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The preparation of egg yolk powder (EYP) with excellent solubility and high retention of active IgY is of great significance for increasing the added value and promoting the application of EYP. A new method of preparing EYP by microwave-assisted freeze-drying (MFD) was researched. Confocal laser scanning microscopy results demonstrated that the supplementation of excipients (sucrose, trehalose, and maltodextrin) could inhibit lipoproteins aggregation in egg yolk induced by freezing. Scanning electron microscopy indicated that drying further damaged the structure of lipoproteins in EYP, leading to lipid separation from it. FTIR and fluorescence spectra confirmed this finding, indicating that excipients enhance protein stability. Compared with conventional freeze-drying (FD), EYP prepared by MFD, particularly that containing excipients, had higher solubility (63 g/100 g), active antibody retention rate and shorter drying time. Therefore, excipients can significantly improve the solubility and stability of EYP and the retention rate of active IgY.

Changes in physiochemical properties of spray-dried camel milk powders during storage at 11–32% RH and 37 °C over 18 weeks were investigated. The results showed that fresh camel milk powders had amorphous structure, clumsy spherical shape particles and almost 100% solubility in water. During storage at controlled low RH levels (

Alterations in surface chemical composition relating to rehydration properties of spray-dried camel milk powders during accelerated storage (11–33% RH, 37 °C) over 18 weeks were investigated. The results showed that the surface of the fresh spray-dried camel milk powder (t = 0) was dominated by lipids (78%), followed by proteins (16%) and lactose (6%). During storage, the surface protein and lactose content decreased while the surface lipid content increased, resulting in an increase in surface hydrophobicity and slight agglomeration of the powder, especially for powder kept at 33% RH. Although fresh camel milk powder had very poor wettability, it displayed very high dispersibility and solubility (99%). During storage, dispersibility and solubility declined with increasing storage time and increasing RH levels, which correlated with an increase in surface lipid content. However, at the end of the storage period, camel milk powder still retained very high solubility (>93%).

Effects of low methoxyl pectin, milk protein concentrate (MPC), and waxy starch on the encapsulation of green tea-polyphenols in alginate gels produced using spray aerosol technique were evaluated. MPC and waxy starch treated first by cold-renneted induced gelation method and gelatinization method, respectively. DSC thermal analysis and FTIR spectroscopy were used to prove the presence of polyphenols in gel matrixes. The encapsulation efficiency (%EE) and the polyphenols release were investigated using Folin-Ciocalteu assay. The results showed that the addition of biopolymers into alginate gels increased the encapsulation efficiency (%EE) but reduced the release percentage of polyphenol in water and simulated gastric fluid (SGF). Among the three biopolymers, cold-renneted MPC gave the best protection for polyphenols encapsulated in alginate microgels. It increased %EE from 63% to 68% in fresh gels, reduced the release percentage in water from 72% to 62% and reduced the release percentage in SGF from 76% to 67%.

Stingless bee honey (SBH) of four stingless bee species (Heterotrigona itama, Geniotrigona thoracica, Tetragonula carbonaria, and Tetragonula hockingsi) from two geographic regions (Malaysia and Australia, n = 36) were studied for their physicochemical parameters, including total phenolic and multi-elemental contents. Sugar analysis confirmed the prominent presence of trehalulose in all samples. All SBH failed to meet the CODEX Standard for honey moisture, free acidity, and total fructose plus glucose levels. One-way ANOVA, principal component analysis (PCA) and hierarchical component analysis (HCA) confirm distinctive differences between Australian and Malaysian SBH with Australian SBH having significantly (P 0.05) higher pH, total phenolic, total mineral, and electrical conductivity attributes. Toxic elements in all SBH were much lower than standard CODEX limit. The species G. thoracica produced honey with significantly (P 0.05) higher trehalulose than both Australian bee species. This research will add value to SBH and hasten new international standards ensuring commercial viability, safety, quality, and marketability of SBH.

