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Isolation of pure aminoacids from wheat bran
Sloupová, Klára ; Diviš, Pavel (referee) ; Pořízka, Jaromír (advisor)
Wheat bran is a promising material containing a wide range of useful components, including proteins. In addition, it is produced in significant volumes. Currently, wheat bran is used for the production of energy by combustion and for feed purposes. Gradually, new methods of valorization of this material are being sought. One of the possibilities of using wheat bran is the isolation of proteins, hydrolysis, and separation of selected amino acids. This diploma thesis deals with this issue, it is focused on the recovery of arginine and leucine from a protein isolate. Proteins were extracted from wheat bran by changing the pH. Thanks to the subsequent lyophilization a protein isolate was gained. Prior to hydrolysis of the resulting isolate, a stability test of arginine and leucine amino acid standards was first performed, to which various hydrolysis methods were applied. Acid hydrolysis using a mineralizer, which was applied to the protein isolate, was proved to be the most effective. This was followed by the derivatization of the hydrolysates with OPA and analysis of the resulting hydrolysates by high-performance liquid chromatography with UV-VIS detection. Then, suitable adsorption and desorption conditions were optimized. It was found that the time dependence does not affect the amount of adsorbed material on the sorbent. Therefore, an application time of 15 minutes was chosen. While optimizing the amount of used standard, it was found that the optimal weight was 0.25 g of sorbent. The selected conditions were applied to the protein hydrolyzate. Two fractions were obtained by the separation of selected amino acids due to the change in the pH of the citrate buffer. After the application of this procedure, 0.26 g of arginine and 0.82 g of leucine were obtained from one kilogram after evaporation. From evaporation two, 1.01 g of arginine and 0.25 g of leucine were obtained after evaporation.
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Preparation and characterization of protein concentrates from wheat bran
Hubačová, Klára ; Diviš, Pavel (referee) ; Pořízka, Jaromír (advisor)
The diploma thesis deals with usage of wheat bran as a source of high-quality proteins. Every year mill industry produces large amounts of by-products. These by-products are constituted by wheat bran. There is a big effort to use these type of materials within a circular economy. Wheat bran contains about 14–18 % proteins which appears to be a good component for valorisation. It is possible to extract proteins from bran according to their behaviour in the range of pH. Proteins are soluble in alkaline pH and can be precipitated around their isoelectric point. The final treatment of precipitated proteins is lyophilisation. The next step is characterisation of the product. There are a few parameters to analyse: purity of the isolate, amino acid profile, composition of minerals, water contain etc. Interest in nutrition is on the rise not only by professional sportsman. This isolated product could serve as a potential protein supplement.
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Production of enzyme hydrolysates from flaxseed proteins and evaluation of their properties
HAŠKOVÁ, Kateřina
This thesis focuses on effect on antioxidant properties and chosen functional properties: solubility, water and fat holding capacity, emulsification activity and stability caused by hydrolysis of protein isolates (PI) made from three different flax varieties (Libra, Agriol and Raciol). Part of this work was production of PI from flax seed. For hydrolysis trypsin, alcalase and papain were used - hydrolysis by trypsin was the mildest, while hydrolysis by papain was the most intensive one. Dynamics and degree of hydrolysis were also observed. Solubility of PI and hydrolysates was discovered to be very high (almost 100%). On the contrary water holding capacity was lower (3,93 g/g and less) than fat holding capacity (4,34 g/g), which increased upon hydrolysis for most enzymes, while water holding capacity decreased. Emulsification activity rised (1,47×) under the effect of hydrolysis, however stability dropped (1,3×). The best emulsifiction properties were found out in trypsin hydrolysates. Hydrolysis caused great impact on content of polyphenols which were in alcalase hydrolysates up to 3× higher and on antioxidant activity which grew in papain hydrolysates up to 2,5×.
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Isolation of pure aminoacids from wheat bran
Sloupová, Klára ; Diviš, Pavel (referee) ; Pořízka, Jaromír (advisor)
Wheat bran is a promising material containing a wide range of useful components, including proteins. In addition, it is produced in significant volumes. Currently, wheat bran is used for the production of energy by combustion and for feed purposes. Gradually, new methods of valorization of this material are being sought. One of the possibilities of using wheat bran is the isolation of proteins, hydrolysis, and separation of selected amino acids. This diploma thesis deals with this issue, it is focused on the recovery of arginine and leucine from a protein isolate. Proteins were extracted from wheat bran by changing the pH. Thanks to the subsequent lyophilization a protein isolate was gained. Prior to hydrolysis of the resulting isolate, a stability test of arginine and leucine amino acid standards was first performed, to which various hydrolysis methods were applied. Acid hydrolysis using a mineralizer, which was applied to the protein isolate, was proved to be the most effective. This was followed by the derivatization of the hydrolysates with OPA and analysis of the resulting hydrolysates by high-performance liquid chromatography with UV-VIS detection. Then, suitable adsorption and desorption conditions were optimized. It was found that the time dependence does not affect the amount of adsorbed material on the sorbent. Therefore, an application time of 15 minutes was chosen. While optimizing the amount of used standard, it was found that the optimal weight was 0.25 g of sorbent. The selected conditions were applied to the protein hydrolyzate. Two fractions were obtained by the separation of selected amino acids due to the change in the pH of the citrate buffer. After the application of this procedure, 0.26 g of arginine and 0.82 g of leucine were obtained from one kilogram after evaporation. From evaporation two, 1.01 g of arginine and 0.25 g of leucine were obtained after evaporation.
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Preparation and characterization of protein concentrates from wheat bran
Hubačová, Klára ; Diviš, Pavel (referee) ; Pořízka, Jaromír (advisor)
The diploma thesis deals with usage of wheat bran as a source of high-quality proteins. Every year mill industry produces large amounts of by-products. These by-products are constituted by wheat bran. There is a big effort to use these type of materials within a circular economy. Wheat bran contains about 14–18 % proteins which appears to be a good component for valorisation. It is possible to extract proteins from bran according to their behaviour in the range of pH. Proteins are soluble in alkaline pH and can be precipitated around their isoelectric point. The final treatment of precipitated proteins is lyophilisation. The next step is characterisation of the product. There are a few parameters to analyse: purity of the isolate, amino acid profile, composition of minerals, water contain etc. Interest in nutrition is on the rise not only by professional sportsman. This isolated product could serve as a potential protein supplement.
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