Related Experiment Video
Updated: Aug 5, 2025

Preparation of Homogeneous MALDI Samples for Quantitative Applications
Published on: October 28, 2016
Addition of Hop (Humulus Lupulus L.) Bitter Acids Yields Modification of Malt Protein Aggregate Profiles during Wort
Mariana B C Pinto1,2, Flavio L Schmidt1, Juri Rappsilber3
1Fruit, Vegetable and Confectionery Products Laboratory, Department of Food Engineering and Technology, School of Food Engineering, Universidade Estadual de Campinas, Rua Monteiro Lobato 80, 13083-862 Campinas, São Paulo, Brazil.
Abstract:
Hop bitter acids are used in the brewing industry to give beer bitterness. However, much of this bitterness is lost during processing, specifically during the wort boiling step. One of the major causes might be the interaction with protein-protein complexes. Therefore, the aim of this study was to clarify the role of hop bitter acids in protein aggregate formation using a proteomic approach. The effect of hop addition on protein composition was analyzed by liquid chromatography-mass spectrometry/MS (LC-MS/MS), and further analyses were performed to characterize the wort before and after boiling. Addition of hop bitter acids yielded a change in wort protein profiles, and hop bitter acids were found to bind primarily to less abundant proteins which are not related to beer quality traits, such as foam or haze. Wort protein aggregate profiles were revealed, and findings from this study suggested the precipitation of particular proteins in the aggregates during boiling when hops were added.
Related Concept Videos
Physical Properties of Alcohols and Phenols
Alcohols possess a higher boiling point than aliphatic hydrocarbons of...
Precipitation Processes
Composition of Polyprotic Acid Solutions as a Function of pH
A graph with the alpha values is plotted against the volume of...
Solvating Effects
Hydrolysis
Hydrolysis is a chemical reaction in which the addition of water breaks down a polymer into its simpler monomer units. For example, peptides break into amino acids, carbohydrates into simple sugars, and DNA into nucleotides. Enzymes often facilitate these processes.
Hydrolysis Reverses Dehydration Synthesis
Complex carbohydrates can be broken down by breaking the bonds between individual sugar units. The reaction breaks a glycosidic bond as water is added to the compound. The...
Distillation: Vapor–Liquid Equilibria

