Clear Beverages Research Articles

Enzyme-glycosylated ovalbumin/chitosan oligosaccharide nanoparticles: Simulation of in vitro digestion for the targeted release of vitamin D3 and application for encapsulation in beverages

Vitamin D3 (VD3) was encapsulated in TGaseOVA–chitosan (COS) composite nanoparticles. Isothermal titration calorimetry was used to explain the hydrophobic interaction between TGaseOVA and VD3 at the molecular level. The 87.7 nm TGaseOVA–COS composite nanoparticles achieved an encapsulation efficiency of 96.34% and loading capacity of 4.68% for 9 μg/ml VD3. An in vitro digestion experiment revealed that TGaseOVA–COS–VD3 composite nanoparticles had good stability in simulated gastric fluid and only 32.67% of the composite nanoparticles were released in simulated intestinal fluid. Meanwhile, sodium dodecyl sulfate polyacrylamide gel electrophoresis confirmed that the composite nanoparticles had a release rate of 100% in simulated intestinal fluid. TGaseOVA–COS–VD3 composite nanoparticles had a VD3 concentration of 8.73 μg/ml after pasteurization, indicating that they provided substantial protection to VD3 during pasteurization. TGaseOVA–COS was subjected to a 1-month simulated shelf life test. High-performance liquid chromatography confirmed that it had a VD3 retention rate of 90%. The concentration-dependent toxicity of VD3 was detected by using Caco-2 cells. VD3 exhibited toxicity at the concentration of 11 μg/ml. Therefore, the embedding dose of 9 μg/ml used in this work was considered a safe dose. TGaseOVA–COS composite nanoparticles have excellent stability and good VD3 slow-release properties. They can be used in concentrated clear beverages and other food and beverage products. Therefore, they have potential for applications in the food and pharmaceutical industries.

Protein Soft Drinks: A Retail Market Analysis and Selected Product Characterization

The market for protein-based drinks is endlessly growing, as the awareness of health-conscious consumers demands a shift from traditional protein smoothies or shakes to clear beverage alternatives that address thirst and hydration. The aim of this study was to investigate the soft drink market on a global scale with a focus on commercially available high-protein soft drinks, carbonated and uncarbonated, from both animal- and plant-based protein sources. Additionally, the physicochemical properties of 25 selected protein soft drinks from the market research were evaluated, including their protein content, density, viscosity, particle size, stability, pH and total titratable acidity (TTA), to explore their quality attributes. From the market research, 6.8% was the highest protein content found out of 138 beverages, with whey protein isolate and collagen hydrolysate being the most popular added protein ingredients. Only 18% of the market contained plant-based proteins, with pea protein isolate being the most common. The pH of all beverages showed acidic values (2.9 to 4.2), where TTA ranged from 0.4 to 1.47 mL (0.1 M NaOH/mL). Protein content, density and viscosity in all beverages exhibited a significantly strong positive correlation. The protein soft drink containing beef protein isolate stood out for highest protein content, density, particle size and TTA. Overall, these results demonstrate the effects and correlations of the different formulations on the quality characteristics. Therefore, the presented results can be utilized in the development and formulation of future protein soft drinks, including nutritional improvement and optimum quality, meeting current consumer trends and that are used as a convenient pre- or post-workout drink for individuals seeking muscle growth and repair.

Sugar beet pectin as a natural carrier for curcumin, a water-insoluble bioactive for food and beverage enrichment: Formation and characterization

