Microbubbles in Food Technology.

Microbubbles are largely unused in the food industry yet have promising capabilities as environmentally friendly cleaning and supporting agents within products and production lines due to their unique physical behaviors. Their small diameters increase their dispersion throughout liquid materials, promote reactivity because of their high specific surface area, enhance dissolution of gases into the surrounding liquid phase, and promote the generation of reactive chemical species. This article reviews techniques to generate microbubbles, their modes of action to enhance cleaning and disinfection, their contributions to functional and mechanical properties of food materials, and their use in supporting the growth of living organisms in hydroponics or bioreactors. The utility and diverse applications of microbubbles, combined with their low intrinsic ingredient cost, strongly encourage their increased adoption within the food industry in coming years.

The effects of whey protein fibrils on the linear and non-linear rheological properties of a gluten-free dough.

The increasing awareness of the celiac disease, an autoimmune disorder caused by the consumption of products containing gluten, has led to a growing interest in the development of gluten-free bakery products. In this study, whey protein fibrils (WPFs) were incorporated to mimic the fibrous network of gluten. The rheological properties and microstructure of the developed gluten-free doughs were evaluated and compared with gluten doughs. Protein fibrils were prepared by heating a whey protein isolate (WPI) solution at 80°C in an acidic environment with low salt concentration, and then the fibril lengths were adjusted by leveling up the solution pH to 3.5 and 7. The dimensions of the fibrils were measured by atomic force microscopy (AFM). Rice and potato starches were mixed with fibrils, WPI, gluten, or without protein, to form different doughs for further investigation. Shear tests, including stress sweep, frequency sweep, and creep recovery, were performed to study the viscoelastic properties of doughs under small or large deformation. The strain-hardening properties of doughs under biaxial extension were studied by the lubricated squeezing flow method. The microstructure of the doughs was characterized by cryo-scanning electron microscopy (cryo-SEM). Compared with doughs prepared with WPI and no proteins, doughs incorporating fibrils showed comparable linear viscoelasticity to gluten dough tested with stress sweep, frequency sweep, and creep recovery in the linear viscoelastic region. More differences between the protein fibril doughs were revealed in the rheological properties in the non-linear region. Creep recovery parameters, such as compliance, elastic moduli during the creep, and recovery stages of gluten dough, were like those of WPF pH7 dough, but significantly different from those of the WPF pH3.5 dough. Strain-hardening properties were found in the WPF pH7 dough, although not in WPF pH3.5 dough. Microstructural characterization showed that both fibrils prepared with the different conditions formed a continuous protein phase for the improvement of dough cohesiveness, but the structure of the phase was different between the two fibrils. To summarize, whey protein fibril at pH 7 seemed to have the potential of being used as an ingredient with similar functions to gluten in gluten-free bakery products.

Polyphenols Weaken Pea Protein Gel by Formation of Large Aggregates with Diminished Noncovalent Interactions.

Polyphenols are well-known native cross-linkers and gel strengthening agents for many animal proteins. However, their role in modifying plant protein gels remains unclear. In this study, multiple techniques were applied to unravel the influence of green tea polyphenols (GTP) on pea protein gels and the underlying mechanisms. We found that the elasticity and viscosity of pea protein gels decreased with increased GTP. The protein backbone became less rigid when GTP was present based on shortened T1ρH in relaxation solid-state NMR measurements. Electron microscopy and small-angle X-ray scattering showed that gels weakened by GTP possessed disrupted networks with the presence of large protein aggregates. Solvent extraction and molecular dynamic simulation revealed a reduction in hydrophobic interactions and hydrogen bonds among proteins in gels containing GTP. The current findings may be applicable to other plant proteins for greater control of gel structures in the presence of polyphenols, expanding their utilization in food and biomedical applications.

Incorporation of Plasticizers and Co-proteins in Zein Electrospun Fibers.

As a means to alter the physical properties of electrospun zein fibers, plasticizers (glycerol, lactic acid, and oleic acid) or co-proteins (casein, whey protein, rice protein) were mixed with zein using the solvents acetic acid or aqueous ethanol with or without sodium hydroxide. Incorporating plasticizers or co-proteins had a negligible impact on solution viscosity, solution surface tension, and fiber formation, although electron microscopy of fiber mats showed an increase in bead formation with added co-proteins. Gel electrophoresis identified casein and whey protein in spun mats. Infrared spectra demonstrated the inclusion of plasticizers in fiber mats. Glycerol, lactic acid, and oleic acid reduced the glass transition temperature of bulk fibers. Nanoindentation tests of individual fibers found reduced Young's moduli with added lactic or oleic acids but increased moduli with added casein. Thus, electrospinning zein with food-grade plasticizers or proteins physically modifies fibers, yet incorporating significant protein quantities remains a challenge.

