Comparison of Pilot-Scale and Rapid Visco Analyzer Process Cheese Manufacture

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.

Lactose-6-phosphate as an alternative to disodium phosphate in the production of processed cheese food

Processed cheese food (PCF) is a dairy product prepared by blending dairy ingredients with nondairy ingredients and heating the blend with agitation to produce a homogeneous product with an extended shelf life. Emulsifying salts (ES), such as disodium phosphate (DSP) and trisodium citrate, have a critical effect on the emulsification characteristics of casein by sequestering the calcium from the calcium-paracaseinate phosphate complex in natural cheese. Lactose-6-phosphate (LP) is an organic compound produced from lactose that has the potential to function as ES. Lactose-6-phosphate is not approved for use as a substitute for ES in the large-scale production of PC. The objective of this study was to produce PCF with LP instead of DSP. Lactose-6-phosphate was prepared by mixing 1 mol of α-lactose with 0.5 mol of sodium cyclo-triphosphate. The pH of recombined solutions was adjusted using sodium hydroxide to get a pH of 12 to obtain 60.74% LP. The solution was stirred for 3 d at room temperature and then concentrated to 52% total solids (TS). The ingredients in the PCF formulations were Cheddar cheese, butter, water, milk permeate powder, and LP (at a ratio of 2.0, 2.4, 2.8, 3.2, 4.0, 5.0, and 6.0%) were formulated to contain 17.0% protein, 25.0% fat, 44.0% moisture, and 2.0% salt. Processed cheese food made with 2.0% DSP was also produced as a control. The PCF was prepared by mixing all ingredients in a Kitchen Aid stand mixer to make a homogeneous paste. A 25-g sample of the mixture was cooked in the rapid visco analyzer (Perten RVA 4500, Macquarie Park, Australia) for 3 min at 95°C at 1,000 rpm for the first 2 min and 160 rpm for the last minute. The PCF was then transferred into molds and refrigerated till further analyses. The PCF was analyzed for moisture, pH, end apparent cooked viscosity, hardness, melted diameter, and melting temperature. The experiment was repeated 3 times using different batches of LP. The moisture of PCF ranged from 42.3% to 44.0% with a pH of 5.6 to 5.8. The end apparent cooked viscosity increased from 818.0 to 2,060.0 cP as the level of LP raised from 0.63% to 1.90%, whereas it was 660.0 cP in control. The hardness of PCF made with LP elevated from 61.9 to 110.1g as the level of LP increased; however, it was 85.6 g in control. The melted diameter decreased from 43 mm in control to 29 mm in 1.90% LP, while the melting temperature of PCF increased from 37.7°C in control to 59.0°C in 1.90% LP. We conclude that LP can be used as a substitute for DSP in PCF manufacture and has more capacity than DSP.

One Pot Cooking of Rice Grains for Preparation of Rice-Gel Samples Using a Small-Scale Viscosity Analyzer: Small-scale Rice-gel Preparation from Grains

Rice-gel prepared by the following three steps: rice grain cooking, shearing of the cooked rice, and cooling for gel formation, is expected as a novel food ingredient for modification of various food products such as bread and noodles. To meet the demand for high-throughput systems for research and developments on the new rice gels, herein we established a mini-cooking system for preparation of rice gel samples from grains using a small-scale viscosity analyzer (Rapid Visco Analyzer; RVA). Polished rice grains (4 g) were cooked with 22 mL of water in a canister, and the paddle equipped in the canister was rotated at 2,000 rpm for 30 min (80 °C was used as a representative) to shear the cooked rice. The sheared paste was cooled to 10 °C at 160 rpm, and the initial gelation property was evaluated by viscosity analysis within the RVA. Alternatively, the sheared paste was transferred to an acrylic mold and kept at 4 °C for 0, 1, 3, and 5 days for determination of the hardness with a compression test. Compressive forces required to penetrate 20 % thickness for three tested rice cultivars were measured, and the trend of the value shifts during preservation is similar to the corresponding trend obtained in 300-g grain scale laboratory tests, whereas the individual values were halved in the former. This small cooking method could offer a useful assay system for a rapid evaluation in the breeding programs and in the high-throughput screening of additives for the modification of properties.

