Cycled high hydrostatic pressure processing of whole and skimmed milk: Effects on physicochemical properties

In this study, we compare the effects of single- and double-cycle HP treatments at 600 MPa on inactivation of the natural microflora and physicochemical properties of whole and skimmed milk of high bacterial load. The results show that two-cycled HP (2 × 2.5 min) was more effective (P < 0.05) on microbial inactivation, and caused similar or slightly less changes (P > 0.05) in physicochemical properties of milk in comparison to single cycled HP (1 × 5 min). In addition to the expected milk protein structure changes, HP at 600 MPa caused only slight effects on milk fat and lactose. Minor decreases in levels of short chain fatty acids were observed with the cycled treatments, and the volatiles in general decreased after HP treatment, depending mostly on the pressure time but also on cycling in skimmed milk. The study confirmed the superior effect of two-cycle HP on microbial inactivation, and shows a slightly better preservation of the physical-chemical milk quality.Industrial relevanceMulti-cycling HP has been shown to be advantageous for microbial inactivation, but limited information is available regarding the effect on milk components in whole milk or skimmed milk. The present study compares the psychochemical properties of whole and skimmed milk processed by multi-cycling in comparison to single cycle HP treatment. Double cycled HP presented a superior effect on microbial inactivation and slightly better preservation of milk quality than one continuous HP.     

Physicochemical,sensorial and rheological characterisation of whole-fat or low-fat milk jams as influenced by calcium chloride,sodium bicarbonate and sucrose content

Rheological properties of sixteen milk jam treatments produced from commercial full-fat (3 g/100 g) and skimmed (0.15 g/100 g) cow milk by the addition of sucrose, sodium bicarbonate and CaCl₂ were examined. pH, titratable acidity, total solids and ash contents in the milk jam samples ranged from 6.2 to 6.8, 1.3 to 3.3 g/100 g, 56.7 to 70.5 g/100 g and 1.7 to 3 g/100 g, respectively, with a significant variability (P < 0.05). The flow behaviour and consistency indices ranged from 0.7 to 0.9 and 2.7 to 208 Pa.sn, respectively. Rheological measurements showed that the maximal G' × 10² value showed considerable variation (5–932 Pa). As sucrose content increased, pH and total solid content increased, whereas ash content and the L value decreased. Also, a negative correlation between pH and L* (lightness) was found (P < 0.05). Dynamic rheology showed that the jam from skimmed milk with full sucrose and without sodium bicarbonate exhibited more solid-like behaviour than the ones prepared with full sucrose and with sodium bicarbonate. In conclusion, the increase in milk fat caused a decrease in resistance of the mixture subjected to the deformation, which is very important for production of quality milk jam.     

Kinetic and thermodynamic study of thermal inactivation of the antimicrobial peptide P34 in milk

The knowledge on thermal inactivation of biopreservatives in a food matrix is essential to allow their proper utilisation in food industry, enabling the reduction of heating times and optimisation of heating temperatures. In this work, thermal inactivation of the antimicrobial peptide P34 in skimmed and fat milk was kinetically investigated within the temperature range of 90–120 °C. The inactivation kinetic follows a first-order reaction with k-values between 0.071 and 0.007 min⁻¹ in skimmed milk, and 0.1346 and 0.0119 min⁻¹ in fat milk. At high temperatures, peptide P34 was less resistant in fat milk, with a significant decrease in residual activity as compared with skimmed milk. At temperatures below 110 °C, the fat globules seem to have protective effect to the peptide P34. Results suggest that peptide P34 is heat stable in milk with activation energy of 90 kJ mol⁻¹ in skimmed milk and 136 kJ mol⁻¹ in fat milk.     

Cholesterol and Antioxidant Vitamins in Fat Fraction of Whole and Skimmed Dairy Products

The skimming procedure is a common practice in dairy industry, and skimmed products contain less fat, less cholesterol and less fat-soluble vitamins than whole products. The aim of this research is to verify if something else happens during the skimming process to these compounds in milk and dairy products. Experimental milk and cream samples, ranging from 0.1 to 51.5 g fat/100 g, have been studied for beta carotene, alfa-tocopherol and cholesterol contents. The degree of antioxidant protection (DAP), useful to estimate the potential oxidative stability of fat in foods, has been calculated, combining these values. The same analytical protocol has been also applied to commercial products (fat content ranging from 0.1 to 85.0 g/100 g). As was expected, there is a good linear correlation between these compounds and fat content in experimental and in commercial samples; nevertheless, the composition of milk fat changes differently. During skimming process, in the residual fat matter, cholesterol concentration increases while antioxidant compound concentration decreases or remains unchanged. Moreover, in experimental and in commercial milk and dairy, the DAP values show that the residual cholesterol is more susceptible to oxidation in skimmed than in whole products. This aspect is particularly important from a safety point of view: actually, cholesterol oxide ingestion can be harmful and should be avoided even in a small amount.     