Electrospinning Induced Orientation of Protein Fibrils.

Amyloid-like fibrils are prepared from protein in the lab by controlled heat treatments, yet these must be further assembled to match the desirable mechanical and structural properties of biological fibers. Here, ß-lactoglobulin fibrils were incorporated into poly(ethylene oxide) fibers of 40-180 nm diameter by electrospinning. Protein fibrils presented as short segments dispersed within electrospun fibers, with no change in fibril diameter after electrospinning. Imaging analysis revealed fibrils were aligned within 20° relative to the fiber long axis, and alignment was further confirmed by polarized FTIR and anisotropic SAXS/WAXS scattering patterns. The elastic modulus of fibers increased with protein fibril content from 0.8 to 2 GPa, which is superior to reported values of silk, collagen, and gelatin. The present setup allows for manufacture of large quantities of polymeric fibers containing protein fibrils with varied diameter and mechanical strength, endowing great potential for a variety of applications.

Harnessing Fiber Diameter-Dependent Effects of Myoblasts Toward Biomimetic Scaffold-Based Skeletal Muscle Regeneration.

Regeneration of skeletal muscles is limited in cases of volumetric muscle loss and muscle degenerative diseases. Therefore, there is a critical need for developing strategies that provide cellular and structural support for skeletal muscle regeneration. In the present work, a bioengineered cell niche composed of mechanically competent aligned polyester fiber scaffolds is developed to mimic the oriented muscle fiber microenvironment by electrospinning poly(lactide-co-glycolide) (PLGA) using a custom-designed rotating collector with interspaced parallel blades. Aligned fiber scaffolds with fiber diameters ranging from 335 ± 154 nm to 3013 ± 531 nm are characterized for their bioactivities in supporting growth and differentiation of myoblasts. During in vitro culture, polymeric scaffolds with larger fiber diameter support enhanced alignment, growth, and differentiation of myoblasts associated with phosphorylation of p38 MAPK and upregulated expression of myogenin and myosin heavy chain. In vivo studies using a dystrophin-deficient mdx mouse model show that optimized fiber scaffolds seeded with primary myoblasts result in formation of dystrophin-positive myofibers network in tibialis anterior muscles. Collectively, these experiments provide critical insights on harnessing interactions between muscle cells and engineered fiber matrices to develop effective biomaterials for accelerated muscle regeneration.

Contributions of protein and milled chitin extracted from domestic cricket powder to emulsion stabilization.

Interfacial and emulsifying properties of fractionated cricket powder were assessed to identify whether emulsification properties originate from protein or chitin particles. Fractions extracted in alkaline water, containing high protein and mineral contents, increased the surface pressure of heptane-water interfaces with near-saturation equilibrium surface pressure of 31 mN/m. Dynamic surface pressure profiles indicated adsorption of protein clusters to the interface. Emulsification capacity of protein fraction was 50% greater than that of the source cricket flour, although oil-in-water emulsions prepared with 1-2% (w/w) protein fraction formed a cream layer within one day of storage. Emulsified layers persisted for up to 20 days, and light scattering measurements described a stable population with surface-volume-mean diameter of approximately 3 µm. Chitin-rich fractions milled to a particle size of 0.5-200 µm contributed negligible surface pressure, and its emulsification capacity was 5% of the value for the source cricket flour. Emulsions prepared with chitin-rich fractions coexisted with an unstable precipitate layer comprising 60% of the added solid, which was attributed to larger particles with poor emulsifying capability. Stable chitin-stabilized emulsion phases were resistant to creaming, yet volume-mean droplet diameter surpassed 50 µm within 24 h of storage. Both protein and chitin fractions have emulsifying capabilities but would require further processing or secondary additives to achieve desirable storage stability.

Interactions Between Flavonoid-Rich Extracts and Sodium Caseinate Modulate Protein Functionality and Flavonoid Bioaccessibility in Model Food Systems.

