The heat stability of milk protein-stabilized oil-in-water emulsions: A review

Soy protein particles as stabilizers of heat-stable O/W emulsions with 20% protein content

In response to the increasing demand for nutritionally rich foods, consumer preference for protein-enriched beverages has grown. However, heat-induced protein aggregation and gelation significantly hinders the production of high-protein drinks. In this study, oil-in-water (O/W) emulsions with exceptional thermal stability were formulated using modified soy protein particles (MSPs). These MSPs effectively resisted gel formation, even at a protein concentration of up to 20% (w/v). In contrast, emulsions prepared with untreated soy proteins (SPs) experienced pronounced gelation under identical conditions. The compact structure of MSPs, in comparison to SPs, imparted resistance to heat-induced denaturation and aggregation. Additionally, the emulsion displayed heightened heat processing insensitivity, due to the enhanced hydrophobicity of MSPs and their rapid adsorption at the oil-water interface, resulting in a denser, more elastic, and resilient interfacial film. These findings provide practical insights for the formulation of protein-rich milk alternatives, meeting the evolving market demands.

Fabrication of cinnamon essential oil nanoemulsions with high antibacterial activities via microfluidization

The high volatility and hydrophobicity of cinnamon essential oils (CiEO) limited their practical application. To enhance their stability and antibacterial activity, nanoemulsions encapsulating CiEO were prepared using hydroxypropyl-β-cyclodextrin/lauroyl arginate (HPCD/LAE) inclusion complexes through high-pressure microfluidization (HPM). Effects of HPM parameters on the stability and antibacterial properties of nanoemulsion were investigated. Results revealed that increased processing pressure and cycle numbers were associated with reduced droplet size and greater homogeneity in CiEO distribution. Storage and thermal stability were optimized at 100 MPa and seven cycles. Moreover, the nanoemulsions showed strong synergistic antibacterial against E. coli (19.79 mm) and S. aureus (23.61 mm) compared with LAE (11.52 mm and 12.82 mm, respectively) and CiEO alone (13.26 mm and 17.68 mm, respectively). This study provided new information for constructing CiEO nanoemulsion, which is suitable for use in the food industry.

Combination of legume proteins and arabinoxylans are efficient emulsifiers to promote vitamin E bioaccessibility during digestion

The emulsification potential of plant-based emulsifiers, that is, pea (PPI) and lentil (LPI) proteins (4%), corn arabinoxylans (CAX, 1%), and legume protein-arabinoxylan mixtures (4% proteins + 0.15 or 0.9% CAX), was evaluated by assessing: the surface tension and potential of emulsifiers, emulsifier antinutritional contents, emulsion droplet size, emulsion physical stability, and vitamin E bioaccessibility from 10% oil-in-water emulsions. Tween 80 (2%) was used as a control. All emulsions presented small droplet sizes, both fresh and upon storage, except 4% LPI + 0.9% CAX emulsion that exhibited bigger droplet sizes (d(4,3) of approximately 18.76 μm vs 0.59 μm for the control) because of droplet bridging. Vitamin E bioaccessibility from emulsions stabilized with the combination of 4% PPI and either 0.15% or 0.9% CAX (28 ± 4.48% and 28.42 ± 3.87%, respectively) was not significantly different from that of emulsions stabilized with Tween 80 (43.56 ± 3.71%), whereas vitamin E bioaccessibility from emulsions stabilized with individual emulsifiers was significantly lower.

Effect of non-covalent binding of tannins to sodium caseinate on the stability of high-internal-phase fish oil emulsions

