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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
                                                                                                                                                                                                                                            #
                    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 .
                                                                                                 #
                    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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