Hop bitter acids: resources, biosynthesis, and applications

2021 ◽  
Author(s):  
Guoqing Zhang ◽  
Nan Zhang ◽  
Anran Yang ◽  
Jingling Huang ◽  
Xueni Ren ◽  
...  
Keyword(s):  
Bitter Acids

scholarly journals Hop Bitter Acids Increase Hippocampal Dopaminergic Activity in a Mouse Model of Social Defeat Stress

2020 ◽  
Vol 21 (24) ◽  
pp. 9612
Author(s):  
Yasuhisa Ano ◽  
Shiho Kitaoka ◽  
Rena Ohya ◽  
Keiji Kondo ◽  
Tomoyuki Furuyashiki
Keyword(s):  
Mouse Model ◽  
Chronic Administration ◽  
Social Defeat ◽  
Underlying Mechanism ◽  
Mental Illnesses ◽  
Social Avoidance ◽  
Social Defeat Stress ◽  
Dopaminergic Activity ◽  
Healthy Older Adults ◽  
Bitter Acids

As daily lifestyle is closely associated with mental illnesses, diet-based preventive approaches are receiving attention. Supplementation with hop bitter acids such as iso-α-acids (IAA) and mature hop bitter acids (MHBA) improves mood states in healthy older adults. However, the underlying mechanism remains unknown. Since acute oral consumption with IAA increases dopamine levels in hippocampus and improves memory impairment via vagal nerve activation, here we investigated the effects of chronic administration of hop bitter acids on the dopaminergic activity associated with emotional disturbance in a mouse model of repeated social defeat stress (R-SDS). Chronic administration of IAA and MHBA significantly increased dopaminergic activity based on the dopamine metabolite to dopamine ratio in the hippocampus and medial prefrontal cortex following R-SDS. Hippocampal dopaminergic activity was inversely correlated with the level of R-SDS-induced social avoidance with or without IAA administration. Therefore, chronic treatment with hop bitter acids enhances stress resilience-related hippocampal dopaminergic activity.

scholarly journals Sub- and Supercritical Extraction of Slovenian Hops (Humulus lupulus L.) Aurora Variety Using Different Solvents

Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1137
Author(s):  
Katja Bizaj ◽  
Mojca Škerget ◽  
Iztok Jože Košir ◽  
Željko Knez
Keyword(s):  
Sulfur Hexafluoride ◽  
Total Yield ◽  
Extraction Yield ◽  
Operating Conditions ◽  
Influence Of Process Parameters ◽  
Humulus Lupulus L ◽  
Bitter Acids ◽  
Temperature And Pressure ◽  
Carbon Dioxide Co2 ◽  
The Mathematical Model

This work investigates the efficiency of supercritical fluid extraction of hops with a variety of solvents including carbon dioxide (CO2), propane, sulfur hexafluoride (SF6), and dimethyl ether (DME) at various densities (low-density and high-density). Operating parameters were 50 bar, 100 bar and 150 bar and 20 °C, 40 °C, 60 °C and 80 °C for all solvents, respectively. The influence of process parameters on the total yield of extraction and content of bitter acids in the extracts has been investigated. The mathematical model based on Fick’s second law well described the experimental extraction results. Furthermore, HPLC analysis has been used to determine α- and β-acids in extracts. The yield of bitter compounds in hop extracts was largely influenced by the type of solvent, the temperature and pressure applied during extraction. The results show that CO2 and propane were roughly equivalent to DME in solvating power, while SF6 was a poor solvent at the same conditions. The highest yield as well as the highest concentration of bitter acids in extracts were obtained by using DME, where the optimal operating conditions were 40 °C and 100 bar for the extraction of α-acids (max. concentration 9.6%), 60 °C and 50 bar for the extraction of β-acids (4.5%) and 60 °C and 150 bar for the maximum extraction yield (25.6%).

In-vitro prenylation of aromatic intermediates in the biosynthesis of bitter acids in humulus lupulus

1998 ◽  
Vol 49 (8) ◽  
pp. 2315-2322 ◽  
Author(s):  
Karin W.M. Zuurbier ◽  
Suen-Ying Fung ◽  
Johannes J.C. Scheffer ◽  
Robert Verpoorte
Keyword(s):  
Humulus Lupulus ◽  
Bitter Acids

scholarly journals Analysis and prognosis of bitter acids content in Czech hop varieties - year 2018 and long-term comparisons and trends

2019 ◽  
Vol 65 (1) ◽  
pp. 23-31
Author(s):  
Alexandr Mikyška ◽  
Marie Jurková
Keyword(s):  
Acid Content ◽  
Dry Matter ◽  
Hplc Method ◽  
Relative Content ◽  
Final Evaluation ◽  
Bitter Acids ◽  
Bitter Acid ◽  
The Stability ◽  
Good Agreement

This article presents the results of the harvest forecast of the alpha- and beta-bitter acids of the Czech hop varieties in the 2018 harvest, the results are discussed in relation to the long-term averages, the composition of the bitter acid analogs and the stability of the varietal characteristics. 180 hop samples were analyzed using EBC 7.7 (HPLC) method. The alpha-acid content of the most important Saaz variety (2.9% in dry matter) was identical to the 2017 harvest and 18% rel. lower than the 26-year average. The alpha-acid content of Sladek (5.0%), Premiant (4.8%), and Saaz Late (1.6%) varieties was significantly lower than the long-term average. The harvest of the hops of the Kazbek and Agnus varieties was close to the long-term average. The ratio of alpha- and beta-acids, the relative content of cohumulone and the relative content of colupulone were consistent with long-term averages for the tested varieties. It was confirmed, that the harvest forecast gives timely information on the alpha-acids content of the harvest, the results were in good agreement with the values of the final evaluation of all harvested hops samples.

scholarly journals Comparison of quality parameters of Czech and foreign hop varieties

2011 ◽  
Vol 49 (No. 6) ◽  
pp. 261-268 ◽  
Author(s):  
K. Krofta
Keyword(s):  
Quality Parameters ◽  
Separate Group ◽  
Hybrid Origin ◽  
Brewing Industry ◽  
Dual Purpose ◽  
Bitter Acids

Market varieties of hops are classified to several groups according to their use in the brewing industry – aroma, bitter (dual-purpose), high-alpha ones. Saaz and other genetically related varieties form a separate group among the aromatic hops. The group called fine aroma hops has a low content of a-bitter acids (3–4% w/w), its content of b-bitter acids is in the range of 4–7% w/w and cohumulone ratio in the interval of 23–26% rel. The composition of hop oils is characterised by the content of b-farnesene in the range of 15–20% rel. and trans-a-bergamotene at the amount of ca. 1% rel. Most market varieties of hops are of hybrid origin. It holds true about the Czech varieties Sládek, Bor, Premiant and Agnus. The content of a-bitter acids in bitter varieties is in the range of 7–10% w/w while the content of a-bitter acids in high-alpha hops is higher than 10% w/w.

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