COMPARISON OF THE PHYSICAL AND SENSORY PROPERTIES OF MODEL LOW-FAT MAYONNAISES DEPENDING ON EMULSIFIER TYPE AND XANTHAN GUM CONCENTRATION

Grażyna Bortnowska¹, Grzegorz Tokarczyk^2
1 Department of Food Technology, West Pomeranian University of Technology, Szczecin, Poland
² Food Technology Department, West Pomeranian University of Technology, Szczecin, Poland

ABSTRACT

In this work selected physical and sensory properties of model mayonnaises containing 20 wt% oil and 0.1-0.6 wt% xanthan gum were compared. The mayonnaises were stabilized by modified maize starch, dried egg yolk or native egg yolk. The studies showed that mayonnaises formed with modified maize starch exhibited higher apparent viscosity than those made with egg yolks. All model low-fat mayonnaises containing 0.6 wt% thickener, showed 100% stability towards creaming. It was found that model low-fat mayonnaises made with modified maize starch revealed the highest whiteness index (W.I.) and the lowest total colour difference (ΔE) irrespective of xanthan gum concentration. Sensory analysis indicated that changes in colour and odour intensity depended on emulsifier type whereas texture parameters: consistency and adhesiveness on xanthan gum concentration. Therefore, it seems that modified maize starch demonstrating similar emulsifying properties to egg yolk may be utilized as its replacer being particularly useful to manufacture food with low cholesterol content.

Key words: ow-fat mayonnaise, stability, odour intensity, colour, modified maize starch, dried egg yolk, native egg yolk.

INTRODUCTION

Mayonnaise a mixture of egg yolk, vinegar, oil and spices is probably one of the oldest and most widely used sauce [11,21]. The commonly known very good physicochemical properties of egg yolk stabilized emulsions are attributed to all constituents of egg yolk which contribute to create an interfacial film between oil and water [4]. However, the lipid fraction of egg yolk may contain up to 5% cholesterol [23,24]. Schmidt [33] reported that reduction of cholesterol in mayonnaises may be achieved by application of modified starch produced from maize instead of egg yolk. For example, starch sodium octenylsuccinate (E 1450) is microbial safe and can be used to produce cold and hot sauces [34]. Apart from that, there is the spread of healthy eating trends and increasing popularity and demand for so called "light" products, in particular low-calorie and reduced-fat products [27] what makes that traditional composition of mayonnaise which may contain up to 80% fat has to be changed [11]. Fat may be replaced in food products by traditional techniques such as substituting water [1], but the reduction of oil phase affects flavor release and textural properties of low-fat products [8]. In particular, large amount of water may bring about very rapid creaming and phase separation in oil-in-water (o/w) emulsions [10,32]. There are some reports that textural properties of the o/w emulsions containing large amount of water may be improved by xanthan gum addition [21,22]. The ability of xanthan gum to thicken and stabilize emulsion systems is attributed to a weak gel-like structure in solution formed by gum molecules in the emulsion continuous phase which prevents the oil droplets to cream since the gravitational lift on the droplets is less  than the yield stress of the xanthan weak gel  [9,17]. However, xanthan gum contains also proteins and may act also as the emulsifier. Huang et al. [15] showed a marked reduction in surface and interfacial tension when compared to the air/water and oil/water interfaces in emulsions containing xanthan gum. Some other authors reported that xanthan gum may also affect behaviour of volatiles release [35,41]. In conclusion, the presented studies allow to suppose that changes in composition of low-fat mayonnaises may influence physical properties and odour intensity of the emulsions.

The objective of this study was assessment of influence of emulsifier type (modified maize starch, native or dried egg yolk) and xanthan gum concentration on the stability, texture, colour and odour intensity of aromatized model mayonnaises containing 20 wt% rapeseed oil.

MATERIALS AND METHODS

MATERIALS
Xanthan gum (E 415) and dried egg yolk (P.P.R.S."Basso" Sp. z o.o.) were purchased from Hortimex® Sp. z o.o. Fresh eggs (PW "Amigo"), vegetable rapeseed oil (Z.T. "Kruszwica" S.A.) and citric acid (Z.P.C. "Cykoria" S.A.) were purchased from the local market. Modified maize starch (starch sodium octenylsuccinate – E 1450) was received from National Starch Food Innovation. Lemon flavouring identical with natural (F.S.Z. "Pollena-Aroma" Sp. z o.o.) was received directly from the manufacturer.

