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In this study dairy phospholipid (PL) gels were made using 3 different concentrations of PL (15%, 30%, and 45%) and soybean oil to determine the gel-forming ability and functional traits that dairy PL have. After 24 h of storage the visual stability, crystal morphology, solid fat content, melting behavior, viscosity, and oil binding capacity of the gels were evaluated. All samples showed visual stability, whereas polarized light microscopy showed that high concentrations of PL reduced PL mobility, preventing tubular micelles from forming at high concentrations of PL (45%). Solid fat content increased with an increase in PL concentration. The melting enthalpy increased as the concentration of PL increased. The viscosity was assessed at 0.01, 0.1, and 1.0 1/s shear rates. A significant difference was observed between the 45% PL samples and the other samples at low and intermediate shear, but at high shear levels, a significant difference was only seen between the 15% PL sample and the other samples. The oil binding capacity showed a significant difference between the 45% PL sample and the other 2 samples. This study shows that dairy PL can be added to a vegetable oil to produce semi-solid material with appropriate functional properties.

The processing of healthy foods remains a challenge and any technology with the ability to tailor the physical properties of new materials is in demand. High-intensity ultrasound (HIU) has been identified as a useful processing technique for such activities particularly for edible lipids. HIU has been known to alter the crystallisation kinetics and in turn the resultant physicochemical properties for specific food applications. The role of cavitation dynamics during treatment of oils with HIU is of interest, with the knowledge gained allowing for insight into the complex and still undefined mechanism of action. To this end, the crystallisation kinetics of an edible lipid were investigated in the presence of several distinctly different cavitation conditions. Several cavitation clusters, including a bifurcated streamer (BiS), located on the surface of a piston-like emitter (PLE) were studied, each generated by a specific ultrasonic power level. Only samples crystallised at a low supercooling (ΔTSC) value display significant differences in induction time for each of the selected HIU powers, at least 5 minutes earlier than without exposure to HIU. Substantially better energy efficiencies were seen for the BiS regime (ΔTSC = 5 °C) which coincided with maximal crystal growth rates. An increase in melting enthalpy and elastic modulus is reported in the presence of HIU for all crystallisation temperatures, this effect is larger overall with increasing ultrasonic power. In addition, sonicated samples in the presence of the BiS event were composed of fewer smaller crystals compared to higher HIU powers after 60 minutes at 30 °C. Bubble dynamics recorded during a 10 s sonication period exhibited a greater acoustic attenuation effect for the highest ultrasonic power (75 W). The results suggest that the dynamics of the cluster and the presence of the BiS event are important in terms of energy efficiency and the physical properties of the crystallised lipid material.

The aim of this research is to crystallize a low saturated interesterified soybean oil (IESBO) using a scraped surface heat exchanger (SSHE) combined with high intensity ultrasound (HIU). The SSHE operated at a flow rate of 3.125 mL/s, crystallization temperature of 32 °C, pressure of 2 bars, and barrels/pin worker speed of 344/208 rpm, respectively. HIU was applied at amplitudes between 20 and 80% using continuous, 5 s or 10 s pulses. The microstructure, melting behavior, rheology, hardness, and oil binding capacity (OBC) of the samples were evaluated. Non-sonicated sample resulted in a crystalline network characterized by 8.9 μm diameter crystals, elasticity values of 25,255Pa, hardness values of 1.3N and OBC values of 61%. Sonication using 50% amplitude for 5 s was the most efficient condition and resulted in a decrease in crystal size to 4.5 μm, an increase in elasticity values to 100,238Pa, and an increase in hardness and OBC values to 3.7N and 81.3%, respectively.

Highlights • Position where HIU should be applied is dependent on temperature and agitation. • At lower crystallization temperature, sample must be sonicated at HIU-1. • At higher crystallization temperature, sample must be sonicated at HIU-3. • HIU was able to improve fat physical properties such as G’ and OBC. • Better physical properties were obtained 20 °C under low agitation in position HIU-1., High-intensity ultrasound (HIU) has been used in the past to change fat crystallization and physical properties of fat crystalline networks. The objective of this work was to evaluate how HIU placed on different positions in a scraped surface heat exchanger (SSHE) using different processing conditions affect the physical properties of an interesterified palm olein. The sample was crystallized at two temperatures (20 °C and 25 °C) and two agitation rates (344/208 rpm and 185/71 rpm, barrels/pin worker). HIU (12.7 mm-diameter tip, 50% amplitude, 5 s pulses) was placed at three different positions within the SSHE. After processing, samples were stored at 25 °C for 48 h and analyzed according to the crystal morphology, solid fat content (SFC), oil binding capacity (OBC), melting behavior, viscoelasticity, and hardness. Physical properties were affected by crystallization conditions, by sonication, and by HIU position. The greatest improvement obtained was at 20 °C using low agitation when HIU was placed at the beginning of the SSHE. These conditions result in a sample with 98.9% of OBC, 274 kPa of viscoelasticity and 31 N of hardness. These results show that HIU can be used as an additional processing tool to improve physical properties of a palm-based fat and that the best improvement was obtained as a combination of crystallization conditions and HIU position.

