Effect of high hydrostatic pressure (HHP) and high dynamic pressure (HDP) on stability and rheological properties of model oil-in-water emulsions

Download

index.pdf

Date

2010

Author

Bigikoçin, Erman

Metadata

Show full item record

Item Usage Stats

229
views

105
downloads

High pressure applications are alternatives to conventional methods in food processing. They provide interesting modifications in food structures which leads to new product formulations. The aim of this study is to identify the effects of two different treatments, high hydrostatic pressure (HHP) and high dynamic pressure (HDP) on stability and rheological properties of model oil-in-water emulsions. Microfluidization was selected among the HDP homogenization techniques. The performance of each process was analyzed in terms of rheological modifications and emulsion stability improvements compared to the coarse emulsions which were prepared with colloid mill homogenization. Stability of emulsions was determined comparatively by using an analytical photo-centrifuge device employing a novel analysis technology. Whey protein isolate (WPI) was used as an emulsifier in combination with a food polysaccharide as a stabilizer. The polysaccharides used were xanthan gum, guar gum and locust bean gum which are widely used stabilizing ingredients in food industry. The effective disruption of oil droplets and the degradation of polysaccharides by the shear forces under high pressure in HDP microfluidization yielded finer emulsions with lower viscosities. The finer emulsions obtained with this homogenization technique led to distinctive improvements in emulsion stability. On the other hand, the improvements in stability by HHP treatment were due to the thickening of the emulsions mainly induced by protein unfolding. The corresponding increases in viscosity were intensified in emulsion formulations with higher oil content. Apart from these, HHP treatment was found to be relatively more contributing to the enhancements in viscoelastic properties.

Subject Keywords

Food processing and manufacture.

URI

http://etd.lib.metu.edu.tr/upload/12612416/index.pdf
https://hdl.handle.net/11511/19959

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Modeling of tempering of frozen potato puree by microwave, infrared assisted microwave and ohmic heating methods Seyhun, Nadide; Şümnü, Servet Gülüm; Department of Food Engineering (2008) The main purpose of this thesis is to develop a model that can predict the temperature profile inside a frozen food sample during microwave tempering and infrared assisted microwave tempering processes. Another goal of the study is to compare the tempering time of frozen foods by using microwave, infrared assisted microwave, and ohmic heating methods. Frozen potato puree was used as the food sample for all studies. Three different microwave power levels (30%, 40%, and 50%) were used for microwave tempering ...
Optimization of microwave-halogen lamp baking of bread Demirekler, Pınar; Şümnü, Servet Gülüm; Department of Food Engineering (2004) The main objective of this study was to optimize the processing conditions of breads baked in halogen lamp-microwave combination oven by using response surface methodology. It was also aimed to construct neural network models for the prediction of quality parameters of bread as a function of processing conditions. Different baking time and power combinations were used in order to find the optimum baking conditions of bread in halogen lamp-microwave combination oven. The independent variables were the baking...
Effect of high hydrostatic pressure on background microflora and furan formation in fruit pur,e based baby foods KULTUR, Gulcin; MISRA, N. N.; BARBA, Francisco J.; KOUBAA, Mohamed; GÖKMEN, VURAL; Alpas, Hami (Springer Science and Business Media LLC, 2018-03-01) The baby foods industry is currently seeking technologies to pasteurize products without formation of processing contaminants such as furan. This work demonstrates the applicability of high hydrostatic pressure (HHP) as a non-thermal decontamination intervention for fruit pur,e based baby foods. HHP processing was evaluated at 200, 300, and 400 MPa pressures, for 5, 10 and 15 min of treatment times at 25, 35 and 45 A degrees C. HHP application at 400 MPa, 45 A degrees C for 15 min ensured complete inactivat...
Optimization of Processing Conditions During Halogen Lamp-Microwave Baking of Cakes Sevimli, Kadriye Melike; Şümnü, Servet Gülüm; Department of Food Engineering (2004) The main objective of this study was to optimize processing conditions during halogen lamp-microwave combination baking of cake by using Response Surface Methodology. It was also aimed to compare quality of products baked in microwave-halogen lamp combination oven, halogen lamp oven, microwave oven and conventional oven. In the first part of the study, as independent variables, baking time for conventional oven; microwave power and baking time for microwave oven; halogen lamp power and baking time for halog...
Infrared-assisted microwave drying in the production of bread crumbs Tireki, Suzan; Şümnü, Servet Gülüm; Department of Food Engineering (2005) This study is aimed to investigate the possibility of using halogen lamp-microwave combination oven for production of bread crumbs and to determine the drying conditions in this oven to produce bread crumbs with the highest quality. Bread crumb dough was dried from about 40.9% to 8% moisture content by conventional oven, microwave, infrared and infrared-assisted microwave drying. In the experiments 30%, 50% and 70% halogen lamp and/or microwave powers were used. As a control, conventional oven drying at 75°...

Citation Formats

E. Bigikoçin, “Effect of high hydrostatic pressure (HHP) and high dynamic pressure (HDP) on stability and rheological properties of model oil-in-water emulsions,” M.S. - Master of Science, Middle East Technical University, 2010.