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Beer foam stabilization using biosurfactants
Jandrtová, Sabina ; Diviš, Pavel (referee) ; Pořízka, Jaromír (advisor)
This diploma thesis focuses on a research of the foam stability of the beer. We specifically observed the influence of ethanol and surface tension on the foam stability, and influence of ethanol and surface tension on the height of the foam. It was observed the influence of the hop acids in non-alcoholic beers. Furthermore, different biosurfactants were added into to the beer to observe better stability of the foam. The theoretical part of this work describes the foam from the physical aspect. There are described fourth key events involved in foam formation. Then it focuses on the beer foam – its structure, substances that influence its behavior and measurement of the foam stability. In this part there are described biosurfactants as well – their characteristics, qualities, distribution and applications. The experimental part is dedicated to the influence of ethanol, surface tension, the amount of iso- acids on foam stability in beer. There is observed the influence of biosurfactants of the foam stability and surface tension, which are added into to the beer. For the measurement of the foam stability was used the Rudin method. Liquid chromatography with DAD detector was used for the measurement the amount of the hop acids. The surface tension was determined by tensiometer. According to the results addition of ethanol changed the characteristics of the foam stability, but it’s not easy to find correlation between the increasing amount of ethanol and its stability. It was found out, that there is connection between the amount of ethanol and surface tension. On the other hand, there is not much connection between the surface tension and foam height. Within the framework of addition of biosurfactants was observed, that these foaming agents interacted the surface tension of the beer (lowering), however these agents accelerated the fall of the beer foam.
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Vliv technologie pěstování kotvičníku zemního (Tribulus terrestris L.) na kvalitu produktu
NEUMANN, Jaroslav
This diploma thesis focuses on the Tribulus terrestris and its cultivation in order to achieve the highest content of biologically active substances. Tribulus has its roots in Chinese traditional medicine and Indian Ayurveda. The monitored substances are protodioscin and diosgenin. These two substances are saponins which are known for many beneficial effects on human health. For example, protodioscin is widely used as a remedy for conception problems. Diosgenin has its use in the fight against cancer. Both of these substances are also used in fitness to increase muscle mass and strength. The most famous is protodioscin, which became famous thanks to the Bulgarian weightlifters. However, the mechanisms of action of protodioscin and, in fact, diosgenin in the human body are not completely known in terms of influencing hormones in our body. In the practical part of this work, acetylsalicylic acid and the commercial preparation NanoFyt Si? are used as an elicitor. Water control was used for control, which was carried out in the same way as elicitor sprays. It is statistically summarized in what concentration the elicitors act or do not act. Based on statistical results, the cultivation procedure is recommended.
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Beer foam stabilization using biosurfactants
Jandrtová, Sabina ; Diviš, Pavel (referee) ; Pořízka, Jaromír (advisor)
This diploma thesis focuses on a research of the foam stability of the beer. We specifically observed the influence of ethanol and surface tension on the foam stability, and influence of ethanol and surface tension on the height of the foam. It was observed the influence of the hop acids in non-alcoholic beers. Furthermore, different biosurfactants were added into to the beer to observe better stability of the foam. The theoretical part of this work describes the foam from the physical aspect. There are described fourth key events involved in foam formation. Then it focuses on the beer foam – its structure, substances that influence its behavior and measurement of the foam stability. In this part there are described biosurfactants as well – their characteristics, qualities, distribution and applications. The experimental part is dedicated to the influence of ethanol, surface tension, the amount of iso- acids on foam stability in beer. There is observed the influence of biosurfactants of the foam stability and surface tension, which are added into to the beer. For the measurement of the foam stability was used the Rudin method. Liquid chromatography with DAD detector was used for the measurement the amount of the hop acids. The surface tension was determined by tensiometer. According to the results addition of ethanol changed the characteristics of the foam stability, but it’s not easy to find correlation between the increasing amount of ethanol and its stability. It was found out, that there is connection between the amount of ethanol and surface tension. On the other hand, there is not much connection between the surface tension and foam height. Within the framework of addition of biosurfactants was observed, that these foaming agents interacted the surface tension of the beer (lowering), however these agents accelerated the fall of the beer foam.
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Technologie pěstování Kotvičníku zemního (Tribulus terrestris L.) a jeho využití
NEUMANN, Jaroslav
This bachelor thesis is about a plant named Puncturevine (Tribulus terrestris), its substances, which are contained and about its possible usage in medicine. Another chapters describes some substances which we can find in a whole plant. The most important substances are saponins, phytosterols and flavonoids. Saponins are most popular for their aphrodisiatic effects, flavonoids for fighting illnes and phytosterols for decreasing cholesterol in blood plasma. Quantity of these substances is highly dependent on the area where, or how the plant is grown and if elicitors were used. In the practical part I found out if tribulus is known amongst people and how to grow it in greenhouse.
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Growing technology earthy Tribulus terrestris (Tribulus terrestris L.) and its use
HUDSKÁ, Miluše
This bachelor thesis deals with Puncturevine (Tribulus terrestris) as for planting, content substances, pharmacological use and with influences of planting technology or elicitors upon the active substance contents. Saponines, flavonoids, and phytosterols are the main active substances of Puncturevine. The saponines act as aphrodisiacs, the flavonoids treat with heart diseases and the phytosterols decrease the cholesterol concentration in blood plasma. The active substance contents depend on the planting and elicitor influences. The practical part is focused on the matters of free soil growing and economy of planting the herb.
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