The purpose of this study was to determine the effect of high-intensity ultrasound (HIU) on the physical properties of an all-purpose shortening and to evaluate how these properties changed during storage (48 hr; 4, 12, and 24 weeks) at 5 °C and 25 °C. Samples were crystallized at 30 °C for 60 min with and without the application of HIU (20 kHz; 3.2 mm-diameter tip, 168 µm amplitude, 10 s). After crystallization, physical properties, such as hardness, elasticity, melting behavior, and solid fat content (SFC), were measured. These properties were also measured during storage. The effect of HIU was significant in changing the SFC, hardness, G' and G'', melting enthalpy, and microstructure of the samples. After 60 min of crystallization, the sonicated samples had higher values of SFC, hardness, elasticity, and melting enthalpy than the ones obtained without sonication (P < 0.05). Changes in these physical properties were associated with the microstructure of the samples since sonication generated smaller, more uniformly sized crystals as well as increased the number of crystals. No differences were observed in the G' of the sonicated samples stored at 25 °C as a function of storage period. The G' of the nonsonicated samples increased until 12 weeks of storage and was maintained up to 24 weeks, suggesting that sonication speed up the formation of a stable crystalline network. Samples stored at 5 °C showed higher value in hardness, G' and G'', and SFC than the ones stored at 25 °C. PRACTICAL APPLICATION: High-intensity ultrasound (HIU) has been widely used as an additional tool to change the crystallization behavior in various lipids; however, the long-term storage effect of HIU has not been studied before. This research evaluates the effect of HIU on the physical properties of a palm-based shortening stored up to 24 weeks at two different temperatures (25 and 5 °C). The application of HIU may help increase the stability of lipid during storage.

The objective of this work was to evaluate the effect that agitation rate, crystallization temperature, and sonication have on the physical properties of a soybean-based fat with low levels of saturated fatty acids crystallized in a scraped surface heat exchanger (SSHE). The sample was crystallized at two temperatures (20 and 25 °C) and agitation rates (344/208 rpm in the barrels/pin worker-high agitation HA and 185/71 rpm barrels/pin worker-low agitation LA), and a constant flow of 11 L/hr. High-intensity ultrasound (HIU - 12.7 mm-diameter tip, 50% amplitude, 5 s pulses) was coupled to a water jacketed flow-cell and placed at three different positions within the SSHE. The combination of all those parameters affected samples' physical properties. Higher oil binding capacity (OBC) and elasticity (G') were obtained at 20 °C compared to 25 °C (77% vs. 63.78% for OBC and 30.4 kPa vs. 6 kPa for G', respectively) due to the smaller crystals formed at 20 °C. Fewer or no differences were observed due to agitation alone, but LA conditions allowed for more secondary nucleation to form due to sonication and resulted in a higher improvement on the properties of the fat. PRACTICAL APPLICATION: Fat crystallization in a scrapped surface heat exchanger (SSHE) combined with a high-intensity ultrasound (HIU) gives a realistic idea of how the HIU would work in an industrial line under continuous flow, shaved shear, and different supercooling. Results from this research will provide industry with tools on how and where to incorporate HIU in their processing line. Moreover, will give information on how to combined crystallization conditions and sonocrystallization in order to obtain improved physical properties.

Aging of cream is an important process to manage production time and to produce butter with consistent quality. The objective of this study was to evaluate the combined effect of temperature (5, 10, and 15°C) and agitation rate (0, 40, and 240 rpm) during aging of cream on the physical properties of cream and butter in a model system. Cream's solid fat content (SFC), melting behavior, and droplet size distribution were measured during and after 90 min of aging. Butter physical properties such as melting behavior, water content, and hardness were measured. The effects of agitation on SFC and droplet size are dependent on aging and churning temperature. Solid fat content increased faster at 5°C, and the maximum SFC was the highest at this temperature. An effect of agitation on SFC was observed only when cream was aged at 15°C. Agitating cream at 40 rpm increased the droplet size regardless of aging temperature. Two melting peaks, medium melting fraction (MMF) and high melting fraction (HMF), were found in cream samples aged at 5 and 10°C, but only a HMF melting peak was seen in the cream aged at 15°C. The enthalpy of MMF in the cream aged at 10°C with 40 rpm and without agitation was significantly lower than that in samples aged at 5°C regardless of agitation rate. Butter can be formed only from cream aged under certain conditions during 14.5 min of churning, which are 5°C with high agitation and 10°C regardless of agitation level. Butter produced with cream aged at 5°C with high agitation showed significantly higher MMF and total enthalpy values. However, no significant difference in enthalpy values was observed among the butter samples made from the cream aged at 10°C. Further crystallization of MMF occurred in the butter produced with cream aged at 10°C during 24 h of storage at 5°C, whereas no further crystallization occurred in the butter made with the cream aged at 5°C with high agitation. The hardest butter was obtained when cream was aged at 5°C with 240 rpm and at 10°C with 40 rpm. Softer butter was obtained when cream aged at 10°C with 240 rpm was used. This butter also had the highest water content. This study shows that butter hardness can be tailored by changing the aging conditions of the cream. Cream can be aged at higher temperature with low agitation without altering the hardness of butter. These results will help dairy producers to optimize butter making processes to obtain desired properties in the final product.

The aim of this study was to investigate the effects of supercooling and degree of saturation on lipid sonocrystallization under similar driving force of crystallization. Samples consisting of 100%, 50%, and 20% interesterified soybean oil (IESBO) diluted in high-oleic sunflower oil (HOSFO) were crystallized with and without high-intensity ultrasound (HIU). Two power levels were used by changing the amplitude of vibration of the tip (24 µm and 108 µm of tip amplitude). HIU operating at a frequency of 20 kHz was applied for 10 s. Sonication induced crystallization in the 100% IESBO sample and sonication power did not affect the results. A greater induction in crystallization was observed when higher power levels were used in the 50% IESBO sample, while no effect was observed in the crystallization kinetics of the 20% IESBO samples. Changes in the crystallization kinetics affected physical properties of the material, influencing elasticity. For example, sonication increased the elasticity of the 100% IESBO sample for both tip amplitudes from 435.9 ± 173.3 Pa to 72735.0 ± 9547.9 Pa for the nonsonicated and sonicated samples using 108 µm of amplitude, respectively. However, sonication only increased the elasticity in the 50% sample when used at the higher power level of 108 µm from 564.2 ± 175.2 Pa to 21774.0 ± 5694.9 Pa, and it did not affect the elasticity of the 20% IESBO samples. These results show that the level of saturation and the degree of supercooling affect sonication efficiency. High-intensity ultrasound (HIU) has been used as a novel method for changing the crystallization behavior of fats. HIU can be used to improve the physical properties of trans-free fats that are low in saturated fatty acids. Although recent studies have proven the effectiveness of this method to induce crystallization, the process must still be optimized to the industrial setting. All process parameters should be considered during the application of HIU, as they directly affect the final product. The aim of this paper was to investigate the effects of HIU and process conditions such as tip amplitude, degree of supercooling, and saturation level on the crystallization behavior of commercial interesterified soybean oil.

