Banu Koc - Academia.edu (original) (raw)

Papers by Banu Koc

Journal of Food Science and Technology, 2012

Journal of Food Science, 2011

The addition of gelatine (G), lactose (L), pullulan (P), and their mixtures at equal ratios (gela... more The addition of gelatine (G), lactose (L), pullulan (P), and their mixtures at equal ratios (gelatine + lactose [GL] and gelatin + pullulan [GP]) to whole egg prior to drying was studied. Their effects on the functional properties (emulsion and gelling ability, water holding capacity of gel, foaming, color) and soluble protein content of spray dried egg powder during the 6 mo of storage at 20 °C and 50% relative humidity were investigated. It was demonstrated that the emulsion and foaming stability, water holding capacity of gel, and color change were significantly affected by the storage time, whereas storage time did not affect the strength of gel texture prepared by egg powders. Gelatine and pullulan improved the foaming stability and water holding capacity. Lactose caused a decrease in emulsion and foaming stability values. The maximum color change was observed for the plain egg powder, showing that mixing whole egg with carbohydrate- and/or protein-based additives before the drying process preserved the color of egg powder. Adding carbohydrate and/or protein caused significant changes in functional properties of egg powder.

Food Hydrocolloids, 2014

ABSTRACT Functional, physico-chemical properties and FTIR analysis of flours and starches of two ... more ABSTRACT Functional, physico-chemical properties and FTIR analysis of flours and starches of two African rice cultivars (Transgressive Segregants TGS 3 and TGS 25) were investigated. The TGS 3 showed higher 1000 kernel grain weight (29.55 g), dockage (1.00 g), immature grain (1.97 g), thickness (2.10 mm), chalkiness (11.17%) and damaged grain (0.70%). However, the TGS 25 showed higher head rice yield (51.11%), milling degree (9.60%), length (6.88 mm) and elongation ratio (3.64). Also, the TGS 25 showed higher alkaline spread value (6.67), amylose content (30.81%), uncooked (7.15 mm) and cooked (10.17 mm) rice length. The WAC (2.77 g/mL) and OAC (1.08 g/mL) of TGS 25 flours were higher than TGS 3. The L value of TGS 25 flour (92.13) and starch (97.88) were higher than those of TGS 3. The TGS 3 flour and starch showed higher peak, breakdown and peak times of 4308 and 3531 cP, 2200 and 1947 cP, 5.43 and 4.60 min, respectively. The TGS 25 (85.67 ° C) starch showed significantly higher boiling point than the TGS 3 (81.33 ° C). Pasting temperatures of TGS 3 and TGS 25 starches were 78.65 and 78.75 °C, respectively. Cyclodextrin (A and B) and L (−) glucose were detected in the starch and flour of TGS 25 but were present in TGS 3 starch but absent in its flour.

Journal of Food Science and Technology Mysore, Apr 1, 2011

Journal of Food Engineering, 2008

Drying Technology, 2010

... of squares (PRESS). [ 29 29. Myers , RH ; Montgomery , DC Response Surface Methodology, Proce... more ... of squares (PRESS). [ 29 29. Myers , RH ; Montgomery , DC Response Surface Methodology, Process and Product Optimization Using Designed Experiments ; John Wiley & Sons : New York , 1995 . View all references ] Maximization ...

Drying Technology, 2011

Physical characterization and oxidative stability of egg powder microencapsulated by spray drying... more Physical characterization and oxidative stability of egg powder microencapsulated by spray drying were studied in this work. The wall material (gelatin, lactose, pullulan, and their mixtures) and liquid egg mixtures were prepared by homogenization at 22,000 rpm for 60 s. The spray drying was carried out at pilot-scale spray dryer (Niro Mobile Minor, Søborg, Denmark). The spray-dried egg powders were analyzed for moisture content, water activity, peroxide value, total cholesterol oxidation products (TCOPs), particle properties, and bulk properties. Using gelatin as wall material resulted in a significant increase in the moisture content and water activity of egg powder during storage and it improved flowability. Egg powders containing pullulan as wall material showed a fibrous structure and had the lowest bulk density. Adding lactose as wall material increased the oxidative stability, which was indicated with lowest peroxide value and TCOPs level of egg powder.

Journal of Food Science and Technology-mysore, 2011

Pasteurized liquid whole egg was subjected to spray drying to determine the effect of spray dryin... more Pasteurized liquid whole egg was subjected to spray drying to determine the effect of spray drying conditions on moisture content, water activity, peroxide value, emulsion stability, gel texture, foaming stability and colour change of the powder product. Drying process was carried out in a pilot scale spray dryer (Mobile Minor Niro-Atomizer, Denmark). The inlet (165–195 °C) and outlet air temperatures (60–80 °C) and the atomization pressure (196–392 kPa) were investigated as spray drying process variables. Perturbation and 3-D graphs revealed that outlet air temperature and atomization pressure had more effect than inlet air temperature, on the properties of whole egg powder. Optimum spray drying conditions of whole egg powder were determined according to the specific end-product requirements (bakery foods, omelette and mayonnaise and salad dressing) targeting to obtain the desired value of functional properties, i.e.; emulsion stability, gel texture, foaming stability and colour change.