Food and beverages enrichment with water-insoluble health-promoting nutraceuticals is important, but technologically challenging. Sugar beet pectin (SBP) is a natural dietary fiber with high emulsifying capacity. However, its potential as a natural encapsulator of hydrophobic nutraceuticals for beverage enrichment, has hardly been explored. Curcumin is a potent antioxidant with numerous attributed health benefits, but very low aqueous-solubility. We herein explored SBP as a carrier for solubilization and protection of curcumin (CUR). Using spectrofluorimetry, the CUR-SBP binding constant determined was (6.74 ± 0.5) ∙ 105M−1. As CUR:SBP molar ratio increased from 14:1 to 140:1, CUR encapsulation capacity increased from 14.5 ± 0.8 to 127.4 ± 0.4 mg CUR/gSBP, and encapsulation efficiency moderately decreased from ~100% to 86 ± 7%. The encapsulation in SBP dramatically decreased CUR particle size, from >17 μm to <0.5 μm, in average, and conferred substantial protection to CUR during simulated shelf-life, decreasing the decay rate constant ~7 fold. Therefore, SBP is a potent natural encapsulator for hydrophobic nutraceuticals for food and even clear beverage enrichment.

Characterization of recombinant GRIP32 as a novel haze protein for protein-polyphenol haze models and prevention of haze formation with polysaccharides in the models

Haze-active proteins are an important factor in haze formation in wine and clear beverages. The aim of this study was to understand the role of haze proteins from pland origin, which are rich in basic amino acids from the plants, in the haze formation involving proteins and polyphenols, as well as to develop strategies to prevent haze formation. The grape ripening-related protein-like (GRIP) containing 12.50% histidine, 28.13% glycine, 16.41% glutamic acid and 1.56% arginine was screened as a potential haze protein from grape by bioinformatics, and recombinantly expressed, purified and characterized. The recombinant GRIP32 (rGRIP32) could be effectively removed by the adsorbents (i.e. bentonite and kaolin), or hydrolyzed by proteases (i.e. papain, neutral protease, and alkaline protease). Procyanidins (PCs) or epigallocatechin gallate (EGCG) were proved to form a haze with rGRIP32. Protein-polyphenol haze models were established using rGRIP32 at 25 °C and pH 5.0. Polysaccharides including pectin, xanthan gum, and guar gum were shown to suppress the haze caused by rGRIP32. The microscale thermophoresis (MST) assay provided new evidences for the binding of proteins and polyphenols to form haze, and demonstrated that the mechanisms of polysaccharide-based haze prevention include competitive binding of polyphenols and formation of ternary complexes with them.

Improved of Smart Vacuum Flask with Beverage Identifier and Temperature Indicator

Vacuum flask has been an essential part of the everyday life of a working person. Nowadays, vacuum flask is not the only function as a liquid carrier but also has been equipped with technology to diversify its function from the essential function. This paper proposes to create a smart vacuum flask that able to classify the beverage type and indicate the temperature range of the beverage. This is attempted to address the user difficulty in remembering the type and temperature of the beverage inside the vacuum flask. This project is built using Arduino as the microcontroller, while LM35 is used to read the temperature sensor. A simple concept of tomography using LDRs and LEDs is used to determine the beverage type. The flask is tested to test nine scenarios: 1) cold and clear beverage; 2) warm and clear beverage; 3) hot and clear beverage; 4) cold and juice beverage; 5) warm and juice beverage; 6) hot and juice beverage; 7) cold and milk beverage; 8) warm and milk beverage; 9) hot and milk beverage. The result obtained indicates that the prototype able to classify all nine scenarios correctly.

Preparation, Physicochemical Characterization and Oxidative Stability of Omega-3 Fish Oil/α-Tocopherol-co-Loaded Nanostructured Lipidic Carriers.

Purpose: This study aimed to improve the pharmacokinetic behavior of polyunsaturated fatty acids (PUFAs) oxidation to enhance oxidative stability for inhibiting formation of toxic hydroperoxides, develops off-flavors and shortens shelf-life. Methods: Nanostructured lipid carrier (NLC) co-encapsulating omega-3 fish oil and α-tocopherol was successfully prepared by melt blending and hot sonication method to enhance the oxidative stability of the fish oil. Encapsulation efficiency (EE) and in vitro release, the oxidative stability of prepared nanoparticles (NPs) were measured using detection of peroxide value (PV) and thiobarbituric acid (TBA) during 40 days. Results: Electron microscopy and particle size analysis showed dispersed and homogenous NPs with an average diameter of 119 nm. Sustained oil release at a physiologic pH, and longterm stability in terms of the size, zeta, and dispersity of NPs was achieved after 75 days of storage. The omega-3 fish oil co-encapsulated with α-tocopherol in the NLC possessed better oxidative stability compared with the all other formulations. Also, it was found that the NLC as an encapsulation method was more successful to inhibit the formation of the primary oxidation products than the secondary oxidation products. Conclusion: Generally, these findings indicated that co-encapsulation of fish oil and α-tocopherol within the NLC can be a suitable delivery system in order to enrich foodstuffs, in particular clear beverages.

