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Demands for plant-based food and beverage products have escalated in recent years. However, many commercial coffee creamers are still being made using dairy derivatives such as sodium caseinate. Therefore, there is a need to investigate the replacement of dairy based proteins with plant-based alternatives. This study was carried out to systematically investigate the properties of model O/W emulsions stabilized by either sodium caseinate (0.25 to 1.5%) or soy lecithin (0.5 to 1.5%). The model emulsions were made of 10% medium chain triglyceride (MCT) oil-in-water emulsions at pH 7. All model O/W emulsions exhibited whitish appearances similar to that of commercial creamers and were effective at lightening black coffee, except those containing the lowest emulsifier concentrations i.e., 0.25% caseinate or 0.5% lecithin. The lightness of the model emulsions depended on the type and level of emulsifier used, with soy lecithin-stabilized emulsions having similar lightening power compare to that stabilized by sodium caseinate. No feathering or free oil were observed in the whitened coffees at the highest emulsifier level used. Mixtures of caseinate and lecithin emulsifiers were also used and model O/W emulsions with similar physical properties to that stabilized by sodium caseinate alone were produced. The mixed emulsifier-stabilized model emulsions had similar lightness when added to coffee than those stabilized by the individual emulsifiers, suggesting similar stabilization mechanisms using these emulsifiers alone or in combination.

Background Antibodies to the aquaporin-4 (AQP4) water channel in neuromyelitis optica spectrum disorder (NMOSD) are reported to trigger the complement cascade, which is implicated in astrocyte damage and subsequent neuronal injury. The PREVENT study demonstrated that the terminal complement inhibitor eculizumab reduces adjudicated relapse risk in patients with anti-AQP4 immunoglobulin G-positive (AQP4+) NMOSD. The objective of this analysis was to evaluate the efficacy of eculizumab in reducing relapse risk and its safety in AQP4+ NMOSD across clinically relevant subgroups in PREVENT. Methods In the randomized, double-blind, time-to-event, phase 3 PREVENT trial, 143 adults received eculizumab (maintenance dose, 1200 mg/2 weeks) or placebo (2:1), with stable-dose concomitant immunosuppressive therapy (IST) permitted (except rituximab and mitoxantrone). Post hoc analyses of relapses and adverse events were performed for prespecified and post hoc subgroups based on concomitant IST and prior rituximab use, demographic and disease characteristics, and autoimmune comorbidity. Results The significant reduction in relapse risk observed for eculizumab versus placebo in the overall PREVENT population was consistently maintained across subgroups based on concomitant IST and previous rituximab use, age, sex, region, race, time since clinical onset of NMOSD, historical annualized relapse rate, baseline Expanded Disability Status Scale score, and history of another autoimmune disorder. The serious infection rate was lower with eculizumab than placebo regardless of rituximab use in the previous year, concomitant IST use, or history of another autoimmune disorder. Conclusion Across a wide range of clinically relevant AQP4+ NMOSD patient subgroups in PREVENT, eculizumab therapy was consistently effective versus placebo in reducing relapse risk, with no apparent increase in serious infection rate. Trial registration NCT01892345 (ClinicalTrials.gov).

In this study, we investigated the tailoring of food emulsions using interactions between rice bran cellulose nanocrystals (CNCs) and lauric arginate (LAE), which is food-grade cationic surfactant. Complexes of anionic CNCs and cationic LAE (CNCs/LAE) were formed through electrostatic attraction which were characterized using isothermal titration calorimetry (ITC), turbidity, and zeta-potential measurements. The saturation complexes could be formed at ratios of 1:2 (w/w) CNCs-to-LAE. Furthermore, the physical and oxidative stability of oil-in-water emulsions containing lipid droplets coated by CNCs/LAE complexes was determined. Electrostatic complexes formed from 0.02% CNCs and 0.1% LAE produced stable Pickering emulsions that were resistant to droplet coalescence. It was also exhibited that 0.02% CNCs and 0.1% LAE complexes stabilized-emulsions was able to extend the lag phase to 20 days for lipid hydroperoxide and to 14 days for hexanal production. This study shows that food-grade Pickering emulsions with good stability can be produced by CNCs with LAE complexes.

Natural emulsifiers, particularly those extracted from plants, are highly wanted by food industry to meet consumers demand for clean label food and beverage products. The potential utilization of soy lecithin as an emulsifier in model coffee creamer was investigated in this study. The model oil-in-water (O/W) emulsions consisted of 10 wt% medium chain triglyceride were stabilized using either 1% or 5% soy lecithin (pH 7.0). The O/W emulsions were of whitish milky color (L* = 88–92) and were able to whiten black coffee solutions (L* from 5.5 for black coffee to 44–56 for white coffees). Model O/W emulsions with smaller mean droplet diameters (0.11 to 1.09 μm), higher surface potentials (ζ = −62 to −72 mV), and better stabilities in hot coffee were fabricated using higher lecithin levels because there was more emulsifier to coat the oil droplet surfaces. Alteration of the electrostatic interactions in the model O/W emulsions (5% lecithin) by pH adjustment or calcium addition led to droplet aggregation under certain conditions, which was attributed to charge reduction by protonation of lecithin head groups and electrostatic screening by counter-ion accumulation and ion-binding. In particular, phase separation of the model creamer occurred at pH value around 4.5 when the system was acidified at a slow rate. Overall, this study suggests that lecithin-stabilized O/W emulsions may become unstable in coffee solutions with high acidity or calcium levels. The information obtained from this study provides insights on the use of plant-based emulsifiers in commercial food and beverage systems.

