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Foaming properties of egg albumen as influenced by enzymatic modifications, xanthan gum and some extrinsic factors

Benjamas, Sumritjate LU (2015) KLGM01 20151
Food Technology and Nutrition (M.Sc.)
Abstract
To improve functional properties, 2 different types of egg albumen powder (high gel instant and ordinary) were hydrolyzed with four proteases (FPC, NPU, BAP and PSP) using different protease concentration (low, medium and high) at 50C for 1 h and subsequently polymerized by transglutaminase at 40C for 24 h. The enzymatic modified egg albumen was analyzed for foaming properties: foamability as %overrun, foam stability as %liquid drainage, the third largest bubble size and the visual appearance of foam. At 5% (w/v) of egg albumen dry matter, the high gel instant showed a higher foamability than the ordinary egg albumen. While the egg albumen hydrolyzed by neutral (FPC and NPU) and alkaline (BAP, pH 9.5) proteases had higher %overrun than... (More)
To improve functional properties, 2 different types of egg albumen powder (high gel instant and ordinary) were hydrolyzed with four proteases (FPC, NPU, BAP and PSP) using different protease concentration (low, medium and high) at 50C for 1 h and subsequently polymerized by transglutaminase at 40C for 24 h. The enzymatic modified egg albumen was analyzed for foaming properties: foamability as %overrun, foam stability as %liquid drainage, the third largest bubble size and the visual appearance of foam. At 5% (w/v) of egg albumen dry matter, the high gel instant showed a higher foamability than the ordinary egg albumen. While the egg albumen hydrolyzed by neutral (FPC and NPU) and alkaline (BAP, pH 9.5) proteases had higher %overrun than that hydrolyzed by acidic protease (PSP, pH 4.0), and greater %overrun was obtained with higher protease concentration. In contrast, the hydrolyzed egg albumen without transglutaminase treatment produced poor foam stability. 1% (w/v) of transglutaminase significantly decreased %liquid drainage of foams. However, the visual appearance of foams obtained from 5% (w/v) of egg albumen and whipped for 45 s were too stiff and unflowable. The effect of egg albumen concentration (5, 4, 3, 2 and 1% (w/v) of high gel instant), the whipping time (45, 35, 30 and 20 s) and temperature before whipping (37, 23 and 11C) were also studied when the enzymatic treatments were conducted by 0.5% (w/w) of NPU and 1% (w/v) of transglutaminase. It demonstrated that the stability of foams significantly decreased with decreasing the egg albumen concentration, but their visual appearance were not affected much. The whipping time had a strong influence on the appearance of foams. Whipping no more than 35 s resulted in a liquid foam behaving as a viscous fluid. Whereas the temperature before whipping did not affect their foaming properties. Next, xanthan gum was used in order to improve the foam stability, and studied at the concentration between 0, 0.2, 0.25 and 0.3% (w/v). At 0.25% (w/v) of xanthan gum was the lowest concentration that can stabilize the enzymatic modified foams up to 3 h, and the addition of xanthan gum did not affect any of the foam parameters that were measured. Whereas, scaling up the foam production from 100 ml to 500 ml, and whipping in different size of containers (8.5, 12.5 and 14.5 cm of inside diameter) showed that higher %overrun was obtained with larger container size. The enzymatic modified egg albumen foam had a higher stability in the acidic conditions by the addition of 29.8 mmol/l of ascorbic acid in the foam formulation compared with the foam without enzymatic treatments. Finally, the foam obtained from a combination of enzymatic modifications and xanthan gum resulted in a minimal disruption of the foam structure during the in vitro digestive test. (Less)
Popular Abstract
Egg albumen, known as egg white, has been used to create foams for a variety of dishes such as meringues, cakes, mousses, and souffl├ęs. Vary widely recipes are advised and any little details could have a large influence on the final product. Basically, foams are complex systems in which air is dispersed in a continuous liquid phase. In nature, the large molecule of proteins consist of both hydrophilic (water-loving) regions, which is exposed to water, and hydrophobic (water-fearing) regions, which is kept inside of their molecular structure. Conformational changes of protein by physical, chemical and enzymatic treatments can cause the proteins to unfold, thus improving or decreasing their functionality such as solubility, foaming... (More)
Egg albumen, known as egg white, has been used to create foams for a variety of dishes such as meringues, cakes, mousses, and souffl├ęs. Vary widely recipes are advised and any little details could have a large influence on the final product. Basically, foams are complex systems in which air is dispersed in a continuous liquid phase. In nature, the large molecule of proteins consist of both hydrophilic (water-loving) regions, which is exposed to water, and hydrophobic (water-fearing) regions, which is kept inside of their molecular structure. Conformational changes of protein by physical, chemical and enzymatic treatments can cause the proteins to unfold, thus improving or decreasing their functionality such as solubility, foaming properties, etc. For example, when the egg albumen is whipped, their hydrophobic regions are exposed and search for any desired area such as the air allowing the entrapment of air bubbles in the foam structure. In addition, some other ingredients such as sugars, salt, stabilizers, etc can also affect their functional properties. The present study aimed to produce the liquid egg albumen foam with desired foamability and good foam stability before and after oral administration when the foam is used in the clinical application. The study mainly focused on the efficiency of the enzymatic treatments using