Sustainable alternative for the food industry: converting whey and orange juice into a micro-filtered beverage

Enhancing industrial sustainability by converting whey into alternative high value-added products is a scientific trend in food science and technology. However, without other ingredients, rennet, or sour, whey has an unappetizing flavor. This sensory challenge can be overcome by blending it with citrus flavor from orange juice. This study assessed a micro-filtered beverage from whey and orange juice without enzymatic treatment. Four formulations (27:10, 8.6:10, 2.4:10 and 1:10 v/v whey:juice ratio) were processed through a 1.4 μm microfiltration system with four different transmembrane pressures (1, 2, 3, and 4.15 bar) and then stored at 5 °C for 28 days. The micro-filtered beverage was analyzed for physicochemical, sensorial and microbial changes. It was possible overcome the technological challenges of orange juice microfiltration without enzymatic treatment with high transmembrane pressures. The whey:orange juice ratio was also decisive for permeation. A clear beverage with lower viscosity, turbidity, and protein levels was obtained, without altering mineral concentrations thus showing that the product has good capacity for hydration. The beverage presented good microbiological quality and remained stable for 28 days at 5 °C. Sensory evaluation data indicate that the beverage can be directed to young people and women, regardless of their physical activity. The combination of whey and orange juice can be explored industrially as a micro-filtered beverage, with satisfactory results of physicochemical, microbiological and sensory acceptance.

Sensory characterisation of a high‐protein beverage

This study investigated the use of sonication to increase the light transmission of protein solutions. Sonicating a five per cent whey/soy blend at pH 4 resulted in a threefold higher light transmission. Sensory analysis showed that panellists preferred the transparency of the sonicated beverage, whereas the smell and flavour of the control beverage were preferred. Overall appearance, colour and mouthfeel were not different. Panellists who preferred the control liked its creamy thickness, while those who preferred the sonicated liked the transparency. Data show that panellists who want a high protein content in their drinks are not looking for clear beverages.

Using protein-fatty acid complexes to improve vitamin D stability.

Liprotides are complexes between lipids and partially denatured proteins in which the protein forms a stabilizing shell around a fatty acid micelle core. We have previously shown that liprotides stabilize small aliphatic molecules such as retinal and tocopherol by sequestering these molecules in the fatty acid core. This opens up the use of liprotides to formulate food additives. Here, we expand our investigations to the large and bulky molecule vitamin D3 (vitD), motivated by the population-wide occurrence of vitD deficiency. We prepared liprotides using different proteins and fatty acids and evaluated their ability to protect vitD upon exposure to heating or intense UV light. Additionally, we determined the stability of liprotides toward pH, Ca(2+), and BSA. The best results were obtained with liprotides made from α-lactalbumin and oleate. These liprotides were able to completely solubilize vitD, increase the stability toward UV light 9-fold, and increase the long-term stability at 37°C up to 1,000-fold. Native α-lactalbumin binds Ca(2+), making Ca(2+) potentially disruptive toward liprotides. However, liprotides prepared by incubation at 80°C were stable toward Ca(2+), in contrast to those made at 20°C. Nevertheless, the fatty acid binding protein BSA reduced the ability of both liprotides to protect vitD; the amount of vitD remianing after 20d at 20°C decreased from 79±3% in the absence of BSA to 49±4 and 23±3% in the presence of BSA for liprotides made at 80 and 20°C, respectively. Both classes of liprotides were able to release their vitD content, as demonstrated by the transfer of vitD encapsulated in liprotides to phospholipid vesicles. Importantly, liprotides were not stable at pH 6 and below, limiting the useful pH range of the liprotides to >pH 6. Our results indicate that vitD may be encapsulated and stabilized for enrichment of clear beverages at neutral pH to improve the intake and bioavailability of vitD.