The effects of cooking methods (pressure cooking, microwave cooking, and atmospheric pressure cooking) and infrared-assisted freeze drying (IRFD) on drying characteristic, crystalline structure, pasting property, rehydration behavior, microstructure, texture, and flavor of instant quinoa samples were investigated. Results showed that IRFD significantly reduced the drying time needed for freeze drying (FD). The crystalline structure of starch in raw quinoa was destroyed in cooking process, IRFD process well maintained the gelatinized state of quinoa samples. The pressure cooked samples owned the highest porosity and best rehydration ability. Pressure cooking and microwave cooking caused the softer and thicker texture of rehydrated instant quinoa samples. As for the flavor of quinoa sample, IRFD possessed the stronger retention ability compared with FD. In summary, pressure cooking and IRFD could be the applicable processing methods for the production of instant quinoa product or other dehydrated instant product with high quality.

This study aims to examine the solubility of CO2 in anhydrous milk fat (AMF) as functions of partial pressure, temperature, chemical composition and physical state of AMF. AMF was fractionated at 21°C to obtain stearin and olein fractions. The CO2 solubility was measured using a home-made experimental apparatus based on changes of CO2 partial pressures. The apparatus was found to be reliable as the measured and theoretical values based on the ideal gas law were comparable. The dissolved CO2 concentration in AMF increased with an increase in CO2 partial pressure (0-101kPa). The apparent CO2 solubility coefficients (molkg-1Pa-1) in the AMF were 5.75±0.16×10-7, 3.9±0.19×10-7 and 1.19±0.14×10-7 at 35, 24 and 4°C, respectively. Higher liquid oil proportions resulted in higher CO2 solubility in the AMF. There was insignificant difference in the dissolved CO2 concentration among the AMF, stearin and olein fractions in their liquid state at 40°C.

The objective of this research was to investigate the effect of individual additions of mono- and divalent electrolytes (NaCl and CaCl2), anionic (sodium dodecyl sulfate, SDS) and non-ionic surfactants (polysorbate 80, Tween 80) at varied concentrations on the generation and stability of bulk nanobubbles (NBs) from carbon dioxide (CO2) gas in aqueous system. Overall, NBs generated in the small-amount salt fluids exhibited significantly (p ≤ 0.05) lower size range (150–350 nm). Smaller diameter and higher zeta potential magnitudes (18–24 mV) of the NBs in SDS medium were also observed and related to the higher CO2 concentration (~1850 ppm) and lower surface tension (~64 mN/m) of the solution. However, the gas NBs were disappeared with the incorporation of Tween 80. The outcomes provide some more research-based details about the impact of potential nano-bubble stabilising agents on characteristics of NBs contributing to the green and sustainable NB-related applications in food sectors.

To understand the specific contributions of amorphous sugars and organic acids to the quality of food matrix, the solid model system of jujube slice skeleton (JSS) was firstly established. Effects of fructose (F), glucose (G), malic acid (M) and citric acid (C) on the glass transition temperature (Tg) and crystallization of JSS were studied. JSS-F/G/M/C blends were prepared by osmosis in the solution at a range of 0 ~ 32 g/100 g. Sugars reduced the Tg in the system, structure of JSS-G/M blends was changed from “amorphous glassy” to “amorphous rubbery” by increasing the osmotic solute concentration. Tg was decreased from 50.8 to 14.0 °C when JSS was osmosed in a 4 g/100 g fructose solution. Organic acids induced their crystallization in JSS. The crystallinity of JSS-M immersed in 32 g/100 g osmotic solution concentration was increased from 2% to 75%. Fructose presented greater influence on the adverse quality of jujube slices.