Mayonnaise preparation
Model mayonnaises were prepared with 2 wt% emulsifier: dried egg yolk, native egg yolk (equivalent of dried egg yolk) or modified maize starch and 20 wt% vegetable rapeseed oil. Samples were thickened by xanthan gum addition at concentrations of: 0.1, 0.2, 0.3, 0.4, 0.5 and 0.6 wt%. As the reference samples were taken mayonnaises without xanthan gum addition. The fresh eggs were initially broken manually and the yolks separated. Following removal of adhering albumen from the yolk by rolling on tissue paper, the vitelline membrane was pierced and the liquid was collected [4]. The mayonnaises aqueous phases were produced by dissolving an appropriate amount of surface-active material (dried egg yolk, native egg yolk or modified maize starch), thickener (xanthan gum) and citric acid (0.1 wt%) in distilled water. Solutions of xanthan gum were prepared as described by Huang et al. 2001). The mayonnaises were produced  by slowly mixing rapeseed oil into aqueous phase, then the mixtures were homogenized using an MPW 302 laboratory homogenizer (Mechanika Precyzyjna, Warsaw) for 30 s at 3.500 rpm. For sensory analyses the model mayonnaises were aromatized with 0.1 wt% lemon flavouring.

METHODS
Emulsifying capacity
Rapeseed oil was dyed with about 4 ppm of Sudan III and added at the rate of 30 cm³ · min^-1 to 50 g of 2.0 wt% water dispersion containing: dried egg yolk, native egg yolk or modified maize starch. The oil and emulsifier suspensions were continuously blended using an MPW 302 laboratory homogenizer (Mechanika Precyzyjna, Warsaw) at speed about 3.500 rpm until the inversion point was reached. The inversion point from an oil-in-water to a water-in-oil emulsion was determined visually by a sudden decrease in viscosity. Emulsifying capacity (EC) was expressed as follows [5,16,36]:

EC = gram oil / gram emulsifier (dry matter)

Stability towards creaming
Stability of the mayonnaises towards creaming was evaluated according to the methods of Huang et al. [15]. The mayonnaises (8.00 ± 0.05 cm³) were placed into 10 cm³ glass tubes and centrifuged at 1983.6 × g for 10 min at room temperature (22 ± 0.5°C) in a MPW 350 centrifuge (Med.-Instruments, Warsaw). The mayonnaise stability (ES) was calculated as follows:

ES (%) = (remaining emulsion height / initial emulsion height) · 100

Solids in native egg yolk
The content of solids in native egg yolk was determined according to method described in AOAC (1995).

pH
The pH was measured by the N 517 OE digital pH meter equipped with a slab electrode (TEL-EKO S.A., Wrocław) at 22 ± 0.5°C.

Density
The density of mayonnaises was determined by picnometry at 22 ± 0.5°C [26].

Colour evaluation
The surface colour of the model mayonnaises was measured using a HunterLab digital color difference meter D25-2A (Hunter Associates Laboratory, Inc., USA), as CIE L, a, b values. In this coordinate system the L value – measures lightness and varies from 100 for perfect white to zero for black, a – measures redness when plus, gray when zero and greenness when minus, b – measures yellowness when plus, gray when zero and blueness when minus. The instrument was calibrated with a white tile supplied by manufacturer (L = +94.08, a = -0.9, b = +1.6). The results were expressed as ΔL, Δa, Δb and calculated as the differences in colour intensity between investigated and control samples (without xanthan gum addition). Additionally the total colour difference (ΔE), whiteness index (W.I.) and chromaticity were calculated from equations as follows [6,19,25]:

ΔE = [(ΔL)² + (Δa)² + (Δb)2]^1/2
W.I. = 100 – [(100 – L)² + a² + b²]^1/2
Chromaticity = (a² + b²)^1/2

Rheological measurements
Rheological measurements were performed with a rheometer (Rheotest 2 – 50 Hz – type RV2, equipped with S/S1 cylinder) using controlled shear rate within the range 3–1312 s^-1. The measurements were carried out at 22 ± 0.5°C. The flow properties of model mayonnaises were calculated using Ostwald-de Waele model [22,38]:

σ = K · γⁿ

where σ = shear stress (Pa), γ = shear rate (s^-1), K = consistency index (Pa · sⁿ ) and n = flow index.