The functional attributes of globular proteins can be extended by controlling the nature of the aggregates they form. In this study, the effect of thermal treatment (85°C/20 min) and high pressure microfluidization (20,000 psi, 1 pass) on the physical properties of whey protein isolate solutions (5–9%; pH 2) was investigated. Heating solutions of native whey protein isolate (8 wt%) under these acidic conditions led to the formation of highly viscous solutions (η = 306 mPa s) with low turbidity (τ = 0.04 cm−1), which was attributed to the formation of protein fibrils (effective d = 310 nm). Microfluidization of these protein fibrils decreased their length (effective d = 97 nm) leading to a substantial reduction in solution viscosity (η = 3.8 mPa s), and a slight reduction in turbidity (τ 1 cm−1) were formed at pH values close to the isoelectric point of the whey proteins (pH 4.5) due to protein self-association caused by reduction of the electrostatic repulsion between the protein molecules. Highly viscous or gelled solutions were formed for the heated and heated-microfluidized proteins across a wide pH range, which was attributed to the presence of fibrils. The study showed that the functional attributes of whey proteins can be modulated by thermal and high-pressure homogenization treatment.

Tocotrienols have been reported to have stronger bioactivities than tocopherols, and may therefore be suitable as a potent source of vitamin E in functional foods, supplements, and pharmaceuticals. However, their inclusion into new products is hindered by their low water-solubility and oral bioavailability. Oil-in-water emulsions (O/W) could provide an adequate delivery system for these bioactive compounds. Tocotrienols were tested in bulk oil and within O/W conventional emulsions (10μm) and nanoemulsions (350nm). The emulsions were prepared with medium chain triglycerides (MCT) as an oil phase (5 to 40% wt) and quillaja saponins as a natural surfactant. The gastrointestinal fate of the emulsion-based delivery systems was investigated using a simulated gastrointestinal tract (GIT). The physical properties of the emulsions (color, apparent viscosity) were affected with increased droplet concentration. The lipid phase composition (emulsion type and particle size) had a pronounced impact on the microstructure of the emulsions in different regions of the GIT. At simulated small intestine conditions, the rate of lipid digestion and tocotrienol bioaccessibility decreased in the following order: nanoemulsionsemulsionsbulk oil. These results suggest that emulsions containing small lipid droplets are particularly suitable for delivering tocotrienols.

The development of plant-based foods and beverages is becoming increasingly popular because of growing consumer concerns about perceived ethical, health, and environmental issues. The current study examined the influence of oil droplet concentration on the physicochemical properties of oil-in-water (O/W) emulsions stabilized with a plant-based surfactant. Emulsions were utilized as model creamers, which consisted of medium chain triglycerides (MCT) as the oil phase and quillaja saponin as a plant-based surfactant. The optical, rheological and stability properties of these model creamers were measured at varied oil content from 0 to 15%, at a constant surfactant-to-oil ratio (1:15). The model creamers had an appearance similar to that of commercial non-dairy creamers, and their whiteness increased with increasing droplet concentration due to enhanced light scattering: L* from 77 to 91 for creamer and L* from 5 to 55 for white coffee. The quillaja saponin-coated lipid droplets were stable to aggregation and gravitational separation when added to hot acidic coffee solutions (85°C, pH4.9), which was attributed to strong steric and electrostatic repulsions. The apparent viscosity of the model creamers increased with increasing droplet concentration due to increased frictional losses associated with the presence of the droplets. This study provides valuable information into the impact of oil content on the physicochemical properties of liquid creamers using plant based surfactants, which is important for the formulation of healthier products.

Rising consumer demand for food products made with natural and plant-based ingredients has led to a search for natural alternatives to synthetic food ingredients. The present study compared the ability of two natural small molecule surfactants – quillaja saponin (0.5–2.5%) and soy lecithin (1–5%) – to stabilize 10% oil-in-water emulsions. Emulsion lightness decreased with increasing emulsifier concentration in both systems, which was attributed to the inherent color of the emulsifiers (increased absorption) and the decrease in droplet size (decreased scattering). The mean droplet diameter decreased with increasing emulsifier concentration (0.5–0.15 μm for quillaja saponin and 0.8 to 0.14 μm for soy lecithin) due to their ability to cover more surface area. Both emulsifiers led to the formation of oil droplets with a high negative charge (ζ = −45 to −70 mV), thereby generating a strong electrostatic repulsion that helped protect them against aggregation. The emulsions remained physically stable when added to an acidic hot coffee solution (85 °C), with no visible phase separation or increase in particle size. This study provides insight into the potential of two natural emulsifiers to form stable emulsions suitable for application in coffee creamers.