In this study, we designed the noncovalent binding of sodium caseinate (SC) to tannic acid (TA) to stabilize high internal phase emulsions (HIPEs) used as fish oil delivery systems. Hydrogen bonding was the dominant binding force, followed by weak hydrophobic interaction and weak van der Waals forces, as demonstrated by FTIR, fluorescence spectroscopy, and molecular docking experiments, with a binding constant of 3.25 × 106, a binding site of 1.2, and a static quenching of the binding. Increasing SC:TA from SC to 2:1 decreased the particle size from 107.37 ± 10.66 to 76.07 ± 2.77 nm and the zeta potential from -6.99 ± 2.71 to -22 ± 2.42 mV. TA increased the interfacial tension of SC, decreased the surface hydrophobicity from 1.3 × 104 to 1.6 × 103 and improved the oxidation resistance of SC. The particle size of high internal phase emulsions stabilized by complexes with different mass ratios (SC:TA from 1:0 to 2:1) increased from 4.9 ± 0.02 to 12.9 μm, the potential increased from -32.37 ± 2.7 to -35.07 ± 2.58 mV, and the instability index decreased from 0.75 to 0.02. Thicker interfacial layers could be observed by laser confocal microscopy, and an increase in the storage modulus indicated a formation of a stronger gel network. SC:TA of 1:0 showed emulsion breakage after 14 d of storage at room temperature. SC:TA of 2:1 showed the lowest degree of oil-water separation after freeze-thaw treatment. Especially, the most stable high endo-phase emulsion (at SC:TA of 2:1) prepared at each mass ratio was selected for further stability exploration. The emulsion particle size increased only from 15.63 ± 0.06 to 22.27 ± 0.35 μm at salt ion concentrations of 50-200 mM and to 249.33 ± 31.79 μm at 300 mM. The instability index and storage modulus of the high endo-phase emulsions increased gradually with increasing salt ion concentrations. At different heating temperatures (55-85 °C), the instability index of the high internal phase emulsion gradually decreased and the storage modulus gradually increased. Meanwhile, at 50 °C for 15 d of accelerated oxidation, the content of hydroperoxide decreased from 53.32 ± 0.18 to 37.48 ± 0.77 nmol/g, about 29.7 %, and the thiobarbituric acid value decreased from 1.06 × 103 to 0.8 × 103, about 24.5 %, in the high endo-phase emulsions prepared by 2:1 SC:TA compared to the fish oils, and the SC-stabilized high endo-phase only emulsion broke at the sixth day of oxidation. From the above findings, it was concluded that the high internal phase emulsion prepared with SC:TA of 2:1 can be used as a good delivery system for fish oil.

Application of legumes in plant-based milk alternatives: a review of limitations and solutions

In recent years, a global shift has been observed toward reducing the consumption of animal-derived foods in favor of healthier and more sustainable dietary choices. This has led to a steady growth in the market for plant-based milk alternatives (PBMAs). Projections suggest that this market will reach a value of USD 69.8 billion by 2030. Legumes, being traditional and nutritious ingredients for PMBAs, are rich in proteins, dietary fibers, and other nutrients, with potential health benefits such as anticancer and cardiovascular disease prevention. In this review, the application of 12 legumes in plant-based milk alternatives was thoroughly discussed for the first time. However, compared to milk, processing of legume-based beverages can lead to deficiencies such as nutritional imbalance, off-flavor, and emulsion stratification. Considering the potential and challenges associated with legume-based beverages, this review aims to provide a scientific comparison between legume-based beverages and cow's milk in terms of nutritional quality, organoleptic attributes and stability, and to summarize ways to improve the deficiencies of legume-based beverages in terms of raw materials and processing method improvements. In conclusion, the legume-based beverage industry will be better enhanced and developed by improving the issues.

The role of polysaccharides in improving the functionality of zein coated nanocarriers: Implications for colloidal stability under environmental stresses

Zein has gained popularity over the past few years as an incredible food and bio-based materials. The potential functions and health benefits of zein microcapsules or micro-/nanoparticles in bioactive components delivery, structured emulsion, etc., have received great attention. However, the development has been limited by colloidal destabilization, especially when thermal processing is involved. There is a recent trend in developing zein-polysaccharide complexes (ZPCs), which has tremendously improved the performance of zein-based colloidal carrier systems or emulsions. Increasing our understanding of zein interactions and their contribution to the structure of various macromolecules can help us to develop novel biomaterials that can be used in food, agriculture, biomedicine, and cosmetics. In addition, these nanocarriers are suitable for the encapsulation and delivery of bioactive compounds which have positive perspective in food industry. Therefore, this article aimed to review recent advances in the ZPCs that can be applied to functional or health-promoting foods, with a focus on the characteristics of different ZPCs, factors and mechanisms affecting the stability (especially thermal stability) of these complexes, and their application in food industry as a carrier for BCs. Further, the stability of ZPCs based emulsions under processing and physiological environments, as well some typical effective methods are introduced. Also, the principal challenges and prospects were enumerated and discussed.