The effects of water content; 15, 30, and 40% (w/w), water droplet size; d 15.0–19.6 µm (larger) and d 1.2–2.7 µm (smaller), and sodium alginate (0.5%, w/w) induced water gelation on crystallization kinetics and water and fat proton relaxation were studied in water-in-milk fat emulsions during in situ cooling from 40 °C to 5 °C. Anhydrous milk fat (AMF) and commercial butter were employed as two separate fat sources. Although emulsions were crystallized faster than the bulk fat, the variations in the water fraction and droplet size did not show major influence on crystallization properties. Smaller droplet size induced significant (p < 0.05) reduction in water mobility with a minimal effect of the temperature. In AMF-based emulsions, gelation of water phase not only immobilized the water molecules but also enhanced the rate of fat crystallization. Globular fat and serum solids in butter-based emulsions showed to fasten the water proton relaxation.

This study aims to characterize CO2-α-cyclodextrin (α-CD) inclusion complexes produced from amorphous α-CD powder at moisture contents (MC) close to or higher than the critical level of crystallization (e.g. 13, 15 and 17% MC on wet basis, w.b.) at 0.4 and 1.6MPa pressure for 72h. The results of (13)C NMR, SEM, DSC and X-ray analyses showed that these MC levels were high enough to induce crystallization of CO2-α-CD complexed powders during encapsulation, by which amount of CO2 encapsulated by amorphous α-CD powder was significantly increased. The formation of inclusion complexes were well confirmed by results of FTIR and (13)C NMR analyses through an appearance of a peak associated with CO2 on the FTIR (2334cm(-1)) and NMR (125.3ppm) spectra. Determination of crystal packing patterns of CO2-α-CD complexed powders showed that during crystallization, α-CD molecules were arranged in cage-type structure in which CO2 molecules were entrapped in isolated cavities.

After prolonged storage or during the shipment of raisins, a crystalline material may be developed on their surface, affecting the final acceptability of the product. The mild thermal pretreatment (50 °C for a period of 12 h and 48 h) was applied to dissolve any potential tiny crystals and nuclei already present in the raisins. The thermal pretreatment of raisins resulted in a reduction on the percentage of crystallized raisins (w/w) from more than 46% in control samples to less than 10% after 30 days of storage at 57% and 66% of relative humidity and 15 °C and 25 °C. X-ray diffraction analysis identified d-Glucose monohydrate as the main crystalline component. All the thermal treatments increased the hardness of the raisins, when they were incubated at 57% relative humidity. To mitigate the problems of crystallization of raisins during shipping, it is recommended that the raisins are thermally pretreated and the shipping conditions are controlled.

The effects of sugar component ratio, water fraction, and storage conditions on crystallisation and glass transition temperature (Tg) of three Chilean dried raisins were examined by using differential scanning calorimetry (DSC), polarised light microscopy and X-ray diffraction (XRD) techniques. Thompson, Flame and Golden raisins differed in fructose:glucose and glucose:water ratios, impacting on their measured Tgs (P

A model system was established to investigate the effect of glycerol on stability of globular proteins. To study whether protective effect of glycerol is dependent on the nature of protein, four kinds of globular protein were used including α-lactalbumin, β-lactoglobulin, native lactoferrin and lysozyme. Differential scanning calorimetry (DSC) was used to study the thermal stability of the proteins with glycerol aqueous (0-80% v/v). The results showed that the stability of β-lactoglobulin and lysozyme (hydrophobicity-dominated proteins) increased with glycerol concentration. However, that of α-lactalbumin and lactoferrin (metalloproteins), regardless of the ion-binding state, initially increased and then decreased. Different protective effects were observed beyond 50% (v/v) glycerol concentrations in liquid phase. The secondary structure and tryptophan exposure remained unchanged. In conclusion, the protection of glycerol on protein stability was highly dependent on the nature of proteins.