Effects of emulsifying conditions on creaming effect, mechanical properties and microstructure of processed cheese using a rapid visco-analyzer

The creaming effects, mechanical properties and microstructures of processed cheeses were investigated under different emulsifying conditions using a rapid visco-analyzer, and the changes in protein network related to the creaming effect and the occurrence of yielding points were discussed. The higher stirring speed affected the fat globules to be smaller, and gave the processed cheese more firmness at fixed stirring time. The longer stirring time caused the protein network to become fine-stranded. A fine-stranded structure promoted the creaming effect, and hence the formation of yielding point in the mechanical properties. The emulsifying salts had active effects on the creaming effect and mechanical properties at longer stirring time. The fine-stranded structures were shown in the cases of a binary mixture of polyphosphate and disodium phosphate (PDSP), polyphosphate (PP), and trisodium citrate (TSC). Monophosphate (MP) showed the lowest ability to alter the protein network, but was assisted at the higher stirring speed.

Evaluation of the synergistic effects of milk proteins in a rapid viscosity analyzer

Protein systems (PS) are routinely used by companies from Brazil and around the globe to improve the texture, yield, and palatability of processed foods. Understanding the synergistic behavior among the different protein structures of these systems during thermal treatment under the influence of pH can help to better define optimum conditions for products and processes. The interpretation of the reactions and interactions that occur simultaneously among the protein constituents of these systems as dispersions during thermal processing is still a major challenge. Here, using a rapid viscosity analyzer, we observed the rheological changes in the startup viscosities of 5 PS obtained by combining varying proportions of milk protein concentrate and whey protein concentrate under different conditions of pH (5.0, 6.5, and 7.0) and heat processing (85°C/15min and 95°C/5min). The solutions were standardized to 25% of total solids and 17% of protein. Ten analytical parameters were used to characterize each of the startup-viscosity ramps for 35 experiments conducted in a 2×3 × 5 mixed planning matrix, using principal component analysis to interpret behavioral similarities. The study showed the clear influence of pH 5.5 in the elevation of the initial temperature of the PS startup viscosity by at least 5°C, as well as the effect of different milk protein concentrate:whey protein concentrate ratios above 15:85 at pH 7.0 on the viscographic profile curves. These results suggested that the primary agent driving the changes was the synergism among the reactions and interactions of casein with whey proteins during processing. This study reinforces the importance of the rapid viscosity analyzer as an analytical tool for the simulation of industrial processes involving PS, and the use of the startup viscosity ramp as a means of interpreting the interactions of system components with respect to changes related to the treatment temperature.

Effect of Formulation and Manufacturing Parameters on Process Cheese Food Functionality—I. Trisodium Citrate

The objective of this research was to use a Rapid Visco Analyzer to study the effect of natural cheese age, trisodium citrate (TSC) concentration, and mixing speed on process cheese food (PCF) functionality. In this study 3 replicates of natural cheese were manufactured, and a portion of each cheese was subjected to 6 different PCF manufacturing treatments at 2, 4, 6, 12, and 18 wk of ripening. These treatments were factorial combinations of 3 levels of TSC (i.e., 2.0, 2.5, and 3.0%) and 2 mixing speeds during manufacture (450 and 1,050 rpm). Functional properties of the PCF evaluated included manufacturing properties [apparent viscosity after manufacture (VAM)], unmelted textural properties (firmness), melted cheese flow properties [hot apparent viscosity (HAV)], and cheese thickening during cooling [time at 5000 cP (T5)]. All 4 parameters (VAM, firmness, HAV, and T5) were significantly affected by natural cheese age and mixing speed, whereas VAM, HAV, and T5 were also significantly influenced by the amount of TSC. The VAM and firmness decreased as cheese age increased, whereas T5 values increased as cheese age increased. Similarly, VAM, HAV, and firmness values increased because of the increased mixing speed, whereas T5 values decreased. The age x mixing speed interaction was significant for VAM and firmness. The age x concentration of the TSC interaction term was significant for VAM, whereas the age x age x TSC concentration term was significant for HAV. The results demonstrate that natural cheese age, mixing speed during manufacture, and concentration of TSC have a significant impact on process cheese functionality.