A comprehensive review on infant formula: nutritional and functional constituents, recent trends in processing and its impact on infants' gut microbiota

Human milk is considered the most valuable form of nutrition for infants for their growth, development and function. So far, there are still some cases where feeding human milk is not feasible. As a result, the market for infant formula is widely increasing, and formula feeding become an alternative or substitute for breastfeeding. The nutritional value of the formula can be improved by adding functional bioactive compounds like probiotics, prebiotics, human milk oligosaccharides, vitamins, minerals, taurine, inositol, osteopontin, lactoferrin, gangliosides, carnitine etc. For processing of infant formula, diverse thermal and non-thermal technologies have been employed. Infant formula can be either in powdered form, which requires reconstitution with water or in ready-to-feed liquid form, among which powder form is readily available, shelf-stable and vastly marketed. Infants' gut microbiota is a complex ecosystem and the nutrient composition of infant formula is recognized to have a lasting effect on it. Likewise, the gut microbiota establishment closely parallels with host immune development and growth. Therefore, it must be contemplated as an important factor for consideration while developing formulas. In this review, we have focused on the formulation and manufacturing of safe and nutritious infant formula equivalent to human milk or aligning with the infant's needs and its ultimate impact on infants' gut microbiota.

Protein interactions during dry and wet heat pre-treatment of skim milk powder (dispersions) and their effect on the heat stability of recombined filled evaporated milk

Skim milk powder (SMP) as well as aqueous dispersions were subjected to dry and wet heat pre-treatment, respectively, to improve the heat stability of recombined filled evaporated milk (RFEM) derived therefrom. However, microrheological analysis revealed that prolonged incubation caused detrimental effects on the heat stability of RFEM, which were thought to be due to protein interactions. SDS-PAGE results indicated that protein aggregation via non-disulfide covalent bonds occurred upon long-time dry or wet heat incubation. This was probably related to some Maillard reaction products, which is sustained by the increase in lactulose and protein carbonyl content. Considerable protein aggregation via disulfide bonds in the serum was found upon wet heat incubation at temperatures of at least 80 °C. Principal component analysis (PCA) revealed that the negative effects of overprocessing on the heat stability of RFEM were predominantly related to protein cross-linking via non-disulfide covalent bonds related to protein carbonylation.

Static stability of partially crystalline emulsions: Impacts of carrageenan and its blends with xanthan gum and/or guar gum

In the present study, four different combinations of gums, including carrageenan (CG), its binary blends with xanthan gum (XG) or guar gum (GG) in equal ratios, and its ternary blends with XG and GG in three equal ratios, were involved into making partially crystalline emulsions (PCEs), respectively. The freshly prepared emulsions were systematically characterized by rheological property, particle size distribution, microscopic morphology, interfacial property, and intermolecular interactions, and their emulsion stabilities were further evaluated using multiple light scattering technique and storage test. All PCEs stabilized by gum blends (CG + XG, CG + GG, and CG + XG + GG) obtained decreased apparent viscosities at 0.01 s^-1 (10.12-25.32 Pa·s), particle sizes (3.12-4.06 μm), as well as interfacial protein concentrations (22.60-27.01 mg/m²), which were much lower than those with single CG (35.98 Pa·s, 6.72 μm, and 47.74 mg/m², respectively). The microscopic morphology showed that blending CG with XG and/or GG contributed to formation of firmer three-dimensional matrix, thereby preventing the aggregation of fat droplets. Inclusion of XG and/or GG also significantly reduced contribution of hydrophobic interactions from 0.72 to 0.24-0.44 mg/mL. Both multiple light scattering and storage test revealed that emulsion instabilities were mainly manifested as a clarification at the bottom and an agglomeration at the top. PCE-CG + XG + GG exhibited superior stability with low creaming index (6.20 %) and viscosity (1180.0 mPa·s) after three months of storage. The research aims to evaluate the effects of CG and its blends with XG and GG on stability of PCEs, and the results potentially provide valuable information for manufacture of stable PCE foods.