Drying Technology, 2012

The aim of this study was to evaluate the effect of moisture on the glass transition temperature ... more The aim of this study was to evaluate the effect of moisture on the glass transition temperature (T g ), flow properties, color, and morphology of spray-dried powdered egg. Powdered egg was stored under environments with different relative humidities at 25°C and the moisture sorption isotherm was determined. The Guggenhiem-Anderson-de Boer (GAB) model fitted the isotherm data well. A differential scanning calorimeter was used to determine the T g of samples with different water activities. The T g data were satisfactorily correlated by the Gordon-Taylor model. The results showed that the glass transition temperature of powdered egg decreased with increasing water activity. The changes in flowability based on the Carr index (CI) and cohesiveness based on the Hausner ratio (HR) with water activity were defined. At low water activity values, the powder had poor flowability and high cohesiveness. These flow properties were also supported with scanning electron microscope (SEM) images.

Drying Technology, 2012

Moisture adsorption isotherms of spray-dried whole egg, microencapsulated with gelatin (G), lacto... more Moisture adsorption isotherms of spray-dried whole egg, microencapsulated with gelatin (G), lactose (L), pullulan (P), and their mixtures at equal ratios (gelatin + lactose [GL] and gelatin +pullulan [GP]), were determined using the standard static-gravimetric method at 25°C. The data were fitted to the various sorption models and the constants were estimated by nonlinear regression analysis. Among the sorption models tested, the Guggenheim-Andersen-de Boer (GAB) and Ferro Fontan equations were recommended for characterizing the adsorption behavior of spray-dried whole egg, either microencapsulated or unencapsulated, in the water activity range of 0.11–0.84. It was indicated that all of the egg powders were stable up to a water activity of 0.43. The oxidative stability of microencapsulated powders was investigated under storage conditions of 20°C and 50% relative humidity (RH). The microencapsulation process resulted in a decrease in the cholesterol oxidation level of egg powder during storage, where it followed a zero-order reaction kinetics and the t rej value representing the time required to reach total cholesterol oxidation products (TCOP) = 384.2 µg/g egg fat as the upper limit of acceptability for fat oxidation was calculated as 1,124 days at 20°C for egg powder microencapsulated with lactose. The relations among glass transition temperatures, oxidation rate constants, and monolayer moisture content values obtained by the GAB model are also highlighted.

Journal of Food Science and Technology, 2012

Journal of Food Science, 2011

The addition of gelatine (G), lactose (L), pullulan (P), and their mixtures at equal ratios (gela... more The addition of gelatine (G), lactose (L), pullulan (P), and their mixtures at equal ratios (gelatine + lactose [GL] and gelatin + pullulan [GP]) to whole egg prior to drying was studied. Their effects on the functional properties (emulsion and gelling ability, water holding capacity of gel, foaming, color) and soluble protein content of spray dried egg powder during the 6 mo of storage at 20 °C and 50% relative humidity were investigated. It was demonstrated that the emulsion and foaming stability, water holding capacity of gel, and color change were significantly affected by the storage time, whereas storage time did not affect the strength of gel texture prepared by egg powders. Gelatine and pullulan improved the foaming stability and water holding capacity. Lactose caused a decrease in emulsion and foaming stability values. The maximum color change was observed for the plain egg powder, showing that mixing whole egg with carbohydrate- and/or protein-based additives before the drying process preserved the color of egg powder. Adding carbohydrate and/or protein caused significant changes in functional properties of egg powder.

Food Hydrocolloids, 2014

ABSTRACT Functional, physico-chemical properties and FTIR analysis of flours and starches of two ... more ABSTRACT Functional, physico-chemical properties and FTIR analysis of flours and starches of two African rice cultivars (Transgressive Segregants TGS 3 and TGS 25) were investigated. The TGS 3 showed higher 1000 kernel grain weight (29.55 g), dockage (1.00 g), immature grain (1.97 g), thickness (2.10 mm), chalkiness (11.17%) and damaged grain (0.70%). However, the TGS 25 showed higher head rice yield (51.11%), milling degree (9.60%), length (6.88 mm) and elongation ratio (3.64). Also, the TGS 25 showed higher alkaline spread value (6.67), amylose content (30.81%), uncooked (7.15 mm) and cooked (10.17 mm) rice length. The WAC (2.77 g/mL) and OAC (1.08 g/mL) of TGS 25 flours were higher than TGS 3. The L value of TGS 25 flour (92.13) and starch (97.88) were higher than those of TGS 3. The TGS 3 flour and starch showed higher peak, breakdown and peak times of 4308 and 3531 cP, 2200 and 1947 cP, 5.43 and 4.60 min, respectively. The TGS 25 (85.67 ° C) starch showed significantly higher boiling point than the TGS 3 (81.33 ° C). Pasting temperatures of TGS 3 and TGS 25 starches were 78.65 and 78.75 °C, respectively. Cyclodextrin (A and B) and L (−) glucose were detected in the starch and flour of TGS 25 but were present in TGS 3 starch but absent in its flour.

