Whey Protein Beverages Research Articles

617-P: Time in Range following Mealtime Protein Supplementation Is Predicted by Liver Health and ß-Cell Function in Adults with Type 2 Diabetes

Background: Consuming mealtime whey protein supplementation increases daily time in euglycemic range [TIR] in adults with type 2 diabetes [T2D] with inter-individual responses. The present post-hoc analysis aimed to identify metabolic predictors to the effectiveness of pre-meal whey protein. Methods: In a randomized-crossover design, 16 individuals with T2D [HbA1c 57±9 mmol/mol) underwent two 7d free-living periods where they consumed a whey protein (15g) or placebo beverage before each main meal. Glucose control was captured by blinded continuous glucose monitoring. Patient anthropometric and fasting markers of liver health and glucose metabolism were obtained at baseline. β-cell function was determined by the ratio of the incremental changes in insulin secretion to glucose during a feeding test. The relationship between TIR and clinical markers were analyzed by correlational analysis, and predictors of TIR were determined by multiple regression. Results: β-cell function was a strong determinant to TIR during both the whey (rs=0.615; p=0.011) and placebo (rs=0.598; p=0.019) weeks. Around 76% of the variance in TIR during the whey week was accounted by β-cell function, and fasting insulin and alanine aminotransferase concentrations (adj R2=0.760; p<0.001). During the whey intervention, TIR was inversely associated with aspartate aminotransferase (rs=−0.506; p=0.046) and tended to be related to fasting glucagon (rs=−0.482; p=0.058), whereas there were no associations between liver health or fasting hormonal markers with TIR during placebo (p>0.05). Conclusions: In a small cohort of people with T2D, our data indicates that those with compromised liver health and reduced β-cell function may experience a reduction in TIR when consuming mealtime protein supplementation. This is possibly due to disruptions in the liver-α-cell axis, which may be further aggravated by increasing plasma amino acid availability from protein supplementation. Disclosure K.Smith: None. G.Taylor: None. M.Walker: None. K.A.Bowden davies: None. E.J.Stevenson: None. D.J.West: None. Funding Francis James Bell Endowment Fund; County Durham Community Foundation

Evaluating the erosive potential of various whey protein drinks on dental composites

Background: Whey protein beverages’ viscosity, lactose content, and acidic pH could all pose risks to the oral cavity’s current composite restorations. Objectives: Assessing the impact of distilled water (DW), whey protein concentrate (WPC), whey protein isolate (WPI), and whey protein water (WPW) on the surface roughness of four restorative composites with various microstructures (Filtek Z 250XT, Filtek Z 350XT,, Filtek P 60 and Filtek Bulk Fill). Materials & Methodology: A total of eighty samples were divided into 4 groups. From each material, 20 disc-shaped samples were created and wet polished. Samples from each group were subsequently separated into four subgroups based on the amount of time they spent submerged in various Whey protein beverages. In each Protein powder beverage, the soaking protocol was carried out twice for a total of 10 minutes. They were then submerged in fake saliva for an additional 10 minutes every day for 30 days. Samples were kept until the following cycle in distilled water. The surface roughness of all the samples was measured before and after immersion using a contact-type surface profilometer. With a 5% level of significance, the data were statistically analysed using the unpaired “t” test and Mann Whitney U test. Results & Conclusions: The surface roughness of all dental composites substantially increased after immersion in all whey protein beverages, although WPW induced the greatest alterations, followed by WPC and WPI. The biggest increase in surface roughness was seen in Filtek Z 250XT composites, followed by Filtek P 60 composites, with Filtek Bulk Fill demonstrating the lowest increase.

Efficacy and safety of pre-gastroscopy commercial carbohydrate-rich whey protein beverage vs. plain water: a randomised controlled trial

Clinical benefits and safety of carbohydrate loading pre-gastroscopy remain unclear. We aimed to determine the effects of a commercial carbohydrate-rich whey protein beverage versus plain water given pre-gastroscopy on gastric residual volume and well-being, and to determine adverse events. This was a single centre, single-blinded, parallel-group, sex-stratified randomized controlled trial. Participants were randomized either to carbohydrate-rich whey protein beverage group (Resource®, Nestle Health Science) or control group (250 ml plain water) given pre-gastroscopy. Gastric contents were aspirated into a suction reservoir bottle to determine the gastric residual volume (GRV). Visual analogue scale (VAS) of well-being (anxiety, hunger, thirst, tiredness, and weakness) was compared before and after the intervention. Adverse events were also evaluated post-intervention. Of 369 screened, 78 participants (36 males, mean age 49 ± 14.3 years) were randomized. Compared with the control group, carbohydrate beverage was associated with significantly higher GRV (p < 0.001). Anxiety was less after intervention with carbohydrate beverage (p = 0.016), and after adjustment for confounders, fewer participants also experienced hunger (p = 0.043) and thirst (p = 0.021). No serious adverse events were reported with both interventions. Commercial carbohydrate-rich whey protein beverage is associated with higher gastric residual volume, better well-being and safe.Trial registration Clinicaltrial.gov. Identifier: NCT03948594, Date of registration: 14/05/2019.

