Rennet Casein Research Articles

Effect of combined treatments of hydrolysis and succinylation on the solubility and emulsion stability of rennet casein and micellar casein

Casein is the most abundant protein in milk with good emulsifying properties and bioavailability. However, the tight micellar structure of casein results in poor solubility. In the case of soft solid materials such as processed cheese, imitation cheese, yoghurt and protein-based oil-in-water emulsions, poor solubility directly affects the homogeneity and stability of the texture structure of such products, leading to a poor user experience. In this study, two protein modification techniques, hydrolysis and succinylation, were combined to improve the solubility of casein and the stability of its emulsions. The individual and combined effects of enzymatic hydrolysis and succinylation modification approaches on the stability of rennet casein (RC) and micellar casein (MC) emulsions were further explored. After double-treatment of casein with enzymatic hydrolysis and succinylation, the solubility of RC and MC was up to about 95 %, which was superior to that of single-treatment. Fourier transform infrared spectroscopy showed that the characteristic wave signals of the double-treated samples were located between the two single-treated samples, and that there may be an opposite effect between the two modifications. After 21 days of storage, the emulsions prepared from double-treated caseins still remained stable. The salt ionic stability and freeze-thaw stability were significantly improved, and the physical stability of MC was increased by nearly three times. The results explained the effects of enzymatic hydrolysis and succinylation on the functional properties of casein, provided a reference for the development of food systems based on oil-in-water emulsions, and offered a new idea for the wide application of succinylated casein.

Transglutaminase Crosslinked Milk Protein Concentrate and Micellar Casein Concentrate: Impact on the Functionality of Imitation Mozzarella Cheese Manufactured on a Small Scale Using a Rapid Visco Analyzer.

In dairy-based imitation mozzarella cheese (IMC) formulations, intact casein is critical and imparts IMC with a firm and elastic, stringy, melted texture. Rennet casein (RCN) is the desired ingredient to provide intact casein in IMC and is preferred over milk protein concentrate (MPC) and micellar casein concentrate (MCC). Transglutaminase (TGase), a crosslinking enzyme, alters the physical properties of MPC or MCC and may change IMC functionality. The objective of this study was to determine the effect of TGase-crosslinked MPC and MCC powders on the functionality of IMCs. The TGase treatment included TGase at 0.3 (L) and 3.0 (H) units/g of protein and a control (C) with no TGase addition. Each IMC formulation was balanced for constituents and was produced in a Rapid Visco Analyzer (RVA). The MCC or MPC powder with high TGase enzyme in IMC formulation did not form an emulsion. The IMC containing TGase-treated powders had a significantly (p ≤ 0.05) higher RVA-viscosity during manufacture and transition temperature (TT), and a significantly (p ≤ 0.05) lower Schreiber melt test area. The IMC made from MPC (with or without TGase) had lower TT values and Schreiber melt test area as compared with that made from MCC. The TGase-treated MPC and MCC, when used for IMC manufacture, were comparable to IMC manufactured with RCN in texture and some measured melted characteristics. In conclusion, TGase treatment alters the melt characteristics of MCC and MPC in IMC applications.

Влияние жировых компонентов на свойства молокосодержащих продуктов, произведенных по технологии термизированных сыров

The research featured the effect of fatty components on the sensory, physicochemical, structural, and mechanical indicators and functional properties of milk-containing products subjected to heat-treated cheese technology. Butter with a fat mass fraction of 72.5 % and a milk fat substitute served as fat components while rennet casein and modified starch were the protein-carbohydrate base. The list of variables included the mass fraction of fat in solids, the concentration of emulsifying salt, and humidity. The aspects tested included taste, smell, consistency, active acidity, and penetration tension. The functional properties were assessed using the pizza cheese rating scale developed at the Institute of Butter- and Cheesemaking. The tests revealed no differences in the effect of milk fat and milk fat substitute on the physicochemical, structural, mechanical, and functional properties and texture. The samples with milk fat substitute had a specific taste while the samples with butter possessed a weak creamy taste. Fat components improved the uniformity of milk-containing products produced by the heat-treated cheese method. As the mass fraction of fat increased, the penetration tension went down. Fats, regardless of their origin, had a positive effect on the gradability, meltability, and extensibility while reducing the number of blisters. If taken at maximum values, the variables led to poor texture, functional properties, and penetration stress. The best combination for heat-treated products included fats of milk origin and 2 % emulsifying salt. The finished product had 50 % moisture mass fraction and 35 % fat in solids.

