LAUSR

BACKGROUND It is well known that duration of pre-drying storage impacts on hop quality. However, little knowledge exists regarding its actual effects on valuable hop components. To investigate these effects, fresh hop cones were stored for 5 h and 24 h respectively and dried for 210 min at 65 °C thereafter. Furthermore, to understand the effect of freezing hop cones on the essential oil content, both fresh and stored samples were frozen before and after drying. RESULTS The results from GC analysis show an increase in linalool, ß-caryophyllene, humulene, geraniol content and decrease in myrcene content dependent on the period of storage. Total colour difference (ΔE) values of 4.61 and 5.27 were obtained for fresh and stored hops respectively; indicating discolouration of hops during storage. Modelling of moisture curves revealed Wang & Singh model to be suitable with a Radj 2 of 0.978 and 0.989 and RMSE of 0.037 and 0.019 for fresh and stored hops respectively. CONCLUSION The results obtained from this study provide an in depth understanding on the changes occurring within the hop cones both during storage and drying and will further help hop processors optimise their storage times. This article is protected by copyright. All rights reserved.