Individual variation in mouthfeel sensitivity: investigating influences of whey protein content, consumer age, food format and fat addition

Individual sensitivity to whey protein derived mouthdrying can vary with protein level and age; however, to date no thresholds for this have been established. Additionally, previous research suggests that increasing fat in whey protein solid models can enhance lubrication and suppress mouthdrying, but this needs testing in older adults. Here, a trained sensory panel (n = 10) determined a mouthdrying detection threshold (MDT) in whey protein beverages (WPB). To compare sensitivity between younger and older adults (n = 116; 18–30; 65+): (1) WPB just-noticeable difference (JND) thresholds were established and (2) liking and perception of whey protein fortified beverages and scones were rated. The trained panel detected mouthdrying at all protein levels (0.14% to 10.0% w/v) with the MDT being established between 0.41% (50% discriminators) and 1.37% (Best Estimate Threshold, BET) w/v protein. The JND mouthdrying threshold was significantly lower (p = 0.02) in older adults compared with younger adults (0.75% versus 0.90% w/v protein; BET). Increasing protein levels in WPBs significantly increased mouthdrying and reduced liking and easiness to consume (utilising rating scales). Whey protein fortified scones with cream topping significantly increased liking, easiness to consume, sweetness, moistness and rate of clearance and reduced mouthdrying and chewiness. Older adults perceived WPBs as significantly easier to consume and the scones significantly chewier than younger adults. Age-related mouthfeel effects and individual differences in mouthdrying sensitivity are key factors for product design.

Viscosity of food influences perceived satiety: A video based online survey

Food texture seems to offer a promising strategy for the control of expected satiety, satiety, satiation and daily caloric intake. The aim of this study was to examine the effect of food texture, more specifically the effect of different levels of viscosity, on perceived satiety through an online survey where the viscosity levels of protein-based beverages were visually perceived using a newly developed video-based demonstration. Whey protein beverages were prepared with viscosities being manipulated using xanthan gum and their viscosity and tribological properties were measured instrumentally. Subjects (n = 211) watched beverages being poured in videos streamed online and were instructed to imagine drinking them. The results showed that instrumentally measured HV (high viscous) and MV (medium viscous) beverages were visually perceived by the participants as being more satiating immediately and 2 h later after the imagined drinking event as compared to LV (low viscous) beverages (p < 0.05). Also, sensory attributes such as visually perceived smoothness, thickness, creaminess and watery were shown to be important factors in the perception of satiety (the creamier or thicker the beverage the higher the perceived satiety scores). Therefore, a video-based online demonstration is a highly feasible and convenient tool to measure the effect of food texture on perceived/expected satiety that can be useful in Covid-19 pandemic situation, latter necessitates online participation in many situations. More importantly, key role of food/beverage texture expressed through visual cues alone, may open new avenues of informing consumers about the degree of the perceived satiety/fullness even before the product is consumed.

Do whey protein beverages affect the microhardness of composites? A laboratory study.

Background:Whey protein supplements might be a potential risk factor for the restoration surface due to its pH and lactose content.Aim:The study aimed to evaluate the effect of whey protein beverages on the microhardness of four restorative composites with different microstructures (Filtek Z 350XT, Filtek Z 250XT, Filtek Bulk Fill (FBF), and Filtek P 60).Materials and Methodology:Forty disc-shaped samples from each material (in total 160) were prepared and wet polished. The samples of each group were randomly divided into four subgroups and subjected to four immersion media namely, whey protein Concentrate (WPC), whey protein Isolate (WPI), whey protein water (WPW), and distilled water (DW). The immersion protocol was performed twice for 10 min daily for 30 days followed by immersion in artificial saliva for another 10 min and stored in DW till the next cycle. The pre immersion and post immersion microhardness of all the samples were recorded with a Microhardness Tester FM-800. Data obtained were statistically analyzed using SPSS 25 software.Results and Conclusions:All composites exhibited decline in microhardness, except for FBF. P 60 composites which showed the highest decline in microhardness. WPC and WPI caused the greatest reduction in microhardness compared to WPW.