Texture profile analysis
The texture profile analyses (TPA) of the studied mayonnaises were carried out with a texture analyzer (model TA-XT2, Stable Micro Systems Ltd., Surrey, U.K.), equipped with software Texture Expert^® for Windows^® v. 1.11. Mayonnaises were poured into back extrusion pot (50 mm internal dia.), so that 3/4 was full and compression disc of 45 mm dia. was applied. The TA-XT2 settings were as follows: option – return to start, pre-test speed – 1.0 mm/s, test speed – 1.0 mm/s, post-test speed – 1.0 mm/s, distance – 30 mm, trigger type – auto (5 g), data acquisition rate – 200 pps. The measured parameters were: firmness (gf), consistency (gf · s), cohesiveness (gf) and adhesiveness (gf · s).

Sensory analysis
The analyses with the method of Quantitative Descriptive Analysis (QDA) were performed by an internal panel consisting of eight assessors who were selected according to PN-ISO 8586-1: 1996. The sensory terms were developed during training sessions by comparing mayonnaises containing xanthan gum and dried egg yolk, native egg yolk or modified maize starch with each other and the definitions were as follows: odour intensity (lemon odour, off odour, odd odour), appearance (colour tone – from white to yellow and colour strength), texture by hand (consistency and adhesiveness while pouring mayonnaises from spoon) (PN-ISO 5496: 1997, Wendin and Hall 2001). The low intensity of the measured parameter was scored as 1 and the highest one as 9 (PN-ISO 4121: 1998). Samples (50 cm³) were served in glass cups with metal lids at ambient temperature, approximately 22 ± 0.5°C in individual randomised order. Seven samples were evaluated at individual speed in 60 min sessions.

Statistical analysis
Three replicates were conducted for all measured parameters and data were statistically treated using Statistica^® 6.0 program PL. Two-way ANOVAs were made with the sources of variation being the emulsifier type and xanthan gum concentration. Tukey's multiple comparison test was performed to identify significant  differences between means (p ≤ 0.05). The extent of correlation between xanthan gum concentration and: consistency index, flow index, pH, density and stability of model low-fat mayonnaises, was determined by Pearson's correlation coefficients.

RESULTS AND DISCUSSION

Among the studied surface-active components used to stabilize model low-fat mayonnaises the highest emulsifying capacity showed native egg yolk and the lowest modified maize starch (Fig. 1). The amount of emulsified oil in samples with addition of native egg yolk, dried egg yolk or modified maize starch was respectively: 11.4, 8.7 and 7.7 gram oil/gram emulsifier – dry matter. Statistical analysis revealed that difference between the amount of emulsified oil in samples containing dried egg yolk and modified maize starch was not statistically significant (Fig. 1). The results suggest that utilizing modified maize starch it is possible to emulsify similar amount of oil as in mayonnaises formed with  dried egg yolk and also make reduction of cholesterol. The observed very good emulsifying capacity of native egg yolk may be related to its complex chemical composition, especially phospholipids, lipoproteins and proteins [23]. On the other hand, temperature treatment may a little affect emulsifying efficiency of lipoproteins [24] what might be the reason that dried egg yolk demonstrated lower than native egg yolk emulsifying capacity. Although, Le Denmat et al. [18] suggested that intact granules of egg yolk withstood more severe heat treatments than the whole egg yolk without lessening their emulsifying properties and Yang and Cotterill [40] presented that yolk can be pasteurized without unduly affecting its emulsifying properties.

The observed comparable with dried egg yolk emulsifying properties of modified maize starch may be referred to the chemical changes in its molecular structure what makes that maize starch is exhibiting hydrophilic and lipophilic properties and was able to emulsify nearly the same amount of oil as dried egg yolk [33].

