Microbacterium represents an emerging microorganism of concern in microfiltered extended shelf-life milk products.

Growing interest in the manufacture of extended shelf-life (ESL) milk, which is typically achieved by a high-temperature treatment called ultra-pasteurization (UP), is driven by distribution challenges, efforts to reduce food waste, and more. Even though high-temperature, short-time (HTST) pasteurized milk has a substantially shorter shelf life than UP milk, HTST milk is preferred in the United States because consumers tend to perceive UP milk as less desirable due to the "cooked" flavor associated with high-temperature processing. While ESL beyond 21 d may be possible for HTST, the survival and outgrowth of psychrotolerant aerobic spore-forming bacteria can still be a limitation to extending shelf life of HTST milk. Microfiltration (MF) is effective for reducing vegetative microorganisms and spores in raw milk, but it is unclear what the effects of membrane pore size, storage temperature, and milk type (i.e., skim vs. whole) are on the microbial shelf life of milk processed by both MF and HTST pasteurization. To investigate these factors, raw skim milk was MF using different pore sizes (0.8 or 1.2 µm), and then MF skim milk and standardized whole milk (MF skim with heat-treated [85°C for 20 s] cream) were HTST pasteurized at 75°C for 20 s. Subsequently, milk was stored at 3°C, 6.5°C, or 10°C and total bacteria counts were measured for up to 63 d. An ANOVA indicated that mean bacterial concentrations between storage temperatures were significantly different from each other, with mean maximum observed concentrations of 3.67, 5.33, and 8.08 log10 cfu/mL for storage temperatures 3°C, 6.5°C, and 10°C, respectively. Additionally, a smaller difference in mean maximum bacterial concentrations throughout shelf life was identified between pore sizes (<1 log cfu/mL), but no significant difference was attributed to milk type. An unexpected outcome of this study was the identification of Microbacterium as a major contributor to the bacterial population in MF ESL milk. Microbacterium is a psychrotolerant, thermoduric gram-positive, non-spore-forming rod with a small cell size (∼0.9 µm length and ∼0.3 µm width), which our data suggest was able to permeate the membranes used in this study, survive HTST pasteurization, and then grow at refrigeration temperatures. While spores continue to be a key concern for the manufacture of MF, ESL milk, our study demonstrates the importance of other psychrotolerant, thermoduric bacteria such as Microbacterium to these products.

Monte Carlo simulation model predicts bactofugation can extend shelf-life of pasteurized fluid milk, even when raw milk with low spore counts is used as the incoming ingredient.

Bacterial spores from raw milk that survive the pasteurization process are responsible for half of all the spoilage of fluid milk. Bactofugation has received more attention as a nonthermal method that can reduce the presence of bacterial spores in milk and with it the spoilage of fluid milk. The objective of this work was to determine the effectiveness of bactofugation in removing spores from raw milk and estimate the effect the spore removal could have on shelf-life of fluid milk. The study was conducted in a commercial fluid milk processing facility where warm spore removal was performed using one-phase bactofuge followed by warm cream separation and high temperature, short time pasteurization. Samples from different stages of fluid milk processing with and without the use of bactofuge were tested for total plate count, mesophilic spore count, psychrotolerant spore count (PSC), and somatic cell count. Results were evaluated to determine the count reductions during different stages of fluid milk processing and compare counts in fluid milk processed with and without bactofugation. Bactofugation on average reduced the total plate count by 1.81 ± 0.72 log cfu/mL, mesophilic spore count by 1.08 ± 0.71 log cfu/mL, PSC by 0.86 ± 0.59 log cfu/mL, and somatic cell count by 135,881 ± 43,942 cells/mL. Psychrotolerant spore count in final pasteurized skim milk processed with and without bactofugation was used to predict the shelf-life of the pasteurized skim milk using the Monte Carlo simulation model. Although PSC in the initial raw milk was already low (-0.63 ± 0.47 log cfu/mL), the predicted values from the simulation model showed that bactofugation would extend the shelf-life of pasteurized skim milk by approximately 2 d. The results of this study will directly help fluid milk processors evaluate the benefits of using bactofugation as an intervention in their plants, and also demonstrate the benefits of using mathematical modeling in decision making.

Nanoporous anodic alumina reduces Staphylococcus biofilm formation.

