Combination of rehydrated whey protein isolate aqueous solution with blackcurrant concentrate and the formation of encapsulates via spray-drying and freeze-drying: Alterations to the functional properties of protein and their anticancer properties.

Novel protein ingredients were produced by encapsulating blackcurrant concentrate (BC) with whey protein through spray-, or freeze-, drying strategies. The effects of encapsulation strategies and the addition of BC on the physical and functional characteristics, and anticancer activity of the ingredients were evaluated. The mechanistic interactions between the blackcurrant anthocyanins (BAs) with the whey protein components were predicted via in silico studies. HPLC results revealed that spray-dried and freeze-dried whey protein-BC encapsulates have effectively delivered the BAs. The physical and functional properties of the proteins were altered by drying strategies and the addition of BC. Anticancer effects were linked to reactive oxygen species production and cell apoptosis towards HepG2. Molecular docking results showed that hydrogen bonds were the main binding forces between BAs and various whey protein molecules, resulting in the formation of complexes. These findings are relevant to the formulation of powdered products to be used as ingredients in practical food matrix.

Fabrication and characterization of whey protein isolates- lotus seedpod proanthocyanin conjugate: Its potential application in oxidizable emulsions.

Emulsified ω-3 polyunsaturated fatty acid have expanding application in different food matrix with improved water solubility while still prone to oxidation. Lotus seedpod proanthocyanidin (LSPC) was grafted to whey protein isolate (WPI) to create nature-derived antioxidant emulsifiers. 1HNMR, SDS-PAGE and multiple spectrometry showed that the structure of protein was changed after grafting. DPPH and FRAP measurements showed that WPI-LSPC conjugate (90.53 ± 1.48% of DPPH scavenging, 691.85 ± 4.54 µg/mL for FRAP assay) possessed a much better antioxidant ability than WPI (17.06 ± 3.34% of DPPH scavenging, 10.43 ± 0.26 µg/mL for FRAP assay). Ultrasonic emulsification and DSC experiments showed that WPI-LSPC conjugate were more effective at forming and stabilizing the flaxseed oil emulsions than pure WPI, with higher thermostability. Likewise, low levels of primary and secondary oxidation products were formed for the conjugate than the pure protein in O/W systems after storage, again suggesting WPI-LSPC could be used as fine antioxidant emulsifiers in oxidizing delivery systems.

Chemical composition as an indicator for evaluating heated whey protein isolate (WPI) and sugar beet pectin (SBP) systems to stabilize O/W emulsions.

We investigated changes in the chemical composition of WPI as a result of heating (60 °C, 72 h) with SBP in solution (pH 6.75). The concentration of WPI was kept at a constant (3%), whereas the level of SBP was varied at 1, 1.5, and 3%. The reaction products were examined using the Ellman's reagent, ninhydrin assay, and gel electrophoresis. The results demonstrated that the losses of the free sulfhydryl (-SH) and primary amine (-NH2) contents in WPI were less severe compared to those occurring in the dry-state at similar conditions (mass ratio, temperature, and reaction duration). The mixtures were used as emulsifiers in an O/W emulsion system at pH 3.20 and 6.75 and showed an improved ability to stabilize the average size of the droplets than WPI alone at acidic pH. The mixtures at higher levels of SBP, ≥ 1.5%, however, adversely affected the emulsion stability at neutral pH.

Influence of heated, unheated whey protein isolate and its combination with modified starch on improvement of encapsulated pomegranate seed oil oxidative stability.

This study aimed at encapsulating pomegranate seed oil (PSO) by emulsification followed by spray drying using whey protein isolate (WPI) in its natural form, heated (Pickering), and combined with modified starch (WPI:Capsul®) as emulsifiers/wall materials. Emulsions were stable under different stress conditions. Pickering emulsions presented bigger droplet size (6.49-9.98 µm) when compared to WPI (1.88-4.62 µm) and WPI:Capsul® emulsions (1.68-5.62 µm). Sixteen fatty acids were identified in PSO. WPI treatment was considered the best formulation since it presented the highest fatty acid retention (68.51, 65.47, 47.27, 53.68, 52.95, and 52.28% for linoleic, oleic, punicic, α-eleostearic, catalpic, and ß-eleostearic acids after 30 days-storage, respectively) and protected the oil against volatile compound formation (heptanal, (E,E)-2,4-heptadienal, (Z)-2-heptenal, octanal, pentanal, (E)-2-hexenal, (E)-2-octenal, nonanal, (E)-2-decenal, and (E,E)-2,4-octadienal), which did not occur with free PSO. Overall, encapsulation protected PSO against oxidation over time, which may allow the development of new functional foods.

Interactions of Whey Proteins with Metal Ions.

Whey proteins tend to interact with metal ions, which have implications in different fields related to human life quality. There are two impacts of such interactions: they can provide opportunities for applications in food and nutraceuticals, but may lead to analytical challenges related to their study and outcomes for food processing, storage, and food interactions. Moreover, interactions of whey proteins with metal ions are complicated, requiring deep understanding, leading to consequences, such as metalloproteins, metallocomplexes, nanoparticles, or aggregates, creating a biologically active system. To understand the phenomena of metal-protein interactions, it is important to develop analytical approaches combined with studies of changes in the biological activity and to analyze the impact of such interactions on different fields. The aim of this review was to discuss chemistry of ß-lactoglobulin, α-lactalbumin, and lactotransferrin, their interactions with different metal ions, analytical techniques used to study them and the implications for food and nutraceuticals.