Postprandial glycine as a biomarker of satiety: A dose-rising randomised control trial of whey protein in overweight women

This study aimed to identify biomarkers of appetite response, modelled using a dose-rising whey protein preload intervention. Female participants (n = 24) with body mass index (BMI) between 23 and 40 kg/m2 consumed preload beverages (0 g protein water control, WC; 12.5 g low-dose protein, LP; or 50.0 g high-dose protein, HP) after an overnight fast, in a randomised cross over design. Repeated venous blood samples were collected to measure plasma biomarkers of appetite response, including glucose, glucoregulatory peptides, gut peptides, and amino acids (AAs). Appetite was assessed using Visual Analogue Scales (VAS) and ad libitum energy intake (EI). Dose-rising protein beverage significantly changed the postprandial trajectory of almost all biomarkers (treatment*time, p < 0.05), but did not suppress postprandial appetite (treatment*time, p > 0.05) or EI (ANOVA, p = 0.799). Circulating glycine had the strongest association with appetite response. Higher area under the curve (AUC0-240) glycine was associated with lower EI (p = 0.026, trend). Furthermore, circulating glycine was associated with decreased Hunger in all treatment groups, whereas the associations of glucose, alanine and amylin with appetite were dependent on treatment groups. Multivariate models, incorporating multiple biomarkers, improved the estimation of appetite response (marginal R2, range: 0.13–0.43). In conclusion, whilst glycine, both alone and within a multivariate model, can estimate appetite response to both water and whey protein beverage consumption, a large proportion of variance in appetite response remains unexplained. Most biomarkers, when assessed in isolation, are poor predictors of appetite response, and likely of utility only in combination with VAS and EI.

Investigating Methods to Mitigate Whey Protein Derived Mouthdrying.

Mouthdrying is commonly associated with whey protein fortified products. Therefore, mitigating strategies could be key to reducing mouthdrying and maximising the benefits from such products. Currently, few studies have successfully mitigated whey protein derived mouthdrying and this paper aims to investigate different strategies to reduce mouthdrying effects. Accordingly, a series of experiments were carried out with a trained sensory panel (n = 11). Two different whey protein food matrices were tested: (a) whey protein beverages (WPB) varying in lactose (0.05–12.4% w/v) and fat (0.9–7.2% w/v) levels and (b) whey protein fortified snacks: cupcakes with differing whey protein concentrate (WPC) powders (standard and heat-stable) and scones with varying fat content (with and without cream topping). Overall results suggested the tested strategies had limited significant effects on whey protein derived mouthdrying. Increasing lactose (9.4% w/v) in WPBs and fat levels (via cream topping) on scones significantly suppressed mouthdrying. However, all other tested strategies (increasing fat in WPBs and heat-stable WPC in cupcakes) had no significant effect on suppressing perceived mouthdrying. This work demonstrates the challenges with mitigating whey protein derived mouthdrying; however, cross-modal taste suppression and increasing lubrication warrant further investigation.

Whey Protein Derived Mouthdrying Found to Relate Directly to Retention Post Consumption but Not to Induced Differences in Salivary Flow Rate.

Whey protein is fortified into beverages to provide functional benefits, however, these beverages are considered mouthdrying. To date whey protein derived mouthdrying has not been quantified using a ‘physical measure’ in parallel with rated perception. Saliva flow could also relate to whey protein derived mouthdrying, however this has not been previously tested as an intervention. Accordingly, volunteers (n = 40) tested mouthdrying in different whey beverages and the sensory profile was evaluated by a trained sensory panel (n = 10). Volunteers also rated mouthdrying combined with collection of saliva samples post beverage consumption to measure retention to the oral cavity. To modulate saliva flow rate, volunteers both chewed on parafilm (to increase saliva flow) and used cotton wool (to remove saliva) before tasting beverages and rating mouthdrying. Both the volunteers and sensory panel rated whey protein beverages (WPB) as significantly more mouthdrying than the control beverage (whey permeate). The significantly higher rating of mouthdrying from the volunteers coincided with significantly higher protein concentration in saliva samples post WPB consumption, supporting mucoadhesion as the mechanism. Modulating saliva flow did not lead to any difference in rated mouthdrying and future work would be beneficial to evaluate further the influence of natural variation in salivary flow rate.