Preservation of meat through freezing entails the use of low temperatures to extend a product’s shelf-life, mainly by reducing the rate of microbial spoilage and deterioration reactions. Characteristics of meat that are important to be preserve include tenderness, water holding capacity, color, and flavor. In general, freezing improves meat tenderness, but negatively impacts other quality attributes. The extent to which these attributes are affected depends on the ice crystalline size and distribution, which itself is governed by freezing rate and storage temperature and duration. Although novel technology has made it possible to mitigate the negative effects of freezing, the complex nature of muscle tissue makes it difficult to accurately and consistently predict outcome of meat quality following freezing. This review provides an overview of the current understanding of energy and heat transfer during freezing and its effect on meat quality. Furthermore, the review provides an overview of the current novel technologies utilized to improve the freezing process.

The objective of this research was to examine the effect of ultrasound frequency and high-speed agitation on lipid crystallization. Interesterified soybean oil was crystallized at 44 °C without and with the application of high intensity ultrasound (HIU—20 and 40 kHz) or with high-speed agitation (6000 and 24,000 rpm). Two tip amplitudes (24 and 108 µm) and three pulse durations were evaluated (5, 10, and 15 s) for the acoustic frequencies tested. Sonication at 20 kHz of frequency significantly reduced crystal size, increased (p < 0.05) elasticity (435.9 ± 173.3–80,218 ± 15,384 Pa) and SFC (0.2 ± 0.0–4.5 ± 0.4%). No significant difference was observed in the crystallization behavior of these samples when sonicated at different amplitudes for 5 and 10 s. The crystallization behavior was significantly delayed (p < 0.05) in samples sonicated using 108 µm amplitude for 15 s. Larger crystals were formed in samples sonicated at 40 kHz compared to those obtained with 20 kHz and lower SFC (3.7 ± 0.0%) and elasticity (3943 ± 1459 Pa) values were obtained. High-speed agitation at 24,000 rpm increased SFC (5.5 ± 0.1%) and crystallized area and decreased the elasticity (42,602 ± 11,775 Pa) compared to the samples sonicated at 20 kHz.

The effects of high-intensity ultrasound application (HIU-20 kHz, 96 W, 3 pulses: 10 s on/5s off) and cooling rate (0.1 and 10 °C/min) on physical properties of monoglycerides (MG) oleogels (3, 4.5, and 6 wt%) were evaluated. Oleogels melting profile, rheological and textural properties, crystal microstructure, crystal length (Lc), polymorphic behavior, oil binding capacity (OBC), and solid fat content (SFC) were determined after 24 h of storage at 5 or 25 °C. HIU caused significant changes in the MG crystallization behavior, producing a decrease in Lc and a stronger and more elastic network with higher OBC. HIU increased the adhesiveness of all samples whereas did not affect their cohesiveness. The effects of HIU application were enhanced by cooling at 0.1 °C/min and storing at 5 °C. Neither SFC nor thermal behavior were affected by HIU and the desired β' polymorphism was obtained in all oleogels. This study shows that physical properties of MG oleogels can be significantly improved by HIU application to obtain suitable fats with low level of saturated fatty acids for food applications.

Several studies have reported the use of high‐intensity ultrasound (HIU) to induce the crystallization of lipids. The effect that HIU has on lipid crystallization is usually attributed to the generation of cavities but acoustic cavitation has never been fully explored in lipids. The dynamics of a particular cavitation cluster next to a piston like emitter (PLE) in an oil was investigated in this study. The lipid systems, which are important in food processing, are studied with high‐speed camera imaging, laser scattering, and acoustic pressure measurements. A sequence of stable clusters was noted. In addition, a bifurcated streamer was detected, which exists within a sequence of clusters. This is shown to originate from two clusters on the PLE tip oscillating with a 180° phase shift in time with respect to one another. Finally, the collapse phase of the cluster is shown to involve a rapid (~10 μs) two‐stage process. These results show that the dynamics of cluster formation and collapse is driven by HIU power levels and might have implications in lipid sonocrystallization.

The objective of this study was to compare the sonocrystallization process of a palm-based fat in batch to a continuous set-up using a scraped surface heat exchanger (SSHE). The sample was crystallized at 32, 30, 28, and 26 °C (Tc). High-intensity ultrasound (HIU, 20 kHz, 12.7 mm horn, 50% amplitude, 57W) was applied using 10s pulses. After crystallization, samples were stored (48 h/25 °C) and analyzed for crystal microstructure, melting behavior, oil binding capacity (OBC), hardness, and viscoelastic properties. HIU improved all physical properties of the material when crystallized in batch at all Tc; however, SSHE at 26 °C was the only condition improved by HIU. G’ and hardness were the highest in sonicated SSHE samples crystallized at 26 °C (141 kPa, 4.5N) and these values were higher than the ones obtained in batch. OBC was also improved in sonicated SSHE samples (77%) but in lower magnitude compared to the OBC obtained in batch (82%). Crystal size was not affected by HIU in the SSHE, but a reduction in crystal size was observed due to HIU in batch for all Tc. Similar behavior was observed for Tp, however, Ton and ΔH were not affected by HIU.