With growing interest in formulating new food products with added protein and flavonoid-rich ingredients for health benefits, direct interactions between these ingredient classes becomes critical in so much as they may impact protein functionality, product quality, and flavonoids bioavailability. In this study, sodium caseinate (SCN)-based model products (foams and emulsions) were formulated with grape seed extract (GSE, rich in galloylated flavonoids) and green tea extract (GTE, rich in nongalloylated flavonoids), respectively, to assess changes in functional properties of SCN and impacts on flavonoid bioaccessibility. Experiments with pure flavonoids suggested that galloylated flavonoids reduced air-water interfacial tension of 0.01% SCN dispersions more significantly than nongalloylated flavonoids at high concentrations (>50 µg/mL). This observation was supported by changes in stability of 5% SCN foam, which showed that foam stability was increased at high levels of GSE (≥50 µg/mL, P < 0.05) but was not affected by GTE. However, flavonoid extracts had modest effects on SCN emulsion. In addition, galloylated flavonoids had higher bioaccessibility in both SCN foam and emulsion. These results suggest that SCN-flavonoid binding interactions can modulate protein functionality leading to difference in performance and flavonoid bioaccessibility of protein-based products. PRACTICAL APPLICATION: As information on the beneficial health effects of flavonoids expands, it is likely that usage of these ingredients in consumer foods will increase. However, the necessary levels to provide such benefits may exceed those that begin to impact functionality of the macronutrients such as proteins. Flavonoid inclusion within protein matrices may modulate protein functionality in a food system and modify critical consumer traits or delivery of these beneficial plant-derived components. The product matrices utilized in this study offer relevant model systems to evaluate how fortification with flavonoid-rich extracts allows for differing effects on formability and stability of the protein-based systems, and on bioaccessibility of fortified flavonoid extracts.

Characterization of Amyloid Fibril Networks by Atomic Force Microscopy.

Dense networks of amyloid nanofibrils fabricated from common globular proteins adsorbed to solid supports can improve cell adhesion, spreading and differentiation compared to traditional flat, stiff 2D cell culture substrates like Tissue Culture Polystyrene (TCPS). This is due to the fibrous, nanotopographic nature of the amyloid fibril networks and the fact that they closely mimic the mechanical properties and architecture of the extracellular matrix (ECM). However, precise cell responses are strongly dependent on the nanostructure of the network at the cell culture interface, thus accurate characterization of the immobilized network is important. Due to its exquisite lateral resolution and simple sample preparation techniques, Atomic Force Microscopy (AFM) is an ideal technique to characterize the fibril network morphology. Thus, here we describe a detailed protocol, for the characterization of amyloid fibril networks by tapping mode AFM.

Preparation of Amyloid Fibril Networks.

Networks of amyloid nanofibrils fabricated from common globular proteins such as lysozyme and ß-lactoglobulin have material properties that mimic the extracellular microenvironment of many cell types. Cells cultured on such amyloid fibril networks show improved attachment, spreading and in the case of mesenchymal stem cells improved differentiation. Here we describe a detailed protocol for fabricating amyloid fibril networks suitable for eukaryotic cell culture applications.

Effect of House Cricket (Acheta domesticus) Flour Addition on Physicochemical and Textural Properties of Meat Emulsion Under Various Formulations.

The objective of this study was to determine the effect of house cricket (Acheta domesticus) flour addition on physicochemical and textural properties of meat emulsion under various formulations. As an initial marker of functionality, protein solubility, water absorption, emulsifying capacity, and gel formation ability of house cricket flour were determined at pH (2 to 10) and NaCl concentrations (0 to 2.10 M). Control emulsion was formulated with 60% lean pork, 20% back fat, and 20% ice. Six treatment emulsions were prepared with replacement of lean pork and/or back fat portions with spray-dried house cricket flour at 5% and 10% levels, based on a total sample weight. The protein solubility of house cricket flour (67 g protein/100 g) was significantly altered depending upon pH (P < 0.0001) and NaCl concentration (P = 0.0421). Similar water absorption capacity, emulsifying capacity, and gel formation ability of house cricket flour were found between 0 and 2.10 M NaCl concentration (P > 0.05). The replacement of lean meat/fat portion with house cricket flour within 10% level could fortify protein and some micronutrients (phosphorus, potassium, and magnesium) in meat emulsion, without negative impacts on cooking yield and textural properties. Our results suggest that house cricket flour can be used as an effective nonmeat functional ingredient to manufacture emulsified meat products. PRACTICAL APPLICATION: To better utilize house cricket flour as a food ingredient in wide application, understanding its technological properties in various pH, and ionic strength conditions is a pivotal step. Protein solubility of house cricket flour would be considerably affected by the varying pH and NaCl concentrations of applied conventional foods. In the case of meat emulsion, within 10% lean meat and/or fat portions could be successfully substituted with house cricket flour without detectable adverse impacts on technological properties associated with cooking yield and instrumental analysis of texture. Thus, our findings suggest that house cricket flour possess the necessary physical properties to be used as an alternative nonmeat ingredient for incorporation within emulsified meat products, which could be further explored in subsequent sensory-based studies.