Spray-Dried Infant Formula Emulsion Stability as Affected by Pre-Heat Treatment and Total Solids Content of the Feed

Pre-spray-drying processing may affect stability after reconstitution of emulsion-based powders, such as infant formulas. This study aimed to evaluate the effects of pasteurization temperature and total solids (TS) of the feed on the stability of the emulsions obtained from the reconstituted powders. Four infant formula powders (50%-75 °C, 50%-100 °C, 60%-75 °C, and 60%-100 °C) were produced at pilot scale, from emulsions with 50 or 60% TS pasteurized at 75 or 100 °C for 18 s. Both the emulsion feeds and the emulsions from the reconstituted powders (12.5% TS) were analyzed. The results showed that feeds with 60% TS were flocculated, as indicated by the large particle size and viscosity and the pseudoplastic behavior. Light microscopy revealed that, during spray drying, the flocs were disrupted in 60%-100 °C, while the 60%-75 °C emulsion remained flocculated, reducing its stability post-reconstitution. Although all four emulsions were mainly stabilized by caseins, the presence of β-lactoglobulin was also detected at the oil-water interface, in native state in the formulas preheated at 75 °C and aggregated in the formulas preheated at 100 °C. In conclusion, both the degree of whey protein denaturation (resulting from pasteurization) and the TS of the concentrates during infant formula production affected the emulsion stability of the reconstituted powders.

Understanding of the key factors influencing the properties of emulsions stabilized by sodium caseinate

Emulsions can be easily destabilized under various conditions during preparation and storage. Therefore, it is necessary to understand the factors that influence the stability of emulsions, which is essential for their subsequent studies. Sodium caseinate (CAS) is a well-used nutritional and functional ingredient in emulsion preparation due to its good solubility and emulsifying properties. CAS-stabilized emulsions can be considered good food emulsion delivery systems, but their applications are still limited under certain conditions due to their instability to creaming and aggregation. Therefore, the purpose of this review is to provide a complete overview of how different environmental stresses and processing conditions affect the stability of CAS-stabilized emulsions and how to improve their stability. Initially, the general properties of CAS as emulsifiers and the characterization of CAS-stabilized oil-in-water (O/W) emulsions were summarized. Second, the major instability mechanisms that operate in CAS-stabilized emulsions were presented. Furthermore, the general factors such as pH, emulsifier concentration, ionic strength, oxidation, and processing conditions, affecting the stability of CAS-stabilized O/W emulsion, were discussed. On this basis, the commonly used methods for evaluating emulsion stability are introduced. Finally, state-of-the-art strategies to improve CAS-based emulsion stability are also described and summarized. This review is expected to provide a theoretical basis for the future applications of CAS in food emulsions.

Coacervation as a Novel Method of Microencapsulation of Essential Oils-A Review

These days, consumers are increasingly "nutritionally aware". The trend of "clean label" is gaining momentum. Synthetic additives and preservatives, as well as natural ones, bearing the E symbol are more often perceived negatively. For this reason, substances of natural origin are sought tfor replacing them. Essential oils can be such substances. However, the wider use of essential oils in the food industry is severely limited. This is because these substances are highly sensitive to light, oxygen, and temperature. This creates problems with their processing and storage. In addition, they have a strong smell and taste, which makes them unacceptable when added to the product. The solution to this situation seems to be microencapsulation through complex coacervation. To reduce the loss of essential oils and the undesirable chemical changes that may occur during their spray drying-the most commonly used method-complex coacervation seems to be an interesting alternative. This article collects information on the limitations of the use of essential oils in food and proposes a solution through complex coacervation with plant proteins and chia mucilage.

Development of Millettia speciosa champ polysaccharide conjugate stabilized oil-in-water emulsion for oral delivery of β-carotene: Protection effect and in vitro digestion fate

In this study, a natural antioxidant emulsifier, Millettia speciosa Champ polysaccharide conjugates (MSC-PC), was used for fabricating oil-in-water emulsion, and the influences of MSC-PC on β-carotene stability and bioaccessibility were studied. Results suggested that MSC-PC stabilized emulsion exhibited excellent resistance to a wide range of salt levels (0-500 mM of Na⁺), thermal treatments (50-90 °C) and pH values (3.0-11.0). MSC-PC also exhibited an outstanding inhibition capacity on lipid oxidation. Besides, MSC-PC stabilized emulsion had a better protective effect on β-carotene than other systems. Interestingly, in spite of similar lipolysis extent, β-carotene bioaccessibility in MSC-PC fabricated emulsion (14.75 %) was markedly higher than that in commercial Tween 80 fabricated emulsion (10.08 %), likely due to the steric-hindrance effect and antioxidant ability of MSC-PC, building interfacial layers that prevented β-carotene from degradation. This work supplied a deep insight into elucidating the mechanisms of emulsifying performance and β-carotene protection effect of MSC-PC fabricated emulsion.