Effect of acetic acid solutions on regenerated fibers from rennet-treated casein micelles

Fibers made from rennet casein micelles promise a wide range of new applications in food-grade products. Understanding the influence of environmental conditions such as pH on the water binding and swelling properties is a crucial factor for embedding them in hydrated matrices in the future. The expansion of the fibers in dilute acetic acids always takes place in two steps, as previously observed in citric acid. Model analyses showed that the rates of the swelling steps decreased with increasing acetic acid strength. In contrast, the simulated plateau values of both swelling steps increased. Differences to swelling in citric acid are discussed for the second swelling step on the basis of the pH value of the swelling media, while different calcium affinities are assumed for the first swelling step.

Safety evaluation of the food enzyme mucorpepsin from the non-genetically modified Rhizomucor miehei strain FRO.

The food enzyme mucorpepsin (EC 3.4.23.23) is produced with the non-genetically modified Rhizomucor miehei strain FRO by DSM Food Specialties B.V. The enzyme can be chemically modified to produce a thermolabile form. The food enzyme is free from viable cells of the production organism. It is intended to be used in three food manufacturing processes: processing of dairy products for the production of (1) cheese, (2) edible rennet casein, (3) fermented dairy products. Dietary exposure to the food enzyme-total organic solids (TOS) was estimated to be up to about 0.072 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 2000 mg TOS/kg bw per day, the highest dose tested, which, when compared with the estimated dietary exposure, results in a margin of exposure of at least 27,778. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and five matches were found. The Panel considered that a risk of allergic reactions upon dietary exposure to this food enzyme cannot be excluded, but is considered low, except for individuals sensitised to mustard proteins, for whom the risk will not exceed that of mustard consumption. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

The effect of whey source on heat-induced aggregation of casein and whey protein mixtures of relevance to infant nutritional product formulation

Sweet and, to a lesser extent, acid whey protein ingredients can be used for the formulation of infant nutritional products. Unlike acid whey, sweet whey contains caseinomacropeptide (CMP), a heat-stable peptide liberated from κ-casein during cheese and rennet casein manufacture. Four protein systems-sweet whey (SW) and acid whey (AW), with or without standardization for CMP protein content-were added to skim milk (50/50, wt/wt) and unheated or heated to 85 or 110°C. These 12 samples were assessed for physicochemical stability in the presence of added calcium at pH 6.8. The effect of CMP content on the physicochemical properties of the protein systems was also assessed. Without preheat treatment, mixtures of AW and skim milk (SM) were more heat stable than SW and SM, demonstrating the effect of whey protein type on heat stability. Preheat treatment of the SW in the presence of SM significantly improved the heat stability of the resultant protein systems on subsequent heating. All of the protein systems had significantly lower heat stability with the addition of Ca, although the reduction was significantly smaller for the heated protein systems than the unheated controls. The findings can help identify heating parameters and ingredients for optimizing processing stability and physicochemical characteristics of nutritional beverages such as infant formulations.

Untargeted metabolomics provide new insights into the implication of Lactobacillus helveticus strains isolated from natural whey starter in methylglyoxal-mediated browning

Hard cheeses may occasionally show a brown discolouration during ripening due to multifactorial phenomena that involve bacteria and give rise to pyrazines arising from methylglyoxal. The present work aimed at developing a novel approach to investigate the role of natural starters in browning. To this object, 11 strains of L. helveticus were incubated in a medium containing 10 % rennet casein dissolved in whey, and then growth was monitored by measuring pH and number of genomes/mL. Browning was assessed through CIELab analysis, methylglyoxal production was determined by targeted mass spectrometry, and untargeted metabolomics was used to extrapolate marker compounds associated with browning discoloration. The medium allowed the growth of all the strains tested and differences in colour were observed, especially for strain A7 (ΔE* value 15.92 ± 0.27). Noteworthy, this strain was also the higher producer of methylglyoxal (2.44 µg/mL). Metabolomics highlighted pyrazines and β-carboline compounds as markers of browning at 42 °C and 16 °C, respectively. Moreover, multivariate statistics pointed out differences in free amino acids and oligopeptides linked to proteolysis, while 1,2-propanediol and S-Lactoylglutathione suggested specific detoxification route in methylglyoxal-producing strains. Our model allowed detecting differences in browning amid strains, paving the way towards the study of individual L. helveticus strains to identify the variables leading to discoloration or to study the interaction between different strains in natural whey starters.