Quantifying Young's moduli of protein fibrils and particles with bimodal force spectroscopy.

Force spectroscopy is a means of obtaining mechanical information of individual nanometer-scale structures in composite materials, such as protein assemblies for use in consumer films or gels. As a recently developed force spectroscopy technique, bimodal force spectroscopy relates frequency shifts in cantilevers simultaneously excited at multiple frequencies to the elastic properties of the contacted material, yet its utility for quantitative characterization of biopolymer assemblies has been limited. In this study, a linear correlation between experimental frequency shift and Young's modulus of polymer films was used to calibrate bimodal force spectroscopy and quantify Young's modulus of two protein nanostructures: ß-lactoglobulin fibrils and zein nanoparticles. Cross-sectional Young's modulus of protein fibrils was determined to be 1.6 GPa while the modulus of zein nanoparticles was determined as 854 MPa. Parallel measurement of ß-lactoglobulin fibril by a competing pulsed-force technique found a higher cross-sectional Young's modulus, highlighting the importance of comparative calibration against known standards in both pulsed and bimodal force spectroscopies. These findings demonstrate a successful procedure for measuring mechanical properties of individual protein assemblies with potential use in biological or packaging applications using bimodal force spectroscopy.

Chitosan-coated amyloid fibrils increase adipogenesis of mesenchymal stem cells.

Mesenchymal stem cells (MSCs) have the potential to revolutionize medicine due to their ability to differentiate into specific lineages for targeted tissue repair. Development of materials and cell culture platforms that improve differentiation of either autologous or allogenic stem cell sources into specific lineages would enhance clinical utilization of MCSs. In this study, nanoscale amyloid fibrils were evaluated as substrate materials to encourage viability, proliferation, multipotency, and differentiation of MSCs. Fibrils assembled from the proteins lysozyme or ß-lactoglobulin, with and without chitosan coatings, were deposited on planar mica surfaces. MSCs were cultured and differentiated on fibril-covered surfaces, as well as on unstructured controls and tissue culture plastic. Expression of CD44 and CD90 proteins indicated that multipotency was maintained for all fibrils, and osteogenic differentiation was similarly comparable among all tested materials. MSCs grown for 7days on fibril-covered surfaces favored multicellular spheroid formation and demonstrated a >75% increase in adipogenesis compared to tissue culture plastic controls, although this benefit could only be achieved if MSCs were transferred to TCP for the final differentiation step. The largest spheroids and greatest tendency to undergo adipogenesis was evidenced among MSCs grown on fibrils coated with the positively-charged polysaccharide chitosan, suggesting that spheroid formation is prompted by both topography and cell-surface interactivity and that there is a connection between multicellular spheroid formation and adipogenesis.

Effect of crosslinking on the physical and chemical properties of ß-lactoglobulin (Blg) microgels.

HYPOTHESIS: Microgels assembled from the protein ß-lactoglobulin are colloidal structures with potential applications in food materials. Modifying the internal crosslinking within these microgels using enzymatic or chemical treatments should affect dissolution, swelling, and viscous attributes under strongly solvating conditions. EXPERIMENTS: Microgels were treated with citric acid, glutaraldehyde and transglutaminase to induce cross-linking or with tris(2-carboxyethyl)phosphine to reduce disulfide linkages. Change in hydrodynamic particle size due to acidic pH, alkaline pH, ionic strength, osmolyte concentration, ethanol, urea, sodium dodecyl sulfate, and reducing agents was evaluated by light scattering measurements. Changes in microgel nanomechanical properties were evaluated via force spectroscopic measurements in water. FINDINGS: Average microgel size increased ∼20% in alkaline pH and with ethanol contents above 10%, and decreased ∼20% with sucrose contents above 10%. Cross-linking by glutaraldehyde and transglutaminase prevented size increases in alkaline pH. Microgel plasticity and elastic modulus were unaffected by treatments. Microgels treated with glutaraldehyde were found to have much greater stability to urea, sodium dodecyl sulfate, and reducing agents when compared to other samples. Even without cross-linking, microgels remained stable against precipitation and dissolution over a wide range conditions, indicating their broad utility as colloidal stabilizers, texture modifiers or controlled release agents in food or other applications.

