Hop Science Newsletter (August 2015)
In this issue: spicing up your hops, measuring hop aroma, and how to use phenolic hop compounds for varietal determination.
SPICE UP YOUR HOPS!
Belgian researchers are thoroughly investigating the spicy fraction of hop oil. The newest findings can be summarized like this: With a high concentration of hop oil you also receive a high concentration of sesquiterpene oxidation products. The formation of these compounds is largely variety independent. However the level of certain oxygenated sequiterpenoids (e.g. cubenol, T-cadinol, gleenol) does not increase upon boiling, supporting the hypothesis that they are not formed by oxidation but are instead related to the hop plant metabolism.¹
MEASURING HOP AROMA
It is of more and more importance, especially for brewers, to be in the position to analyse the sensory relevant hop aroma components such as geraniol, citronellol etc. This poster describes a highly selective, accurate quantification of hop-derived monoterpene alcohols in beer which is achieved via HS-SPME in combination with GC-ion trap tandem MS. As you might guess, the investment in this equipment is well worth the benefit…²
HOW TO USE PHENOLIC HOP COMPOUNDS FOR VARIETAL DETERMINATION!
Czech researchers have developed a high performance liquid chromatography-high resolution mass spectrometric (HPLC-HRMS) method to characterize and identify flavonoid O-glycosides in hops. This method can be used in combination with chemometrics as a fingerprinting method to differentiate hop varieties based on profiling of flavone and flavonol di- and triglycosides.³
Every year brewers are feverishly waiting for the Barth-Haas Report. Here is the NEW ONE! It is available for download on our website.