Staphylococcus epidermidis and Staphylococcus aureus, two bacterial strains commonly associated with biofilm-related medical infections and food poisoning, can rapidly colonize biotic and abiotic surfaces. The present study investigates the ability of anodic alumina surfaces with nanoporous surface topography to minimize the attachment and biofilm formation mediated by these pathogenic bacterial strains. Early attachment and subsequent biofilm development were retarded on surfaces with nanopores of 15-25 nm in diameter compared to surfaces with 50-100 nm pore diameter and nanosmooth surfaces. After 30 min of incubation in nutritive media, the biomass accumulation per unit surface area was 2·93 ± 1·72 µm3  µm-2 for the 15 nm, 3·49 ± 1·97 µm3  µm-2 for the 25 nm, as compared to 14·04 ± 6·39 µm3  µm-2 for the nanosmooth, 11·88 ± 9·72 µm3  µm-2 for the 50 nm and 12·09 ± 11·84 µm3  µm-2 for the 100 nm surfaces respectively. These findings suggest that anodic alumina with small size nanoscale pores could reduce the incidence of staphylococcal biofilms and infections, and shows promise as a material for a variety of medical applications and food contact surfaces. SIGNIFICANCE AND IMPACT OF THE STUDY: This paper reports on a simple, robust and scientifically sound method to reduce attachment and biofilm formation by Staphylococcus aureus and Staphylococcus epidermidis to abiotic surfaces using a carefully designed nanoscale topography. This approach can help to reduce the incidence of staphylococcal biofilms and infections without imposing selective stresses on bacteria, thus preventing the creation of resistant strains.

Pulsed light and antimicrobial combination treatments for surface decontamination of cheese: Favorable and antagonistic effects.

Postprocessing cross-contamination of cheese can lead to both food safety issues and significant losses due to spoilage. Pulsed light (PL) treatment, consisting of short, high-energy, broad-spectrum light pulses, has been proven effective in reducing the microbial load on cheese surface. As PL treatment effectiveness is limited by light-cheese interactions, the possibility to improve its effectiveness by combining it with the antimicrobial nisin was explored. The effect of natamycin, which is added to cheeses as an antifungal agent, on PL effectiveness was also investigated. Pseudomonas fluorescens, Escherichia coli ATCC 25922, and Listeria innocua were used as challenge microorganisms. Bacterial cultures in stationary growth phase were diluted to initial inoculum levels of 5 or 7 log cfu per cheese slice. Slices of sharp white Cheddar cheese and white American singles were cut in rectangles of 2.5 × 5 cm. For cheese slices receiving antimicrobial treatment before PL, slices were dipped in natamycin or nisin, spot inoculated with 100 µL of bacterial suspension, and then treated with PL. Cheese slices receiving PL treatment before antimicrobials were spot inoculated, treated with PL, and then treated with antimicrobials. The PL fluence levels from 1.02 to 12.29 J/cm2 were used. Survivors were enumerated by standard plate counting or the most probable number technique, as appropriate. All treatments were performed in triplicate, and the data were analyzed using a general linear model. Treatment with nisin or natamycin before PL decreased the effectiveness of PL for all bacteria tested. For instance, PL reduced P. fluorescens on Cheddar cheese by 2.19 ± 0.27 log after 6.14 J/cm2, whereas combination treatments at the same PL fluence yielded barely 1 log reduction. Inactivation of L. innocua on Cheddar was only 0.78 ± 0.01 log when using PL after nisin, compared with a 1.30 ± 0.76 log reduction by nisin alone. This was attributed to the absorption of UV light by the 2 antimicrobials, which diminished the UV fluence received by the bacteria. Increased inactivation was obtained when antimicrobials were applied after PL. On process cheese, a maximum reduction of 3.73 ± 0.96 log of L. innocua was obtained at 9.22 J/cm2 for PL followed by nisin, compared with 3.01 ± 0.48 by PL alone. This study demonstrates that antimicrobials may increase the antimicrobial effectiveness of PL on cheese surface, but the order of treatments is critical.

Short communication: Influence of pulsed light treatment on the quality and sensory characteristics of Cheddar cheese.

