
1.4
#
P-value = 5.862*10-4
for one way ANOVA
1.2
1
0.8
0.6
*
*
*
0.2
0
• Extraction and
Purification
Arabinose
Xylose
Galactose
2.5
bd
0.4
L1
L2
L3
Brewing Conditions
0.7
0.6
Arabinose
Xylose
Galactose
Rhamnose
Mannose
Glucose
0.5
0.4
0.3
0.2
0.1
L4
0
L1
L2
L3
Brewing Conditions
L4
(b)
(a)
Figure 4: Abundance of (a)oligosaccharides and (b)their structural monosaccharides in four liquid coffee brewed by different conditions
(Note: due to the proprietary nature of this work, the detailed information of brewing conditions are not shown here)
Figure 3 and Figure 4 indicate that the different processing and brewing conditions have significant effect on the
abundance of coffee oligosaccharides and their structural monosaccharides
Liquid/Liquid Extraction
Work in Progress: Testing the bioactivity of coffee OS purified
in lab scale
Identification by Mass Spectrometer
Bifidobacterium spp. + Trial #1 Bifidobacterium spp.+ Trial #2
Solid Phase Extraction
Methanolysis & Derivatization
8 Hexose
Number of
bacteria (CFU/mL)
Coffee
Oligosaccharide
Trial #1
Coffee
Oligosaccharide
Trial #2
3.1 * 106
3 * 106
Figure 5. The growth of one Bifidobacterium spp. on MRS medium plate
after inoculation with two coffee oligosaccharide extracts
14 Hexose
Arabninose
Rhamnose
Xylose
Mannose
Galactose
Glucose
Figure 1: nanoLC-Chip-QToF Base Peak Chromatogram of
Coffee Oligosaccharides (DP range: 3 to 14 of Hexose or Hexose-Pentose)
Table 1. The number of bacteria in two coffee oligosaccharides extract
Quantification by GC-FID
Results: Identification and Quantification Of Coffee OS
3 Hexose
a
bcd
3
Abundance of OS
(mg/ mL of extract )
MALDI
ToF
Hot Water Extraction
6
0
Nano
LC- Chip
QToF
P-value =
for one way ANOVA
a
5
3
5.068*10-5
Abundance of structural monosaccharide
(mg/g of coffee
Materials and Method
7
Abundance of structural monosaccharides
(mg/mL of coffee)
Oligosaccharides (OS) are functional carbohydrates polymers widely studied in human milk and dairy products.
They are also found in plants; however there is no oligosaccharides present in green coffee beans other than
sucrose and only an handful of oligosaccharides have been described in roasted coffee beans. The presence or
potential bioactivities of oligosaccharides in coffee has not been deeply investigated. In this work we studied the
overall distribution of oligosaccharides in brewed coffee by using an advanced analytical platform. We propose that
coffee infusions contain complex oligosaccharides structures that are potential prebiotics. The formation of
prebiotic oligosaccharides-rich fractions can be induced via processing and brewing. The objective is to extract,
purify, identify and quantify coffee oligosaccharides with combination of analytical platforms and then evaluate
their potential prebiotic activity.
Result: Effect of Processing and Brewing on OS Abundance
Amount of OS (mg/g coffee)
Introduction
Figure 2: Monosaccharide Composition of
Oligosaccharides in Roasted Coffee
Figure 1 and 2 show that coffee oligosaccharides have a diversity in size and monosaccharides composition that
requires different enzymatic capabilities for deconstruction. This provides the basis for matching the coffee
oligosaccharides as potential prebiotics to specific probiotic bacteria, for developing next generation selective
prebiotics.
We produced sufficient amounts of purified coffee oligosaccharides by using lab scale extraction and purification
and used them to grow selected Bifidobacterium species. The results in figure 5 and table 1 show utilization of
coffee oligosaccharides by certain species of Bifidobacterium.
Conclusion
There is increasing interest in food products enriched with bioactive oligosaccharides. Interestingly, we
discovered that the composition, structure and abundance of coffee oligosaccharides vary among different
processing and brewing conditions. The demonstrated diversity of monosaccharides composition of coffee
oligosaccharides may requires different bacterial enzymatic machineries for utilization as carbon source, thus
providing the basis for matching these prebiotics to specific existing probiotic bacteria. In conclusion, the
present work shows that oligosaccharides in coffee have diverse range of size and monosaccharides composition
thus coffee represents a promising source of next general selective prebiotics.
Acknowledgement:
The author would like to thank Barile’s group for supporting the research