Journal of Food Science and Technology Mysore, Apr 1, 2011

Journal of Food Engineering, 2008

Drying Technology, 2010

... of squares (PRESS). [ 29 29. Myers , RH ; Montgomery , DC Response Surface Methodology, Proce... more ... of squares (PRESS). [ 29 29. Myers , RH ; Montgomery , DC Response Surface Methodology, Process and Product Optimization Using Designed Experiments ; John Wiley & Sons : New York , 1995 . View all references ] Maximization ...

Drying Technology, 2011

Physical characterization and oxidative stability of egg powder microencapsulated by spray drying... more Physical characterization and oxidative stability of egg powder microencapsulated by spray drying were studied in this work. The wall material (gelatin, lactose, pullulan, and their mixtures) and liquid egg mixtures were prepared by homogenization at 22,000 rpm for 60 s. The spray drying was carried out at pilot-scale spray dryer (Niro Mobile Minor, Søborg, Denmark). The spray-dried egg powders were analyzed for moisture content, water activity, peroxide value, total cholesterol oxidation products (TCOPs), particle properties, and bulk properties. Using gelatin as wall material resulted in a significant increase in the moisture content and water activity of egg powder during storage and it improved flowability. Egg powders containing pullulan as wall material showed a fibrous structure and had the lowest bulk density. Adding lactose as wall material increased the oxidative stability, which was indicated with lowest peroxide value and TCOPs level of egg powder.

Journal of Food Science and Technology-mysore, 2011

Pasteurized liquid whole egg was subjected to spray drying to determine the effect of spray dryin... more Pasteurized liquid whole egg was subjected to spray drying to determine the effect of spray drying conditions on moisture content, water activity, peroxide value, emulsion stability, gel texture, foaming stability and colour change of the powder product. Drying process was carried out in a pilot scale spray dryer (Mobile Minor Niro-Atomizer, Denmark). The inlet (165–195 °C) and outlet air temperatures (60–80 °C) and the atomization pressure (196–392 kPa) were investigated as spray drying process variables. Perturbation and 3-D graphs revealed that outlet air temperature and atomization pressure had more effect than inlet air temperature, on the properties of whole egg powder. Optimum spray drying conditions of whole egg powder were determined according to the specific end-product requirements (bakery foods, omelette and mayonnaise and salad dressing) targeting to obtain the desired value of functional properties, i.e.; emulsion stability, gel texture, foaming stability and colour change.

Drying Technology, 2012

The aim of this study was to evaluate the effect of moisture on the glass transition temperature ... more The aim of this study was to evaluate the effect of moisture on the glass transition temperature (T g ), flow properties, color, and morphology of spray-dried powdered egg. Powdered egg was stored under environments with different relative humidities at 25°C and the moisture sorption isotherm was determined. The Guggenhiem-Anderson-de Boer (GAB) model fitted the isotherm data well. A differential scanning calorimeter was used to determine the T g of samples with different water activities. The T g data were satisfactorily correlated by the Gordon-Taylor model. The results showed that the glass transition temperature of powdered egg decreased with increasing water activity. The changes in flowability based on the Carr index (CI) and cohesiveness based on the Hausner ratio (HR) with water activity were defined. At low water activity values, the powder had poor flowability and high cohesiveness. These flow properties were also supported with scanning electron microscope (SEM) images.

Drying Technology, 2012

Moisture adsorption isotherms of spray-dried whole egg, microencapsulated with gelatin (G), lacto... more Moisture adsorption isotherms of spray-dried whole egg, microencapsulated with gelatin (G), lactose (L), pullulan (P), and their mixtures at equal ratios (gelatin + lactose [GL] and gelatin +pullulan [GP]), were determined using the standard static-gravimetric method at 25°C. The data were fitted to the various sorption models and the constants were estimated by nonlinear regression analysis. Among the sorption models tested, the Guggenheim-Andersen-de Boer (GAB) and Ferro Fontan equations were recommended for characterizing the adsorption behavior of spray-dried whole egg, either microencapsulated or unencapsulated, in the water activity range of 0.11–0.84. It was indicated that all of the egg powders were stable up to a water activity of 0.43. The oxidative stability of microencapsulated powders was investigated under storage conditions of 20°C and 50% relative humidity (RH). The microencapsulation process resulted in a decrease in the cholesterol oxidation level of egg powder during storage, where it followed a zero-order reaction kinetics and the t rej value representing the time required to reach total cholesterol oxidation products (TCOP) = 384.2 µg/g egg fat as the upper limit of acceptability for fat oxidation was calculated as 1,124 days at 20°C for egg powder microencapsulated with lactose. The relations among glass transition temperatures, oxidation rate constants, and monolayer moisture content values obtained by the GAB model are also highlighted.