Addition Of Whey Protein Isolate Research Articles

Physical Quality of Edible Film with the Addition of Isolate Whey Protein on Water Content, Solubility, Thickness and Transparency

Edible film is a thin layer used to coat food, which functions as a barrier against mass transfer, such as water, oxygen, and fat. Edible film is a packaging material formed first in the form of a thin layer (film) before being applied to food ingredients and products. Adding whey protein isolate (WPI) to edible film can improve its physical quality. This research aims to determine the effect of adding whey protein isolate to edible film on the physical quality of edible film. The method used in this research was a completely randomized laboratory experimental design with five treatments and four replications. The addition of WPI 0.3%, 0.6%, 0.9%, and 1.2% to Edible Film gave a high significant effect (P<0.01) on solubility, degree of swelling, thickness, and transparency, and gave no significant effect (P>0.05) on water content. The results of testing edible films made from chitosan with the addition of 0.3%, 0.6%, 0.9% and 1.2% isolate whey proteine produced a water content 16.60-20.64%, solubility of 17.44-23.08%, swelling degree 71.08-76.42%, thickness 0.0725-0.0975 mm, and transparency 0.20-1.69. The addition of whey protein isolate (WPI) to edible film is thought to improve the physical quality of edible film.

Effect of whey protein on the formation, structure and gastrointestinal breakdown of quinoa flour-based composite gels

Whole grain flour has captured increasing attention due to its health benefits. Herein, the quinoa flour-based composite gels were fabricated by heating quinoa flour dispersions containing 0-7 w/w% whey protein isolate (WPI). The thermal properties and gel formation of the dispersions were determined, along with the large deformation and fracture properties, microstructure, and molecular reorganization of the resulting gels. Protein hydrolysis, solid loss, glucose release and microstructural changes were monitored to characterize the gastrointestinal breakdown of the gels. Results showed that quinoa starch was gelatinized at 60-70 °C. Upon heating, quinoa starch was segregated into microparticles of ∼ 3 μm, which aggregated into the starch phase, whereas protein aggregates filled the gap of the starch gel network. A bicontinuous structure was formed with increasing WPI concentration to 7 w/w%. Meanwhile, the storage modulus, gel hardness and fracture stress of the gels increased by 5-8 times. The addition of WPI inhibited gel disintegration during in vitro digestion. However, intestinal glucose release was not delayed because of the phase-separated structure of the gels. With increasing WPI concentration, larger protein aggregates survived after 5 min of intestinal digestion, demonstrating that the enhanced protein network was the main contributor slowing down gel disintegration during in vitro digestion. This work would promote the development of quinoa flour-based products with controlled digestion.

Development of Oleogel-in-Water High Internal Phase Emulsions with Improved Physicochemical Stability and Their Application in Mayonnaise.

Egg-free mayonnaise is receiving greater attention due to its potential health benefits. This study used whey protein isolate (WPI) as an emulsifier to develop high internal phase emulsions (HIPEs) based on beeswax (BW) oleogels through a simple one-step method. The effects of WPI, NaCl and sucrose on the physicochemical properties of HIPEs were investigated. A novel simulated mayonnaise was then prepared and characterized. Microstructural observation revealed that WPI enveloped oil droplets at the interface, forming a typical O/W emulsion. Increase in WPI content led to significantly enhanced stability of HIPEs, and HIPEs with 5% WPI had the smallest particle size (11.9 ± 0.18 μm). With the increase in NaCl concentration, particle size was increased and ζ-potential was decreased. Higher sucrose content led to reduced particle size and ζ-potential, and slightly improved stability. Rheological tests indicated solid-like properties and shear-thinning behaviors in all HIPEs. The addition of WPI and sucrose improved the structures and viscosity of HIPEs. Simulated mayonnaises (WE-0.3%, WE-1% and YE) were then prepared based on the above HIPEs. Compared to commercial mayonnaises, the mayonnaises based on HIPEs exhibited higher viscoelastic modulus and similar tribological characteristics, indicating the potential application feasibility of oleogel-based HIPEs in mayonnaise. These findings provided insights into the development of novel and healthier mayonnaise alternatives.