Mechanistic insights into the improved properties of mayonnaise from the changes in protein structures of enzymatic modification-treated egg yolk

Heat treatment is an important step in mayonnaise production but can affect the quality of mayonnaise because thermal treatment can accelerate oil droplet coalescence. To resolve this issue, in this study, enzymatically modified egg yolks were applied to produce mayonnaise. Egg yolk hydrolyzed with 0.2% neutral protease could effectively produce mayonnaise with superior heat stability, and this effect was attributed to enzymatic modifications that increased the degree of amino acid ionization, the overall hydrophilicity and the ability to adsorb proteins. Moreover, electrophoresis and FT-IR results showed that the enzymatically modified egg yolk proteins had a smaller molecular weight and more flexible structure, which could also favor the improved properties. The study elucidated why mayonnaise prepared by enzymatic modification-treated egg yolk has better thermal stability.

Heat treatment is an important step in mayonnaise production but can affect the quality of mayonnaise because thermal treatment can accelerate oil droplet coalescence.

Microcapsules Consisting of Whey Proteins-Coated Droplets of Lipids Embedded in Wall Matrices of Spray-Dried Microcapsules Consisting Mainly of Non-Fat Milk Solids

The effects of wall composition and heat treatment on the formation and properties of core-in-wall emulsions (CIWEs) consisting of whey protein-coated milkfat (AMF) droplets and a dispersion of non-fat milk solids (MSNF) were investigated. Microcapsules were prepared by spray drying these CIWEs. The d_3.2 of the CIWEs ranged from 0.36 to 0.54 μm. Surface excess of the CIWEs ranged from 1.39 to 6.57 mg/m², and was influenced by concentration of whey proteins and heat treatment (30 min at 90 °C). Results indicated a preferential adsorption of β-lg at the O/W interface. Whey proteins accounted for up to 90% of the proteins adsorbed at the O/W interface. The core retention during spray drying ranged from 90.3% to 97.6% and microencapsulation efficiency ranged from 77.9% to 93.3%. The microcapsules exhibited an excellent long-term oxidative stability at 20 and 30 °C that was superior to that of microcapsules consisting of milkfat and MSNF, where the O/W interface was populated mainly by caseins. The superior oxidative stability could be attributed to the formation of dense whey-proteins-based films at the O/W interfaces of the CIWEs that isolated the core domains from the environment. The results open new opportunities in developing highly stable lipids-containing microcapsules and dairy powders.

Investigation of the flowability, thermal stability and emulsification properties of two milk protein concentrates having different levels of native whey proteins

Milk protein concentrate-85 (MPC85) is a dairy ingredient which has a diverse range of applications in food products. The technofunctional properties of two MPC85 samples having similar gross composition but different levels of native whey protein (WP), i.e., MPC85S1 and MPC85S2 with 16.6 and 6.0 g native WP/100 g protein, respectively, were compared. Rheometeric analysis showed that under an applied normal stress of 1.0-15.0 kPa, the compressibility, the air permeability and the cohesiveness of MPC85S2 was higher compared to MPC85S1. Differential scanning calorimetry showed that protein denaturation in MPC85S1 began at 63 °C while for MPC85S2 it began at 70 °C. The heat coagulation time (HCT at 140 °C) for 4.2% (w/v, on a protein basis) reconstituted MPC85S1 and MPC85S2 was 2.2 and 2.7 min, respectively. While a higher lightness for MPC85S1 was evidenced using colourimeter analysis, the colour stability on oven drying at 95 °C for MPC85S2 was higher than MPC85S1. The emulsion produced with MPC85S1 flocculated after 1 d and phase separation occurred after 14 d. In the case of MPC85S2, flocculation began after 4 d while phase separation was observed at 33 d. The viscosity of MPC85S2 (4.2% (w/v) protein) was higher than MPC85S1. This study showed differences between the flowability, viscosity, colour properties, thermal stability (in powder and in reconstituted format), emulsification and buffering capacity for MPC samples having two different levels of WP denaturation. The results demonstrated that the MPCs studied having two different levels of WP denaturation could be targeted for different functional applications. The minimal/maximum level of denaturation required to induce technofunctional property differences requires further study.