Rheological data revealed that irrespective of emulsifier type all model low-fat mayonnaises showed pseudoplastic behaviour hence, apparent viscosity decreased with increasing shear rate. The differences of apparent viscosity were observed at low and high shear rates in all studied samples and significantly depended on concentration of thickener in emulsions (Fig. 2). The highest apparent viscosity was stated in model low-fat mayonnaises stabilized by modified maize starch and the lowest in emulsions made with dried egg yolk in majority of the samples regardless of xanthan gum concentration. The consistency index (K) of model mayonnaises ranged from 0.8 to 8.22 Pa·sⁿ, mostly in samples containing more than 0.4 % xanthan gum (Table 1). Model mayonnaises made with addition of 0.6% thickener and 2% egg yolks exhibited consistency index on average 7.5 Pa·sⁿ and this value was nearly by 10% lower than noticed in samples prepared with modified maize starch. In contrast, changes of the flow indexes (n) of model low-fat mayonnaises in majority of the samples were not statistically significant and low correlated with thickener concentration (Table 1). Furthermore, the studies showed that increase of thickener concentration in model low-fat mayonnaises caused higher firmness, consistency, cohesiveness and adhesiveness irrespective of emulsifier type (Fig. 3). The highest changes in rheological profile were observed in samples containing more than 0.4% xanthan gum, similarly as it was registered in the same samples during measurement of consistency indexes with a rheometer (Table 1, Fig. 3). The studies also demonstrated that texture parameters of model low-fat mayonnaises with modified maize starch addition were more similar to those found in samples composed of dried egg yolk than native egg yolk. Results from the two-way ANOVA indicated that thickener addition considerably more influenced texture parameters than emulsifier type (Table 2).

Changes in apparent viscosity of the studied samples with increasing shear rate probably depended on physical properties of xanthan gum. When dispersed in water, xanthan high-molecular-weight molecules form complex aggregates through hydrogen bonds and polymer entanglement. Because of these highly ordered networks and entanglements, xanthan solutions exhibit a high viscosity at low shear rates, and a lower viscosity at high shear rates, due to the disaggregation of the network and the alignment of the individual macromolecules in the direction of the shear [14,22]. On the other hand high differences in apparent viscosity between studied samples at high and low shear rates were probably caused by addition of xanthan gum at relatively considerably differentiated concentrations what did not allow the same orientation of xanthan gum macromolecules and structure disruption. Although, additional factors, other than the resistance of molecules to be oriented, might also contribute to flow pseudoplasticity [13]. One of them is pH which has a dramatic effect on the structure of egg based – emulsions. Depree and Savage [11] reported that the highest viscoelascity of the mayonnaise was at a pH of 3.9. The studies showed that pH, in dried egg yolk-stabilized mayonnaises and native egg yolk-stabilized mayonnaises, changed within the range 4.2–4.8 and 3.7–5.0, respectively (Table 1) what may suggest relationship between pH and viscosity of the mayonnaises. However, probably more studies are required to understand influence of pH on viscosity of emulsions made with modified maize starch.

The stability of model mayonnaises increased as the concentration of xanthan gum was higher irrespective of the emulsifier type and these changes were highly correlated (p ≤ 0.001) (Table 1). Model mayonnaises made without  thickener addition were stabile within the range 25.8–29.1% whereas all samples containing 0.6% thickener exhibited stability on the level of 100%. Results from the two-way ANOVA indicated that concentration of xanthan gum affected more (p ≤ 0.001) than emulsifier type (p ≤ 0.01) stability of model low-fat mayonnaises (Table 3). Significant differences in stability of  studied mayonnaises, caused by addition of xanthan gum, suggest a very good technological utility of this thickener to manufacture cold sauces. Furthermore, the results also indicate a very high emulsifying activity of modified maize starch which was able to stabilize emulsions on the comparable with dried egg yolk level. Higher stability of the emulsions formed with native egg yolk than with dried egg yolk may be related to the specific physical properties of constituents of egg yolk in native form which tend to form strong membranes at the oil-water interface and were probably responsible for the stability of oil-in-water emulsions [2,3] Whereas, considerable increase of the emulsion stability caused by addition of xanthan gum was probably mainly due to ability of this thickener  to stabilize dispersed oil droplets against separation from a continuous phase and its ability to absorb large quantity of water [37]. Xanthan gum is also composed of small amount of proteins which might contribute to the increase of the emulsion stability [15].