Small-Scale Manufacture of Process Cheese Using a Rapid Visco Analyzer

Numerous formulation and processing parameters influence the functional properties of process cheese. Recently, a small-scale (25 g) manufacturing and analysis method was developed using a rapid visco analyzer (RVA), which was designed to evaluate the functional properties of process cheese when subjected to various formulations and processing conditions. Although this method successfully manufactured process cheese, there was a significant difference in the functional properties of the process cheese compared with process cheese manufactured on a pilot scale. In the present study, adjustments in the RVA methodology involving the RVA processing conditions, preblend preparation, and texture profile analysis (TPA) techniques for the final process cheese were investigated. Fourteen samples of pasteurized processed cheese food (PCF) were manufactured from 14 different preblends. Each pre-blend was prepared using 1 of the 14 different natural cheeses and was balanced for moisture, fat, and salt. Each of these 14 preblends was split into 3 portions and each portion was subjected to 3 different manufacturing treatments. The first treatment was manufactured in a pilot-scale Blentech twin screw (BTS) cooker, and the remaining 2 treatments were manufactured in an RVA with different processing profiles. The RVA treatments were produced in triplicate. The resulting process cheeses were analyzed for moisture and functional properties. Texture profile analysis and RVA melt analyses were performed on all PCF treatments. Additionally, for the RVA treatments, the data for time of emulsification and end apparent viscosity during RVA manufacture were collected and recorded. The functional properties of the PCF manufactured using the RVA treatments showed good correlation with the functional properties of the PCF produced on the pilot scale. Additionally, the end apparent viscosity during RVA manufacture was correlated with the functional properties of the process cheese. Consequently, the RVA can be used as a small-scale manufacturing and analysis tool for predicting the functional properties of process cheese, and for evaluating how various formulations and processing parameters affect these functional properties. Moreover, the adjustments in the RVA methodology produced process cheese with functionality similar to process cheese produced in the BTS.

Melt Analysis of Process Cheese Spread or Product Using a Rapid Visco Analyzer

The objective of this study was to evaluate a rapid visco analyzer (RVA) method for measuring the melting characteristics of process cheese spread or product. The melt properties of 32 commercial process cheese spread and process cheese product samples from 4 manufacturers were analyzed with the RVA, tube melt test, texture profile analysis (TPA) hardness, and dynamic stress rheometry (DSR). For the RVA melt test, a 15-g disc of cheese was packed into the RVA canister and subjected to a heating, holding, and cooling profile during continuous mixing. During the test, the apparent viscosity was continuously measured and several data points (melt time, hot viscosity, time at 5000 cP during cooling, and solidification time) were collected from the viscosity vs. time curve. There was a high correlation (R2= 0.91) between the DSR melt temperature and the tube melt test. There was also a high correlation between the RVA melt time and the DSR melt temperature or the tube melt test (R2= 0.84 and 0.74, respectively). The RVA hot viscosity had a low correlation (R2< 0.44) with the DSR melt temperature and the tube melt test but had a high correlation (R2= 0.74) with DSR G'' at 85 degrees C. The results of this study indicate that RVA melt analysis of process cheese spread/product is correlated with the results from other melt tests and is capable of measuring the melt properties quantified by other methods. The RVA melt test may also provide additional information on the melt characteristics of process cheese spread/product not measured in other tests.