Functional properties of tropical banded cricket (Gryllodes sigillatus) protein hydrolysates.

Recently, the benefits of entomophagy have been widely discussed. Due to western cultures' reluctance, entomophagy practices are leaning more towards incorporating insects into food products. In this study, whole crickets (Gryllodes sigillatus) were hydrolyzed with alcalase at 0.5, 1.5, and 3.0% (w/w) for 30, 60, and 90min. Degree of hydrolysis (DH), amino acid composition, solubility, emulsion and foaming properties were evaluated. Hydrolysis produced peptides with 26-52% DH compared to the control containing no enzyme (5% DH). Protein solubility of hydrolysates improved (p<0.05) over a range of pH's, exhibiting >30% soluble protein at pH 3 and 7 and 50-90% at alkaline pH, compared with the control. Emulsion activity index ranged from 7 to 32m2/g, while foamability ranged from 100 to 155% for all hydrolysates. These improved functional properties demonstrate the potential to develop cricket protein hydrolysates as a source of functional alternative protein in food ingredient formulations.

Dynamic and viscoelastic interfacial behavior of ß-lactoglobulin microgels of varying sizes at fluid interfaces.

HYPOTHESIS: Microgel particles formed from the whey protein ß-lactoglobulin are able to stabilize emulsion and foam interfaces, yet their interfacial properties have not been fully characterized. Smaller microgels are expected to adsorb to and deform at the interface more rapidly, facilitating the development of highly elastic interfaces. METHODS: Microgels were produced by thermal treatment under controlled pH conditions. Dynamic surface pressure and dilatational interfacial rheometry measurements were performed on heptane-water droplets to examine microgel interfacial adsorption and behavior. Langmuir compression and atomic force microscopy were used to examine the changes in microgel and monolayer characteristics during adsorption and equilibration. FINDINGS: Microgel interfacial adsorption was influenced by bulk concentration and particle size, with smaller particles adsorbing faster. Microgel-stabilized interfaces were dominantly elastic, and elasticity increased more rapidly when smaller microgels were employed as stabilizers. Interfacial compression increased surface pressure but not elasticity, possibly due to mechanical disruption of inter-particle interactions. Monolayer images showed the presence of small aggregates, suggesting that microgel structure can be disrupted at low interfacial loadings. The ability of ß-lactoglobulin microgels to form highly elastic interfacial layers may enable improvements in the colloidal stability of food, pharmaceutical and cosmetic products in addition to applications in controlled release and flavor delivery systems.

Influence of PEGylation on the ability of carboxymethyl-dextran to form complexes with α-lactalbumin.

Electrostatic interactions between α-lactalbumin (α-lac) and carboxymethyldextran (CMD) in acidic solutions lead to phase-separated complexes. By adding a non-ionic poly(ethylene glycol) (PEG) chain onto the reducing end of CMD, forming carboxymethyl-dextran-block-poly(ethylene glycol) (CMD-b-PEG), the PEG block was hypothesized to reduce interactions with α-lac and promote formation of a micelle-like complex structure. Formation of complexes between α-lac and CMD-b-PEG or α-lac and CMD was determined following acidification by light scattering and electrophoretic mobility. Phase separation, size, and structure of α-lac/CMD-b-PEG complexes were characterized by turbidimetry, dynamic light scattering, and electron microscopy, respectively. Complexes of α-lac/CMD-b-PEG formed at pH values near pH 6, while α-lac/CMD complexes formed at pH 5.5. Both CMD and CMD-b-PEG decreased the charge of α-lac below pH 5.5 and led to phase separation below pH 5. Shift in charge and the critical pH of phase separation were both sensitive to the α-lac to CMD ratio, while the relative amount of CMD-b-PEG did not significantly influence either. Hydrodynamic radii of α-lac/CMD-b-PEG complexes was between 11 and 20 nm, which increased with increasing α-lac to CMD-b-PEG ratio and with decreasing pH. Spheroidal structures of ∼10 nm were also observed in micrographs that were attributed to α-lac/CMD-b-PEG complexes.

