Hops are a well-known source of resins, essential oils and polyphenolic substances, such as proanthocyanidins or prenylflavonoids with significant representatives of xanthohumol, isoxanthohumol, and 8-prenylnaringenine, and represent an essential ingredient in beer production. Recently, however, many additional bioactive effects of hop compounds have been investigated.A systematic review of the structure-function relationship between the individual hop-derived compounds and their bio-activity has been lacking. In this review we summarize some recent findings in this area from reports from our as well as other studies. It shows multiple bio-medical effects of the individual hop derived compounds, which can act individually, or in a synergistic manner.The hops can serve as a source of bio-active compounds in phyto-medicine and as such, more attention and detailed studies are warranted to utilize the broad spectrum of effects of individual compounds in future treatments.An increasing number of pathogenic strains of bacteria (and viruses) resistant to different types of antimicrobials poses a major medical problem. Secondary metabolites of hops have been described

A simple and selective method is reported for the simultaneous determination of 48 fungicide, insecticide and herbicide residues in hops by LC–MS/MS. The extraction of pesticide residues from the hop matrix was conducted by a method based on the QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) sample preparation approach in combination with dispersive solid‐phase extraction using various sorbent blends consisting of primary–secondary amine, C18 and zirconia based sorbents. The matrix effect of all applied sorbent blends was evaluated. The results showed that the QuEChERS method required further optimization of the dispersive solid‐phase extraction cleaning step owing to co‐extraction of matrix components such as chlorophyll and hop resins. These contaminants resulted in signal suppression, elevated background, and other negative matrix effects. The accuracy, precision, specificity, linearity, limit of detection and limit of quantification were evaluated. The recovery ranged from 70 to 120% for most of the pesticides and RSD was <20% for all pesticides. The limit of quantification was estimated at 0.02 mg/kg or, in the worst cases, 0.05 mg/kg. The results meet the European Commission standard legislation, implying that this method is both accurate and reproducible. Copyright © 2018 The Institute of Brewing & Distilling

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The study presents tracking of 58 pesticide residues associated with hops to estimate their carryover into brewed beer. The pesticides were spiked onto organic hops at a concentration of 15 mg/kg, and the wort was boiled with the artificially contaminated hops and fermented on a laboratory scale. Samples were collected during the whole brewing process and pesticide residues were extracted using a method known as QuEChERS (quick, easy, cheap, effective, rugged, and safe). An HPLC-HR-MS/MS method was developed and validated to identify and quantitate pesticide residues in treated hops, spent hops, hopped wort, green beer, and beer samples. Quantitation was achieved using standard addition with isotopically labeled standards. The carryover percentages into hopped wort and the percentages of decay reduction relative to the amount spiked on hops were calculated. The relationship between the partition coefficients n-octanol-water (log P values) and the residual ratios ( R and R) of a pesticide were evaluated to predict their behavior during hopping of wort and fermentation. Pesticides with a high log P values (>3.75) tended to remain in spent hops. The pesticides that have a low log P value up to approximately 3 could represent the demarcation lines of appreciable transfer rate of pesticides from hops to beer. Consequently, the pesticides were divided into three categories depending upon their fate during the brewing process. The most potential risk category represents a group involving the thermostable pesticides, such as azoxystrobin, boscalid, dimethomorph, flonicamid, imidacloprid, mandipropamid, myclobutanil, and thiamethoxam, which were transferred at high rates from the pesticide enriched hops into beer during the laboratory brewing trial. These results can be used as a guideline in the application of pesticides on hop plants that would reduce the level of pesticide residues in beer and their exposure in humans.