Consumer demands for natural and clean label ingredients is promoting food and beverage manufacturers to replace synthetic emulsifiers with natural alternatives. This study examined the potential use of quillaja saponin (Q-Naturale 200®) as a natural emulsifier in model coffee creamers. The model liquid creamer was an oil-in-water emulsion (2% quillaja saponin, 10% medium chain triglycerides) that had a whitish milk color (lightness, L* = 86–90) similar to a commercial liquid creamer (L* = 91–93). The model creamer was stable to droplet aggregation and creaming from pH 3.5 to 7.0, which was attributed to the small droplet diameter (d

Consumer concern about human and environmental health is encouraging food manufacturers to use more natural and sustainable food ingredients. In particular, there is interest in replacing synthetic ingredients with natural ones, and in replacing animal-based ingredients with plant-based ones. This article provides a review of the various types of natural emulsifiers with potential application in the food industry, including phospholipids, biosurfactants, proteins, polysaccharides, and natural colloidal particles. Increased utilization of natural emulsifiers in food products may lead to a healthier and more sustainable food supply. However, more research is needed to identify, isolate, and characterize new sources of commercially viable natural emulsifiers suitable for food use.

Oil-in-water emulsions are the main component of creamers, which are used to cream cold or hot coffee. These emulsions must provide the required lightening power and remain physically stable when introduced into hot acidic coffee solutions. In this study, model oil-in-water emulsions stabilized with mixed emulsifiers of sodium caseinate (0.5%) and soy lecithin (0.5%) were fabricated and their physical properties were examined over a range of pH values (pH 3.5 to 7). These model oil-in-water emulsions had strong lightening power (L* ≈ 87) and good physical stability from pH 5.5 to 7 but were unstable to gravitational separation below pH 5 due to caseinate aggregation around its isoelectric point. Addition of λ-carrageenan (0.05 to 0.175%) to the formulations prior to homogenization effectively improved their pH stability, while addition of κ-carrageenan was ineffective. The significantly higher level of sulfated ester groups in λ-carrageenan may have created a strong electrostatic repulsion between the oil particles, inhibiting their association. Our study suggests that some of the caseinate in coffee creamers can be replaced with plant-based lecithins, but that a plant-based polysaccharide is also needed to ensure their stability when added to hot acidic coffees.

This study investigated the potential of gum arabic to improve the stability of anthocyanins that are used in commercial beverages as natural colourants. The degradation of purple carrot anthocyanin in model beverage systems (pH 3.0) containing L-ascorbic acid proceeded with a first-order reaction rate during storage (40 °C for 5 days in light). The addition of gum arabic (0.05-5.0%) significantly enhanced the colour stability of anthocyanin, with the most stable systems observed at intermediate levels (1.5%). A further increase in concentration (>1.5%) reduced its efficacy due to a change in the conformation of the gum arabic molecules that hindered their exposure to the anthocyanins. Fluorescence quenching measurements showed that the anthocyanin could have interacted with the glycoprotein fractions of the gum arabic through hydrogen bonding, resulting in enhanced stability. Overall, this study provides valuable information about enhancing the stability of anthocyanins in beverage systems using natural ingredients.

There is an increasing market for food and beverage products enriched in proteins and dietary fibers due to their potential health benefits. In this study, the effect of heating (85 °C, 20 min), microfluidization (20,000 psi), and pH (2 to 6.5) on the physicochemical properties of aqueous solutions containing mixtures of whey protein fibrils (7.5%; WPF) and chitosan (0.5%; CN) were examined. Heating of the mixed systems increased their turbidity and apparent viscosity, which was attributed to the formation of protein-rich particles. Interestingly, heating the mixed systems and then applying microfluidization led to phase separation and a lower apparent viscosity, which was attributed to high-pressure disruption of the whey protein fibrils. The pH of the systems significantly influenced their appearance, turbidity, particle size, and apparent viscosity, with high turbidity and viscosity, and large particle size occurring from pH 3.5 to 5.5. These effects were attributed to protein aggregation close to its isoelectric point (pH 5) coupled with electrostatic attraction between anionic groups on the whey protein and cationic groups on the chitosan. The addition of chitosan increased the net isoelectric point from pH 5 for pure whey protein to pH 6 for the mixed system. Overall, this study showed that the appearance and rheological properties of protein-dietary fiber mixtures could be manipulated by heating, microfluidization, and pH adjustment. This information may be useful for designing protein and fiber enriched food and beverage products with desirable physical and sensory properties.

The physicochemical properties of nanoemulsions play an important role in determining their functional attributes and suitability for application in commercial products, such as food, supplements, pharmaceutical, or personal care products. In particular, the optical properties (appearance), rheology (texture), and stability (shelf life) of nanoemulsion-based products strongly impact their ability to be used in specific applications. This chapter provides an overview of the different analytical tools available to characterize the optical, stability, and rheological properties of nanoemulsions.