The objective of this study was to examine the effect of pulsed light (PL) treatment on the color, oxidative stability, and onset of molding of Cheddar cheese. Slices of sharp white Cheddar cheese of 2.5 × 5 cm were treated on one side with PL doses from 1.02 to 12.29 J/cm2, sealed in polyethylene bags, and stored at 6°C for up to 1 mo. Peroxide value, color parameters, and the onset of molding were evaluated. No significant changes in color or peroxide value were observed for PL-treated samples compared with the untreated controls. Pulsed light was able to significantly delay surface molding during refrigerated storage, with a PL dose of 9.22 J/cm2 delaying the onset of molding by 7 d. The effect of PL on the taste, appearance, and acceptability of Cheddar cheese slices treated with a PL dose of 9.22 J/cm2 on each side was assessed. In triangle tests, 60 untrained panelists were unable to detect significant differences between the control and PL-treated samples, although PL had a significant effect on overall liking, flavor, and appearance. These findings suggest that although PL can be effective for surface decontamination of cheese, it may have some detrimental effects on sensory properties.

Pulsed-light inactivation of pathogenic and spoilage bacteria on cheese surface.

Cheese products are susceptible to postprocessing cross-contamination by bacterial surface contamination during slicing, handling, or packaging, which can lead to food safety issues and significant losses due to spoilage. This study examined the effectiveness of pulsed-light (PL) treatment on the inactivation of the spoilage microorganism Pseudomonas fluorescens, the nonenterohemorrhagic Escherichia coli ATCC 25922 (nonpathogenic surrogate of Escherichia coli O157:H7), and Listeria innocua (nonpathogenic surrogate of Listeria monocytogenes) on cheese surface. The effects of inoculum level and cheese surface topography and the presence of clear polyethylene packaging were evaluated in a full factorial experimental design. The challenge microorganisms were grown to early stationary phase and subsequently diluted to reach initial inoculum levels of either 5 or 7 log cfu/slice. White Cheddar and process cheeses were cut into 2.5×5 cm slices, which were spot-inoculated with 100 µL of bacterial suspension. Inoculated cheese samples were exposed to PL doses of 1.02 to 12.29 J/cm(2). Recovered survivors were enumerated by standard plate counting or the most probable number technique, as appropriate. The PL treatments were performed in triplicate and data were analyzed using a general linear model. Listeria innocua was the least sensitive to PL treatment, with a maximum inactivation level of 3.37±0.2 log, followed by P. fluorescens, with a maximum inactivation of 3.74±0.8 log. Escherichia coli was the most sensitive to PL, with a maximum reduction of 5.41±0.1 log. All PL inactivation curves were nonlinear, and inactivation reached a plateau after 3 pulses (3.07 J/cm(2)). The PL treatments through UV-transparent packaging and without packaging consistently resulted in similar inactivation levels. This study demonstrates that PL has strong potential for decontamination of the cheese surface.

A physicochemical investigation of membrane fouling in cold microfiltration of skim milk.

The main challenge in microfiltration (MF) is membrane fouling, which leads to a significant decline in permeate flux and a change in membrane selectivity over time. This work aims to elucidate the mechanisms of membrane fouling in cold MF of skim milk by identifying and quantifying the proteins and minerals involved in external and internal membrane fouling. Microfiltration was conducted using a 1.4-µm ceramic membrane, at a temperature of 6±1°C, cross-flow velocity of 6m/s, and transmembrane pressure of 159kPa, for 90min. Internal and external foulants were extracted from a ceramic membrane both after a brief contact between the membrane and skim milk, to evaluate instantaneous adsorption of foulants, and after MF. Four foulant streams were collected: weakly attached external foulants, weakly attached internal foulants, strongly attached external foulants, and strongly attached internal foulants. Liquid chromatography coupled with tandem mass spectrometry analysis showed that all major milk proteins were present in all foulant streams. Proteins did appear to be the major cause of membrane fouling. Proteomics analysis of the foulants indicated elevated levels of serum proteins as compared with milk in the foulant fractions collected from the adsorption study. Caseins were preferentially introduced into the fouling layer during MF, when transmembrane pressure was applied, as confirmed both by proteomics and mineral analyses. The knowledge generated in this study advances the understanding of fouling mechanisms in cold MF of skim milk and can be used to identify solutions for minimizing membrane fouling and increasing the efficiency of milk MF.

Use of micellar casein concentrate for Greek-style yogurt manufacturing: effects on processing and product properties.