Control of thermal fabrication and size of ß-lactoglobulin-based microgels and their potential applications.

HYPOTHESIS: Factors influencing fabrication and size of microgels formed from ß-lactoglobulin with or without pectin can tune selected attributes for material applications. Protein aggregation was expected to be influenced by pH, added anions, and reducing agents, while ionic strength was expected to be more influenced by electrostatically interacting pectin. EXPERIMENTS: Turbidity measurements during thermal aggregation to form microgels were determined for pure ß-lactoglobulin as a function of pH, added ionic strength, anion type (chloride, sulfate, and thiocyanate), and reducing agent concentration. ß-lactoglobulin and pectin complexation pH values and thermal aggregation were determined by turbidity measurements with added potassium chloride, sulfate, and thiocyanate. Microgel size and morphology were determined by light scattering and atomic force microscopy, respectively. FINDINGS: Thermal aggregation of pure ß-lactoglobulin increased with decreased pH, reducing conditions, and increased ionic strength with no observed anion effect. ß-lactoglobulin microgel radii increased from 86 to 115nm with decreasing pH and increased to 124nm in reducing conditions, while salts promoted agglomeration. Increased ionic strength (0-100mmol/kg) decreased ß-lactoglobulin-pectin complexation pH from 5.40 to 5.00, while first increasing and then decreasing thermal aggregation. Thermal aggregation and microgel size were greatest with potassium thiocyanate, followed by potassium chloride and potassium sulfate.

Influence of sulphate, chloride, and thiocyanate salts on formation of ß-lactoglobulin-pectin microgels.

Effects of sulphate, chloride, and thiocyanate salts on the heat-induced formation of protein-based microgels from ß-lactoglobulin-pectin complexes were determined as a function of pH and protein-to-polysaccharide ratio. Aggregation temperatures were initially decreased at low ionic strength due to shielding of electrostatic interactions between ß-lactoglobulin and pectin but increased with further increases in ionic strength. Turbidity of heated mixtures and associated sizes of formed microgels were increased with up to 75 mmol kg(-1) ionic strength. Aggregation and microgel formation were relatively increased in the presence of thiocyanate salts compared to chloride salts and relatively decreased in the presence of sulphate salts, indicating that the inverse Hofmeister series was relevant in this system. Topographical analysis of dried microgels by atomic force microscopy verified that microgels were smallest in the presence of sulphate salts and showed that added ions, particularly thiocyanate, increased the deformability of microgels during drying.

Electrostatic stabilization of ß-lactoglobulin fibrils at increased pH with cationic polymers.

In order to improve the stability of ß-lactoglobulin fibrils formed in acidic conditions to increased pH values (pH 3-7), formation of electrostatic complexes between fibrils and cationic polymers chitosan (CH), amine-terminated poly(ethylene glycol) (APEG), low molecular weight poly(ethylenimine) (LPEI), and high molecular weight poly(ethylenimine) (HPEI) was investigated by electrophoretic mobility, turbidimetry, and atomic force microscopy. Except for suspensions with APEG, addition of polycations increased ζ-potential values of the fibrils at pH 5, 6, and 7, verifying their interactions with fibrils. Maximal increase in ζ-potential at pH 7, indicating optimal electrostatic interactivity, occurred at concentrations (w/w) of 0.05, 0.01, and 0.01% (corresponding to 6.9, 50, and 4 µmol·kg(-1)) for CH, LPEI, and HPEI, respectively. Turbidity of fibril solutions at pH 5, indicating isoelectric instability, was decreased significantly with increasing concentration of CH, LPEI, and BPEI, but not with added APEG. Turbidity was increased at pH 7 with added polycation, except for suspensions containing ≥0.02% HPEI. Fibril length and resistance to aggregation, as observed by atomic force microscopy, were increased at pH 5 with increasing concentration of CH and LPEI, yet only HPEI was capable of maintaining the morphology of fibrils at pH 7. Calculated persistence lengths of the fibrils, as compared to pure fibrils at pH 3 (∼4 µm), were only slightly reduced at pH 5 with CH and at pH 7 with HPEI, but increased at pH 5 with LPEI and HPEI. Improvement in the stability of ß-lactoglobulin fibrils at higher pH conditions with the addition of polycations will contribute to their potential utilization in packaging, food, and pharmaceutical applications.