Different formulations and crystallising conditions were employed to vary the bulk phase structuring of oleogels. The oleogels were formed only at monoacylglycerol:native phytosterol (MAG:NPS) ratios of 10:0, 7:3 and 5:5. NPS co-crystallised with MAG in the oleogel mixtures and influenced the growth of lipidic crystal network. Faster cooling rates caused smaller crystals whereas thermal history affected the rigidity of oleogel samples. The oleogel samples were whipped and characterised for whipping time, foam overrun, microstructure, rheology and half-life of foam. The whipped oleogels were structured by layer(s) of lipidic crystals surrounding the air bubbles, which had non-spherical shapes and rough textures. The whipping time was remarkably reduced by 80% in the oleogel samples containing smaller lipidic crystals. All whippable oleogel samples had similar foam overrun values and extremely stable against foam collapse. The obtained oil foams exhibited liquid-like behaviour at low frequency as measured by the frequency sweep test.

The co-melting behaviour of sugar mixtures, comprising sucrose, glucose and fructose at various binary (3:1, 1:1, 1:3, 1:7, 1:15) and ternary (4:1:1, 2:1:1, 1:1:1, 2:5:5, 2:11:11, 1:4:1, 1:10:1) ratios, was studied using DSC. The melting temperature of sucrose was found to decrease in the presence of either fructose or glucose. In the sugar mixtures, the melting enthalpy of sucrose decreased compared with the proportional calculated values, using the percentage equation, whilst the melting enthalpy of fructose or glucose increased at the same time, implying the melting or dissolution of sucrose together with fructose or glucose. The tested enthalpy is usually higher than the calculated enthalpy for fructose, but lower than the calculated enthalpy for sucrose. Microscopic pictures showed that sucrose crystals could melt and dissolve gradually in the fructose melt liquid. This study provides useful information for both fundamental understanding of sugars co-melting and food industry applications.

Carbon dioxide complexation was undertaken into solid matrices of amorphous and crystalline α-cyclodextrin (α-CD) powders, under various pressures (0.4-1.6 MPa) and time periods (4-96 h). The results show that the encapsulation capacity of crystalline α-CD was significantly lower than that of amorphous α-CD at low pressure and short time (0.4-0.8 MPa and 4-24 h), but was markedly enhanced with an increase of pressure and prolongation of encapsulation time. For each pressure level tested, the time required to reach a near equilibrium encapsulation capacity of the crystalline powder was around 48 h, which was much longer than that of the amorphous one, which only required about 8h. The inclusion complex formation of both types of α-CD powders was confirmed by the appearance of a CO2 peak on the FTIR and NMR spectra. Moreover, inclusion complexes were also characterized by DSC, TGA, SEM and X-ray analyses.

Lactoferrin (Lf) samples with ca. 25%, 50%, 75%, 85% and 100% iron saturation were prepared for the purpose of evaluating Chromametry, Differential Scanning Calorimetry (DSC) and Circular Dichroism (CD) spectropolarimetry for their suitability in determining the iron saturation level. Numerical values for colour from Chromametry, enthalpy change of denaturation (ΔHcal) from DSC and molar ellipticities from CD were statistically analysed to evaluate their correlation with the level of iron saturation in Lf. Linear regression analysis of colour coordinates Chroma (C(∗)) and hue (h°) angle on percentage iron saturation level of Lf showed that the values can be used to estimate the iron saturation level. The ΔHcal for the iron saturated peak and the CD ellipticities in the 310-340 nm region provided reliable data for the estimation of iron saturation level of Lf up to 75%. Mono- and di-saturated Lf displayed the same thermal stability and very similar tertiary structures.

Lactosylation in stored milk powder was quantified by multiple reaction monitoring (MRM), a mass spectrometry-based quantification method. The MRM method was developed from a knowledge of peptide fragmentation. The neutral losses of 162 Da (cleavage of galactose) and 216 Da (the formation of furylium ion) which were representative of lactosylated peptides were specifically selected as MRM transitions. Quantification of lactosylated protein was based on the peak areas of these fragmentation ions. The MRM results showed an increase in peak areas of the two transition fragments from tryptic digests of whey proteins in stored milk protein concentrate powder. A good correlation between the MRM and furosine results indicated that MRM based on tryptic digests of whole products was a feasible method for quantification of modified milk proteins.