Between all studied physical parameters of model low-fat mayonnaises the highest changes were observed in colour which markedly differentiated samples stabilized by modified maize starch and egg yolks regardless of their form of preparation before they were added to the emulsions. The model low-fat mayonnaises made with modified maize starch demonstrated the highest whiteness indexes (W.I.) and the lowest total colour differences (ΔE) irrespective of xanthan gum concentration. The highest lightness with whiteness indexes of: 85.2, 83.7 and 93.0, showed model low-fat mayonnaises containing 0.6% xanthan gum, prepared with: dried egg yolk, native egg yolk and modified maize starch, respectively (Table 4). Changes in total colour difference of model low-fat mayonnaises caused by different concentration of xanthan gum depended in majority on all investigated parameters: L, a and b, regardless of emulsifier type and for example in samples containing 0.6% thickener, stabilized by dried egg yolk, native egg yolk or modified maize starch, the values of ΔL were registered respectively as: 7.0, 5.9 and 2.3 (Fig. 4). Type of emulsifier markedly changed chromaticity of model low-fat mayonnaises, which rather did not depend on concentration of xanthan gum. The average values of chromaticity of model low-fat mayonnaises formed with dried egg yolk, native egg yolk or modified maize starch were: 16.4, 17.2 and 5.7, respectively (Fig. 4). Colour of egg yolk-stabilized emulsions is mainly dependent on carotenoids concentration [19] therefore their content might influence measured parameters as total colour difference (ΔE), whiteness index (W.I.) and chromaticity. On the other hand, the observed differences of measured parameters might be also affected by addition of xanthan gum which did not lower content of carotenoids, but changed their mass fraction in investigated mayonnaises and could induce changes in colour parameters.

Sensory analysis of odour intensity, appearance and texture showed their significant dependence on thickener concentration and emulsifier type. Increase of xanthan gum concentration affected consistency and adhesiveness and the highest values of these parameters were registered in samples containing modified maize starch. Consistency and adhesiveness of model low-fat mayonnaises containing 0.6% xanthan gum and stabilized by modified maize starch were scored respectively as 8.1 and 8.5 on 1–9 scale whereas mayonnaises made with dried egg yolk or native egg yolk were scored: 7.6 and 7.2 or 7.4  and 7.8, respectively (Fig. 5). Colour tone and colour strength considerably depended on the emulsifier type applied to stabilize model low-fat mayonnaises and in samples made with egg yolks these values were in the range from 1.0 to 6.7 scores whereas in samples composed of modified maize starch ranged from 0.5 to 1.5 scores (Fig. 5). Intensity of lemon odour released from model low-fat mayonnaises depended more on concentration of xanthan gum than emulsifier type (Table 5) and changed in the range from 5.6 to 2.5 exhibiting the lowest values in samples containing 0.6% thickener and stabilized by modified maize starch (Fig. 5). Additionally, sensory analysis showed that increase of xanthan gum concentration and emulsifier type in the lowest extent, with values within the range 0.1–3.0 scores (p ≤ 0.001), influenced on off odour and odd odour sensed from all model low-fat mayonnaises (Fig. 5, Table 5).

Results from two-way ANOVA indicated that texture of model low-fat mayonnaises depended more on thickener concentration whereas colour and partly odour intensity were impacted by emulsifier type (Table 5). The perceived intensity of lemon odour seems to be dependent on xanthan gum concentration in the mayonnaises due to the fact that diffusion of flavour molecules is reduced as solution viscosity increases, as it is predicted by the Stokes-Einstein and Wilke-Chang equations [7,31,35] whereas the observed small changes in density of model low-fat mayonnaises (Table 1) rather did not influence odour release. However, the volatility of the aroma molecules might also be affected by specific binding interactions with thickener or ingredients of egg yolk [12,20].

CONCLUSIONS

1. Model low-fat mayonnaises stabilized by modified maize starch exhibited higher apparent viscosity than samples formed with dried or native egg yolk.

2. All studied emulsions containing 0.6% xanthan gum demonstrated 100% stability towards creaming regardless of emulsifier type.