The effect of milk fat content on microstructure and rheological properties of rennet casein gel emulsions

Cheese is described as an emulsion gel, in which the dispersed phase comprises milk fat globules while the continuous phase consists of a casein gel network. By embedding fat into the casein network, it is possible to tailor the viscoelastic and physiochemical properties of casein emulsion gels and design customized cheese products. In this study, we incorporated 0.1, 7, 11, and 18% (w/w) milk fat in casein gels made from renneted skimmed milk curd and investigated its effect on microstructure, rheological properties, and melting behavior of the gels. Confocal laser scanning microscopy images revealed the presence of larger fat globules and serum pockets in samples with a fat content >11%, which also led to a more porous protein gel network structure. A higher proportion of water with high mobility, observed by low-field nuclear magnetic resonance, confirmed the presence of more or larger serum pockets in gels with the highest fat content. Rheological analysis showed that casein gels exhibited a behavior typical of weak solid viscoelastic materials. Increasing fat content increased gels strength, as revealed by a rise in storage modulus, but made them more susceptible to deformation. The gel-sol transition temperature increased from 65.5 ± 0.7 to 71.9 ± 0.2 °C with increased fat content due to the relatively lower moisture content in gels with a fat content >11%. The results obtained provided a better understanding of the possibility to modulate structural and rheological properties of casein emulsion gels emulsified with milk fat.

Microstructural Characterization of High-Protein Dairy Powders

Dairy proteins are potential and multipurpose ingredients used to prepare various food products. It exhibits many beneficial functionalities and bioactivities in the processing of food products. All the functionalities of different dairy proteins depend on their peculiar structural characteristics. So, the present study aimed to characterize high-protein powders with different matrices (milk protein concentrate (MPC), rennet casein (RCN), micellar casein concentrate (MCC), whey protein isolate (WPI), and native whey concentrate (NWC)) for their composition, handling, and reconstitution properties, and microstructure and compared them with whole milk powder (WMP) and skim milk powder (SMP). The bulk density of the high-protein powders was significantly (p < 0.05) lower than WMP and NFDM. Due to the low bulk density of the high-protein powders, the wettability of these powders in the water was very high. Microstructural analysis of powders by scanning electron microscopy reveals that the high-protein powder had tetrahedron-to-polyhedron-shaped particles depending on the protein level. The idea regarding the powder’s morphology might be helpful for further improvement in the production processes to modify the functional properties of high-protein milk powders.

Influence of pH, temperature and concentration of calcium sequestering salts on the solubilisation of individual caseins and minerals from rennet casein

The effect of the calcium sequestering salts (CSS) disodium phosphate (DSP), trisodium citrate (TSC) and sodium hexametaphosphate (SHMP), pH (5.8 or 6.7), and heat treatment (90 °C for 5 min) on the solubilisation of individual caseins and minerals from 5% (w/w) rennet casein suspensions was studied. Levels of non-sedimentable caseins increased up to 150 mm DSP, 50 mm TSC and 10 mm SHMP, after which they plateaued or decreased. Higher levels of non-sedimentable caseins were found at pH 6.7 than at pH 5.8, whereas heating reduced levels of non-sedimentable caseins, Ca and P. Non-sedimentable Ca decreased with increasing level of DSP but increased with increasing level of TSC and SHMP. The results suggest different mechanism for different CSS; DSP may act through forming insoluble Ca-phosphate complexes, whereas TSC likely forms soluble Ca-citrate complexes and solubilises phosphate. SHMP likely cross-links caseins via calcium-casein phosphate complexes, enabling interaction with cations and caseins simultaneously.

Regenerated Fibers from Rennet-Treated Casein Micelles during Acidification.

Micellar casein fibers of defined size and internal structure can be produced by the extrusion of cold-renneted casein micelles into a warm, calcium-rich coagulation bath. Calcium phosphate contacts within the casein matrix are important for fiber stability and production but become less important under acidic pH conditions. We demonstrate this with swelling experiments in media with pH < 2, which we adjust with citric acid of different molarities. In contrast to the simple swelling of dried casein fibers in water, a two-phase process takes place in citric acid similar to swelling in 1 N HCl. However, instead of a second deswelling step, we observe in citric acid that the fiber swells further. The observation is explained by a pH-dependent transition from a rennet casein gel to an acidified rennet gel. This can be simulated with a kinetic model that couples two second-order rate equations via a time-varying ratio. The final swelling values decrease with increasing proton concentration via a scaling relation, which is also confirmed by swelling in other acids (HCl or acetic acid) in this pH range. We attribute this to a decrease in the molecular weights of the aggregated casein structures within the strands of the gel network.