The Effects of Receptacle on the Expected Flavor of a Colored Beverage: Cross‐Cultural Comparison Among French, Japanese, and Norwegian Consumers

AbstractThe present online study was designed to investigate whether the expected flavor associated with a colored beverage is affected by the type of receptacle in which the drink is presented. More than 400 participants from France, Japan and Norway viewed photographs of red, green, yellow, blue, orange, brown and clear beverages presented in a water glass, a wine glass, a cocktail glass or a plastic cup. They had to indicate the first flavor that came to mind by choosing a flavor from a list of 24 options, and to rate the familiarity and pleasantness of each drink. The results revealed that the nature of the receptacle modulated the meaning (expected flavor) of color for the red, green, yellow, blue and orange drinks. Cultural differences were observed in terms of the expected flavor elicited by the blue drinks, as well as how different receptacles influenced the familiarity and pleasantness ratings of the same drinks.Practical ApplicationsThe present study provides a better understanding of the crossmodal correspondences observed in the case of beverages. We demonstrate how the type of receptacle, an important but all too frequently neglected contextual factor, influences the expected flavor elicited by color. These findings regarding crossmodal correspondences are relevant to sensory scientists interested in the flavor‐color associations of beverages. What is more, our results also reveal cross‐cultural differences in the perception of beverages, and demonstrate how associations that people in certain countries/cultures may take for granted could be very surprising or novel in other cultures/countries. Specially, the present study provides new evidence concerning how people from France and Japan (both of which are well known for their unique and distinctive food cultures) would respond to the same colored drinks in similar or different ways to other groups of people (who have been tested in the present or previous research). Therefore, our findings are also important in terms of international marketing, and highlight the importance of getting the receptacle right when displaying a beverage in online marketing.

Potato protein based nanovehicles for health promoting hydrophobic bioactives in clear beverages

Vitamin D is a fat soluble nutraceutical of great importance for multi-system function: calcium and bone metabolism, insulin reactivity, cell differentiation, the immune system and more. However its deficiency is a pandemic problem, which calls for fortification of staple foods and popular beverages with this vital micronutrient. Fortifying beverages with vitamin D poses tough challenges especially due to its low aqueous solubility, and acid-sensitivity. We studied the possibility of using potato proteins as protective nanovehicle for delivery of vitamin D in clear beverage solutions. Potato proteins are produced from a widely available and inexpensive raw material. They are considered GRAS and non-allergenic. Moreover, Potato proteins are natural and applicable in vegetarian, vegan and KOSHER PARVE products. Vitamin D3 (VD) – potato protein nanoparticles were formed in phosphate buffer at pH 2.5 and the solutions obtained were transparent. The VD – potato protein co-assemblies were much smaller than the VD aggregates without potato protein. The nanocomplexation provided significant protection and reduced VD losses during pasteurization, and during simulated shelf life tests under several different sets of storage conditions. Hence potato protein shows promise as a good protective carrier for VD, and possibly other hydrophobic bioactives, for enrichment of clear beverages and other food & drink products, to promote human health.

National beer in a global age: technology, taste, and mobility, 1880-1914

This paper uses professional brewing journals from the United States, Britain, and Germany in order to understand the construction of a particular variety of lager beer as a global standard. During the nineteenth and twentieth centuries, European beer traveled the world through circuits of trade, migration, and colonialism. In doing so, it came to be assciated with a global version of consumer culture. Informed by Bruno latour, George Marcus, and Elizabeth Zanoni, this paper examines intellectual, professional, and market exchanges between brewers in different countries as well as the debates over production techniques and taste that accompanied the evolution of brewing over this period. It seeks to incorporate notions of mobility studies, particularly the relationship of things that travel with things that stay rooted, to see the connections between global commodity chains, itinerant brewers, migrant populations, and ideals of localism over the course of two centuries. it concludes that cosmopolitan brewers attempted to claim distinctive national styles during a period of international rivalry on the eve of World War I, notwithstanding the increasing convergence of their products toward the homogenized tastes that the craft movement would later decry: light, clear beverages that were low in body and alcohol.