Understanding the effects of nutrition and post-exercise nutrition on skeletal muscle protein turnover: Insights from stable isotope studies

Understanding the effects of nutrition and post-exercise nutrition on skeletal muscle protein turnover: Insights from stable isotope studies

In Vitro Analysis of the Erosive Potential of Whey Protein

The objective of this study was to evaluate the pH and total soluble solids (TSS) content of whey protein beverages. Nine products of three different flavors (vanilla, strawberry and chocolate) of the following brands Muke®, Best Whey®, and Essencial Nutrition Whey®, had their pH evaluated by potentiometry, and their TSS evaluated by refractometry. The lowest pH recorded was for Muke® Chocolate (5.75), and the highest was for Essencial Nutrition Whey® Cacao (6.91). Regarding TSS, the lowest average was for Essencial Nutrition Whey® Vanilla (10.17), and the highest was for Essencial Nutrition Whey® Red Berry (16.66). There was no statistically significant difference in pH and TSS among the flavors and brands evaluated. It was concluded that the analyzed beverages had a higher pH than the pH that is critical to dental enamel and the TSS content was considered high.

An Investigation of the Influence of Age and Saliva Flow on the Oral Retention of Whey Protein and Its Potential Effect on the Perception and Acceptance of Whey Protein Beverages.

Protein fortified products are regularly recommended to older adults to improve nutritional status and limit sarcopenia. However protein fortification can elicit negative sensory attributes such as mouthdrying. Sensitivity to mouthdrying can increase with age, yet the influence of saliva flow and mucoadhesion remain uncertain. Here, two studies tested different whey protein beverages (WPB); 22 healthy younger volunteers completed a pilot and 84 healthy volunteers from two age groups (18–30; 65+) completed the main study. In both studies salivary flow rates (mL/min) were measured and saliva samples were collected at time intervals post beverage consumption to measure mucoadhesion to the oral cavity, where protein concentration was analysed by Bradford Assay. Volunteers rated perception and acceptability of WPBs in the main study. WPB consumption resulted in significantly increased protein concentration (p < 0.0001) in saliva samples compared with a control whey permeate beverage. Older adults had significantly lower unstimulated saliva flow (p = 0.003) and significantly increased protein concentration (p = 0.02) in saliva samples, compared with younger adults. Heating of WPB significantly (p < 0.05) increased mouthdrying and thickness perception and reduced sweetness compared with unheated WPB. Mucoadhesion is concluded to be a true phenomenon in WPBs and increases with age.

Comparative Studies on Physico-chemical and Sensory Attributes of Natural and Artificial Whey Protein Beverages

Whey, the liquid remaining after the precipitation of milk casein was used and there physicochemical properties were measured. The aim of the study was to utilise the valuable nutrients present in whey by preparing a ready-to-serve modified whey beverage. Two types of beverages were prepared i.e., natural whey beverage using Himsagar mango and other one was artificial beverage using artificial colours and flavours. Shelf life of these beverages were studied (0-11th day) and compared on the basis of acidity, viscosity, ph and organoleptic properties. Student t-test was applied here and found that the natural whey beverage was curdled on the 7th day but the artificial whey beverage remained normal till 11th day of the study. From this observation, it was concluded that the natural whey beverage tasted better initially but curdled on the 7th day and in case of artificial whey beverage, though the taste of the beverage initially was not acceptable but gradually it improved its taste on storage and it remained in good condition till the 11th day. Keywords: Whey beverage, Channa, Paneer, Casein, Serum albumin, β-lactoglobulin. Cite this Article Debasree Ghosh, Deep Biswas. Comparative Studies on Physico-chemical and Sensory Attributes of Natural and Artificial Whey Protein Beverages. Research & Reviews: Journal of Food Science & Technology. 2020; 9(1): 1–6p.

Exceptional colloidal stability of acidified whey protein beverages stabilized by soybean soluble polysaccharide.