Heat stability of emulsions using functionalized milk protein concentrate generated by supercritical fluid extrusion

In this study, thermostable oil-in-water emulsions containing high protein contents were developed using milk protein concentrate (MPC) that was functionalized by supercritical fluid extrusion (SCFX) processing at low temperature and shear. Functionalized MPC (f-MPC) emulsions (3% protein-80% oil and 10% protein-50% oil) were compared with emulsions stabilized by commercial MPC (c-MPC), sodium caseinate (NaCas), and a commercial mayonnaise for their emulsifying properties and heat stability at 70 and 90 °C for 30 min, and 121 °C for 15 min. Zeta-potentials and interfacial protein concentrations of f-MPC emulsions were higher than that of c-MPC emulsions. f-MPC emulsions remained stable against creaming for at least 8 weeks at room temperature (23 °C), while their c-MPC counterparts showed significant creaming at the same conditions. Even after heating at 121 °C for 15 min, f-MPC emulsions retained their structural integrity as observed from their confocal images, droplet size distributions, and viscosities. In contrast, c-MPC emulsions and mayonnaise disintegrated upon heating at 121 °C for 15 min, and oil droplets of mayonnaise partially coalesced during heating at 90 °C for 30 min. f-MPC emulsions revealed higher viscosities compared to c-MPC emulsions, providing them improved stability. Viscosities of f-MPC emulsions were not significantly affected by heating at 90 °C for 30 min, while other emulsions exhibited a substantial increase in their viscosities due to protein denaturation and aggregation. Thus, f-MPC emulsions can be utilized in the development of protein-enriched functional foods (e.g., spreads) that are stable against high heat treatments.

A molecular docking and molecular dynamics simulation study on the interaction between cyanidin-3-O-glucoside and major proteins in cow's milk

The objective of this study was to investigate the molecular interaction and complex stability of four major cow's milk (CM) proteins (α-LA, β-LG, α_s1 -CA, and β-CA) with cyanidin-3-O-glucoside (C3G) using computational methods. The results of molecular docking analysis revealed that hydrogen bond and hydrophobic interaction were the main binding forces to maintain the stability of the C3G-CM protein complexes. Molecular dynamics simulation results showed that all complexes except for C3G-α_s1 -CA were found to reach equilibrium within 50 ns of simulation. α_s1 -CA and β-CA switched to a more compact conformation after binding with C3G. Additionally, the radius of gyration, number of hydrogen bond, radial distribution function, and interaction energy showed that β-CA is the best C3G carrier protein among the four CM proteins. This study can provide valuable information for CM proteins to serve as C3G delivery carriers. PRACTICAL APPLICATIONS: Anthocyanins (ACNs) are flavonoid-based pigments that play an important functional role in regulating human's health. Cow's milk (CM) proteins are the most representative protein-based carriers that can improve the short-term bioavailability and stability of ACNs. Thus, it is important to study the interactions between ACNs and CM proteins at the molecular level for the development of effective ACNs delivery carriers. Our study showed that caseins (α_s1 -CA and β-CA) had more hydrophobic and hydrogen-bonding sites with cyanidin-3-O-glucoside (C3G) than whey proteins using computational methods. Among the four CM proteins, β-CA was the best C3G carrier protein showing the best interaction stability with C3G. Thus, it is helpful for us to screen effective ACNs carriers from multiple protein sources by computational methods.

Formation of heated whey protein isolate-pectin complexes at pH greater than the isoelectric point with improved emulsification properties

In this study, heated whey protein isolate and pectin complexes (HCPX) formed at pH > isoelectric point (pI) were used to stabilize oil-in-water emulsions containing 5% oil and 1.5% (wt%) protein at pH 5.5. The effects of pectin concentration and heating temperature on emulsification and emulsion stabilization properties were determined. The HCPX were produced by heating mixed 3% (wt) whey protein isolate and pectin (0.1 or 0.3 wt%) at pH 6.2 and 75 or 85°C for 15 min. Aggregate sizes significantly increased with increasing heating temperature but decreased with the addition of pectin. The HCPX became more negatively charged with increasing pectin concentration; however, the effect of heating temperature was significant only at 0.1% pectin. Unheated complexes and HCPX successfully adsorbed at the oil-in-water interface and improved the emulsification properties as shown by higher negative charge and smaller droplet sizes. Despite the presence of pectin, rheological properties of the emulsions were not significantly different. All complexes showed increased emulsion stability; however, HCPX made at 85°C formed emulsions that were the most stable against creaming and heating.

