@article{ryan_foegeding_2015, title={Formation of soluble whey protein aggregates and their stability in beverages}, volume={43}, ISSN={["1873-7137"]}, DOI={10.1016/j.foodhyd.2014.05.025}, abstractNote={The objectives of this work were to 1) determine the role of pH in forming thermally stable whey protein isolate (WPI) soluble aggregates (SA), 2) evaluate the functionality of SA formed under a range of conditions, and 3) evaluate SA stability in a model beverage. Whey protein isolate SA were formed using two sources of WPI at pH 6.5 or 7.5, and thermal stability was tested in the presence of 30–60 mM NaCl or 15–30 mM CaCl2. Soluble aggregates from the two sources of WPI exhibited physicochemical and functional differences over the range of conditions investigated. Soluble aggregates formed at pH 7.5, 7% w/w protein, by heating statically at 90 °C for 10 min exhibited lower turbidity and viscosity, and higher solubility when thermally treated in solutions containing salt for both types of WPI, and were more sensitive to CaCl2. Soluble aggregates and a model beverage containing the SA were prepared at pilot scale and evaluated for shelf stability. Soluble aggregates were formed under continuous flow at pH 6.5, 7% w/w WPI, added at 5% w/w to the beverage, and thermally processed. Over nine weeks of storage at 22.5 °C, the beverage with SA had lower turbidity, aggregate size, and viscosity; and the aggregates had a more negative zeta potential. Results indicate that SA can be used to improve thermal and storage stability in beverages containing salts, and that solution and heating conditions can be optimized for improved thermal stability.}, journal={FOOD HYDROCOLLOIDS}, author={Ryan, Kelsey N. and Foegeding, E. Allen}, year={2015}, month={Jan}, pages={265–274} }
 @article{ryan_stevenson_hayes_2012, title={Mechanism of decreased heat-induced activation of plasminogen in the presence of cysteine}, volume={23}, ISSN={0958-6946}, url={http://dx.doi.org/10.1016/j.idairyj.2011.11.004}, DOI={10.1016/j.idairyj.2011.11.004}, abstractNote={The mechanism by which activation of plasminogen (PG) is reduced by heating in the presence of free sulphydryl groups was characterized, and the effect on PG structure was evaluated. Activity assays were performed on PG or milk containing 3–4 cysteine concentrations and heated at three temperatures. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis was carried out in one and two dimensions to visualize changes in PG. Activity assays with other sulphydryl- and non-sulphydryl-containing reducing agents, β-mercaptoethanol, glutathione and sodium borohydride, were performed. In heated PG samples, increasing cysteine concentration decreased activation of PG; temperature had less affect. Electrophoresis results confirmed the presence of disulphide-bonded PG polymers and the reversibility of polymerization. Activity assays with the other reducing agents confirmed that the mechanism was related to free sulphydryl groups. Activation of PG in milk can be partially controlled by addition of cysteine before pasteurization, due to a sulphydryl-reducing and polymerization mechanism.}, number={2}, journal={International Dairy Journal}, publisher={Elsevier BV}, author={Ryan, Kelsey N. and Stevenson, Clinton D. and Hayes, Kirby D.}, year={2012}, month={Apr}, pages={79–85} }
 @article{ryan_vardhanabhuti_jaramillo_zanten_coupland_foegeding_2012, title={Stability and mechanism of whey protein soluble aggregates thermally treated with salts}, volume={27}, DOI={10.1016/j.foodhyd.2011.11.006}, abstractNote={The formation of whey protein aggregates, often termed soluble aggregates, with specific physicochemical properties has been shown to result in improved functionality in gels, foams, emulsions, encapsulation, films and coatings. This work evaluated the potential of whey protein soluble aggregates to improve thermal stability in the presence of salts and determine the mechanism of improved thermal stability. Solutions of whey protein isolate (WPI) or β-lactoglobulin (β-lg) (7% w/w, pH 6.8) were heated for 10 min at 90 °C to form soluble aggregates. Native proteins and soluble aggregates were diluted to 3% w/w in solutions containing 0–108 mM NaCl and thermally treated (90 °C, 5 min). Turbidity, solubility, and viscosity were evaluated, in addition to ζ-potential and So (surface hydrophobicity). Size exclusion chromatography coupled with multi-angle laser light scattering (SEC-MALLS) and dynamic light scattering were used to determine aggregate size and transmission electron microscopy (TEM) was used to evaluate aggregate shape. Use of soluble aggregates improved thermal stability due to their altered aggregate shape and higher charge, and resulted in final aggregates that were smaller and less dense, leading to reduced viscosity and turbidity, and increased solubility compared to native proteins. It is concluded that soluble aggregates formed under the appropriate conditions to produce the desirable physicochemical properties can be used to improve whey protein thermal stability with a possible application in beverages.}, number={2}, journal={Food Hydrocolloids}, author={Ryan, K. N. and Vardhanabhuti, B. and Jaramillo, D. P. and Zanten, J. H. and Coupland, J. N. and Foegeding, E. A.}, year={2012}, pages={411–420} }
 @article{barden_cakir_leksrisompong_ryan_foegeding_drake_2010, title={EFFECT OF FLAVOR ON PERCEIVED TEXTURE OF WHEY PROTEIN ISOLATE GELS}, volume={25}, ISSN={["1745-459X"]}, DOI={10.1111/j.1745-459x.2010.00274.x}, abstractNote={ABSTRACT This study investigated the role of flavor on trained panelist and consumer perception of texture properties. Whey protein isolate (WPI) gels were prepared with sodium chloride (25 mM) at different pH (pH 6.0 or 7.0), and calcium chloride concentrations (0 or 10 mM). The same gel treatments were produced with and without added flavor. Instrumental torsion analysis showed that flavor addition had no impact (P > 0.05) on fracture stress and strain. Texture properties of gels were evaluated by a trained descriptive panel and untrained consumers (n = 60) for their perception of gel firmness, fracturability, juiciness, mouth coating and overall disliking. Distinct texture properties among the gels were documented by both trained panelists and consumers (P < 0.05). Flavor addition did not influence (P > 0.05) texture perception. Therefore, flavor addition does not impact panelist (trained or untrained) ability to evaluate textural differences in WPI gels.}, number={3}, journal={JOURNAL OF SENSORY STUDIES}, author={Barden, L. M. and Cakir, E. and Leksrisompong, P. N. and Ryan, K. N. and Foegeding, E. A. and Drake, M. A.}, year={2010}, month={Jun}, pages={447–462} }