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Surface rheology and Morphology of Air-Water interfaces with adsorbed layers of Beer proteins and Isohumulones

Choi, Bobae LU (2018) KLGM01 20181
Food Technology and Nutrition (M.Sc.)
Abstract (Swedish)
A good head of beer gives nice texture and prevents releasing of aroma. The beer foam stability depends on numerous parameters. In this study, it was focused on the interfacial rheological properties such as surface tension and dilational modulus in relation the film formation by isohumulones and beer proteins at the air-water interfaces. The isohumulones and beer protein samples were prepared individually from polaris pellet and barley malt. Both isohumulones and proteins are surface active and the combination of them have even more enhanced properties. The adsorbed layer formed by only isohumulone, pre-mixed solution of proteins and isohumulones and proteins with the sequential addition of isohumulones. Thus, it can be concluded that the... (More)
A good head of beer gives nice texture and prevents releasing of aroma. The beer foam stability depends on numerous parameters. In this study, it was focused on the interfacial rheological properties such as surface tension and dilational modulus in relation the film formation by isohumulones and beer proteins at the air-water interfaces. The isohumulones and beer protein samples were prepared individually from polaris pellet and barley malt. Both isohumulones and proteins are surface active and the combination of them have even more enhanced properties. The adsorbed layer formed by only isohumulone, pre-mixed solution of proteins and isohumulones and proteins with the sequential addition of isohumulones. Thus, it can be concluded that the properties of the surface film depends on the composition and of the addition sequence of the components. The simultaneously mixed solution forms a layer with evenly distributed components over the surface and it accounts for the exceptionally high surface activity and rigidity. (Less)
Popular Abstract
What makes beer foam stable?

Beer is one of the most beloved beverages all over the world. When we think about a good beer, we end up with beer foam. This is because the foam prevents releasing of aroma and gives a good texture when drinking. Beer foam is a mixture of air and liquid containing beer components such as ethanol, proteins, hop acids and other nutrients. Beer proteins are from the barley malt and hop acids are from hop. Hop acids are bitter tasting compounds.
In order to avoid collapsing of foams, it is necessary to have a surface-active agents (surfactants), for example, a detergent. Surfactant is a compound which can interact with both water and oil and these properties are called as hydrophilic (water-loving) and... (More)
What makes beer foam stable?

Beer is one of the most beloved beverages all over the world. When we think about a good beer, we end up with beer foam. This is because the foam prevents releasing of aroma and gives a good texture when drinking. Beer foam is a mixture of air and liquid containing beer components such as ethanol, proteins, hop acids and other nutrients. Beer proteins are from the barley malt and hop acids are from hop. Hop acids are bitter tasting compounds.
In order to avoid collapsing of foams, it is necessary to have a surface-active agents (surfactants), for example, a detergent. Surfactant is a compound which can interact with both water and oil and these properties are called as hydrophilic (water-loving) and hydrophobic (water-hating). The air is composed of mostly nitrogen gas, which is hydrophobic. Proteins naturally contain both hydrophilic and hydrophobic properties due to the different kinds of amino acids. Hop acids are not a typical surfactant but if we look into the chemical structure of them, we can see the hydrophilic and hydrophobic parts.
The mixture of proteins and hop acids gives much higher surface activity compared to the individual components. Also, the way of mixing components plays an important role in determining the surface activity. (Less)
Please use this url to cite or link to this publication:
author
Choi, Bobae LU
supervisor
organization
course
KLGM01 20181
year
type
H2 - Master's Degree (Two Years)
subject
keywords
food technology, livsmedelsteknologi
language
English
id
8956420
date added to LUP
2018-08-20 14:05:06
date last changed
2018-08-20 14:05:06
@misc{8956420,
  abstract     = {A good head of beer gives nice texture and prevents releasing of aroma. The beer foam stability depends on numerous parameters. In this study, it was focused on the interfacial rheological properties such as surface tension and dilational modulus in relation the film formation by isohumulones and beer proteins at the air-water interfaces. The isohumulones and beer protein samples were prepared individually from polaris pellet and barley malt. Both isohumulones and proteins are surface active and the combination of them have even more enhanced properties. The adsorbed layer formed by only isohumulone, pre-mixed solution of proteins and isohumulones and proteins with the sequential addition of isohumulones. Thus, it can be concluded that the properties of the surface film depends on the composition and of the addition sequence of the components. The simultaneously mixed solution forms a layer with evenly distributed components over the surface and it accounts for the exceptionally high surface activity and rigidity.},
  author       = {Choi, Bobae},
  keyword      = {food technology,livsmedelsteknologi},
  language     = {eng},
  note         = {Student Paper},
  title        = {Surface rheology and Morphology of Air-Water interfaces with adsorbed layers of Beer proteins and Isohumulones},
  year         = {2018},
}