Protein-rich beverages have gained significant attention in recent years. It is a challenge to produce whey protein beverages with high stability, good transparency, and a smooth mouthfeel. The polysaccharide (PS)-protein complex might help the food industry overcome these obstacles. In this study, soybean soluble polysaccharide (SSPS) and high methoxylated pectin (HMP, a traditional PS) are used, at different ratios to the protein, to improve the colloidal stability of the acidified whey protein solution. Both heated and unheated complexes were studied. SSPS-whey protein complexes have shown exceptional stabilities in all ratios while HMP-whey protein complexes revealed coacervation after 72 hr of storage. The prepared complexes exhibited comparable sizes and ζ-potentials. The SSPS-whey protein complexes were less turbid than HMP-whey protein complexes at similar PS to protein ratios. Results also show that greater repulsive interactions occurred in SSPS-whey protein complexes when compared to HMP-whey protein complexes, as examined by free thiol content and intrinsic fluorescence intensity measurements. PRACTICAL APPLICATION: It is a challenge to produce whey protein isolate (WPI) beverages with high stability, good transparency, and smooth mouthfeel. The polysaccharide (PS)-protein complex might help the food industry overcome these obstacles. We have demonstrated that soybean soluble polysaccharide (SSPS), at [SSPS]:[acWPI] ratios of 1:2 to 1:30, can significantly improve the colloidal stability of the acidified whey protein beverages. This SSPS-whey protein system could be used as a stable beverage base for a variety of beverages.

Comparison of a central location test versus a home usage test for consumer perception of ready-to-mix protein beverages

Ready-to-mix (RTM) whey protein beverages are an expanding product category, and sensory properties strongly affect consumer acceptance and purchase intent. Because consumers themselves prepare RTM whey protein beverages, understanding possible gaps between central location test (CLT) and home usage test (HUT) results is critical. The objectives of this study were to compare results obtained from a CLT and a HUT and to identify the drivers of liking and disliking vanilla-flavored RTM whey protein beverages. Fourteen commercial vanilla-flavored RTM whey protein beverages were rehydrated with spring water at 15% solids (wt/vol) and evaluated by a trained panel (n = 8). Ten representative products were selected for consumer testing. Rehydrated beverages were subsequently evaluated by protein beverage consumers (n = 160) in a CLT. Nine representative products were selected for the HUT. Consumers prepared and evaluated individual beverages over 3 consecutive weeks, trying 3 samples each week. Overall liking and other attributes were scored by consumers in both tests. Data were evaluated by univariate and multivariate statistical analyses. Overall liking scores from the HUT were higher than scores from the CLT. The products with the highest and lowest overall liking scores were consistent between the CLT and HUT. More differences were observed among beverages by CLT compared with HUT when liking was averaged across all consumers. Both methods identified 2 distinct consumer clusters. Fruity flavor and sweet taste were drivers of liking, whereas cardboard flavor and bitter taste were drivers of disliking in both methods. The HUT exclusively identified thickness (viscosity) as a driver of liking and astringency as a driver of disliking. These results suggest that a CLT can be used to differentiate consumer acceptance among vanilla-flavored RTM whey protein beverages. A HUT should be used to provide more intensive insights for mouthfeel and mixing experience-related attributes.

Short communication: Comparison of 3 rapid methods for analysis of vitamin degradation compounds in fluid skim milk

Vitamin fortification of dairy products, including fluid milk and fortified whey protein beverages, is an industry standard but can lead to the development of off-flavor compounds that are difficult to extract and detect by instrumental methods. Previous work has identified these compounds and their specific role in off-flavors in skim milk, but efficient extraction and quantification of these compounds remains a challenge. Three rapid methods (stir bar sorptive extraction, solvent-assisted stir bar sorptive extraction, and solid-phase microextraction) were compared for their ability to effectively recover vitamin degradation volatiles from fluid skim milk. The performance of the 3 methods for detecting and quantifying vitamin degradation-related volatile compounds was determined by linear regression of standard curves prepared from spiked standards of 5 vitamin degradation volatiles, the reproducibility on the same day and between days as measured by the average relative standard deviation of each standard curve, and the limits of detection and quantitation. Measurement of vitamin degradation compounds in commercial pasteurized fortified skim milks was also conducted using each method. Detection of selected vitamin degradation volatiles was linear in skim milk (0.005-200 μg/kg). Coefficient of determination values differed between methods and compounds. Within-day and between-day percentage of relative standard deviation also varied with compound and method. Limits of detection and quantitation values for all methods except solid-phase microextraction were lower than concentrations of selected volatile compounds typically found in commercial milk. Solvent-assisted stir bar sorptive extraction with a 10-mL sample volume provided the most consistent detection of selected compounds in commercial milks. Based on linearity, relative standard deviation, and limits of detection and quantitation, cyclohexane solvent-assisted stir bar sorptive extraction with 10-mL sample volume is recommended for the quantitation of vitamin degradation-related volatiles in fluid skim milk.