3. Model low-fat mayonnaises prepared with modified maize starch showed higher whiteness indexes (W.I.) and lower values of total colour difference (ΔE) than samples formed with egg yolks irrespective of thickener concentration.

4. Sensory analysis of model low-fat mayonnaises showed that emulsifier type mostly affected colour and partly odour intensity whereas concentration of thickener impacted on texture parameters.

5. It seems that modified maize starch demonstrating similar to the dried egg yolk physical and sensory properties may be its replacer and applied to manufacture low-fat mayonnaises with lower content of cholesterol.

REFERENCES

1. Akoh C.C., 1998. Fat replacers. Food Technol. 52, 3, 47–53.

2. Aluko R.E., Mine Y., 1998. Characterization of oil-in-water emulsions stabilized by hen's egg yolk granule. Food Hydrocoll. 12, 203–210.

3. Anton M., Beaumal V., Gandemer G., 2000. Adsorption at the oil-water interface and emulsifying properties of native granules from egg yolk: effect of aggregated state. Food Hydrocoll. 14, 327–335.

4. Anton M., Gandemer G., 1999. Effect of pH on interface composition and on quality of oil-in-water emulsions made with hen egg yolk. Coll. Surfaces B: Biointerfaces 12, 351–358.

5. Askraf H.R.L., 1986. Emulsifying properties of ethanol soaked soybean flour. J. Food Sci. 51, 1, 193–196.

6. Beltrán-Lugo A.I., Maeda-Martinez A.N., Pacheco-Aguilar R., Nolasco-Soria H.G., Ocaño-Higuera V.M., 2005. Physical, textural, and microstructural properties of restructured adductor muscles of 2 scallop species using 2 cold-binding systems. J. Food Sci. 70, 2, E78–E84.

7. Bortnowska G., 2008. Release of carvone and limonene from oil-polysaccharide mixtures. EJPAU 11(1), #16.

8. Brauss M.S., Linforth R.S.T., Cayeux I., Harvey B., Taylor A.J., 1999. Altering the fat content affects flavour release in a model yogurt system. J. Agric. Food Chem. 47, 2055–2059.

9. Bryant C.M., McClements D.J., 2000. Influence of xanthan gum on physical characteristics of heat-denatured whey protein solutions and gels. Food Hydrocoll. 14, 383–390.

10. Dalgleish D.G., 1997. Adsorption of protein and stability of emulsions. Trends Food Sci. Technol. 8, 1–6.

11. Depree J.A., Savage G.P., 2001. Physical and flavour stability of mayonnaise. Trends Food Sci. Technol. 12 (5–6), 157–163.

12. Godshall M.A., 1997. How carbohydrates influence food flavor. Food Technol. 51, 1, 63–67.

13. González-Tomás L., Carbonell I., Costell E., 2004. Influence of type, concentration and flow behaviour of hydrocolloid solutions on aroma perception. Eur. Food Res. Technol. 218, 248–252.

14. Hemar Y., Tamehana M., Munro P., Singh H., 2001. Influence of xanthan gum on the formation and stability of sodium caseinate oil-in-water emulsions. Food Hydrocoll. 15, 513–519.

15. Huang X., Kakuda Y., Cui W., 2001. Hydrocolloids in emulsions: particle size distribution and interfacial activity. Food Hydrocoll. 15, 533–542.

16. Jung S., Murphy P.A., Johnson L.A., 2005. Physicochemical and functional properties of soy protein substrates modified by low levels of protease hydrolysis. J. Food Sci. 70, 2, C180–C187.

17. Kiosseoglou A., Papalamprou E., Makri E., Doxastakis G., Kiosseoglou V., 2003. Functionality of medium molecular weight xanthan gum produced by Xanthomonas Campestris ATTC 1395 in batch culture. Food Res. Int. 36, 425–430.

18. Le Denmat M., Anton M., Gandemer G., 1999. Protein denaturation and emulsifying properties of plasma and granules of egg yolk as related to heat treatment. J. Food Sci. 64, 2, 194–197.

19. Lennersten M., Lingnert H., 2000. Influence of wavelength and packaging material on lipid oxidation and colour changes in low- fat mayonnaise. Lebens.- Wiss. u.-Technol. 33, 253–260.