The objective of this study was to induce crystallization in enzymatically interesterified fats (IE) with 20 and 30% palmitic acid at the sn-2 position using high intensity ultrasound (HIU). The physical blends (PB) used to prepare these two IE were consisted of tripalmitin and high oleic sunflower oil and contained 13.2 and 27.1% tripalmitin, respectively. Crystallization behavior of IE was compared with PB at supercoolings of 9, 6 and 3 °C. Results show that the melting point, SFC, and crystallization rate of PB were higher than IE and were driven mainly by tripalmitin content. HIU induced crystallization and generated small crystals in the IE samples. At 9 °C supercooling, sonication did not increase the viscosity of IE C16:0 20%, while that of the IE C16:0 30% increased significantly from 192.4 ± 118.9 to 3297.7 ± 1368.6 Pa·s. The elastic modulus (G’) for IE C16:0 30% increased from 12521 ± 2739.8 to 75076.7 ± 18259 Pa upon sonication at 9 °C supercooling, while the G’ of the IE C16:0 20% did not increase. Similar behavior was observed for the other supercoolings tested. This research suggests that HIU can improve the functional properties of IE with low content of C16:0 creating more viscous and elastic materials. These fats with low C16:0 content and improved functional properties could be used as trans-free fat alternatives.

The objective of this research is to evaluate the crystallization behavior of coconut oil (CO) and palm olein (PO) as affected by the addition of two monoacylglycerols (MAG) emulsifiers and by the use of high intensity ultrasound (HIU). MAG with high content of palmitic, oleic, and linoleic acid (EM1) and MAG with high content of stearic acid and no unsaturated fatty acids (EM2) were used. Results show that the addition of emulsifiers did not affect crystallization kinetics of CO and similar solid fat contents (1.32 ± 0.94) (SFC) and melting enthalpies (5.90 ± 4.56) were obtained. The addition of EM1, however, significantly delayed the crystallization of PO as evidenced by a significantly lower SFC and melting enthalpy. SFC for PO was 8.56 ± 0.913 while SFC for PO + EM1 was 3.63 ± 1.38. Sonication induced the crystallization of CO samples crystallized with and without EM1 and EM2 while only induced the crystallization of PO + EM1 as measured with SFC. The induction in crystallization by HIU was also evidenced by higher enthalpy with values up to a range of 8 J/g to 11 J/g. A decrease in elasticity from 3.17 × 106 to 2.52 × 105 was observed in CO crystallized with emulsifiers which could be reverted by the application of HIU. Contrarily, the addition of emulsifiers increased elasticity of PO from 3.35 × 102 to 4.83 × 104 and sonication did not affect these values significantly. Differences observed in elasticity values are attributed not only to the amount of solid material obtained but also to the type of microstructure of the crystalline network formed during crystallization.

The objective of this work was to introduce high-intensity ultrasound (HIU) in different positions within a scraped surface heat exchanger (SSHE) and evaluate the crystallization behavior and physical properties of a low saturated, soybean-based fat. The SSHE in this study was composed of one pump (flow rate of 11 L/h), two crystallization barrels (32 °C, 344 rpm), and one pin worker (208 rpm). HIU was placed before the first crystallization step, or barrel 1 (HIU-0), between the two barrels (HIU-1), between barrels 2 and the pin worker (HIU-2) and after complete crystallization in the SSHE (HIU-3). HIU amplitudes of 20% or 50% using 5-s pulses were used. Physical properties of the crystallized material such as microstructure, solid fat content, oil binding capacity (OBC), viscoelasticity, hardness, and melting behavior were evaluated. HIU induced crystallization and improved all physical properties when positioned at HIU-2 and HIU-3 using 50% amplitude, but in HIU-3 the effect was more pronounced than in HIU-2. Samples sonicated using 50% amplitude at HIU-3 position showed the following improvements (p

The physical qualities of butter are affected by the physical properties of the cream used to make it. The objective of this study was to evaluate the effect of high-intensity ultrasound (HIU) on the physical properties of cream and butter. High-intensity ultrasound (frequency: 20 kHz, amplitude: 108 µm), often called sonication, was applied for 0, 10, 30, 60, and 90 s using a 1.27-cm-diameter tip to heavy cream (40% fat; 300 g) that was aged at 7.5°C with low agitation (40 rpm) for 90 min. Sonicated cream was churned at 7.5°C until butter grains were formed. The solid fat content (SFC), melting behavior, and average fat droplet size of cream were measured after HIU treatment. Butter was characterized by SFC and melting behavior immediately after production and was tested for SFC, melting behavior, and hardness after storage for 24 h at 5°C. High-intensity ultrasound did not affect the average fat droplet size of cream. Sonicating cream for 30, 60, and 90 s slightly decreased SFC due to the temperature increase (2–6°C) that occurred during HIU application. Two melting peaks were observed at approximately 17 and 33°C in all the cream samples. A significantly lower peak temperature was observed in cream sonicated for 10 s compared with creams sonicated for 30 and 60 s. A relatively shorter churning time of sonicated cream compared with nonsonicated cream was observed, possibly because HIU weakens the fat globule membrane. Two melting peaks were observed in all butter samples at approximately 16 and 33°C. Treatment with HIU for 10 to 60 s significantly increased the hardness of butter. When HIU was applied to cream for 10 s, the hardest butter was obtained, with the lowest onset temperatures and highest enthalpy values for both melting peaks. Treatment with HIU for 10 s promoted crystallization of low-melting-point triacylglycerols (TAG) during churning, which resulted in a harder material. Significantly lower enthalpy values for the high-melting-fraction TAG were observed in butters treated with HIU for 60 and 90 s compared with non-HIU-treated butter, which suggests that a longer duration of HIU promotes melting of high-melting-point TAG. The hardness of butter was correlated with the enthalpy values of the low-melting fraction and with total enthalpy values of fresh butter. However, further crystallization occurred in the butter during 24 h of storage at 5°C, and all differences in enthalpy values disappeared. In conclusion, exposure of cream to HIU can be used to modify the physical properties of butter, and the effects of HIU depend on the length of HIU treatment.