The mechanism of improved thermal stability of protein-enriched O/W emulsions by soy protein particles

Growing interest in nutritional and functional foods has motivated the design of protein-enriched products in the food industry, which, however, is greatly challenged by undesirable aggregation and gelation of proteins induced by heating from the pasteurization process. In this study, we reported the preparation of heat-stable soy protein particles (SPPs) by a simple preheating process (100 °C for 30 min) at pH 6.2 and 0.5% (w/v) protein concentration. As a proof of concept, the thermal stability of high-protein emulsions prepared by SPPs compared to native soy proteins (SPs) was investigated. The results showed that high-protein emulsions stabilized by SPPs exhibited appreciable heat stability, whereas SPs gelled when both samples were tested at an identical concentration (10%, w/v). In addition, the emulsions prepared by SPPs demonstrated lower values of storage modulus and viscosity along with a stable size by heat treatment as well as a more stable coated protein layer, in contrast to those prepared by SPs presenting macroscopic aggregation and an unstable coated protein layer. The results would provide valuable information in terms of the development of heat-stable, high-protein, and well-dispersed food emulsions that may find numerous applications in the food industry.

Design of new protein drug delivery system (PDDS) with photoactive compounds as a potential application in the treatment of glioblastoma brain cancer

Glioblastoma multiforme (GBM) is an extremely aggressive malignant brain tumor. Despite advances in treatment modalities, it remains largely incurable. This unfavorable prognosis for GBM is at least partly due to the lack of a successful drug delivery system across the blood-brain barrier (BBB). The delivery of drugs through nanomedicines combined with less invasive alternative therapies represents an important hope for the future of these incurable brain tumors. Whey protein nanocarriers represent promising strategy for targeted drug delivery to tumor cells by enhancing the drug's bioavailability and distribution, and reducing the body's response towards drug resistance. They have been extensively studied to find new alternatives for capacity to encapsulate different drugs and no need for cross-linkers. In this study, we report for the first time the incorporation and administration of Aluminum phthalocyanine chloride (AlClPc)-loaded whey protein drug delivery system (AlClPc-PDDS) for the treatment of glioblastoma brain cancer. This system was designed and optimized (with the use of the spray drying technique) to obtain the required particle size (in the range of 100 to 300 nm), zeta potential and drug loading. Our results suggest that we have developed a drug delivery system from a low-cost raw material and preparation method that is capable of incorporating hydrophobic drugs which, in combination with irradiation, cause photodamage to neoplasic cells, working as an effective adjuvant treatment for malignant glioma.

Impact of proteins and polysaccharides on flavor release from oil-in-water emulsions during simulated cooking

Our objective was to establish the influence of biopolymer additives on the flavor release profiles of model food emulsions during simulated cooking. Allyl methyl disulfide (AMDS), a volatile hydrophobic flavor found in garlic, was used as a model aroma. This type of flavor compound is easily lost from foods during thermal processing and so there is a need to identify effective strategies to improve its retention and modulate its release profile. The impact of protein (sodium caseinate and whey protein) and polysaccharide (maltodextrin, xanthan gum, sodium alginate, corn starch, methyl cellulose, and β-cyclodextrin) addition (0.5%) on the flavor retention profile of AMDS-loaded emulsions subjected to simulated cooking was determined. Corn oil was used as the oil phase to formulate the oil-in-water emulsions. Emulsions were heated from room temperature to boiling and then held for 30 min to establish the impact of biopolymer addition on their flavor retention profiles. The impact of biopolymer concentration on flavor retention was also studied using maltodextrin (0-40%) and xanthan gum (0-0.5%). The flavor retention profiles of the emulsions containing 0.5% maltodextrin, sodium alginate, whey protein, sodium caseinate, or corn starch, were the same as those as the control (no additives). Conversely, addition of 0.5% methyl cellulose, β-cyclodextrin, or xanthan gum led to faster flavor release during cooking. The thermal stability of the emulsions appeared to be the dominant factor determining their flavor release: additives that promoted coalescence during heating led to faster flavor release. Moreover, addition of high levels of maltodextrin and xanthan gum promoted depletion flocculation, which also led to faster flavor release during heating. In contrast, there appeared to be no correlation between emulsion viscosity and the flavor release profile. These results are important for designing emulsion-based food products, such as sauces and soups, with controlled flavor release profiles during cooking.

