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Carbohydrates Hop Degradation Analysis – Alpha Acids
There are four major classes of carbohydrates. These include (e.g. glucose) up to 10 sugar oligosaccharides called Hops, a major ingredient in beer, contain components called In this example, the left chromatogram is for the alpha acids
monosaccharides, disaccharides, oligosaccharides, and decasaccharides (e.g. B-DP-10)*. The method requires an HPLC alpha acids (humulones) and beta acids (lupulones). Through and beta acids in hop pellets before the brewing process*,
polysaccharides, where the prefixes mean one, two, few, and with a Refractive Index Detector (RID). Generally, RID is more the brewing process, alpha acids are converted to iso-alpha whereas the right chromatogram shows the analysis of alpha
many sugars, respectively. Monitoring these sugars is an than sensitive enough; however, a low-temperature evaporative acids (isohumulones), which are bitter components of beer. Beta acids and iso-alpha acids in beer after the brewing process
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indication of where the fermentation process is at during the light scattering detector (ELSD-LT) can provide even more acids are said to influence the bitterness balance. utilizing the Nexera XR UHPLC with SPD detection.
brewing process. sensitivity as in the example below .
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Shown is a chromatogram of the analysis of monosaccharides
Peaks
1 Fructose
2 Glucose
3 Maltose
4 Maltotriose
2 5 L-DP-4
1
6 L-DP-5
7 B-DP-5
8 L-DP-6
9 B-DP-6
10 B-DP-7
11 B-DP-8
12 B-DP-9
13 B-DP-10
4
5
3
6 9 10 11 12
7 8
13
0 5 10 15 20 (min)
Analysis of Carbohydrates in Beer Prominence HPLC with RID-20A for carbohydrate analysis Nexera XR UHPLC
mAU
35.0 30.0
32.5 27.5 Peaks
1. trans-Isocohumulone
30.0 25.0 a 2. trans-Isohumulone
Peaks 1 27.5 3. trans-Isoadhumulone
1.Fructose 2 22.5 b 4. Cohumulone
2.Glucose 3 25.0 5. Humulone
3.Sucrose 22.5 20.0 6. Adhumulone
4.Maltose 17.5 a. cis-Isocohumulone
20.0
4 b. cis-Isohumulone
17.5 15.0 1 c. cis-Isoadhumulone
15.0 12.5
12.5 10.0 2
ELSD-LT 10.0 7.5
7.5
1 2 3 5.0 c
4 5.0
RID 2.5 3
2.5
4 5 6
0.0 0.0
0 1 2 3 4 5 6 7 8 9 10 11 12 -2.5 -2.5
min 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 min 0.0 2.5 5.0 7.5 10.0 min
Example of comparison of sensitivity between an
ELSD-LT and RID for sugars* Analysis of alpha acids and beta acids in hop pellets Analysis of alpha acids and iso-alpha acids in beer
by Nexera XR system* by Nexera XR system #
* http://www.shimadzu.com/an/industry/foodbeverages/e8o1ci00000006r9.htm
# Shimadzu Application News No.L294: “Application of Evaporative Light Scattering * Shimadzu Application News No.L389
Detector ELSD-LT (Part 2) Analysis of Oligosaccharides in Beer” # Shimadzu Application News No.L397
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