The objective of this research was to evaluate the physical properties of different types of wax/oil systems. Olive (OO), corn (CO), soybean (SBO), sunflower (SFO), safflower (SAFO), and canola (CAO) oils were mixed with sunflower oil wax (SFOW), paraffin wax (PW), and beeswax (BW) at different concentrations (1% to 10%). Results from this study show that the physical properties of wax/oil systems is affected not only by the concentration and type of wax used, but also by the type of oil used. In general, wax/oil systems formulated with SFOW generated crystalline networks with high enthalpies (1 to 22 J/g) and high G' values (2 to 6 × 10(6) Pa) compared with the values obtained for BW and PW. SFOW crystalline networks were characterized by needle-like crystals independently of the wax concentrations and type of oil used. BW crystalline networks, however, were characterized by different crystal morphologies (needle-like or spherulites) depending on the wax concentration and type of oil used. PW samples were characterized by a crystalline network formed by needle- and platelet-like crystals. Enthalpy values of BW and PW samples were similar (0.3 to 20 J/g), but BW samples resulted in significantly higher (P < 0.05) G' values in the 5% and 10% samples with values of 3.9 × 10(6) and 6.1 × 10(5) Pa for 10% BW and PW, respectively.

The objective of this research was to evaluate the effect of high-intensity ultrasound (HIU) and crystallization temperature (T c) on the crystallization behavior, melting profile, and elasticity of a soft stearin fraction of high-stearic high-oleic sunflower oil. Results showed that HIU can be used to induce and increase the rate of crystallization of the soft stearin with significantly higher SFC values obtained in the sonicated samples, especially at higher T c. SFC values were fitted using the Avrami model, and higher k n and lower n values were obtained when samples were crystallized with sonication, suggesting that sonicated samples crystallized faster and through an instantaneous nucleation mechanism. In addition, the crystal morphology, melting behavior, and viscoelasticity were significantly affected by sonication.

Cavitation clusters and streamers are characterised in lipid materials (specifically sunflower oil) and compared to water systems. The lipid systems, which are important in food processing, are studied with high-speed camera imaging, laser scattering and pressure measurements. In these oils, clusters formed at an aged (roughened) tip of the sound source (a piston like emitter, PLE) are shown to collapse with varied periodicity in relation to the drive amplitude employed. A distinct streamer (an area of increased flow emanating from the cavitation cluster) is seen in the lipid media which is collimated directly awayfrom the tip of the PLE source whereas in water the cavitation plume is visually less distinct. The velocity of bubbles in the lipid streamer near the cluster on the order of 10 m s-1. Local heating effects, within the streamer, are detected using a dual thermocouple measurement at extended distances. Viscosity, temperature and the outgassing within the oils are suggested to play a key role in the streamer formation in these systems.

High-intensity ultrasound (HIU) was used in a continuous system to change the crystallization behavior of palm oil. Different power levels (75, 110, and 180 W) and pulse durations (continuous application and 5, 10, and 15 s pulses) were used to optimize sonication conditions. Results showed that HIU applied at low power level (75 W) was the most efficient condition in inducing palm oil crystallization at 35 °C, generating a crystalline network with higher solid fat content (SFC), higher elasticity, and sharper melting profile after 60 min of crystallization. Changes in elasticity observed as a consequence of sonication were maintained after tempering the samples at 25 °C for 24 h, but were lost after tempering at 5 °C. No significant differences (α = 0.05) were observed in SFC values of the sonicated and nonsonicated samples after tempering, whereas the sharper melting behavior observed in the sonicated sample was maintained after tempering.

The objective of this study was to evaluate the effect of wax concentration (0.5 and 1%), cooling rate (0.1, 1, and 10 °C/min), and high-intensity ultrasound (HIU) on the crystallization behavior of beeswax (BW) in six different edible oils. Samples were crystallized at 25 °C with and without HIU. Crystal sizes and morphologies and melting profiles were measured by microscopy and differential scanning calorimetry, respectively, after 7 days of incubation. Higher wax concentrations resulted in faster crystallization and more turbidity. Phase separation was observed due to crystals' sedimentation when samples were crystallized at slow cooling rates. Results showed that HIU induced the crystallization of 0.5% BW samples and delayed phase separation in sunflower, olive, soybean, and corn oils. Similar effects were observed in 1% samples where HIU delayed phase separation in canola, soybean, olive, and safflower oils.

The effect of the stearic sucrose ester (SE) S-170 on crystallization behavior and polymorphism of two stearins obtained from a new variety of high stearic high oleic sunflower oil was studied by pulsed nuclear magnetic resonance (p-NMR), small (SAXS) and wide (WAXS) angle X-ray scattering using synchrotron light and differential scanning calorimetry (DSC). p-NMR studies showed that there is always a crystallization temperature below which SE S-170 accelerated crystallization and above which SE S-170 delayed nucleation and growth. The effect of SE S-170 strongly depended on supercooling. It was efficient as a seed for high supercooling (low crystallization temperatures) but this efficiency diminished at low supercooling (temperatures close to the melting point) when few crystals were formed. SAXS and WAXS results demonstrated that depending on crystallization temperature SE S-170 promoted crystallization of α and β forms with more polymorphic similarity and inhibited occurrence of β′ forms especially the β′2 polymorph. However, in some conditions SE S-170 favored crystallization of β′1 polymorph. DSC experiments showed that SE S-170 significantly diminished total melting enthalpies when the effect was a delay in crystallization. For other conditions no significant differences were found in melting temperatures or total melting enthalpies. When stearins were stored at 25 °C, crystallization in the β2 form was promoted. Depending on crystallization temperature, polymorphic forms β′1 and β2 may be obtained as the main polymorphic forms. This is very relevant from the technological point of view. Depending on the application, SE S-170 may help obtain the required polymorphic form: β′1 form for spreads and β2 polymorph for chocolate production. Fil: Rincón Cardona, Jaime A.. Universidad Nacional de San Martín. Instituto de Investigación E Ingeniería Ambiental; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Tecnologia En Polimeros y Nanotecnologia; Argentina Fil: Agudelo Laverde, Lina Marcela. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Tecnologia En Polimeros y Nanotecnologia; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Tecnologia En Polimeros y Nanotecnologia; Argentina Fil: Martini, Silvana. State University Of Utah; Estados Unidos Fil: Candal, Roberto Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental; Argentina Fil: Herrera, Maria Lidia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de Los Materiales, Medioambiente y Energía; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Tecnologia En Polimeros y Nanotecnologia; Argentina