An evaluation of dairy product quality where chlorine-free cleaning is employed across the dairy processing chain from bacterial and chemical residue perspectives

Chlorate is a residue of concern in the dairy industry and is linked to cleaning-in-place strategies that utilise chlorinated chemicals. Chlorine-free chemicals were adopted to minimise chlorate occurrence, but little is known about their performance. To address this, samples from single batches of commercially produced rennet casein powder and salted sweet cream butter were taken throughout their manufacturing processes. Manufacturing equipment was cleaned using chlorine-free chemicals. Samples were analysed for chlorate and total bacteria, thermoduric and spore former counts with 16S sequencing conducted on spore formers. Chlorate levels were 0.026 mg kg−1 in powder but were undetectable (<0.01 mg kg−1) in butter. Bacterial counts from butter and powder processes were ≤2.00 log10 cfu mL−1 and ≤4.00 log10 cfu mL−1, respectively. Spore formers were predominantly identified as Bacillus. This study demonstrates that satisfactory bacterial levels are achievable where chlorine-free chemicals are used for cleaning.

Improving vitamin D stability and antioxidant activity in imitation mozzarella cheese by conjugated cricket protein with fructooligosaccharide

Conjugated cricket protein with fructooligosaccharide (FOS), called CPF, is a new alternative protein ingredient with great potential for food industry applications. This study aimed to investigate the effect of CPF as a partial substitute for rennet casein on the composition, appearance, color, antioxidant activities, sensory characteristics, and functional characteristics of imitated mozzarella cheese. The effect of CPF on vitamin D retention of cheese after processing and 28 subsequent days of storage was also studied. Incorporation of CPF by 10–40 g/100g resulted in significantly increased FOS as prebiotic fibers by about 0.1–4.2 g/100g in imitation mozzarella cheese, but slightly decreased the protein content and shifted color balance darker, with more yellow and red. The addition of CPF reduced hardness, cohesiveness, springiness, and stretchability (25.0–3.6 cm) but increased meltability, adhesiveness, and free oil release (2.0–9.3 cm) of cheeses. In addition, CPF enhanced vitamin D stability in the cheese matrix by about 3 times after heat treatment and 2.8 times after 28 days of storage (4 °C) when compared to the control. It is concluded that adding 10–20 g/100g CPF in imitation cheese improved vitamin D stability and provided acceptable sensory scores for consumers (like moderately, 7.1–7.3).

A Review on the Effect of Calcium Sequestering Salts on Casein Micelles: From Model Milk Protein Systems to Processed Cheese.

Phosphates and citrates are calcium sequestering salts (CSS) most commonly used in the manufacture of processed cheese, either singly or in mixtures. Caseins are the main structure forming elements in processed cheese. Calcium sequestering salts decrease the concentration of free calcium ions by sequestering calcium from the aqueous phase and dissociates the casein micelles into small clusters by altering the calcium equilibrium, thereby resulting in enhanced hydration and voluminosity of the micelles. Several researchers have studied milk protein systems such as rennet casein, milk protein concentrate, skim milk powder, and micellar casein concentrate to elucidate the influence of calcium sequestering salts on (para-)casein micelles. This review paper provides an overview of the effects of calcium sequestering salts on the properties of casein micelles and consequently the physico-chemical, textural, functional, and sensorial attributes of processed cheese. A lack of proper understanding of the mechanisms underlying the action of calcium sequestering salts on the processed cheese characteristics increases the risk of failed production, leading to the waste of resources and unacceptable sensorial, appearance, and textural attributes, which adversely affect the financial side of processors and customer expectations.

Greener bio-based spherical nanoparticles for efficient multilayer textile fabrics nanocoating with outstanding fire retardancy, toxic gases suppression, reinforcement and antibacterial properties