An innovative method to encapsulate tea tree oil (TTO) by direct complexation with solid amorphous beta-cyclodextrin (β-CD) was investigated. A β-CD to TTO ratio of 90.5:9.5 (104.9 mg TTO/g β-CD) was used in all complexation methods. The encapsulation was performed by direct mixing, and direct mixing was followed by the addition of water (13–17% moisture content, MC) or absolute ethanol (1:1, 1:2, 1:3 and 1:4 TTO:ethanol). The direct mixing method complexed the lowest amount of TTO (60.77 mg TTO/g β-CD). Powder recrystallized using 17% MC included 99.63 mg of TTO/g β-CD. The addition of ethanol at 1:2 and 1:3 TTO:ethanol ratios resulted in the inclusion of 94.3 and 98.45 mg of TTO/g β-CD respectively, which was similar to that of TTO encapsulated in the conventional paste method (95.56 mg TTO/g β-CD), suggesting an effective solid encapsulation method. The XRD and DSC results indicated that the amorphous TTO-β-CD complex was crystallized by the addition of water and ethanol.

Solid milk fat stearin (S25) can be a promising oxidation retarder due to its capacity to entrap liquid oils, especially for incorporating omega-3 (ω-3) rich oils into dairy products. Thermal properties of S25/ω-3 rich oil mixtures are necessary for such application. The effects of S25 on the crystallization and melting behaviours of ω-3 rich oils, namely fish oil (FO), linseed oil (LO) and krill oil (KO), were investigated by differential scanning calorimetry (DSC). Thermograms showed that with S25 concentration increasing, transitions of FO and LO shifted to lower and largely to higher temperatures, respectively, while crystallization temperature of KO slightly decreased. Negative, positive and low values of interaction enthalpy (ΔHint) suggested the adverse, beneficial and limited effect of S25 on the crystallization of S25/FO, S25/LO and S25/KO mixtures, respectively. LO could have the best oxidative stability upon the addition of S25 since their interactions facilitated earlier and stronger crystallization.

International audience; The objectives of this study were to evaluate the ability of X-ray photoelectron spectroscopy (XPS) to differentiate rice macromolecules and to calculate the surface composition of rice kernels and flours. The uncooked kernels and flours surface composition of the two selected rice varieties, Thadokkham-11 (TDK11) and Doongara (DG) demonstrated an over-expression of lipids and proteins and an under-expression of starch compared to the bulk composition. The results of the study showed that XPS was able to differentiate rice polysaccharides (mainly starch), proteins and lipids in uncooked rice kernels and flours. Nevertheless, it was unable to distinguish components in cooked rice samples possibly due to complex interactions between gelatinized starch, denatured proteins and lipids. High resolution imaging methods (Scanning Electron Microscopy and Confocal Laser Scanning Microscopy) were employed to obtain complementary information about the properties and location of starch, proteins and lipids in rice kernels and flours.

Kinetics of enthalpy relaxation of milk protein concentrate (MPC) powder upon short-term (up to 67 h) storage at 25 °C and aw 0.85, and long-term (up to 48 days) storage at 25 °C and a range of aw values (0-0.85) were studied by differential scanning calorimetry (DSC). The short-term study showed a rapid recovery of enthalpy for the first 48 h, followed by a slower steady increase with time. The non-exponential β parameter was calculated using the Kohlrausch-Williams-Watts function and found to be 0.39. Long-term storage showed that enthalpy relaxation depends on both storage period and water activity. The enthalpy value was much less for lower moisture content (mc) (aw ≤ 0.23, mc ≤ 5.5%) than for higher mc (aw ≥ 0.45, mc ≥ 8%) samples for a particular storage period. The results suggest that the presence of more water molecules, in close proximity to the protein surface facilitates kinetic unfreezing and subsequent motion of molecular segments of protein molecules towards thermodynamic equilibrium. Although de-ageing of stored samples did not reverse storage-induced solubility losses, the timescale of enthalpy relaxation was similar to that of solubility loss. It is suggested that enthalpy relaxation within stored samples allows structural rearrangements that are responsible for subsequent solubility decreases.