20. Lubbers S., Landy P., Voilley A., 1998. Retention and release of aroma compounds in foods containing proteins. Food Technol. 52, 5, 68–74, 208–214.

21. Ma L., Barbarosa-Cánovas V., 1995. Rheological characterization of mayonnaise. Part 2: Flow and viscoelastic properties at different oil and xanthan gum concentrations. J. Food Eng. 25, 409–425.

22. Mandala I.G., Savvas T.P., Kostaropoulos A.E., 2004. Xanthan and locust bean gum influence on the rheology and structure of white model-sauce. J. Food Eng. 64, 335–342.

23. Mine Y., 1998 . Adsorption behavior of egg yolk low-density lipoproteins in oil-in-water emulsions. J. Agric. Food Chem. 46, 36–41.

24. Mine Y., 1998 . Emulsifying characterization of hens egg yolk proteins in oil-in-water emulsions. Food Hydrocoll. 12, 409–415.

25. Mohammadi A., Rafie S., Emam-Djomeh Z., Keyhani A., 2008. Kinetic models for colour changes in kiwifruit slices during hot air drying. World J. Agric. Sci. 4(3), 376–383.

26. Official methods of analysis of AOAC international. 1995. Ed. P. Cunniff. AOAC Arlington, Virginia (USA).

27. Peressini D., Sensidoni A., de Cindio B., 1998. Rheological characterization of traditional and light mayonnaises. J. Food Eng. 35, 409–417.

28. PN-ISO 4121. 1998. Sensory analysis – Methodology – Evaluation of food products by methods using scales.

29. PN-ISO 5496. 1997. Sensory analysis – Methodology – Initiation and training of assessors in the detection and recognition of odours.

30. PN-ISO 8586-1. 1996. Sensory analysis – General guidance for the selection, training and monitoring of assessors – Part 1: Selected assessors.

31. Roberts D.D., Elmore J.S., Langley K.R., Bakker J., 1996. Effects of sucrose, guar gum, and carboxymethylcellulose on the release of volatile flavor compounds under dynamic conditions. J. Agric. Food Chem. 44, 1321–1326.

32. Robins M.M., 2000. Emulsion-creaming phenomena. Curr. Opin. Coll. Interface Sci. 5, 265–272.

33. Schmidt S., 2005. Sukces emulsji bezjajecznych [Success of emulsions without eggs]. Przem. Piek. Cukier. (11), 64–65 [in Polish].

34. Schube V., Kaliszan E., Ratusz K., 2003. Skrobie modyfikowane we wsadach owocowych, majonezach, dresingach [Modified starches in fruity products, mayonnaises, dressings]. Przem. Spoż. 57(3), 22–23 i 26 [in Polish].

35. Secouard S., Malhiac C., Grisel M., Decroix B., 2003. Release of limonene from polysaccharide matrices: viscosity and synergy effect. Food Chem. 82, 227–234.

36. Seher A., 2006. Effects of salt and phosphate levels on the emulsion properties of fresh and frozen hen meats. Afr. J. Biotechnol. 5(10), 1006–1012.

37. Sharma S.C., 1981. Gums and hydrocolloids in oil-water emulsions. Food Technol. 1, 59–67.

38. Tárrega A., Costell E., 2006. Effect of inulin addition on rheological and sensory properties of fat – free starch – based dairy desserts. Int. Dairy J., 16, 1104–1112.

39. Wendin K., Hall G., 2001. Influences of fat, thickener and emulsifier contents on salad dressing: static and dynamic sensory and rheological analyses. Lebensm.-Wiss. u -Technol. 34, 222–233.

40. Yang S.S., Cotterill O.J., 1989. Physical and functional properties of 10% salted egg yolk in mayonnaise. J. Food Sci. 54, 1, 210–213.

41. Yven C., Guichard E., Giboreau A., Roberts D.D., 1998. Assessment of interactions between hydrocolloids and flavor compounds by sensory, headspace, and binding methodologies. J. Agric. Food Chem. 46, 4, 1510–1514.

Accepted for print: 30.07.2009

Responses to this article, comments are invited and should be submitted within three months of the publication of the article. If accepted for publication, they will be published in the chapter headed 'Discussions' and hyperlinked to the article.