Formation, optical property and stability of orange oil nanoemulsions stabilized by Quallija saponins

Nanoemulsions have the potential to deliver insoluble materials and yet provide a transparent appearance in clear beverage applications. The influence of oil phase composition, phase viscosity and homogenization conditions on the formation, stability and optical properties of orange oil-based nanoemulsions was investigated. The nanoemulsions were formed using Quillaja saponins (QS) and homogenization accomplished using Microfluidization®. The results indicated oil phase composition and viscosity ratio between phases are key parameters determining the mean droplet diameter (MDD) of the prepared nanoemulsions. Orange oil nanoemulsions stabilized by QS showed MDD as small as 67 nm corresponding to turbidity of 71 NTU at dispersed phase concentration of 0.5 mg/g. Lipid phase refractive index showed no effect on turbidity of orange oil nanoemulsions at MDD<150 nm, while MDD was linearly related to the turbidity with MDD ranging from 60 nm to 120 nm. Ostwald ripening was identified as main destabilization mechanism of orange oil nanoemulsions stabilized by QS at the early stage of storage. The rate of Ostwald ripening was reduced with increasing amounts of medium chain triglycerides (MCT) in the dispersed phase. An insoluble material, e.g., ester gum or MCT, was required to form stable orange oil-based nanoemulsions.

Preparation and characterization of nanoemulsions stabilized by food biopolymers using microfluidization

AbstractEmulsions are widely used in beverage products and typically impart cloudiness to the beverage. Nanoemulsions have the potential to provide a transparent appearance to the beverage. The objective of the present study was to investigate the formation of nanoemulsions using food biopolymers and its potential for clear beverage applications. The biopolymers chosen for study were Gum Arabic (GA), modified gum arabic (MGA), whey protein isolate (WPI) and modified starch (Purity Gum 2000, MS). Weighted orange oil terpenes (OT) and medium chain triglycerides (MCT) were used as the dispersed phase. Nanoemulsions were characterized by dynamic light scattering (DLS), cryogenic scanning electron microscopy (Cryo‐SEM) and turbidimeter. Except for the WPI stabilized nanoemulsions, higher homogenization pressures (up to 22 000 psi) and a greater number of passes (up to 7) through a Microfluidizer® produced nanoemulsions with a smaller mean droplet diameter in volume (MDD, dV). MS showed the best performance of the food biopolymers resulting in a MDD as small as 77 nm and a corresponding turbidity of 72 NTU (Nephelometric Turbidity Units) at 0.05% of the dispersed phase, whereas GA produced emulsions with the largest MDD. The MDD of MS stabilized nanoemulsions decreased with increasing MS concentrations (from 5 to 25 wt %). The effect of oil types on MDD was complex being dependent on the emulsifier and homogenization pressure. Turbidity of diluted nanoemulsions increases with MDD within the range of 70–300 nm. This study shows food biopolymers can be used to produce nanoemulsions using microfluidization under a high pressure. It was also demonstrated that nanoemulsions with a MDD &lt; 100 nm can provide a clear appearance in beverage applications. The results provide an understanding of how manufacturing parameters and formulation influence the formation of nanoemulsions. Copyright © 2015 John Wiley &amp; Sons, Ltd.

Efficacy and mechanisms of murine norovirus inhibition by pulsed-light technology.