The objective of this work was to evaluate the effect of high intensity ultrasound (HIU) on the physical properties of a commercial shortening crystallized at a constant temperature and during temperature cycling at two different cooling rates (0.5 and 1 °C/min). Different ultrasound power levels and different durations were evaluated during crystallization at a constant temperature and the best conditions were used to evaluate the effect of HIU during temperature cycling. The physical properties tested were crystal microstructure, viscoelasticity, and melting profile. Results show that HIU is more efficient at changing crystal microstructure when used at 20 °C using a 1/2″ tip. No difference was found on the microstructure of the crystals formed when different durations of ultrasound exposure were tested. A significant increase (p

A low saturated shortening (IES) was treated with high intensity ultrasound (US) to generate small lipid crystals and harder materials. IES samples were crystallized at 32 °C and tempered for 48 h at 5 and 25 °C. US-treated and non US-treated IES were used to produce baked products such as cakes, cookies, and pie crust. US-treated IES decreased (p

Physical blends (PB) of high oleic sunflower oil and tristearin with 20 and 30% stearic acid and their interesterified (IE) products where 20 and 30% of the fatty acids are stearic acid at the sn-2 position crystallized without and with application of high intensity ultrasound (HIU). IE samples were crystallized at supercooling temperatures (ΔT) of 12, 9, 6, and 3 °C while PB were crystallized at ΔT = 12 °C. HIU induced crystallization in PB samples, but not in the IE ones. Induction in crystallization with HIU was also observed at ΔT = 6 and 3 °C for IE C18:0 20 and 30% and at ΔT = 9 °C only for the 30% samples. Smaller crystals were obtained in all sonicated samples. Melting profiles showed that HIU induced crystallization of low melting triacylglycerols (TAGs) and promoted co-crystallization of low and high melting TAGs. In general, HIU significantly changed the viscosity, G′, and G″ of the IE 20% samples except at ΔT = 12 °C. While G′ and G″ of IE 30% did not increase significantly, the viscosity increased significantly at ΔT = 9, 6, and 3 °C from 1526 ± 880 to 6818 ± 901 Pa.s at ΔT = 3 °C. The improved physical properties of the sonicated IE can make them good contenders for trans-fatty acids replacers.

The objective of this study is to analyze the physical properties of 2.5% (wt. basis) binary wax in soybean oil (SBO) system. Differential scanning calorimetry, pulsed nuclear magnetic resonance, rheology, and polarized light microscopy were used to measure melting profiles, solid fat content, viscoelastic parameters, and crystal morphology, respectively. Binary blends were prepared using beeswax (BW), rice bran wax (RBW), and sunflower wax (SFW) in 0, 20, 50, 80 and 100% proportions. Melting behavior of binary waxes was significantly affected by the type and proportion of wax used. Melting Ton and Tp for RBW/SFW and RBW/BW blends were significantly higher than those observed for SFW/BW. Enthalpy values suggest that different molecules present in the wax affect intermolecular interactions in the binary blends by either inducing (SFW/BW) or delaying (RBW/BW) crystallization. Iso-solid diagrams show that there is certainly a softening effect when different proportions of RBW/BW and SFW/BW are used, while a solid solution is formed in RBW/SFW systems. Viscoelastic parameters (G', G″) results show that RBW has the highest G' value (3.1×104±1×103Pa) followed by SFW (2.7×104±0.2×104Pa) and BW having the lowest (90.7±74.4Pa). Higher G' values in all proportions of RBW/SFW binary system in SBO indicate significantly more solid-like behavior than any other combinations. However, blending of two different waxes does not necessary result in a linear increase in elastic properties and in some cases no changes in elasticity is observed as the amount of the high melting wax is added to the low melting one.

The objective of the present research was to monitor bubble and crystal formation in lipids during high-intensity insonation. High-intensity ultrasound was generated with a 20-kHz probe. Bubble and crystal formations were recorded using a low-intensity ultrasound spectrometer operating at 1 MHz central frequency. Bubble formation was monitored in soybean oil (SBO) during insonation for different time periods (5, 10 and 60 s) and at different temperatures (22, 24, 26, 28, and 30 °C). Ultrasound attenuation due to the presence of bubbles was observed in all conditions tested. Attenuation increased with temperature and at intermediate frequencies (1 MHz). In addition, the presence of bubbles was detected after insonation was stopped, particularly for SBO sonicated for 60 s at 30 °C. Low-intensity ultrasound spectroscopy was used to monitor the crystallization behavior of interesterified SBO. The acoustic velocity increased during crystallization, but significantly decreased during insonation.