Foods contain varying amounts of salts and acids, which alters the electrostatic interactions between biopolymer molecules. This study therefore examined the influence of NaCl content (0–400 mM) and pH (3–8) on the physical properties of hydrogel particles fabricated by mixing sodium caseinate (1.5%) and pectin (1.5%). The hydrogel particles were assembled using a biopolymer phase separation approach that involved both segregation (thermodynamic incompatibility) and aggregation (complex coacervation) mechanisms. The addition of NaCl increased hydrogel particle size and altered the shape from spherical to rod-like, which was attributed to the influence of salt on the electrostatic attraction between biopolymers. There was a reduction in the lightness and increase in the shear viscosity of the hydrogel particle suspensions with NaCl addition, which was attributed to changes in particle dimensions and morphology. Solution pH also altered particle size and shape, and therefore the lightness and viscosity of the suspensions. In particular, the lightness of the suspensions was greater at pH 3–5, than at higher pH values. This study highlighted the significant effects of salt and pH on the properties of hydrogel particles. This knowledge could be used to manipulate food formulations to achieve desirable physicochemical or sensory properties.

Biopolymer-based hydrogel particles were fabricated using a segregation-aggregation phase separation mechanism. Pectin-coated whey protein isolate (WPI) hydrogel particles (d ~ 2 μm) were formed when solutions of heat-denatured (90 °C/10 min) WPI (1.5 %) and pectin (1.5 %) were mixed at pH 7, and then adjusted to pH 5 with constant stirring. Hydrogel particle properties and suspension appearance were strongly influenced by pH (2 to 8) and calcium chloride (0–5 mM) due to the importance of electrostatic interactions. At pH 2 to 3, extensive biopolymer complexation occurred leading to highly viscous solutions. At pH 6 to 8, biopolymer complexes disintegrated due to weakening of electrostatic attraction leading to clear solutions. Calcium addition promoted biopolymer aggregation and an increase in viscosity. All systems containing intact hydrogel particles had a whitish appearance similar to that of milk. These biopolymer-based hydrogel particles may be suitable as texture modifiers, fat replacers, or delivery systems for utilization in foods.

Fat plays multiple important roles in imparting desirable sensory attributes to emulsion-based food products, such as sauces, dressings, soups, beverages, and desserts. However, there is concern that over consumption of fats leads to increased incidences of chronic diseases, such as obesity, coronary heart disease, and diabetes. Consequently, there is a need to develop reduced fat products with desirable sensory profiles that match those of their full-fat counterparts. The successful design of high quality reduced-fat products requires an understanding of the many roles that fat plays in determining the sensory attributes of food emulsions, and of appropriate strategies to replace some or all of these attributes. This paper reviews our current understanding of the influence of fat on the physicochemical and physiological attributes of food emulsions, and highlights some of the main approaches that can be used to create high quality emulsion-based food products with reduced fat contents.

There is a growing demand for use of natural ingredients in food manufacturing. This study utilized a natural emulsifier, quillaja saponin (1%) to fabricate non-dairy model creamer emulsions (containing 10% medium chain triglycerides oil). Varying homogenization conditions, ranging from a high-shear mixer to passing through a microfluidizer at 20,000psi, were applied to fabricate emulsions. The effect of particle size on the appearance, tristimulus color coordinates, and electrical characteristics of the model creamers and white coffee drinks were investigated. The average droplet size varied from 0.2 to 16μm. All model creamers had whitish milk-like appearance and the white coffee solutions had light brown color. All systems were physically stable except for the systems with largest oil droplets (1.8 and 16μm), which had creaming. The lightness, L* (whiteness) of the model creamer and the white coffee increased with decreasing oil droplet size, as smaller droplets scatter more light. Decreasing the oil droplet size led to lower zeta potential (from -73 to -54mV) due to lesser negative charge group accumulated on the interfacial layer of the droplets. The oil droplets were also found to be stable to aggregation in hot acidic coffee solutions prepared using model hard water. Overall, this study found that oil droplets stabilized with natural plant-based surfactant have potential for application in liquid coffee creamers and their stability and whitening power were dependent on the droplet size.

The potential of using microparticulated whey protein (MWP) in combination with either modified starch or locust bean gum (LBG) as fat mimetics to fabricate reduced calorie emulsion-based sauces and dressings was studied. The influence of food matrix composition (protein, polysaccharide, and fat content), ionic strength, and pH on the properties of thermally processed model emulsions (90°C/10min) was investigated. Increasing protein concentration (2.5-7.5%) increased the mean (d3,2) particle diameter due to the formation of large protein aggregates. All MWP-containing systems had a creamy white appearance with high lightness (L*>75). Addition of fat droplets (5%) further increased their lightness (L*>90) due to enhanced light scattering. Addition of starch, LBG, or MWP increased emulsion viscosity due to the increased effective volume fraction of the dispersed phase. Addition of calcium chloride (10mM) and pH adjustment (2-8) caused little change in the physicochemical properties of the mixed systems. Overall, the appearance and rheological properties of the mixed systems were similar to commercial sauces and dressings. This study demonstrates that reduced calorie food emulsions with appearance and consistency similar to those of full-fat versions can be formulated using protein microparticles and polysaccharides.