Pulsed light is a nonthermal processing technology recognized by the FDA for killing microorganisms on food surfaces, with cumulative fluences up to 12 J cm(-2). In this study, we investigated its efficacy for inactivating murine norovirus 1 (MNV-1) as a human norovirus surrogate in phosphate-buffered saline, hard water, mineral water, turbid water, and sewage treatment effluent and on food contact surfaces, including high-density polyethylene, polyvinyl chloride, and stainless steel, free or in an alginate matrix. The pulsed-light device emitted a broadband spectrum (200 to 1,000 nm) at a fluence of 0.67 J cm(-2) per pulse, with 2% UV at 8 cm beneath the lamp. Reductions in viral infectivity exceeded 3 log10 in less than 3 s (5 pulses; 3.45 J cm(-2)) in clear suspensions and on clean surfaces, even in the presence of alginate, and in 6 s (11 pulses; 7.60 J cm(-2)) on fouled surfaces except for stainless steel (2.6 log10). The presence of protein or bentonite interfered with viral inactivation. Analysis of the morphology, the viral proteins, and the RNA integrity of treated MNV-1 allowed us to elucidate the mechanisms involved in the antiviral activity of pulsed light. Pulsed light appeared to disrupt MNV-1 structure and degrade viral protein and RNA. The results suggest that pulsed-light technology could provide an effective alternative means of inactivating noroviruses in wastewaters, in clear beverages, in drinking water, or on food-handling surfaces in the presence or absence of biofilms.

Amphiphilic zein hydrolysate as a novel nano-delivery vehicle for curcumin.

In this paper, we developed amphiphilic zein hydrolysate (ZH) as a novel delivery vehicle, which could be used for preparing curcumin (Cur) nanocomplexes. These ZH-Cur nanocomplexes exhibited spherical morphology with a monodisperse size distribution (<50 nm), and the dispersion was transparent, which could have a great application potential in nutraceutical-fortified food and clear beverages. The water solubility of curcumin was considerably enhanced by the nanocomplexation above 8200-fold (vs. free curcumin in water). The good colloidal and storage stability of ZH-Cur nanocomplexes was greatly improved, and more than 60% of curcumin was retained in 72 h storage under ambient conditions. These phenomena appeared to be attributable to the fact that amphiphilic ZH displayed self-assembly properties in water solution and strong interfacial activity at the oil-water interface, as confirmed by micelle formation and dynamic interfacial adsorption respectively. Fluorescence titration and FTIR results indicated the existence of strong hydrophobic interactions between ZH and Cur, which was responsible for the complexation.

Soy β-Conglycinin−Curcumin Nanocomplexes for Enrichment of Clear Beverages

Delivery of sensitive health-promoting compounds in foods and beverages is an important and timely challenge. Curcumin, a natural polyphenol and the major pigment of the turmeric root, is a potent antioxidant with numerous attributed health benefits. However the major hurdle for applicability of curcumin as a food ingredient is its extremely low solubility in aqueous solutions at both acidic and neutral pH, and its consequent poor bioavailability. Here we have studied the possibility of using the soybean protein β-conglycinin (β-Cg) to form co-assembled nanovehicles for delivery of curcumin in clear beverages, where dietary and religious constraints preclude the use of milk proteins. Using visible light spectrophotometry we found high affinity between β-Cg and curcumin with a binding constant of about 1.27 · 106 M−1. The curcumin − β-Cg co-assemblies were much smaller than the curcumin aggregates without β-Cg. While in the absence of β-Cg, curcumin aggregates were several microns large and visible by eye, in the presence of β-Cg, particles were much smaller and showed a bimodal size distribution, with modal-average diameters of 27 nm (~90 % of the particles on a volume basis) and 110 nm (~10 %), and average of 46 nm, as measured by dynamic light scattering, and supported by cryoTEM images. Therefore, transparency was maintained in the β-Cg-curcumin co-assembly systems, enabling application in clear beverages. The curcumin – β-Cg system was characterized at increasing molar ratios. The binding sites saturation point of β-Cg was found to be around 15:1 curcumin:β-Cg molar ratio, or about 3 g curcumin/100 g β-Cg. Based on light microscopy observations, the presence of β-Cg both suppressed curcumin crystallization and modified crystal morphology. Moreover, β-Cg − curcumin co-assemblies were found to confer considerable protection to curcumin against light and oxidation induced degradation.