Enrichment of the conjugated linoleic acid content of bovine milk fat by dry fractionation

This study investigated the effect of fat fractionation on the conjugated linoleic acid (cis-9, trans-11-C_18 : 2) content of bovine milk fat. Anhydrous milk fat was fractionated into hard and soft fractions using controlled cooling and agitation. Fractionation of milk fat pre-melted at 60°C using a temperature programme of 33–10°C and a cooling rate of 0.58°C h⁻¹ yielded a soft fraction containing 63.2% more conjugated linoleic acid (2.22 g 100 g⁻¹ FAME), which was also enriched in polyunsaturated fatty acids and vaccenic acid (trans-11-C_18 : 1) compared with the parent fat. Agitation following fractionation was found to have a negative effect on the conjugated linoleic acid content of the soft fraction. Refractionation of the soft fraction did not increase the yield of conjugated linoleic acid. The conjugated linoleic acid and trans fatty acid content of 26 selected food products ranging in milk fat content from 0 to 100% is reported. Conjugated linoleic acid concentrations ranged from 0 to 16.2 mg g⁻¹ fat and were generally lower than the trans fatty acid content which ranged from 0 to 155.7 mg g⁻¹ fat. Spreads containing vegetable oils contained higher trans fatty acid and lower conjugated linoleic acid contents than milk fat-containing products. This study highlights that a milk fat fraction enriched in conjugated linoleic acid may be achieved by dry fractionation.     

Production of a red–purple food colorant from Opuntia stricta fruits by spray drying and its application in food model systems

Opuntia stricta fruit juice is a potential source of betacyanin pigments which can be used as a natural red-purple food colorant. In this work a powder food colorant was obtained by co-current spray drying of O. stricta fruit juices with a bench-scale two fluid nozzle spray dryer. Glucose syrup (DE 29) was used as drying aid. Optimum conditions for spray drying were as follow: juice content (20% v/v; 1.2 °Brix), glucose syrup content (10% w/v), liquid feed rate (0.72 l/h), spray air flow-rate (0.47 m³/h), drying air flow-rate (36 m³/h), and inlet drying air temperature 160 °C. Color was retained during the drying process (>98%) and drying yield was high (58%). The powder colorant showed high color strength (4.0), being this color strength stable when stored at room temperature for one month. This colorant was successfully applied in two food model systems: a yogurt and a soft-drink. Food presented a vivid red-purple tonality very attractive for consumers that was maintained after one month under refrigeration (4 °C) (ΔE < 5).     

Heat and light stability of three natural blue colorants for use in confectionery and beverages

The stabilities of three natural blue colorants—gardenia blue, phycocyanin and indigo—toward heat and light were studied in simple solutions of various pH. Gardenia blue was found to be stable at temperatures up to 80 °C in aqueous solution at pH 3, 5 and 7. Exposure to light of 3×10⁵ lux for 24 hours resulted in approximately 50% degradation of gardenia blue in aqueous solution. Phycocyanin was found to be unstable to heat and light in aqueous solution. Phycocyanin is insoluble in acidic solution (pH 3) and denatures at temperatures above 45 °C at pH 5 and 7, leading to a color change. Exposure to light of 3×10⁵ lux for 24 hours in aqueous solution at pH 5 and 7 caused ~80% degradation. Indigo was found to be stable in medium-chain-triglyceride oil for temperatures up to 90 °C, but to photodegrade (by approximately 70% after five hours of exposure to 3×10⁵ lux), corresponding to a quantum yield of 1.8×10^–4 mol Einstein^–1 for visible light and 1.4×10^–2 mol Einstein^–1 for UV, as determined for monochromatic light of 600 and 313 nm, respectively. Exploratory studies have been carried out with the three blue colorants in application media such as soft drink, jelly gum, hard candy and sugar coating for soft candy. Despite its lower stability towards heat and light, phycocyanin was concluded to be the more versatile blue food colorant among the three studied, showing a bright blue color in jelly gum and coated soft candy.     