Impact of gum Arabic on the partition and stability of resveratrol in sunflower oil emulsions stabilized by whey protein isolate.

In protein-stabilized oil-in-water emulsions, a co-emulsifier may also be an antioxidant, increasing the oxidative stability of the oil and adding nutritional value to the formulation. We investigated the impact of gum Arabic on the partition and stability of resveratrol in sunflower oil emulsions produced using whey protein isolate in the absence and presence of calcium. Gum Arabic increased the protein and resveratrol contents at the oil-water interface and the stability of resveratrol, which was enhanced by calcium. Resveratrol increased the oxidative stability of the oil. These results indicate that resveratrol is stable in the interfacial membrane of emulsions made with whey protein isolate, calcium and gum Arabic and suggest that oil-in-water emulsions could be used as potential carriers of co-encapsulated functional oils and polyphenolic antioxidants.

Rheological and microstructural properties of cold-set emulsion gels fabricated from mixed proteins: Whey protein and lactoferrin.

Cold-set emulsion gels were fabricated from oil droplets coated by mixed proteins: whey protein and lactoferrin. The impact of protein composition, droplet concentration, pH, and ionic strength on the microstructure, texture, and stability of the cold-set emulsion gels was determined. Protein composition had a major influence on gel strength, with the strongest emulsion gels being formed at an optimized protein composition (0.5 wt% whey protein and 1.5 wt% lactoferrin). The storage modulus of the emulsion gels increased from 149 to 1590 Pa as the droplet concentration increased from 10 to 40 wt%. The gel strength could also be modulated by adjusting pH, with the strongest gels being formed at pH = 6.5, where the net charge on the droplets was neutral. Increasing the ionic strength weakened the electrostatic interactions, which inhibited droplet aggregation and led to a decrease in gel strength. These results may be useful for designing cold-set emulsion gels with rheological properties that can be tailored for specific commercial products.

Affinity chromatography matrices for depletion and purification of casein glycomacropeptide from bovine whey.

Casein glycomacropeptide (CMP) is a 64- amino acid peptide found in cheese whey, which is released after κ-casein specific cleavage by chymosin. CMP lacks aromatic amino acids, a characteristic that makes it usable as a nutritional supplement for people with phenylketonuria. CMP consists of two nonglycosylated isoforms (aCMP A and aCMP B) and its different glycosylated forms (gCMP A and gCMP B). The most predominant carbohydrate of gCMP is N-acetylneuraminic acid (sialic acid). Here, we developed a CMP purification process based on the affinity of sialic acid for wheat germ agglutinin (WGA). After formation of chitosan beads and adsorption of WGA, the agglutinin was covalently attached with glutaraldehyde. Two matrices with different WGA density were assayed for CMP adsorption. Maximum adsorption capacities were calculated according to the Langmuir model from adsorption isotherms developed at pH 7.0, being 137.0 mg/g for the matrix with the best performance. In CMP reduction from whey, maximum removal percentage was 79% (specifically 33.7% of gCMP A and B, 75.8% of aCMP A, and 93.9% of aCMP B). The CMP was recovered as an aggregate with an overall yield of 64%. Therefore, the matrices developed are promising for CMP purification from cheese whey. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 33:171-180, 2017.

Sensory and Functionality Differences of Whey Protein Isolate Bleached by Hydrogen or Benzoyl Peroxide.

UNLABELLED: Whey protein is a highly functional food ingredient used in a wide variety of applications. A large portion of fluid whey produced in the United States is derived from Cheddar cheese manufacture and contains annatto (norbixin), and therefore must be bleached. The objective of this study was to compare sensory and functionality differences between whey protein isolate (WPI) bleached by benzoyl peroxide (BP) or hydrogen peroxide (HP). HP and BP bleached WPI and unbleached controls were manufactured in triplicate. Descriptive sensory analysis and gas chromatography-mass spectrometry were conducted to determine flavor differences between treatments. Functionality differences were evaluated by measurement of foam stability, protein solubility, SDS-PAGE, and effect of NaCl concentration on gelation relative to an unbleached control. HP bleached WPI had higher concentrations of lipid oxidation and sulfur containing volatile compounds than both BP and unbleached WPI (P < 0.05). HP bleached WPI was characterized by high aroma intensity, cardboard, cabbage, and fatty flavors, while BP bleached WPI was differentiated by low bitter taste. Overrun and yield stress were not different among WPI (P < 0.05). Soluble protein loss at pH 4.6 of WPI decreased by bleaching with either hydrogen peroxide or benzoyl peroxide (P < 0.05), and the heat stability of WPI was also distinct among WPI (P < 0.05). SDS PAGE results suggested that bleaching of whey with either BP or HP resulted in protein degradation, which likely contributed to functionality differences. These results demonstrate that bleaching has flavor effects as well as effects on many of the functionality characteristics of whey proteins. PRACTICAL APPLICATIONS: Whey protein isolate (WPI) is often used for its functional properties, but the effect of oxidative bleaching chemicals on the functional properties of WPI is not known. This study identifies the effects of hydrogen peroxide and benzoyl peroxide on functional and flavor characteristics of WPI bleached by hydrogen and benzoyl peroxide and provides insights for the product applications which may benefit from bleaching.