Protein beverages containing anthocyanins of jabuticaba

Abstract The objective of this study was to develop, characterize and evaluate the stability of whey protein beverages containing anthocyanins from jabuticaba skins. Beverage formulations containing 0.5% (F1), 2.0% (F2), 4.0% (F3) and 6.0% (F4) of whey proteins and 2.0 mL of the concentrated phenolic extract from jabuticaba skins were developed. Physicochemical parameters (pH, acidity, total soluble solids, protein content, viscosity, color), antioxidant capacity, total anthocyanins and total phenols of the beverages were determined. In addition, a sensory acceptance test and a stability study were performed. The physicochemical analyses indicated that the protein concentration significantly (p 0.05) in the total anthocyanins and in the physicochemical properties of F3 over storage time, which indicated a good stability and a great market potential of the whey protein beverages containing anthocyanins from jabuticaba skins.

Consumer acceptance of natural sweeteners in protein beverages

Protein beverage consumption by Americans has increased in recent years. Coupled with this increased consumption is an interest in natural sweeteners. The objective of this study was to evaluate the sensory properties of naturally sweetened ready-to-mix (RTM) whey protein beverages using 3 temporal methods and to formulate a natural noncaloric sweetener blend that could be added to RTM protein beverages to provide sweetness while still appealing in flavor to consumers. Iso-sweet concentrations of sweeteners (sucralose, sucrose, fructose, stevia, monk fruit) in RTM vanilla whey protein beverages (25 g of protein/360 mL of water) were established using magnitude estimation scaling and 2-alternative forced-choice testing. Temporal sensory profiling was then conducted on each beverage by a trained panel using time intensity, temporal dominance of sensations, and temporal check-all-that-apply. These findings were used to formulate natural sweetener blends that closely matched the temporality of sucrose-sweetened RTM vanilla protein beverages for consumer testing. One sugar-free blend (25% stevia/75% monk fruit) and 1 reduced-sugar blend (25% stevia/25% monk fruit/50% fructose) were selected for consumer testing (n = 150 consumers) in addition to 3 control RTM beverages containing sucralose, stevia, or monk fruit. Two distinct consumer clusters were identified. The label-conscious segment of consumers preferred beverages sweetened with natural blends when primed. The flavor-driven segment of consumers conceptually preferred naturally sweetened beverages but preferred sucralose-sweetened beverages when primed. An all-natural label claim was most preferred across all consumers. Application of these findings to commercially produced RTM protein beverages aids in the development of naturally sweetened protein beverages with reduced calories and desirable sensory properties and highlights the importance of label claims to consumers overall but to a label-conscious segment of consumers in particular.

The effect of direct and indirect heat treatment on the attributes of whey protein beverages

Thermal processing of ready-to-drink high protein beverages can have a substantial impact on the physical and sensory properties of the final product for long-life milks such as extended shelf life and ultra high temperature processed products. Direct and indirect heat treatment technologies were applied to whey protein isolate (WPI) -based beverages containing 4, 6 or 8% (w/w) protein. Lower levels of protein denaturation (66–94%) were observed using direct heating compared with indirect heating (95–99%) across protein levels and heating temperatures (121 and 135 °C final heat). Direct heat treatment resulted in significantly lower viscosity and less extensive changes to the volatile profile, compared with indirect heat treatment. Overall, the application of direct and indirect heat treatment to WPI solutions resulted in significantly different final products in terms of appearance, physical characteristics and volatile profile, with direct heating resulting in many enhanced properties compared with conventional indirect heat treatment.

Effect of surfactant addition on particle properties of whey proteins and their subsequent complexation with salivary proteins

The astringency of acidified whey protein beverages is unpleasant to consumers and a challenge to the industry to overcome. It may be associated with whey-salivary protein interactions. We examined the influence of complexation of whey proteins with a low molecular weight surfactant (Tween) on some characteristics of subsequently formed whey-salivary protein aggregates. Surface tension measurements indicated that hydrophobic interaction between Tween and whey proteins was initiated at a Tween-to-WPI ratio of 1:50. Tween dissociated β-lactoglobulin dimers to monomers, decreased the size and percentage of non-soluble aggregates (>4000 nm) and decreased the ζ-potential of WPI samples. Surfactant complexation also decreased the surface hydrophobicity of whey proteins. In addition, based on Fourier-transform infrared spectroscopy, surfactant reduced intermolecular protein interactions. Nonetheless, measurement of accessible thiol group content revealed that surfactant-whey protein interaction did not unfold the proteins. Surfactant complexation resulted in smaller aggregates and a lower turbidity of whey protein-saliva mixture.