Apparent thermal and UHT stability of native, homogenized and recombined creams with different average fat globule sizes

Milk fat globule size plays a significant role in stability, microstructure and nutritional functionalities of dairy-based products. Understanding of thermal stability of differentiated-size fat globules in dairy creams can provide intervention opportunities for improving functionalities and shelf-life of dairy-based products. This study focused on apparent thermal and UHT stability of native, homogenized (from native cream) and recombined creams (sodium caseinate-stabilized anhydrous milk fat) as a function of their fat globule sizes at 18 and 36% fat contents. Native creams were fractionated by the two-stage centrifugal method into five sizes (~1.45, ~2.45-3.65, ~3.85 and ~4.5 μm) whereas homogenized and recombined creams (~1.45, ~2.45, ~3.85 and ~4.5 μm) were obtained by microfluidisation. All cream samples were tested for thermal stability at 140 °C following a test similar to Heat Coagulation Time. Some selected creams were also studied for UHT stability at 140 °C for 4 s. Native creams exhibited diverse thermal stability depending upon fat content and size; however, native creams (~2.45-3.65 and ~4.5 μm) were UHT stable. Native creams of all sizes were also significantly more thermal stable than homogenized creams. Homogenized creams of all sizes at both fat contents showed poor apparent thermal and UHT stability. It appeared that small fat globules of native creams were more heat stable than larger fat globules at 18% fat content. Recombined creams made with sodium caseinate as emulsifier (without the presence of other milk components) were the most stable among all. However, dilution of recombined cream with skim milk or lactose significantly reduced their apparent thermal stability, but they were UHT stable.

Proteomics and microstructure profiling of goat milk protein after homogenization

This study investigated the protein changes in goat milk during the homogenization process using label-free quantification. We quantified 310 and 315 proteins in the control group (CG) and homogenized group (HG), respectively, and 16 proteins were significantly different between the 2 groups. For HG, the goat milk protein particle sizes were smaller and more evenly distributed and exhibited an increase in the regular arrangement of the secondary structures. Proteomics analysis verified that xanthine dehydrogenase and asparaginase-like 1 expression in CG were higher than in HG, whereas the opposite was observed for fructose-bisphosphate aldolase, κ-casein, and β-casein. Significant changes were found in the homogenization-treated goat milk proteome that were related to goat milk glycolysis/gluconeogenesis metabolism. This work provides updated information on the current proteome characteristics of homogenized goat milk, which may be important for applying the protein component of goat milk to human nutrition and health.

Physicochemical changes and microbial inactivation after high-intensity ultrasound processing of prebiotic whey beverage applying different ultrasonic power levels

In this work, we investigated the effects of the ultrasonic power (0, 200, 400 and 600 W) on non-thermal processing of an inulin-enriched whey beverage. We studied the effects of high-intensity ultrasound (HIUS) on microbial inactivation (aerobic mesophilic heterotrophic bacteria (AMHB), total and thermotolerant coliforms and yeasts and molds), zeta potential, microstructure (optical microscopy, particle size distribution), rheology, kinetic stability and color. The non-thermal processing applying 600 W of ultrasonic power was comparable to high-temperature short-time (HTST) treatment (75 °C for 15 s) concerning the inactivation of AMHB and yeasts and molds (2 vs 2 log and 0.2 vs 0.4 log, respectively), although HIUS has reached a lower output temperature (53 ± 3 °C). The HIUS was better than HTST to improve beverage kinetic stability, avoiding phase separation, which was mainly attributed to the decrease of particles size, denaturation of whey proteins and gelation of polysaccharides (inulin and gellan gum). Thus, non-thermal processing by HIUS seems to be an interesting technology for prebiotic dairy beverages production.