Increasing consumer demand for higher quality, cheaper, more convenient, and healthier emulsion-based products means that the food industry must have a good understanding of the relationship between the structural and functional properties of food emulsions. This review article provides an overview of the relationship between the composition and structural organization of oil-in-water emulsions and their physicochemical (optical, rheological, and stability) and sensory (appearance, texture, flavor, and mouthfeel) properties. It also discusses recent advances in the design of structured emulsions with novel functional properties, such as multiple emulsions, filled-hydrogel particles, multilayer emulsions, microclusters, and air-filled emulsions.

The influence of composition and microstructure on the physicochemical properties of model food emulsions containing fat droplets, starch granules, and hydrocolloids was studied. These multicomponent model systems consisted of 5% protein-coated fat droplets, 3.75% modified starch, and 0–1% locust bean gum (LBG) and could be characterized as non-ideal plastics that exhibited shear-thinning behavior. The gelatinized starch granules played the most important role in determining the overall rheology of the mixed systems because of their relatively high effective volume fraction (∼38%), but the fat droplets and hydrocolloid also played an important role. The apparent viscosity (at 10 s −1 ) and yield stress of the mixed systems increased with increasing LBG concentration. The fat droplets and starch granules played the most important role in determining the lightness of the mixed systems, with changes in LBG concentration having little impact on the overall optical properties. This research provides some important information about the influence of hydrocolloids on the properties of multicomponent model emulsions, which may be useful in the development of reduced-fat foods with desirable sensory properties.

Many of the sauces used in frozen meals are oil-in-water emulsions that consist of fat droplets dispersed within an aqueous medium. This type of emulsion must remain physically and chemically stable throughout processing, freezing, storage, and defrosting conditions. Knowledge of the fundamental physicochemical mechanisms responsible for the stability of emulsion-based sauces is needed to design and fabricate high-quality sauces with the desired sensory attributes. This review provides an overview of the current understanding of the influence of freezing and thawing on the stability of oil-in-water emulsions. In particular, it focuses on the influence of product composition (such as emulsifiers, biopolymers, salts, and cryoprotectants), homogenization conditions, and freezing/thawing conditions on the stability of emulsions. The information contained in this review may be useful for optimizing the design of emulsion-based sauces for utilization in commercial food products.

The potential utilization of microparticulated whey protein (MWP) as a fat mimetic in reduced calorie model sauces and dressings was examined. The influence of solution composition (pH and salt) and processing (homogenization and heating) on the properties of MWP (0–20%) suspensions (0.01 M phosphate buffer, pH 6) was studied. High-pressure homogenization (6000 psi, 1 pass) of MWP suspensions significantly reduced protein particle size and improved their stability to sedimentation. The lightness and viscosity of the suspensions increased with MWP concentration, which was attributed to the influence of the protein particles on light scattering and fluid flow. Thermal treatment (90 °C for 5 min) of MWP suspensions increased their viscosity, which was associated with increased protein aggregation. Solution pH (2–8) also had an impact on the particle size and microstructure of the MWP suspensions, which was attributed to changes in particle charge: the charge went from negative to positive with decreasing pH, with an isoelectric point around pH 4.5. Addition of calcium chloride (10 mM) to heated systems did not cause significant changes in suspension rheology, which was attributed to pre-denaturation of the MWP. Overall, this study highlights conditions where MWP can be used as potential fat replacers in low calorie food emulsions. MWP increases the lightness and viscosity of products, thereby mimicking some of the desirable characteristics of fat droplets.

There is increasing interest in creating novel structures in food products so as to create desirable textural characteristics. Cold-set gelation of pre-heated (90 °C/10 min) whey protein isolate (WPI) solutions (2.5, 5.0 and 10.0 g/100 g) and WPI-starch mixtures (2.5 g/100 g and 3.75 g/100 g, respectively) were initiated with calcium chloride (10 and 20 mmol/L). Calcium addition promoted gelation of the pre-heated systems at ambient temperature and led to increased turbidity, complex shear modulus (G*), and optical lightness. These measured properties increased with increasing protein and/or calcium concentration, which was attributed to more extensive protein network formation. In the WPI-starch mixed systems, the presence of swollen starch granules caused discontinuous protein network formation and led to lower gelation kinetics in comparison to protein-only WPI gels. Our results have useful implications for the formulation of semi-solid food products with specific rheological properties, i.e., gel-like or paste-like characteristics.