The objective of this work was to develop and optimize an alternative make process for Greek-style yogurt (GSY), in which the desired level of protein was reached by fortification with micellar casein concentrate (MCC) obtained from milk by microfiltration. Two MCC preparations with 58 and 88% total protein (MCC-58 and MCC-88) were used to fortify yogurt milk to 9.80% (wt/wt) protein. Strained GSY of similar protein content was used as the control. Yogurt milk bases were inoculated with 0.02% (wt/wt) or 0.04% (wt/wt) direct vat set starter culture and fermented until pH 4.5. The acidification rate was faster for the MCC-fortified GSY than for the control, regardless of the inoculation level, which was attributed to the higher nonprotein nitrogen content in the MCC-fortified milk. Steady shear rate rheological analysis indicated a shear-thinning behavior for all GSY samples, which fitted well with the power law model. Dynamic rheological analysis at 5°C showed a weak frequency dependency of the elastic modulus (G') and viscous modulus (G") for all GSY samples, with G' > G", indicating a weak gel structure. Differences in the magnitude of viscoelastic parameters between the 2 types of GSY were found, with G' of MCC-fortified GSY < G' of control, indicating a different extent of protein interactionsin the 2 types of yogurt. Differences were also noticed in water-holding capacity, which was lower for the MCC-fortified GSY compared with the control, attributed to lower serum protein content in the former. Despite some differences in the physicochemical characteristics of the final product compared with GSY manufactured by straining, the alternative process developed here is a feasible alternative to the traditional GSY make process, with environmental and possibly financial benefits to the dairy industry.

Heat stability of micellar casein concentrates as affected by temperature and pH.

The increased interest in using micellar casein concentrates (MCC) obtained by microfiltration in the manufacture of shelf-stable high-protein beverages creates a need to understand the effect of sterilization treatments on the stability of this ingredient. The goals of this work were to (1) elucidate the effects of pH and heat treatment temperatures in the sterilization range on the stability of MCC, and (2) use the generated knowledge to develop solutions for stabilizing the MCC during sterilization treatments. Micellar casein concentrate powders were reconstituted, and the resulting casein dispersions were adjusted to pH values of 6.5 to 7.3. Subsequently, the MCC samples were heated in an oil bath to 110 to 150°C. The treated samples were evaluated for particle size, soluble minerals, and casein dissociation. At pH <6.7, all heat-treated samples were visibly aggregated or coagulated. At pH 6.9, higher temperatures led to increased particle size, whereas at pH >6.9, few or no changes were observed after heat treatment. Casein dissociation increased with increasing pH for all caseins, at all temperatures, with dissociation of κ-casein and ß-casein being the most pronounced. At higher pH, the levels of dissociated α(s)-casein decreased after heat treatment, suggesting aggregation of α(s)-casein in the presence of Ca and protection lost by κ-casein. It was concluded that increased stability of MCC requires increasing the pH or lowering the processing temperature. After applying these modifications, MCC was submitted to both retorting and UHT sterilization, at equivalent lethality. A significant reduction in particle size was obtained and no coagulation or aggregation occurred after retorting or UHT under the modified conditions as compared with the controls. The knowledge generated in this study will allow the effective stabilization of MCC in practical applications, such as the production of high-protein, shelf-stable beverages.

Steady shear rheological properties of micellar casein concentrates obtained by membrane filtration as a function of shear rate, concentration, and temperature.

The use of casein preparations obtained by membrane separation is receiving increasing interest from the dairy and food industry. The objective of this work was to generate information about the steady shear rheological properties of micellar casein concentrates (MCC) and the effect of composition, temperature, and shear rate on these properties. Micellar casein concentrate preparations with 2 levels of serum proteins (SP; 65 and 95% SP reduced, respectively), were obtained from skim milk by microfiltration followed by spray drying. Micellar casein concentrate preparations with casein concentrations ranging from 2.5 to 12.5% were obtained by dispersing the MCC powders in ultrapure water. Steady shear rheological analyses at temperatures ranging from 0 to 80°C were performed using a strain-controlled rheometer. Viscosity versus shear rate curves were used to evaluate the effect of shear on viscosity, and the apparent viscosity at a shear rate of 100 s(-1) was used to make direct comparisons between various concentration and temperature conditions. The 65% SP-reduced MCC had lower viscosity than the 95% SP-reduced MCC at the same casein concentration and temperature. Protein preparations at casein concentrations above 7.5% displayed shear-thinning behavior, which was more pronounced as concentration increased. The viscosity of MCC increased exponentially with casein concentration and decreased with temperature. The dependency of viscosity on temperature followed an Arrhenius relationship. A modified Arrhenius model able to accurately predict rheological properties under desired shear, temperature, and concentration conditions was developed and validated. This study provides critical rheological data necessary for developing practical applications of micellar casein preparations.