Milk proteins undergo chemical changes such as lactosylation, deamidation and protein cross-linking during processing and storage of milk products. A proteomic technique combining two-dimensional gel electrophoresis and mass spectrometry was used to investigate chemical modifications to proteins, in milk protein concentrate (MPC80), during storage. Lactosylation, deamidation and protein cross-linking were observed on 2-DE gels. They were storage temperature-, humidity- and time-dependent. Lactosylated whey proteins were well separated on 2-DE in vertical stacks of spots. The masses of the spots varied by multiples of 324, indicating the attachment of lactose to lysine residues in the proteins. The trypsin-digested spots of α-lactalbumin were analysed by MALDI-TOF mass spectrometry, which indicated multiple lactosylation sites. The lactose adducts on gels were quantified by image analysis, allowing development of adducts over time to be monitored. The results show that proteomics can be used for the detection and quantification of chemical modifications to proteins in stored MPC80.

Bayberry juice was spray dried with maltodextrin (DE 10) as a carrier and then stored under different temperature and water activities (aw). The retention of the total phenolic content (TPC) and total anthocaynins (ACN) during the drying process were about 96% and 94%, respectively, suggesting spray drying was a satisfactory technique for drying heat sensitive polyphenols. Under an aw of 0.11-0.44, the TPC and ACN in bayberry powders decreased by about 6-8% and 7-27%, respectively, after 6months storage at 4°C; at 25°C for the same storage period the decreases were between 6-9% and 9-37%, respectively, while at 40°C the decreases were in the range 7-37% and 9-94%. The anthocyanin component was more readily degraded relative to other phenolic compounds. The results suggest that bayberry powder should be stored at less than 25°C and aw of 0.33, on account of greater polyphenol stability under such conditions.

Ethylene was included into α-cyclodextrin (α-CD) by molecular encapsulation. Characterisation of the ethylene-α-CD inclusion complexes (ICs) using X-ray diffractometry (XRD) and scanning electron microscopy (SEM) confirmed their crystalline structures. Release kinetics of ethylene gas from the ICs was investigated. Release characteristics experiments were carried out at various relative humidities (RH) (52.9%, 75.5%, and 93.6%) and temperatures (45, 65, 85, and 105°C). The Power Law and Avrami's equations were used to analyse release kinetics. The latter showed better fit for ethylene release. Kinetics analysis based on Avrami's equation showed that the release of ethylene was accelerated by increases in RH and temperature. For humidity treatments, the release parameter n represented a diffusive mechanism at 52.9% and 75.5% RH and a first-order mode at 93.6% RH. However, a diffusive mechanism was found in all temperature experiments. Release rate constants increased as a function of increasing temperature. Temperature coefficient (Q10), activation energy (Ea) and half-life release of ethylene gas were also analysed.

Molecular encapsulation of various apolar compounds with α-cyclodextrin (α-CD) is becoming a widely applied technique to produce food, pharmaceutical and agricultural materials. Encapsulated ethylene in the form of inclusion complexes (ICs) with cyclodextrin, which is in powder form, could be used in fruit ripening and other aspect of plant growth regulation. In this research, ethylene was complexed with an α-CD under 0.2–1.5 MPa for 12–120 h. Ethylene concentration in the inclusion complexes (ICs) varied from 0.98 to 1.03 mol ethylene/mole CD. Pressure and time did not increase ethylene concentrations in the complexes, but did yield significantly higher amounts of the crystal complex. The physico-chemical properties of the ethylene-α-CD complexes at various concentration of ethylene were characterised using X-ray diffractometry (XRD), nuclear magnetic resonance spectroscopy (CP–MAS 13 C NMR), differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Complex formation was confirmed by sharp peaks in the XRD diffractograms, crystal images by SEM, double bond of ethylene gas and chemical shifts at C 4 , C 3 and C 5 in NMR spectra, intensity changes of C–H bending and C C stretching in the FTIR spectra, and water loss and physico-chemical property modifications in the DSC and TGA scans.