Enhancing bioactive compounds retention in pomegranate juice powder through foam mat drying

AbstractThe effect of addition of whey protein isolate (WPI; 0%, 5%, 7.5% and 10%) and carboxy methyl cellulose (CMC; 0%, 0.25%, 0.5% and 0.75%) was studied for its foaming properties and stability in pomegranate juice (PJ). High‐quality powders can be produced from fruit juices and heat‐sensitive food items using foam mat drying (FMD). The PJ foam with 10% WPI, a foaming agent, and 0.25% CMC, a stabilizer had high foam expansion (FE) (455.28%) and low foam density (FD) (0.2030 g/cc) and foam drainage volume (FDV) (20.10 mL). The PJ foam was subjected to different drying temperatures (50, 60 and 70°C) and thickness (3 and 6 mm). The drying temperature of 60°C and foam thickness of 3 mm were found to be the acceptable drying conditions based on drying time (180 min) and retention of bioactive compounds. At optimum drying conditions, the retention of phenols, anthocyanin, ascorbic acid, and antioxidant capacity was 97.86%, 83.90%, 77.29%, and 87.11%, respectively. The sensory evaluation of the reconstituted foam mat dried pomegranate juice powder (FPJP) showed lower overall acceptability scores than fresh juice (FJ), but the overall acceptability of the powder dried at optimum drying conditions was within liking limits (>6). FPJP has an amorphous nature with a particle size of 3564 nm and a porous and irregular structure. Bioactive compounds in FPJP were studied after 8 months of storage, with higher retention of bioactive compounds in refrigerated conditions.Practical applicationThe studies revealed that foam mat drying is suitable for the pomegranate juice which has high moisture and sugar content. It requires shorter drying time of 180 min. for drying up to moisture content of 4% (db). The foam mat dried juice powder obtained at optimum drying conditions has retained higher bioactive compounds and has higher sensorial acceptability when compared with the other treatment combinations. This drying process requires low initial investment and can easily be scaled up to the commercial level thus making it profitable business venture. Further, higher storage stability up to 8 months, low volume and consequent low transport cost improves the technical and financial viability of the process in industrial application. The Foam mat dried pomegranate juice developed can be used in many food products such as reconstituted beverages, ice creams, confectioneries, etc.

Characteristics of soy films as affected by transglutaminase cross-linking and inclusions of pectin and protein enhancers.

Previously, we showed that water extract (soymilk, except pH was increased to 8 from 6.5) of whole soybean could be used directly as a raw material for producing edible soy films by deposition of the film-forming solution (soy extract with enhancers). However, the strength of such soy films needed improvement because they were weak. The purpose of this study was to investigate how transglutaminase (TG) cross-linking reactions and film enhancers, including pectin (low- and high-methoxyl pectin), whey protein isolate (WPI), and soy protein isolate (SPI), improve the physical properties of soy films. Soy films prepared with TG had tensile strength (TS) of 3.01MPa and puncture strength (PS) of 0.78MPa, which were higher by as much as 51% and 30% than that of soy films without TG treatment, respectively. Pectin showed significant effects on the mechanical properties of TG-added soy films in terms of TS, PS, and % elongation. On the other hand, only TS and PS were increased by the addition of WPI or SPI. Heat curing had a significant effect on soy film's physical properties. TG treatment significantly reduced film solubility when soaked in water and various levels of acid (vinegar) and base (baking soda) solutions. Under the experimental conditions of 35 unit TG and 28min of reaction, the degrees of cross-linking were evidenced by the disappearance of individual protein subunits, except the basic subunit of glycinin, and the reduction of 21% of lysine residues of the proteins. HIGHLIGHTS: Edible soy films were made with transglutaminase and about 21% lysine cross-linked. The mechanical strength of soy films was increased by incorporating film enhancers. Transglutaminase enhanced the mechanical properties of soy films.

Whey protein isolate regulates the oral processing characteristics of lotus root starch

This study aimed to investigate the influence of different levels of added whey protein isolate (WPI) on the oral processing characteristics of lotus root starch (LRS). The IDDSI test results indicated that WPI-LRS composite gels could be classified as foods suitable for individuals with dysphagia. During in vitro oral digestion process, addition of WPI increased the viscosity of the composite system. When the amount of WPI reached 100% (w/w), the reducing sugar content decreased from 105.23 to 42.35 mg. Inverted fluorescence images revealed that WPI formed a continuous network structure in the starch matrix and served as a barrier against amylase digestion. Different levels of WPI addition had diverse effects on the oral friction characteristics and rheological properties of the composite system. As the protein addition amounts were lower than 45% (w/w), the composite gels had lower lubrication properties and elastic modulus. While as the addition levels were higher than 45% (w/w), the composite gels exhibited higher lubrication properties and elastic modulus. Texture analysis indicated that the hardness value of the composite gel increased from 0.65 N for the individual LRS gel to 4.75 N for the composite gel of LRS+100% WPI. Furthermore, it was found through low-field nuclear magnetic analysis that the addition of WPI restricted the free movement of water molecules and enhanced the water-holding capacity of the composite gels.