Herein, sustainable and innovative textile fabrics nanocoatings were developed achieving textile fabrics with superior fire safety, antibacterial, reinforcement and toxic gases suppression properties. Hence, spherical rennet casein nanoparticles were synthesized for the first time using energy saving and green magnetic stirring tool at ambient condition yielded nanoparticles of an average size of 116 nm. Moreover, spherical chitosan nanoparticles of an average size of 26 nm were also synthesized using the same approach. The size and distribution of newly developed nanoparticles were optimized using varied stirring time intervals (24–96 h). The developed spherical nanoparticles were elucidated using dynamic light scattering and microscopic tools. Then, the fabricated polyanions rennet casein nanoparticles and polycations chitosan nanoparticles were utilized as an alternating bilayer for constructing nanocoating on the surface of cotton and polyester fabrics individually by layer-by-layer approach. The bilayers coating number was altered in 3, 5 and 10 multilayers. The flame retardancy of developed textile fabrics was significantly improved achieving zero rate of burning and 34% of limiting oxygen index (LOI) value compared to 119 mm/min and 18.5% for uncoated cotton sample. This is in addition to outstanding toxic gases suppression achieving 76%, 73% and 64% for CO2, CO and SO2, respectively. Additionally, significant enhancement in tensile strength of coated fabrics was attained recording 241% improvement. The newly developed textile fabrics coatings inhibit the growth of Escherichia coli bacteria on surface of both cotton and polyester fabrics achieving clear inhibition zone of 16 mm. The developed sustainable coatings afford durable properties to textile fabrics. Moreover, the flame retardancy, toxic gases suppression mechanisms and economic feasibility for scalable production were studied.

Preparation and characterisation of plant and dairy-based high protein Chinese steamed breads (mantou): Microstructural characteristics and gastro-small intestinal starch digestion in vitro

The effects of dairy and plant protein addition on microstructural characteristics and in vitro gastro-small intestinal starch digestion characteristics of Chinese steamed breads (CSBs) were studied. Breads containing rennet casein (RC) and a mixture of soy protein isolate and milk protein concentrate (SM) at two different levels (RC I, RC II; SM I, SM II) were prepared. Microstructural characteristics of the undigested and digested control (100% wheat flour) bread and high protein steam bread (HPCSB) versions were compared through scanning electron microscopy. The compact microstructure of HPCSBs displayed a network of proteins wrapped around starch granules and had fewer air cells compared to the control. The addition of both proteins influenced the microstructure of HPCSBs, which in turn affected their textural and starch digestion properties. The in vitro starch digestion of control CSB and HPCSBs confirmed that the addition of proteins is capable of lowering the starch hydrolysis (%). The highest starch hydrolysis was observed for the control wheat bread, followed by SM1 > RC I > SM II and RC II at the end of the small-intestinal digestion. The estimated glycaemic indices (eGI) for all HPCSBs were statistically lower than the control CSB. In comparison to control CSB, the microstructure of HPCSBs appeared more irregular, less porous, and compact during gastric and small intestinal digestion.

The effect of pH on the rheological and physical properties of analogue pizza cheese.

This study aimed to evaluate the effect of the pH levels (5.8, 6.0, 6.2, and 6.4) on analogue pizza cheese (APC) rheological and physical characteristics. The APC formulation included 25% vegetable oil and 18.5% rennet casein. The APC samples were made using a Thermomix device and the cheese was stored at + 5°C for 5days before it was transferred to - 18°C. Rotational rheometer measurements showed that all samples followed Herchel-Buckley viscoplastic Model with a different yield stress, highest apparent viscosity, and shear stress values were obtained at pH 6.4 followed by pH 6.2; then the values were dropped by 70%. Melting and stretching showed the best characteristics for the APC sample at pH 6.4, whereas at pH 6.0 stretching values decreased by 77%. The APC samples at pH ≥ 6.2 showed better stability after 6months of frozen storage in the apparent viscosity than other cheeses. This study concluded that better rheological and physical properties were obtained for the APC at pH ≥ 6.20 and that significant variation for the rheological behavior of the APC can be based on the pH alone, as a slight alteration in the pH was found to affect product quality and acceptability.

Development and characterisation of plant and dairy-based high protein Chinese steamed breads (mantou): Physico-chemical and textural characteristics

High protein versions of popular, highly consumed food products such as Chinese steamed bread (CSB) can be useful to improve the health status of our populations. In the current study, high protein Chinese steamed breads (HPCSBs) were developed using plant (soy protein isolate, SPI) or dairy (rennet casein, RC and milk protein concentrate, MPC) proteins. These proteins were blended into wheat flour at two different levels (RC I, RC II; SM (soy protein isolate-SPI + milk protein concentrate-MPC) I, SM II) to prepare breads, which were then compared to a control (100% wheat flour-based) Chinese steamed bread for physico-chemical and textural characteristics. The addition of proteins darkened the colour of HPCSBs and decreased the specific bread volume with RC II showing the lowest. All the high protein formulations recorded an increase in RVA pasting temperature, whereas a decrease in the peak, final and breakdown viscosities of pastes was observed with the addition of both RC and SM at all levels. Similarly, the DSC onset transition temperatures were observed to increase when either RC or SM was added to the formulation. The textural characteristics of HPCSBs showed an increase in hardness, gumminess, and resistance for penetration along with tensile strength than the control CSB.