This study investigated the effects of water-induced crystallization of amorphous alpha-cyclodextrin (α-CD) powder on CO2 encapsulation at 0.4-1.6 MPa pressure for 1-72 h through the addition of water (to reach to 13, 15 and 17% wet basis, w.b.) into amorphous α-CD powder prior to the encapsulation. The results showed that the α-CD encapsulation capacity was over 1 mol CO2/mol α-CD after pressurizing for longer than 48 h. The encapsulated CO2 concentration by the addition of water was considerably higher (p

The triacylglycerol (TAG) crystal structures and morphologies of fractionated milk lipids in nanoemulsions were investigated at 4°C. Droplet size (0.17 versus 1.20 μm), lipid composition (stearin versus olein) and cooling rate (1 versus 10°C min(-1)) had an influence on the structural properties. Five crystal polymorphs (α, β'1, β'2, β1, and β2) were formed with either triple and/or double chain length structures in the solid phases of the emulsified systems. X-ray scattering peak intensities were reduced with the nanoemulsion particles. The internal structure of TAG exhibited stacking of individual lamellar layers (3.8-4.2 nm). Various anisometric shapes of fat nanoparticles were formed due to a highly sharp curvature of the nano-size droplets. The shape of olein nanoparticles was more polyhedral compared to the stearin. TAG crystals arranged in a planar-layered organisation at the slower cooling rate. These differences imply that the nanometric confinement of oil droplets modifies the fat crystal habit.

The crystallisation properties of milk fat emulsions containing dairy-based ingredients as functions of emulsion droplet size, cooling rate, and emulsifier type were investigated using a differential scanning calorimeter (DSC). Anhydrous milk fat and its fractions (stearin and olein) were emulsified with whey protein concentrate, sodium caseinate, and Tween80 by homogenisation to produce emulsions in various size ranges (0.13-3.10 μm). Particle size, cooling rate, and types of emulsifier all had an influence on the crystallisation properties of fat in the emulsions. In general, the crystallisation temperature of emulsified fats decreased with decreasing average droplet size and was of an exponent function of size, indicating that the influence of particle size on crystallisation temperature is more pronounced in the sub-micron range. This particle size effect was also verified by electron microscopy.

Three forms of bovine lactoferrin (Lf), apo-, native- and holo- with 0.9%, 12.9% and 99.7% iron content, respectively, were characterised for their physico-chemical properties. Colour, surface tension, thermal properties, particle charge and rheological behaviour of Lf were found to be affected by the form of Lf. The surface tension of Lf tends to decrease with decrease in iron content. The Circular Dichroism (CD) spectra confirmed that all forms of Lf had similar secondary structures while the tertiary structure was different for holo-Lf. The Differential Scanning Calorimeter (DSC) analysis showed that the apo- and holo-Lf in aqueous solution displayed thermal denaturation temperatures of 71±0.2 and 91±0.5 °C, respectively, suggesting that the iron saturation of Lf tends to increase its thermal stability. The study of particle charge properties (ζ-potential) in 1 mM KCl salt solution showed that apo-Lf reached the net charge of zero in the pH range 5.5-6.5 whereas native and holo-Lf in the pH range 8.0-9.0. The apparent viscosity of 1% (wt/wt) solution of the different forms of Lf showed no difference between apo- and native-Lf (≈1.4 mPas) while the value was significantly higher (2.38 mPas) for holo-Lf.