Quality characteristics of low-fat chicken sausages formulated with whey protein isolate and guar gum at different storage conditions

ABSTRACT We aimed to explore the physiochemical and microbiological attributes of cooked chicken sausages, incorporating sesame seeds, whey protein isolate (WPI), and guar gum (GG) as non-meat replacers. Both control and sausage samples were subjected to storage under refrigeration (4°C ±1°C) and frozen (−8°C ±1°C) conditions. The pH values of the chicken sausages exhibited a significant upward trend (p < .05) under both refrigeration and frozen storage conditions. The formulated sausages exhibited elevated average cooking losses of 13.26% (p < .05). Importantly, peroxide values remained below the acceptable threshold for oily food. Furthermore, the inclusion of WPI and GG in the sausages led to a lower average water activity value of 0.55 Aw (p < .05) under frozen conditions than the water activity of 0.90 Aw (p < .05) under refrigerated conditions. The total viable count was not significantly affected (p > .05) by the addition of WPI and GG under freezer conditions. Consequently, it can be inferred that the cooked chicken sausages can be safely stored under frozen conditions for a duration of 60 days.

Effect of alkaline salts and whey protein isolate on the quality of rice-maize gluten-free pasta

The objective of this study was to investigate the effect of the addition of alkaline salts (sodium + potassium carbonates) and/or whey protein isolate on the quality of rice-maize gluten-free (GF) pasta. Different levels of incorporation, i.e. 0.5 and 1% alkaline salts, 5% whey protein isolate (WPI) and 1% alkaline salts with 5% WPI, were evaluated. The GF pasta samples were tested for surface microstructure (by Scanning Electron Microscopy), pasting properties, colour, geometrical and cooking quality (weight gain and cooking loss) and textural properties (firmness and compression-extrusion energy). Compared to the control, the alkaline salts addition significantly (p ≤ 0.05) increased viscosity, cooking loss, redness, yellowness and dimensions, and decreased weight gain, luminosity, firmness, and total compression-extrusion energy of cooked pasta. The WPI addition significantly (p ≤ 0.05) increased cooking loss (13–18%), luminosity and yellowness of pasta while decreasing viscosity, firmness (22–27%) and total compression-extrusion energy (15%). However, the WPI addition enhanced the nutritional quality by increasing up to 48% the protein content and, in combination with alkaline salts, produced pasta with good cooking performance. The outcomes of this research can be useful in developing healthier GF pasta without extensively penalizing the cooking performance.

Effect of whey protein isolate addition on set-type camel milk yogurt: Rheological properties and biological activities of the bioaccessible fraction

The manufacture of camel milk (CM) yogurt has been associated with several challenges, such as the weak structure and watery texture, thereby decreasing its acceptability. Therefore, this study aimed to investigate the effect of whey protein isolate (WPI) addition on the health-promoting benefits, texture profile, and rheological properties of CM yogurt after 1 and 15 d of storage. Yogurt was prepared from CM supplemented with 0, 3, and 5% of WPI and compared with bovine milk yogurt. The results show that the water holding capacity was affected by WPI addition representing 31.3%, 56.8%, 64.7%, and 45.1% for yogurt from CM containing 0, 3 or 5% WPI, and bovine milk yogurt, respectively, after 15 d. The addition of WPI increased yogurt hardness, adhesiveness, and decreased the resilience. CM yogurt without WPI showed lower apparent viscosity, storage modulus, and loss modulus values compared with other samples. The supplementation of CM with WPI improved the rheological properties of the obtained yogurt. Furthermore, the antioxidant activities of yogurt before and after in vitro digestion varied among yogurt treatments, which significantly increased after digestion except the superoxide anion scavenging and lipid oxidation inhibition. After in vitro digestion at d 1, the superoxide anion scavenging of the 4 yogurt treatments respectively decreased from 83.7%, 83.0%, 79.1%, and 87.4% to 36.7%, 38.3%, 44.6%, and 41.3%. The inhibition of α-amylase and α-glucosidase, angiotensin-converting enzyme inhibition, cholesterol removal, and degree of hydrolysis exhibited different values before and after in vitro digestion.