The food industry needs effective strategies to develop reduced calorie products with desirable sensory attributes. This study utilizes controlled phase separation of biopolymer mixtures to form oil-filled hydrogel particles suitable for use in food products. Filled hydrogel particles were fabricated from fat droplets (0 to 1%), sodium caseinate (1.5 to 3%) and high-methoxy pectin (1.5 to 3%) mixtures (pH 5) using two different approaches: multistep and simple methods. The multistep method involved inducing segregative phase separation of the mixed biopolymers at pH 7 (due to electrostatic repulsion), and then reducing to pH 5 to promote aggregative phase separation (due to electrostatic attraction). The simple method involved mixing all the components together at pH 7 and then adjusting to pH 5. The oil-filled hydrogel particles were spheroid in shape, with mean particle diameters (d43) around 10 μm. They consisted of fat droplets trapped within caseinate-rich hydrogel particles that were dispersed within a pectin-rich phase. The hydrogel particles increased the lightness and viscosity of aqueous solutions, and may therefore be suitable to replace fat droplets or starch granules in reduced calorie products. Industrial relevance The food industry needs effective strategies to develop reduced calorie products with desirable sensory attributes. This study utilizes controlled phase separation of biopolymer mixtures to form oil-filled hydrogel particles suitable for use in food products. They consisted of fat droplets trapped within caseinate-rich hydrogel particles dispersed within a pectin-rich phase. The hydrogel particles increased the lightness and viscosity of aqueous solutions, and may be suitable to replace fat droplets or starch granules within reduced calorie products.

The influence of locust bean gum (LBG) on the physicochemical properties of model food sauces containing fat droplets was investigated. The particle size, microstructure, optical lightness, rheology, and storage stability of aqueous solutions and oil-in-water emulsions containing different LBG concentrations (0.05–1 wt%) were measured. Non-dissolved hydrogel microparticles were observed in both aqueous solutions and emulsions above a certain LBG level (≥0.4%). The mean particle diameter ( d 4,3 ) and apparent viscosity of the emulsions increased steeply when the LBG concentration exceeded about 0.2–0.4%, while the lightness and flocculation stability decreased. The emulsions were highly prone to creaming and phase separation at intermediate LBG concentrations (0.2–0.8%). The changes in the physicochemical properties of the emulsions with increasing LBG concentration were attributed to a number of factors: (i) viscosity enhancement; (ii) depletion flocculation; (iii) hydrogel formation. These results have important implications for the rational design and production of reduced-fat food emulsions, such as sauces, dressings, and deserts.

The ability of a recently developed simulated mastication method to characterize the rheological properties of model food sauces was determined. This method uses integrated compression–shear–decompression motions to mimic the motions of the tongue against the palate, and includes the addition of saliva. Model sauces contained swollen starch granules (3.75%), fat droplets (0, 5, 10, and 15%), and hydrophilic polymer (0 or 0.2% locust bean gum). The texture of the sauces was characterized by the simulated mastication method, shear viscometry, and sensory methods, and the parameters derived from the instrumental analysis were correlated to those derived by sensory analysis. The optical properties (lightness) and microstructure (light scattering and microscopy) of the sauces were also measured. There was a good correlation (r2 > 0.95) between the “consistency” (maximum peak force) derived from the simulated mastication method and the “viscosity/thickness” derived from sensory analysis. In both cases, the consistency of the sauces increased with increasing fat content and with locust bean gum addition. The microstructures of sauces masticated within a human mouth and within the simulated mastication instrument were similar. Overall our results suggest that the simulated mastication method can be used to characterize the textural properties of semi-solid foods within the mouth.

Mixed colloidal dispersions, consisting of starch granules and lipid droplets, were used as model systems to represent commercial food products, such as sauces, desserts, and soups. Colloidal dispersions were prepared by mixing unheated modified starch (3.5 or 5.0 wt%) and lipid droplets (2.5, 5.0 or 8.0 wt% oil) together and then heating (90 °C for 5 min) to promote starch gelatinization. The lipid droplets were stabilized by a food-grade surfactant consisting of a mixture of diacetyl tartaric acid ester of mono-diglycerides (DATEM) and mono-diglycerides. The influence of thermal processing and composition (starch, lipid, surfactant content) on the particle size, microstructure, lightness, and shear viscosity of the model sauces was examined. There was a pronounced increase in shear viscosity upon heating, which was attributed to the swelling of the starch granules leading to a close-packed particle suspension. The shear viscosity and lightness of the colloidal dispersions increased with increasing starch and fat content, with fat droplets dominating lightness and starch granules dominating viscosity. The amount of surfactant present also influenced the rheology of the mixed colloidal dispersions, which was attributed to its ability to modify starch granule interactions. Overall, these results have important implications for designing high quality emulsion-based food products, such as soups, sauces, desserts, and beverages.

This article focuses on hydrogel-based strategies for creating reduced calorie foods with desirable physicochemical, sensory, and nutritional properties. Initially, the role of fat droplets and starch granules in foods is discussed, and then different methods for fabricating hydrogel beads are reviewed, including phase separation, antisolvent precipitation, injection, and emulsion template methods. Finally, the potential application of hydrogel beads as fat droplet and starch granule replacements is discussed. There is still a need for large-scale, high-throughout, and economical methods of fabricating hydrogel beads suitable for utilization within the food industry.