β-Lactoglobulin–naringenin complexes: Nano-vehicles for the delivery of a hydrophobic nutraceutical

Naringin, a glycosylated polyphenol of the flavanones class and its aglycone, naringenin, have been shown to possess many health benefits, therefore they show promise for supplementation of staple foods and beverages, as a mean of preventive medicine. Major obstacles to the successful implementation of these flavanones as nutraceuticals are their low water-solubility and the related low oral bioavailability. Naringin is more soluble but is also very bitter. To allow the enrichment of clear beverages with these important health promoters, we have used native and preheated β-Lactoglobulin (β-Lg) based nanovehicles. Using UV spectrophotometry and intrinsic fluorescence methods, we have found that naringenin forms complexes with preheated and non-preheated β-Lg, with Ka in the order of 104 M−1. No binding was found between naringin and β-Lg, probably due to the lower hydrophobicity of naringin and the steric interference of its sugar. Naringenin: β-Lg binding stoichiometry was 2:1, suggesting naringenin was probably bound at the two main hydrophobic binding sites of the protein, the calyx and the cleft near the alpha-helix. The complex formation with both native and preheated protein solubilized naringenin up to 3 times its solubility limit and prevented crystal formation in the aqueous medium. Such crystallization is responsible for both reduced bioavailability and hampered visual attractiveness of the product. Dynamic light scattering revealed the existence of nanoparticles of ∼10 nm, marginally larger than those of the pure protein (∼7 nm), therefore the solution was clear, hence suitable for clear beverages. Reconstitution after freeze drying was good, but only after quench freezing.

Milk protein–vitamin interactions: Formation of beta-lactoglobulin/folic acid nano-complexes and their impact on in vitro gastro-duodenal proteolysis

Growing attempts are being made to rationally utilize foods for human health improvement and disease prevention. Milk proteins are well suited for this purpose, since they are widely consumed, offer nutritional benefits and have been shown to be potentially suitable carriers for bioactive ingredients, such as vitamins and nutraceuticals. This work characterizes the interactions between β-lactoglobulin (β-lg) and folic acid (FA) at different load ratio and their functional implications, in terms of colloidal behavior and digestibility. Dynamic light scattering, isothermal titration calorimetery and atomic force microscopy were used to investigate β-lg/FA nano-complexes (mean size < 10 nm) formed at protein:vitamin molar ratio 1:10, whereas three FA molecules were found to be bound to one protein molecule. Colloidal stability tests (3 < pH < 10) revealed that nano-complexes formation improved β-lg dissolution near its isoelectric point and at low pH-values. This was also found to be accompanied by a shift in zeta-potential values at pH = 5 for pure β-lg (0.95 ± 0.09 mV) versus β-lg/FA nano-complexes (−20.13 ± 1.29 mV). SDS-PAGE analysis of digesta, collected from gastric and duodenal in vitro digestion of β-lg and its nano-complexes, revealed no marked alterations in the proteolytic susceptibility of β-lg. The study findings show the interactions of FA and β-lg in the formation of nano-complexes may be harnessed for delivery of FA in clear beverages with minimal effects to the protein's sensitivity to proteolysis.

Stability of vitamin D3 encapsulated in nanoparticles of whey protein isolate

Vitamin D3 was entrapped in whey protein isolate (WPI) nanoparticles prepared by different calcium concentration and aggregation pH. Its stability was investigated in presence of air for 7days. Residual of vitamin D3 in nanoparticles was higher compared to control samples (water, native WPI and denaturized WPI). Presence of calcium in composition of particles resulted in formation of compact structure and inhibition of oxygen diffusion in particle. Lower concentration of vitamin D3 (280μg/ml versus 560μg/ml) had negative effect on residual amount of vitamin. The loss of vitamin D3 during storage time was described by a second order reaction. The results illustrate that these nanoparticles can be used in clear or non clear beverages as enriching agent.