Effects of whey protein isolate and ferulic acid/phloridzin/naringin/cysteine on the thermal stability of mulberry anthocyanin extract at neutral pH

In this study, the effects of whey protein isolate (WPI) and four copigments, including ferulic acid (FA), phloridzin, naringin, and cysteine (Cys), on the thermal stability (80 °C/2h) of mulberry anthocyanin extract (MAE) pigment solution at pH 6.3 were studied. WPI addition or copigment (except for Cys) addition alone could protect anthocyanin from degradation to a certain degree, and FA exhibited the best effect among copigments. Compared with the MAE-WPI and MAE-FA binary systems, ΔE of the MAE-WPI-FA ternary system decreased by 20.9% and 21.1%, respectively, and the total anthocyanin degradation rate decreased by 38.0% and 39.3%, respectively, indicating the best stabilizing effect. Remarkably, interactions between anthocyanins and Cys, which generate four anthocyanin derivatives with 513-nm UV absorption during heat treatment, did not alter the color stability of MAE solution; however, they accelerated anthocyanin degradation. These results favor the combined use of multiple methods to stabilize anthocyanins at neutral conditions.

Constitution and reconstitution of microcapsules with high diacylglycerol oil loading capacity based on whey protein isolate / octenyl succinic anhydride starch/ inulin matrix

The aim of this study was to constitute microcapsule systems with high oil loading capacity by octenyl succinic anhydride (OSA) starch, whey protein isolate (WPI) and inulin (IN) substrates to provide a new method for encapsulating diacylglycerol oil. Specifically, this study characterizes the physicochemical properties and reconstitution capacity of highly oil loading diacylglycerol microcapsules by comparing the wall encapsulation capacity of the binary wall system OSA-IN, WPI-IN and the ternary wall system WPI-OSA (1:9, 5:5, 9:1)-IN for diacylglycerol oil. It was found that WPI-OSA (5:5)-IN significantly improved the water solubility of microcapsules (86.11 %) compared to OSA-IN microcapsules, and the addition of WPI made the surface of microcapsules smoother and increased the thermal stability and solubility of microcapsules; the addition of OSA enhanced the wettability of microcapsules compared to WPI-IN. In addition, WPI-OSA (5:5)-IN microcapsules have the highest encapsulation efficiency (96.03 %), high emulsion stability after reconstitution, and the smallest droplet size (212.83 nm) after 28 d. Therefore, the WPI-OSA-IN composite system is suitable for the production of highly oil-loaded microencapsulated systems with excellent reconstitution ability to expand the application of diacylglycerol oil.

The effect of vegetable oil pre-emulsified with whey protein and pectin on physicochemical properties and microstructure of low-fat yogurt.

The effects of whey protein isolate (WPI)-pectin pre-emulsified vegetable oil on the physicochemical properties and microstructure of low-fat yogurt (LFY) were investigated by particle size distribution, water-holding capacity (WHC), texture, rheology, electron microscopy, storage stability, and sensory analysis. The vegetable oil was pre-emulsified into two types of emulsions, a mixed emulsion (ME: WPI-pectin complexes were adsorbed directly at the interface) and a bilayer emulsion (BE: Pectin was added to a previously established WPI-stabilized interface). The results showed that yogurts added with pre-emulsified vegetable oil (ME-Y, BE-Y) had significantly better quality than LFY, with better WHC, textural properties, rheological properties, and storage stability. The average particle size of ME (11.96µm) was larger than that of BE (10.23µm). The consistency of yogurt added with ME (ME-Y) was significantly higher than that of yogurt added with BE (BE-Y), at 2359.10 and 2181.12gs, respectively. Meanwhile, ME-Y exhibited storage stability similar to full-fat control (FFY) and higher sensory scores. Interestingly, the WHC of BE-Y (49.03%) was higher than that of ME-Y (45.63%). In addition, WPI+Pectin-Y exhibited higher WHC (53.81%) and consistency (2518.73gs) compared to ME-Y and BE-Y, but the particle size distribution was not uniform, and the direct addition of WPI, pectin, and oil had no positive effect on improving the rheological properties of yogurt. Overall, the addition of WPI-pectin pre-emulsified vegetable oil improved the quality of LFY. These findings are particularly relevant for the production of higher quality LFY.