Anthocyanins are prone to chemical degradation and color fading in the presence of vitamin C. The potential of three amino acids (l-phenylalanine, l-tyrosine, l-tryptophan) and a polypeptide (e-poly-l-lysine) in prolonging the color stability of purple carrot anthocyanins (0.025%) in model beverages (0.05% l-ascorbic acid, citric acid, pH 3.0) stored at elevated temperature (40°C/7 days) was examined. In the absence of amino acids or peptides, anthocyanin degraded at first-order reaction rate. Addition of amino acids or peptide (0.1%) increased the color stability of anthocyanins, with the most significant improvement observed for l-tryptophan. The average half-life of anthocyanin color increased from 2 days to 6 days with l-tryptophan addition. Fluorescence quenching measurements revealed that the l-tryptophan interacted with anthocyanins mainly through hydrogen bonding, although some hydrophobic interaction may also have been involved. Overall, this study suggests that amino acid or peptide addition may prolong the color stability of anthocyanin in beverage products.

Anthocyanins are widely used as natural colorants in foods, but they are highly susceptible to chemical degradation during storage leading to color fading. This study examined the potential of natural quillaja saponin and polyphenols (vanillin, epigallocatechin gallate, green tea extract, and protocatechualdehyde) at inhibiting color fading of anthocyanins in model beverages. The purple carrot anthocyanin (0.025%) in model beverages (citric acid, pH 3.0) containing l-ascorbic acid (0.050%) degraded with a first-order reaction rate during storage (40°C/7days in light). The addition of polyphenols (0.2%) delayed color fading, with the most notable improvement observed with green tea extract addition. The half-life for anthocyanin color fading increased from 2.9 to 6.7days with green tea extract. Fluorescence quenching measurements showed that the green tea extract contained components that interacted with anthocyanins probably through hydrophobic interactions. Overall, this study provides valuable information about enhancing the stability of anthocyanins in beverage systems using polyphenols.

A method was developed to characterize the textural attributes of semi-solid foods during “instrumental mastication”. This method integrates squeezing flow rheometry and shear viscometry in a single instrument. The sample to be tested is placed between two horizontal parallel plates that undergo a series of compression–shear-decompression cycles designed to mimic mastication. The normal forces measured on the upper plate provide information about the rheological properties of the sample, including maximum peak force (related to consistency), maximum trough force (related to adhesiveness), residual force (related to yield stress), and apparent shear viscosity. The sample to be tested can be mixed with artificial saliva prior to testing to more closely simulate oral conditions. Preliminary experiments showed that this technique can be used to monitor textural changes of starch-based food products during oral processing, e.g., a decrease in consistency due to starch degradation by amylase in saliva. This instrumental mastication assay may be able to facilitate the design of semi-solid foods with desirable textural attributes.

The influence of fat content and emulsifier type on the rheology, optical properties, stability, and microstructure of bimodal particle suspensions containing small fat droplets and large starch particles was studied. Fat droplets were coated by either small molecule surfactants (non-ionic/anionic mixture) or globular proteins (whey protein). Mixed systems containing oil droplets (0 to 30 wt.%) and modified starch (5 wt.%) were heated (90 °C for 5 min) to promote starch gelatinization. The flow behavior, yield stress, and apparent viscosity of these systems were determined from shear stress versus shear rate measurements. For both emulsifiers, the yield stress of the mixed systems increased with increasing fat content, indicating that a close-packed system was formed. The apparent viscosity (at 20 s− 1) increased with increasing fat content for protein-coated fat droplets as expected from theory, but it increased and then decreased for surfactant-coated lipid droplets. The unexpected behavior of the surfactant-based mixed systems was attributed to droplet coalescence and phase separation, as shown by microscopy and visual observation. Overall, these results have important implications for designing high quality food products (such as sauces, dressings, and desserts) with reduced calories.

Microencapsulated fish oil powders (50% oil:25% protein:25% starch) were prepared using a physical blend or a heated mixture of sodium caseinate and pre-processed resistant starch as encapsulants. The in vitro digestibility of microcapsules by lipase, amylase and proteases were examined. Heat treatment of the encapsulants and exposure of microcapsules to simulated gastric fluid (SGF) prior to addition of lipase, trypsin and amylase altered the susceptibility of the microcapsules to digestion. Lipolysis of microcapsules occurred in the presence of lipase alone and was increased in the presence of amylase and/or trypsin. Pre-exposure of microcapsules to SGF had different effects on lipolysis, which depended on the nature of the encapsulant material. Lipolysis in the presence of lipase alone was due to the displacement of the interfacial layer. Increased lipolysis in the presence of amylase and/or trypsin was attributed to the digestion of the encapsulant, which facilitated displacement of the interface of oil droplets by bile salts.