protease, which have the ability to cut proteins into smaller molecules, and transglutaminase, which have the ability of binding protein leading to a larger molecular size. Several factors, the egg albumen type and concentration, the protease type and concentration, the presence of transglutaminase, whipping time, temperature, xanthan gum concentration, the addition of ascorbic acid, the container size including the in vitro digestive test, were investigated their effects on the foaming properties of egg albumen protein. The foamability referring to the amount of air incorporated in the foam at a certain time in term of overrun was examined by comparing the weight of a known volume of egg albumen foam to the weight of the same volume of egg albumen dispersion. While the foam stability was examined by measuring the amount of liquid drained out from the foam structure after 3 h storage, and the bubble size was determined by imaging the microstructure. The visual appearance of foam samples was also observed in order to investigate their stiffness and flowability. The results showed that the enzymatic treatments by a neutral protease followed by transglutaminase cross-linking had a high efficiency to improve both foamability and stability of the egg albumen, but the addition of xanthan gum was the most effective way in order to improve the foam stability. When the egg albumen concentration was decreased, the main effect was observed in the foam stability, which decreased with decreasing the egg albumen concentration. While the whipping time and container size strongly affected the amount of air incorporated into the foam structure. Foams obtained from a longer whipping time were more stiff and unflowable, and whipping in a larger container resulted in foams with higher %overrun but not homogeneous. However, the temperature before whipping did not affect any foaming properties. Furthermore, the stability of enzymatic modified foams were not influenced by the addition of ascorbic acid, and foams obtained from a combination of enzymatic treatments and the addition of xanthan gum resulted in a minimal disruption of the foam structure during the in vitro gastric and duodenal digestion. (Less)
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author
Benjamas, Sumritjate LU
supervisor
organization
course
KLGM01 20151
year
type
H2 - Master's Degree (Two Years)
subject
keywords
transglutaminase, polymerization, egg albumen protein, hydrolysis, food technology, livsmedelsteknologi, in vitro digestion, foaming, ascorbic acid, xanthan gum
language
English
id
7373900
date added to LUP
2015-06-23 15:28:28
date last changed
2015-06-23 15:28:28
@misc{7373900,
  abstract     = {To improve functional properties, 2 different types of egg albumen powder (high gel instant and ordinary) were hydrolyzed with four proteases (FPC, NPU, BAP and PSP) using different protease concentration (low, medium and high) at 50C for 1 h and subsequently polymerized by transglutaminase at 40C for 24 h. The enzymatic modified egg albumen was analyzed for foaming properties: foamability as %overrun, foam stability as %liquid drainage, the third largest bubble size and the visual appearance of foam. At 5% (w/v) of egg albumen dry matter, the high gel instant showed a higher foamability than the ordinary egg albumen. While the egg albumen hydrolyzed by neutral (FPC and NPU) and alkaline (BAP, pH 9.5) proteases had higher %overrun than that hydrolyzed by acidic protease (PSP, pH 4.0), and greater %overrun was obtained with higher protease concentration. In contrast, the hydrolyzed egg albumen without transglutaminase treatment produced poor foam stability. 1% (w/v) of transglutaminase significantly decreased %liquid drainage of foams. However, the visual appearance of foams obtained from 5% (w/v) of egg albumen and whipped for 45 s were too stiff and unflowable. The effect of egg albumen concentration (5, 4, 3, 2 and 1% (w/v) of high gel instant), the whipping time (45, 35, 30 and 20 s) and temperature before whipping (37, 23 and 11C) were also studied when the enzymatic treatments were conducted by 0.5% (w/w) of NPU and 1% (w/v) of transglutaminase. It demonstrated that the stability of foams significantly decreased with decreasing the egg albumen concentration, but their visual appearance were not affected much. The whipping time had a strong influence on the appearance of foams. Whipping no more than 35 s resulted in a liquid foam behaving as a viscous fluid. Whereas the temperature before whipping did not affect their foaming properties. Next, xanthan gum was used in order to improve the foam stability, and studied at the concentration between 0, 0.2, 0.25 and 0.3% (w/v). At 0.25% (w/v) of xanthan gum was the lowest concentration that can stabilize the enzymatic modified foams up to 3 h, and the addition of xanthan gum did not affect any of the foam parameters that were measured. Whereas, scaling up the foam production from 100 ml to 500 ml, and whipping in different size of containers (8.5, 12.5 and 14.5 cm of inside diameter) showed that higher %overrun was obtained with larger container size. The enzymatic modified egg albumen foam had a higher stability in the acidic conditions by the addition of 29.8 mmol/l of ascorbic acid in the foam formulation compared with the foam without enzymatic treatments. Finally, the foam obtained from a combination of enzymatic modifications and xanthan gum resulted in a minimal disruption of the foam structure during the in vitro digestive test.},
  author       = {Benjamas, Sumritjate},
  keyword      = {transglutaminase,polymerization,egg albumen protein,hydrolysis,food technology,livsmedelsteknologi,in vitro digestion,foaming,ascorbic acid,xanthan gum},
  language     = {eng},
  note         = {Student Paper},
  title        = {Foaming properties of egg albumen as influenced by enzymatic modifications, xanthan gum and some extrinsic factors},
  year         = {2015},
}