Quality Improvement of Garlic Paste by Whey Protein Isolate Combined with High Hydrostatic Pressure Treatment

Garlic, one of the most popular spices and medical herbs, has a unique pungent flavor and taste. Conventional homogenization and thermal treatment commonly lead to flavor and color deterioration in garlic paste, because allicin is highly susceptible to degradation and reaction. The present study was to investigate the effects of whey protein isolate (WPI) and different levels of high hydrostatic pressure (HHP, 200, 300, 400, 500, and 600 MPa) on the quality of garlic paste. Results showed that the addition of WPI in the homogenization of garlic significantly prevented green discoloration. Furthermore, WPI plus HHP under 500 MPa could better protect the color of garlic paste. Higher pressure (600 MPa) led to WPI aggregation, resulting in higher green color chroma of garlic paste. GC-MS results revealed that the application of WPI and HHP in garlic paste increased the relative level of pungent flavor compounds and decreased those of unpleasant odor compounds. The correlation analysis results revealed that WPI efficiently prevented garlic green discoloration, which is attributed to the thiol group in WPI exchanging the sulfonyl groups in allicin. In consideration of the microbial load, flavor and color quality of garlic paste, the optimal processing conditions were found at 500 MPa for 5 min with 2% WPI addition, extending shelf life to 25 days.

Development and physicochemical properties of reformulated, high-protein, untempered sugar-free dark chocolates with addition of whey protein isolate and erythritol

The aim of this study was to determine the effect of whey protein isolate (WPI) and erythritol on physicochemical properties of untempered high-protein (16%, 20% and 24% of protein), sugar-free dark chocolates intended for athletes and diabetics. Surface properties were determined from contact angles, roughness and colour analysis. Melting characteristics were evaluated by Turbiscan. Water activity and viscosity were also tested. Higher WPI concentrations produced more hydrophobic surfaces of the samples and slightly increased their surface roughness. Increased whey protein addition improved shelf life, mechanical properties of chocolates and their resistance to melting; however, it had a minor effect on colour coordinates. Confocal microscopy proved the differences in the microstructure, samples with the highest WPI addition demonstrated more packed and denser structure. Application of WPI and erythritol induced an anti-blooming effect, which enabled skipping of tempering operation, and thus contributing to lower chocolate production costs and their improved nutritional profile.

Lubrication properties of model dairy beverages: Effect of the characteristics of protein dispersions and emulsions

In this study we investigated the individual contribution of different ingredients to the lubrication properties of dairy-based model beverages containing whey protein (native or aggregated), micellar casein and emulsified oil in different combinations. In single-component systems, whey protein isolate (WPI) solutions showed the lowest friction coefficients of all protein samples. Whey protein aggregates (WPA, ∼247 nm, irregular morphology) led to higher friction coefficients than micellar casein isolate (MCI) with comparable size (∼207 nm, near spherical shape). When protein particles were combined, i.e. WPA and MCI, lubrication was not much affected. However, when WPI was added to either WPA or MCI, higher friction coefficients were observed compared to single-component systems. Emulsions (droplet size ∼ 440 nm) provided better lubrication than the protein samples. Oil droplets stabilized by soy lecithin (SL) were more efficient at reducing friction than those stabilized by WPI. The friction coefficient of SE strongly increased in the presence of WPI. In comparison, lubrication of WE was less affected by the addition of WPI. These results show that different proteins affect the lubrication properties of emulsions stabilized with different emulsifiers in a different way. Our research also indicates that multicomponent systems are complex, and that control over the lubrication properties requires a better understanding of the contribution of individual components.

Structuring wheat flour-based crackers using whey protein isolate

The physicochemical and sensorial properties of whey protein isolate (WPI) wheat-based crackers were evaluated by varying WPI at the levels of 0, 5, 15 and 20% (w/w). Textural properties, water activity, protein, moisture content, dough rheology, sensorial properties, as well as colour, thickness and spread factor were assessed. Addition of WPI from 0 to 15% (w/w) decreased the viscoelasticity of cracker dough significantly due to the high water hydration ability of the WPI. As a consequence, it influenced overall cracker texture and spread ratio. However, increasing the WPI to 20% (w/w) improved dough viscoelasticity behaviour as the G’ and G” increased sharply. WPI-wheat based crackers were softer and addition of 20% (w/w) showed good overall acceptability. Therefore, addition of WPI could be a promising technique to improve the structure and quality of wheat-based crackers.

