The Bitter Chemodiversity of Hops (Humulus lupulus L.)

Abstract

This paper evaluates the influence of genotype on the photosynthetic activity of hops in the period critical for generating yield. Results over three years from measuring the photosynthesis rate statistically show an increase in the photosynthetic activity of hop plants in the flowering stage. The average photosynthetic rates from measurements on the second date (BBA 65) in the years 2007, 2008, and 2009 increased by 17.9%, 45.6%, and 49.2%, respectively. Different photosynthesis curve trends during the final stage of ontogenesis of the plants indicate the maturity level of each hop genotype. As regards the genotypes for which photosynthesis did not reduce significantly, it may be assumed that such plants had not reached technical maturity. The results from the three-year study also show that any promising genotype, with respect to the photosynthesis rate and yield, is the result of breeding of new varieties with greater resistance to drought and high temperatures. Very good results in photosynthetic activity were reached by the new varieties exhibiting high yield and a similar chemical composition to Saaz hop and those sharing the same origins to Saaz, showing a higher content of bitter substances. In 2008 and 2009, all three new forms reached yield levels of 2.35 to 3.12 t/ha of dry hops.

Inhibition of Growth and Ammonia Production of Ruminal Hyper Ammonia-Producing Bacteria by Chinook or Galena Hops after Long-Term Storage

“…It is unknown if DM changed in storage, and the differences before and after drying might also include some volatile compounds. That said, these results were consistent with a recent thorough evaluation of hop metabolite stability [16]. This latter study included quantification of many flavor and aroma components of 75 hop varieties, and their stability under different storage conditions.…”

Phytochemical Characterization of Wild Hops (Humulus lupulus ssp. lupuloides) Germplasm Resources From the Maritimes Region of Canada

“…Female hops flowers, also known as cones, are primarily used in brewing beer; most of the bitter flavor and characteristic zesty beer aromas arise from hops cones added at various points during wort boiling, secondary fermentation, and the aging process. A wide variety of phytochemicals, some uniquely found in hops, have previously been reported (Almaguer et al, 2014;Dresel et al, 2016;Karabín et al, 2016), with a particular focus on prenylflavonoids, alpha and beta acids (soft resins), and volatile terpenoids. In addition to their importance in beer brewing, hops have been used in traditional herbal medicines as a sleep aid, while modern biomedical research has focused on various components in the development of new therapeutic agents (Stevens and Page 2004;Gerhäuser 2005;Zanoli and Zavatti 2008;Van Cleemput et al, 2009;Karabín et al, 2016).…”

Beer produced via hydrodynamic cavitation retains higher amounts of xanthohumol and other hops prenylflavonoids

“…Among the hops, different combinations of pelletized German Perle (hereinafter, Perle), Saaz and German Hersbrucker (hereinafter, Hers) were used. Table 1 shows the average concentration of the three prenylflavonoids under study in the used hops, drawn from available sources (Dresel et al, 2016;. Source: (Dresel et al, 2016).…”

“…Table 1 shows the average concentration of the three prenylflavonoids under study in the used hops, drawn from available sources (Dresel et al, 2016;. Source: (Dresel et al, 2016).…”

“…Higher XN levels in beers can be achieved by means of late addition of hops to the boiling wort, addition of XN-enriched hops extracts, and the use of special malts, leading to concentrations as high as 3.5 mg/L (Magalhães et al, 2008), or even 10 mg/L without negatively affecting fermentation (Magalhães et al, 2011). Impacts of XN-enrichment on beers' aroma, taste and shelf-life were found positive (Dresel, Vogt, Dunkel, & Hofmann, 2016).…”