The effect of commercial sterilization regimens on micellar casein concentrates.

This work focused on evaluating the effects of UHT sterilization and in-container retorting on the stability and physical properties of micellar casein concentrates (MCC). The study was performed on MCC obtained by membrane separation, with casein concentrations between 5 and 10%. The UHT and retorting regimens were designed to achieve the same microbial inactivation effect. Ultra-high temperature treatment was performed in a pilot-scale MicroThermics heating system (MicroThermics Inc., Raleigh, NC), and retorting in an FMC multipurpose laboratory retort (Steritort; FMC Corp., San Jose, CA). The heat-treated and the non-heat-treated MCC controls were evaluated for pH, mineral profile, ζ-potential, particle size, and rheological properties for up to 24h after heat treatment. The treatments were performed in triplicate, and differences among samples were evaluated using statistical analyses. Retorting resulted in slight aggregation in the MCC, whereas UHT caused the formation of visible aggregates and coagulation. The UHT-treated MCC had higher viscosity than retorted MCC, and displayed predominantly solid-like rheological behavior, indicative of structure formation. These effects were, at least in part, attributed to a change in mineral equilibrium, which affected the stability of the casein micelles, but additional mechanisms such as κ-casein dissociation may also play a significant role in these heat-induced changes. Drying of MCC accentuated the observed instabilities, as dried and reconstituted micellar casein concentrates (R-MCC) were more unstable to UHT sterilization than the MCC that had not undergone drying. The results of this study provide valuable information about the sterilization behavior and physical properties of MCC, which can be useful to processors in the development and manufacture of shelf-stable casein-based products and beverages.

Inactivation of Escherichia coli in milk and concentrated milk using pulsed-light treatment.

Pulsed light (PL) treatment has been viewed as an alternative to thermal treatments for the inactivation of pathogenic and spoilage microorganisms in recent years. The objectives of this study were to quantify the effectiveness of PL on inactivating Escherichia coli in cow milk and to evaluate the effect of total solids and fat content on inactivation. Samples of reconstituted milk with variable total solids levels (9.8, 25, and 45%) and commercial cow milk with different fat contents (skim milk, 2% fat, and whole milk) were inoculated with nonpathogenic E. coli ATCC 25922 at a concentration of 10(7)cfu/mL. One milliliter of the inoculated sample was placed in a thin layer in a glass chamber and exposed to PL doses of up to 14.9 J/cm(2), both in static mode and turbulent mode. Survivors were quantified using standard plate counting. All experiments were performed in triplicate. Pulsed light treatment of the concentrated milks of 25 and 45% solids content resulted in reductions of less than 1 log, even in turbulent mode, whereas for the milk with 9.8% solids content, reduction levels of 2.5 log cfu were obtained after treatment with 8.4 J/cm(2) in turbulent mode. In the skim milk, a 3.4 log cfu reduction at 14.9 J/cm(2) was obtained and a plateau of the inactivation curve typical of PL treatment was not achieved. Under the same conditions, both 2% and whole milk attained inactivation levels greater than 2.5 log cfu. These data indicate that PL is effective for the inactivation of E. coli in milk, but has limited effectiveness for microbial inactivation in concentrated milk, due to the absorption of light by the milk solids and shielding of the bacteria in the concentrated substrates. Milk fat also diminishes the effectiveness of PL to some extent, due to light-scattering effects.

Effect of solvent and temperature on the size distribution of casein micelles measured by dynamic light scattering.