Use of micellar casein concentrate and milk protein concentrate treated with transglutaminase in imitation cheese products—Unmelted texture

The amount of intact casein provided by dairy ingredients is a critical parameter in dairy-based imitation mozzarella cheese (IMC) formulation because it has a significant effect on unmelted textural parameters such as hardness. From a functionality perspective, rennet casein (RCN) is the preferred ingredient. Milk protein concentrate (MPC) and micellar casein concentrate (MCC) cannot provide the required functionality due to the higher steric stability of casein micelle. However, the use of transglutaminase (TGase) has the potential to modify the surface properties of MPC and MCC and may improve their functionality in IMC. The objective of this study was to determine the effect of TGase-treated MPC and MCC powders on the unmelted textural properties of IMC and compare them with IMC made using commercially available RCN. Additionally, we studied the degree of crosslinking by TGase in MPC and MCC retentates using capillary gel electrophoresis. Three lots of MCC and MPC retentate were produced from pasteurized skim milk via microfiltration and ultrafiltration, respectively, and randomly assigned to 1 of 3 treatments: no TGase (control); low TGase: 0.3 units/g of protein; and high TGase: 3.0 units/g of protein, followed by inactivation of enzyme (72°C for 10 min), and spray drying. Each MCC, MPC, and RCN was then used to formulate IMC that was standardized to 21% fat, 1% salt, 48% moisture, and 20% protein. The IMC were manufactured by blending, mixing, and heating ingredients (4.0 kg) in a twin-screw cooker. The capillary gel electrophoresis analysis showed extensive inter- and intramolecular crosslinking. The IMC formulation using the highest TGase level in MCC or MPC did not form an emulsion because of extensive crosslinking. In MPC with a high level of TGase, whey protein and casein crosslinking were observed. In contrast, crosslinking and hydrolysis of proteins were observed in MCC. The IMC made from MCC powder had significantly higher texture profile analysis hardness compared with the corresponding MPC powder. Further, many-to-one (multiple) comparisons using the Dunnett test showed no significant differences between IMC made using RCN and treatment powders in hardness. Our results demonstrated that TGase treatment causes crosslinking hydrolysis of MCC and MPC at higher TGase levels, and MPC and MCC have the potential to be used as ingredients in IMC applications.

Use of micellar casein concentrate and milk protein concentrate treated with transglutaminase in imitation cheese products—Melt and stretch properties

Melt and stretch properties in dairy-based imitation mozzarella cheese (IMC) are affected by the amount of intact casein provided by dairy ingredients in the formulation. Rennet casein (RCN) is the preferred ingredient to provide intact casein in a formulation. Ingredients produced using membrane technology, such as milk protein concentrate (MPC) and micellar casein concentrate (MCC), are unable to provide the required functionality. However, the use of transglutaminase (TGase) has potential to modify the physical properties of MPC or MCC and may improve their functionality in IMC. The objective of this study was to determine the effect of TGase-treated MPC and MCC retentates on melt and stretch properties when they are used in IMC and to compare them with IMC made using RCN. The MCC and MPC retentates were produced using 3 different lots of pasteurized skim milk and treated with 3 levels of TGase enzyme: no TGase (control), low TGase: 0.3 units/g of protein, and high TGase: 3.0 units/g of protein. Each of the MCC and MPC treatments was heated to 72°C for 10 min to inactivate TGase and then spray dried. Each MCC, MPC, and RCN powder was then used in an IMC formulation that was standardized to 48% moisture, 21% fat, 20% protein, and 1% salt. The IMC were manufactured in a twin-screw cooker by blending, mixing, and heating various ingredients (4.0 kg). Due to extensive crosslinking, the IMC formulation with the highest TGase level (MCC or MPC) did not form an emulsion. The IMC made from MCC treatments had significantly higher stretchability on pizza compared with their respective MPC treatments. The IMC made from TGase-treated MCC and MPC had significantly lower melt area and significantly higher transition temperature (TT) and stretchability compared with their respective controls. Comparison of IMC made using TGase-treated MCC and MPC to the RCN IMC indicated no difference in TT or texture profile analysis-stretchability; however, the Schreiber melt test area was significantly lower. Our results demonstrated that TGase treatment modifies the melt and stretch characteristics of MCC and MPC in IMC applications, and TGase-treated MPC and MCC can be used to replace RCN in IMC formulations.