High intensity ultrasound (HIU) was used to change the crystallization behavior, generate small crystals, and improve the texture of a low saturated shortening (interesterified soybean oil). Samples were crystallized at different temperatures (26, 28, 30, and 32 °C) without and with the application of HIU. Different acoustic power levels (110, 72, 61, 54, and 44 W) were used. Results show that higher acoustic powers had a greater effect on crystal size reduction, induced crystallization, and generated harder, more elastic and viscous materials. These effects were more significant when HIU was applied in the presence of crystals and when the sample was crystallized at 32 °C.

The objective of this study was to evaluate the stability and flavour intensity of docosahexaenoic acid (DHA)-fortified emulsions as affected by processing temperature (−5 and −10 °C) and oil content (20% and 40% oil-in-water emulsions). The emulsions’ physical stability was measured using backscattering measurements. Flavour attributes, such as oxidised, rancid, fishy and buttery, were quantified using a descriptive panel. For all conditions, DHA-fortified emulsions had a significantly higher fishy flavour; and flavour intensities were higher for emulsions crystallised at −10 °C than for emulsions crystallised at −5 °C. These differences were significant ( P

Ultrasound has been used for the last 50 y in different processing applications. Depending on the power and frequency of the sound waves, ultrasound techniques can be classified in different categories. Low-intensity ultrasound uses high frequencies in the range of 100 kHz to 10 MHz and is mostly used for therapeutic purpose (frequencies between 1 and 10 MHz) and to passively monitor the characteristics of materials (frequencies between 100 kHz and 10 MHz). High-intensity ultrasound (HIU), on the other hand, uses lower frequencies in the range of 20 to 100 kHz and it is commonly used for cleaning, disrupting, and restructuring materials. The objective of this study is to evaluate the effect of HIU on functional properties of anhydrous milk fat (AMF), palm kernel oil (PKO), and an all-purpose shortening (Sh). Results from this research shows that HIU induced primary and secondary nucleation in the lipid, generating smaller crystals and as a consequence harder materials. HIU affected hardness more efficiently when applied at higher crystallization temperatures (26 and 28 degrees C) as shown for AMF data, and when the sonication was applied after the first crystals were formed as observed for PKO and Sh systems. In addition to changes in hardness, AMF and Sh networks obtained after sonication were characterized by a steeper and sharper melting profile. This research shows that HIU can be used as an additional processing tool to tailor the functional properties of lipids with the potential to be used in the processing of trans-free shortenings.

The effect of cooling rate on the destabilization of oil-in-water (o/w) emulsions was studied as a function of oil content (20% and 40% o/w), homogenization conditions, and crystallization temperatures (10, 5, 0, −5 and −10 °C). The lipid phase was a mixture of anhydrous milk fat and soybean oil, and whey protein was used as the emulsifier. Differential scanning calorimetry was used to analyze the crystallization and melting behaviors; while a vertical scan macroscopic analyzer measured the physicochemical stability. Slow cooling rate increased the stability of emulsions with 20% oil. In addition, slow cooling promoted the onset of crystallization and delayed crystal growth. These effects were more significant in emulsions formulated with 20% oil and formulated under processing conditions that resulted in bigger droplet sizes (∼0.9 μm).

The destabilisation mechanism of oil-in-water (o/w) emulsions was studied as a function of oil content (20% and 40% o/w), homogenisation conditions and crystallisation temperatures (10, 5, 0, −5 and −10 °C). A mixture of anhydrous milk fat and soya bean oil was used as the lipid phase and whey protein isolate (2 wt%) as emulsifier. Crystallisation and melting behaviours were analysed using differential scanning calorimetry. Physicochemical stability was measured with a vertical scan macroscopic analyser. Emulsions with 20% oil were found to be less stable than those with 40% oil. For 20% o/w emulsions, the crystallisation was delayed and inhibited in emulsions with smaller droplets and promoted in emulsions with larger droplets when compared with 40% o/w emulsions. Depending on the droplet sizes in the emulsion, the formation of lipid crystals (in combination with the emulsifier) either stabilises (small droplets) or destabilises (big droplets) the emulsion.

Physicochemical characteristics of lipid-based foods depend, among other factors, on the microstructure and the characteristics of the lipid network formed during crystallization. The objective of this study, was to evaluate the effect of the addition of sunflower oil waxes on the crystallization and melting behavior of anhydrous milk fat (AMF), a lipid with a low content of palmitic and trans-fatty acids. The crystallization and melting behavior of AMF alone and with the addition of 0.25 and 0.5% of waxes was studied using a differential scanning calorimeter. The morphology of the crystallized samples was evaluated with a polarized light microscope. The addition of waxes induced and promoted the crystallization of AMF at high temperatures (>25 °C) as evidenced by lower induction times of crystallization and higher crystallization and melting enthalpies. In addition, smaller crystals and different morphologies were obtained when AMF was crystallized with the addition of waxes. These results suggest that waxes could be used as an additive to modify lipid networks and their physicochemical characteristics, such as texture, smoothness and mouthfeel. © 2008 AOCS. Fil: Martini, Silvana. State University of Utah; Estados Unidos Fil: Carelli Albarracin, Amalia Antonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina Fil: Lee, Jiwon. State University of Utah; Estados Unidos

The quality of shortenings, such as solid fat content (SFC) and texture, strongly depends on temperature fluctuations during storage and handling. The quality of a shortening might be affected not only by temperature fluctuations but also by its chemical composition and the presence of emulsifiers. The objective of this work was to investigate the effect of emulsifier addition and storage conditions on the texture, thermal behavior and SFC of low-trans shortenings formulated with palm oil, palm kernel oil, and vegetable oils such as sunflower and soybean oils. Several conclusions can be drawn from this study: (a) The crystallization behavior of fat blends strongly depends on the type of emulsifier used and the chemical composition of the sample; (b) the addition of emulsifiers affects not only the type of crystals formed (fractionation) but also the amount of crystals obtained (enthalpy, SFC), inducing or delaying the crystallization process; (c) emulsifiers affect the texture of the crystalline structure formed by making it softer; (d) the storage conditions affect both the texture and the SFC of the materials. This study shows that samples that are highly super-cooled during storage become harder while samples that are less super-cooled become softer with storage conditions.