Effects of whey protein on the in vitro digestibility and physicochemical properties of potato starch

The aim of this study was to examine the effect of whey protein isolate (WPI) on the digestibility and physicochemical properties of potato starch (PS) after heat treatment. WPI reduced the digestibility of PS and increased the order and aggregation structure of gelatinized PS. Examination of the rheological properties of the PS-WPI mixed system before and after adding different chemicals (sodium chloride, urea, and sodium dodecyl sulfate) indicated an involvement of hydrogen bonds and hydrophobic interactions in the PS-WPI gelatinization system. The pasting properties, swelling power, and thermal properties indicated that WPI suppressed the swelling and gelatinization of PS. The addition of WPI reduced the amylose leaching rate from the starch granules, indicating that the presence of exogenous protein could prevent amylose diffusion from the starch granules. Native WPI and its hydrolysate also inhibited amyloglucosidase activity. These findings indicated that the mechanism by which WPI reduces PS digestion involves hydrophobic interactions and hydrogen bonding between WPI and PS, as well as enzyme activity inhibition.

Influence of whey protein isolate on pasting, thermal, and structural characteristics of oat starch

We investigated the effects of different concentrations of whey protein isolate (WPI) on oat starch characteristics in terms of pasting, thermal, and structural properties. The pasting properties of the starch showed that hot paste viscosity increased with the addition of WPI in the system, and relative breakdown decreased. Thermal analysis showed a significant effect of WPI on oat starch by increasing the peak temperature of differential scanning calorimeter endotherms. The X-ray diffraction and Fourier transform infrared spectroscopy studies revealed that WPI increased the ordered structuration of starch paste, as evident by an increase in relative crystallinity; in addition, a decrease in infrared bands at 1,024 cm-1 and 1,080 cm-1 suggested decreased gelatinization of oat starch granules. Overall, WPI at different concentrations affected the oat starch gelatinization properties.

Effect of whey protein isolate addition on thermoplasticized pectin packaging properties

AbstractPectin is a natural polysaccharide from plants and the peel of some fruits and is available as a byproduct from the fruit juice industry. Whey protein isolate (WPI) is available as a byproduct of cheese production. Both the pectin and WPI are biodegradable polymers, atoxic, biocompatible, and not expensive. The aim of this article was the study the effect of the WPI addition (0, 5, 10, 15, and 20 wt%) on thermoplasticized extruded/thermo‐compressed pectin film (TPP). The films were compact and homogenous and did not present statistical differences in mechanical properties, independent of WPI concentration. Furthermore, infrared spectra of the samples with WPI presented an indication of Maillard reaction by the characteristic presence of melanoidin, which was also observed in colorimetric results. Thermogravimetric results indicated the samples were thermal stable with the increase of WPI amount. Moreover, the barrier properties and contact angles suggested the films presented major barrier properties and hydrophilic surfaces for samples with WPI. Finally, the addition of WPI in TPP resulted in a potential material for applications in several industries.Practical applicationsPectin and whey protein isolate (WPI) are biodegradable polymers and byproducts of the food industry. The aim of this article was the study the effect of the WPI addition on thermoplasticized extruded/thermo‐compressed pectin film (TPP), in other words, packagings produced by the industrial method. The samples with WPI presented an indicative of Maillard reaction by the presence of melanoidin, which was also observed in color. The addition of WPI in TPP resulted in a potential material for applications in several industries.

Non-Fat Yogurt Fortified with Whey Protein Isolate: Physicochemical, Rheological, and Microstructural Properties.

The demand for low- and non-fat products has recently increased due to the health problems, such as obesity, diabetes, and cardiovascular diseases, that have resulted from high-fat products. However, the reduction in fat can affect the quality of products adversely. The objective of this work was to explore the potential of whey protein isolate (WPI) in improving the quality of non-fat yogurt prepared using skim milk powder (SMP). Yogurt mixes (standardized at 14% total solids) were formulated using SMP as a milk base enriched with WPI. The SMP was replaced by WPI in the yogurt mixes at a rate of 3, 5, 7, and 9%. Full-fat and non-fat set-style yogurts were prepared from whole milk and skim milk, respectively, as controls. Yogurts were fermented at 43 °C to get a pH of 4.6 and stored at 4 °C for the next day. The texture, microstructure, rheological characteristics, and sensory properties of the yogurt samples were studied. The incorporation of WPI increased the water holding capacity to 50% as compared to the non-fat control. This improved the rheological properties while the yogurt viscosity increased in direct proportion with increasing the WPI. The firmness of yogurt was inversely proportional to the increase in WPI, which resulted in 180 g firmness when 9% WPI was added to the non-fat yogurt formulations. Yogurts’ microstructure improved by the addition of WPI. The non-fat yogurt incorporated with 3 and 7% WPI had comparable sensory and textural characteristics to the full-fat yogurt. WPI can be used as a fat replacer to develop low-fat yogurt with desired features. WPI may be a natural and economical ingredient for producing low- and non-fat fermented dairy food products.