The objectives of this study were to investigate the effect of the solvent on the accuracy of casein micelle particle size determination by dynamic light scattering (DLS) at different temperatures and to establish a clear protocol for these measurements. Dynamic light scattering analyses were performed at 6, 20, and 50 degrees C using a 90Plus Nanoparticle Size Analyzer (Brookhaven Instruments, Holtsville, NY). Raw and pasteurized skim milk were used as sources of casein micelles. Simulated milk ultrafiltrate, ultrafiltered water, and permeate obtained by ultrafiltration of skim milk using a 10-kDa cutoff membrane were used as solvents. The pH, ionic concentration, refractive index, and viscosity of all solvents were determined. The solvents were evaluated by DLS to ensure that they did not have a significant influence on the results of the particle size measurements. Experimental protocols were developed for accurate measurement of particle sizes in all solvents and experimental conditions. All measurements had good reproducibility, with coefficients of variation below 5%. Both the solvent and the temperature had a significant effect on the measured effective diameter of the casein micelles. When ultrafiltered permeate was used as a solvent, the particle size and polydispersity of casein micelles decreased as temperature increased. The effective diameter of casein micelles from raw skim milk diluted with ultrafiltered permeate was 176.4 +/- 5.3 nm at 6 degrees C, 177.4 +/- 1.9 nm at 20 degrees C, and 137.3 +/- 2.7 nm at 50 degrees C. This trend was justified by the increased strength of hydrophobic bonds with increasing temperature. Overall, the results of this study suggest that the most suitable solvent for the DLS analyses of casein micelles was casein-depleted ultrafiltered permeate. Dilution with water led to micelle dissociation, which significantly affected the DLS measurements, especially at 6 and 20 degrees C. Simulated milk ultrafiltrate seemed to give accurate results only at 20 degrees C. Results obtained in simulated milk ultrafiltrate at 6 degrees C could not be explained based on the known effects of temperature on the casein micelle, whereas at 50 degrees C, precipitation of amorphous calcium phosphate affected the DLS measurement.

Development and optimization of a carbon dioxide-aided cold microfiltration process for the physical removal of microorganisms and somatic cells from skim milk.

Physical removal of microorganisms from skim milk by microfiltration (MF) is becoming increasingly attractive to the dairy industry. Typically, this process is performed at temperatures of approximately 50 degrees C. Additional shelf-life and quality benefits might be gained by conducting the MF process at low temperatures. Cold MF could also minimize microbial fouling of the membrane and prevent the germination of thermophilic spores. The objective of this study was to optimize a cold MF process for the effective removal of microbial and somatic cells from skim milk. An experimental MF setup containing a tubular Tami ceramic membrane with a nominal pore size of 1.4 microm was used for MF of raw skim milk at a temperature of 6 +/- 1 degrees C. The processing conditions used were cross-flow velocities of 5 to 7 m/s, and transmembrane pressures of 52 to 131 kPa. All MF experiments were performed in triplicate. The permeate flux was determined gravimetrically. Microbiological, chemical, and somatic cell analyses were performed to evaluate the effect of MF on the composition of skim milk. The permeate flux increased drastically when velocity was increased from 5 to 7 m/s. The critical transmembrane pressure range conducive to maximum fluxes was 60 to 85 kPa. When MF was conducted under optimal conditions, very efficient removal of vegetative bacteria, spores, and somatic cells, as well as near complete transmission of proteins into the MF milk, was achieved. To further enhance the flux, a CO(2) backpulsing system was developed. This technique is able both to increase the flux and to maintain it steadily for an extended period of time. The CO(2)-aided cold MF process has the potential to become economically attractive to the dairy industry, with direct benefits for the quality and shelf life of dairy products.

Nucleation and Expansion During Extrusion and Microwave Heating of Cereal Foods.

Expansion of biopolymer matrices is the basis for the production of a wide variety of cereal foods. A limited number of manufacturing processes provide practical solutions for the development of an impressive variety of expanded products, just by changing process variables. It is therefore essential that the mechanisms involved in expansion are well known and controlled. This paper summarizes the knowledge of nucleation and expansion in extruded and microwaved products available to date. The effect of processing conditions and properties of the biopolymeric matrix on nucleation and expansion are discussed. Moisture content enables the glassy polymeric matrix to turn into rubbery state at process temperatures, which allows superheated steam bubbles to form at nuclei and then expand, expansion being governed by the biaxial extensional viscosity of the matrix. Nucleation and expansion theories are presented along with quantitative data that support them.

Influence of modified starches on the stability of beef jerky analogs during storage.

Textural stabilization of extruded beef jerky analogs (BJA) by using modified starches was studied. From a series of modified starches studied, Frigex W and Instant Pure Flo were identified to show very reduced retrogradation, both in gels and after extrusion. These starches were used as textural stabilizers for BJA, an extruded product obtained from potato granules and ground beef. The partial substitution of potato granules with modified starches, at a level of 5% of the formulation, led to increased moisture sorption capacity of the analogs. After a storage period of 1 mo, the samples that contained modified starch had a degree of swelling with 30% higher and much lower elastic modulus as compared to those that contained only potato starch.