High-intensity ultrasound (HIU) has been used in recent years to change the crystallization behavior of edible lipids. This technique can be used in combination with other processing technologies to tailor lipids' functional properties and broaden their application for various food products. In general, sonication induces crystallization, increases crystallization rate, and generates a harder and more elastic crystalline network characterized by smaller crystals with a sharper melting profile. An important application of HIU is to improve the hardness and elasticity of shortenings that have a low content of saturated fatty acids and are free of trans-fats. This review summarizes recent research that used HIU to change the physical and functional properties of edible lipids and focuses on the importance of controlling processing variables such as sonication power level and duration and crystallization temperature.

This study investigated the effects of high intensity ultrasound (temperature, amplitude, and time) on the inactivation of indigenous bacteria in pasteurized milk,Bacillus atrophaeusspores inoculated into sterile milk, andSaccharomyces cerevisiaeinoculated into sterile orange juice using response surface methodology. The variables investigated were sonication temperature (range from 0 to 84°C), amplitude (range from 0 to 216 μm), and time (range from 0.17 to 5 min) on the response, log microbe reduction. Data were analyzed by statistical analysis system software and three models were developed, each for bacteria, spore, and yeast reduction. Regression analysis identified sonication temperature and amplitude to be significant variables on microbe reduction. Optimization of the inactivation of microbes was found to be at 84.8°C, 216 μm amplitude, and 5.8 min. In addition, the predicted log reductions of microbes at common processing conditions (72°C for 20 sec) using 216 μm amplitude were computed. The experimental responses for bacteria, spore, and yeast reductions fell within the predicted levels, confirming the accuracy of the models.

Polymorphism and growth behavior of blends of a high-melting fraction of milk fat (HMF) and sunflower oil (SFO) formulated with and without the addition of sucrose esters (SE) P-170, P-1670, and S-170 were studied by pulsed 1H NMR spectroscopy, X-ray diffraction, and polarized light microscopy. The effect of SE on the solid content maximum (Smax) or crystallization rate was observed only at low supercooling (values of ΔT below 15°C). The Avrami kn decreased as n values increased, indicating that SE inhibited growth and impeded nucleation. Addition of SFO modified the polymorphic behavior of milk fat, most likely owing to the increase in the C54 fraction (mostly 18∶1 cis) in crystals composition. P-170 and S-170 modified the polymorphic behavior of HMF when it crystallized in the α-form or in blends with up to 40% SFO at all crystallization temperatures (Tc) selected. Addition of P-170 and S-170 favored crystallization in the β′-form, and the appearance of the β-form was delayed. P-1670 had no effect on polymorphism. When HMF and the blends were crystallized under dynamic conditions, addition of P-170 and S-170 markedly decreased crystal sizes. P-1670, however, showed no effect on microstructure.

The influence of structure on the water vapor permeability (WVP) of fat films was determined in this study. Statistically significant (P < 0.1) correlations were found between WVP and chemical composition (% stearic acid), the Avrami index (n), the half-time of crystallization (t1/2), the maximum solid fat content, and crystalline domain size determined by powder X-ray diffraction (XS). Larger domain sizes translate into a smaller grain boundary surface area through which water vapor can migrate, resulting in a lower WVP. High values of XS were associated with fats with high SFC and stearic acid contents. These fats also crystallize rapidly, with low n and t1/2 values.

Crystallization studies are usually performed under isothermal conditions. Kinetic parameters characterizing the isothermal nucleation and growth processes can be obtained using classical nucleation and growth models. However, crystallization regimes found in nature, as well as those used in food and pharmaceutical processing, are rarely isothermal. Focusing on the nucleation stage, the approach followed in this work was to define a new parameter to characterize the driving force of nucleation, the supercooling-time exposure (β), which not only depends on the difference between the melting temperature (Tm) and the onset temperature of nucleation (Tc) ΔTc but also on the induction time of nucleation, tc, and therefore the cooling rate (φ), namely, β = (1/2)ΔTctc = ΔTc2/2φ. An exponential probability density function of the values of β was utilized to model changes in nucleation rate as a function of β in the form J/Jmax =ke -k√β . From this parametrization procedure, the energy of activation for the nucleation process in palm oil, milkfat, and other palm oil based fats could be estimated.

The effect of highly hydrophobic emulsifiers, the palmitic sucrose ester P-170 (hydrophilic/lipophilic balance (HLB) = 1.0), the stearic sucrose ester S-170 (HLB = 1.0), the polyglycerol ester decaglycerol decastearate DAS 7S (HLB = 3.7) and the polyglycerol ester decaglycerol dodecabehenate DDB 750 (HLB = 2.6), on the nucleation of a high melting point milk fat fraction (HMF) and its blends with sunflower oil (SFO) was investigated by polarized laser light turbidimetry, X-ray diffractometry and polarized light microscopy (PLM). Addition of polyglycerol esters accelerated nucleation, giving shorter induction times for the same supercooling. On the contrary, sucrose esters inhibited nucleation since induction times were elongated in all conditions selected. Addition of emulsifiers modified the polymorphic behavior in the blends with SFO. The β' form was promoted especially with the addition of S-170. DAS 7S and DDB 750 promoted crystallization. PLM images showed many small crystals that did not appear in HMF images. Addition of P-170 and S-170 delayed nucleation and inhibited crystal growth. Crystals were notoriously smaller than the ones that appeared in HMF images. The Fisher–Turnbull model was used to calculate activation free energies of nucleation. In all cases, sucrose esters elevated the energy barrier for nucleation. Polyglycerol esters, however, if they had an effect on the energy barrier, lowered the values.