The aim of the study was to assess the effects of modification of encapsulant materials before emulsion formation on the viscosity and interfacial properties of the emulsions and their influence on the susceptibility of emulsions to in vitro lipolysis. Emulsions (oil/protein ratio 2:1) were prepared by homogenizing mixtures containing fish oil and non-heated or heated (100 °C/120 min) dispersions comprising (a) sodium caseinate (NaCas), (b) mixtures of NaCas and a high amylose-resistant starch (Hylon VII; 1:1 mass ratio), and (c) mixtures of NaCas and previously modified resistant starch (heat/microfluidized [MF] Hylon VII; 1:1 mass ratio), followed by freeze drying. Reconstituted emulsion containing heated mixture of NaCas and heat/MF Hylon VII was the most viscous. The extent of lipolysis was the same in all emulsions stabilized by non-heated NaCas or non-heated mixtures of NaCas with resistant starch. Heat treatment of NaCas increased lipolysis of emulsions stabilized with protein alone, but heating NaCas with Hylon VII or heat/MF Hylon VII before emulsion formation reduced lipolysis. The emulsion stabilized with the heated NaCas–heat/MF Hylon VII mixture was the most resistant to lipolysis. Overall, the resistance to lipolysis was considered to be primarily dependent on the interfacial properties of the microcapsules. These findings of in vitro lipolysis of NaCas-resistant starch formulated oil powders may be relevant to an understanding of in vivo digestibility of the oil powders. The insights may be used as a guide to formulate oil systems for altering the susceptibility to lipolysis of ingested oil emulsions.

Anthocyanins are often used in functional foods and beverages as colorants and nutraceuticals. However, these natural compounds may undergo chemical degradation during storage leading to color fading and loss of bioactivity. In particular, vitamin C (l-ascorbic acid) is known to accelerate anthocyanin degradation. In this study, the influence of various food-grade biopolymers on the physical and chemical stability of model beverages containing anthocyanin (0.025%), ascorbic acid (0 or 0.05%), and calcium salt (0 or 0.01%) was examined under accelerated conditions (40°C for 7days). Four biopolymers (1%) were examined for their potential to inhibit anthocyanin degradation: native whey protein; denatured whey protein; citrus pectin; and beet pectin. The physical stability was determined by measuring changes in absorbance, color, and visual appearance. Solutions containing anthocyanin and calcium salt (0 or 0.01%) were stable throughout storage, while those with added ascorbic acid were the least stable. The addition of biopolymers, particularly heat denatured whey protein, significantly enhanced the stability of the anthocyanin during storage. Fluorescence quenching studies showed that the anthocyanin may have formed complexes with the whey protein through hydrogen bonding that resulted in their enhanced stability in the presence of ascorbic acid. This study provides information that may improve the stability of anthocyanins in food and beverage systems.

Many of the sauces used in frozen meals are oil-in-water emulsions that consist of fat droplets dispersed within an aqueous medium. This type of emulsion must remain physically and chemically stable throughout processing, freezing, storage, and defrosting conditions. Knowledge of the fundamental physicochemical mechanisms responsible for the stability of emulsion-based sauces is needed to design and fabricate high-quality sauces with the desired sensory attributes. This review provides an overview of the current understanding of the influence of freezing and thawing on the stability of oil-in-water emulsions. In particular, it focuses on the influence of product composition (such as emulsifiers, biopolymers, salts, and cryoprotectants), homogenization conditions, and freezing/thawing conditions on the stability of emulsions. The information contained in this review may be useful for optimizing the design of emulsion-based sauces for utilization in commercial food products.

The properties of resistant starch (RS) modified by heating starch suspensions (Heat RS) or heating followed by microfluidization (Heat-MF RS) and their functionality as co-encapsulants in sodium caseinate (NaCas) based fish oil microcapsules (50%oil:25%NaCas:25%starch) were examined. RS modification reduced molecular weight and crystallinity of the starch, with the effects being more evident for Heat-MF RS. The properties of fish oil microcapsules were influenced by the starch type used (RS, Heat RS, or Heat-MF RS) in combination with NaCas. With both physical blends and heated mixtures of NaCas and starch as encapsulants, highest encapsulation efficiency but lowest oxidative stability was obtained for the microcapsules containing Heat-MF RS. Oxidative stability was independent of heat treatment applied to the mixtures of NaCas and starch and also not related to encapsulation efficiency of the freeze-dried microcapsules. The properties of the starch used in combination with NaCas were the major determinant of the oxidative stability, with lower molecular weight and decreased crystallinity providing less protection against oxidation.

Temporal pulse amplitude was recorded bilaterally in 56 participants before, during and after three ice-water immersions of the foot. Half of the participants were told that prolonged exposure to freezing temperatures could cause frostbite. Increases in pulse amplitude were greater in the ipsilateral than contralateral temple during and after the three foot-immersions. Although pulse amplitude decreased after threatening instructions and repeated immersion of the foot, the vasodilator response persisted during all three immersions. These findings suggest that nociceptive stimulation of the foot evokes an ipsilateral supra-spinal extracranial vasodilator response, possibly as part of a broader defense response.