Factors Affecting Light-Induced Pink Discoloration of Annatto-Colored Cheese

The effects of light type, exposure and intensity, storage temperature, pH, fat content, and age and source of colorant were evaluated on stability of annatto colorants in cheese. Exposure to cool white fluorescent lighting resulted in a decrease in Hunter b values and hue throughout storage. Decreased temperature reduced the loss of a and b values after 2 days of light exposure. As time of exposure increased, reduction of a and b also increased. As pH changed from 5.4 to 4.8, b values were reduced at a faster rate than a values resulting in an intense pink color. Commercial cheese colorants extracted from annatto seeds were variable in color stability.     

Study of butter fat content in milk on the inactivation of Listeria innocua ATCC 51742 by thermo-sonication

Ultrasound combined with heat treatment has yielded favorable results in the inactivation of microorganisms; however, the composition of food influences the rate of microbial inactivation. The objective of this research was to study the effect of butter fat content in milk on the inactivation of Listeria innocua and compositional parameters after thermo-sonication. Four butter fat contents in milk were evaluated at 63 °C for 30 min of sonication (Hielscher® UP400S, 400 W, 24 kHz, 120 μm amplitude). Results showed that inactivation of Listeria cells occurs first in fat free milk, and that the rate of inactivation decreases with increasing fat content. No degradation of protein content or color variation was observed after the treatments. The pH dropped to 6.22, and lactic acid content showed an increase of 0.015% after the treatment; solids-non-fat, density and freezing point decreased. During storage life, growth of mesophiles was retarded with sonication.Industrial relevanceUltrasound is an emerging technology that has shown positive effects in milk processing. Listeria monocytogenes represent one of the main foodborne pathogenic microorganisms in the food industry. Results of this research show that thermo-sonication is a viable technology capable of inactivating Listeria cells in milk and extending shelf-life without significant nutritional or physicochemical changes.     

Effect of tomato by-products in the diet of Comisana sheep on composition and conjugated linoleic acid content of milk fat

To evaluate the effect of supplementing the diet of Comisana sheep with by-products from industrial tomato manufacture on the fat composition and conjugated linoleic acid (CLA) content of milk fat, two groups of 50 ewes each were fed either total mixed ration standard (TMRS) or total mixed ration with added tomato by-products (TMRA). Milk fat composition was determined by high-resolution gas chromatography (HRGC). The milk fat content for the animals fed the TMRA diet increased by 6.41% (P < 0.01) after six weeks, compared with the animals fed the TMRS diet. The CLA content in the milk fat for the group of animals fed the TMRA diet was 19.8% (P < 0.05) higher than for those fed the TMRS diet, and reached 1.33 g 100 g^?1 fat, while the polyunsaturated fatty acid (PUFA) content increased by a 6.43% (P < 0.05) and reached 7.12 g 100 g^?1 fat. The fatty acid composition showed an increase in the amount of polyunsaturated fatty acids. The n ? 3:n ? 6 ratio increased by 13% in the milk from sheep fed with the TMRA diet. These observations were confirmed by triglyceride analysis, which showed a decrease in the amount of short-chain (C₂₈–C₃₂) and medium-chain (C₃₄–C₄₂) triglycerides after six weeks, while the opposite was observed for the long-chain triglycerides (C₄₄–C₅₄).     

Soft cheese-like product development enriched with soy protein concentrates

The objective of this work was to develop spreadable cheese-like product from skimmed cow's milk, supplemented with soybean proteins. The proteins were concentrated by ultrafiltration, and then freeze-dried. The cheese-like products were prepared using the acid coagulation method, without maturation, obtaining smooth products with creamy texture. The samples were identified as low-fat cheese, being the fat content between 10 and 13 (g/100 g), with moisture in the range of 68.07–70.75 (g/100 g). Compared to a control cheese, the samples containing soy protein concentrate, showed an increase of 6.8–17 in proteins and 22–32 (g/100 g) in fats; also the yield increased. The viscoelastic behavior of the samples was analyzed using oscillatory dynamic tests; in all the samples G′ was higher than G″. Texture, surface color and microstructure of the cheese samples were determined. Microbial analysis showed that the incorporation of potassium sorbate increased more than twice the shelf-life of the products (up to 60 days) in comparison to the samples without preservative. Furthermore, the products were accepted by a sensory panel. Considering that both, proteins and fats, are of vegetable origin with high biological value and unsaturated fats, the developed cheese-like products were considered as functional foods.     

Removal of color from fruit candy waste by activated carbon adsorption

The research in this paper was aimed at finding a treatment method for recovery of fruit candy (fruit leathers) wastes. Fruit leather wastes were dissolved in water to investigate the efficacy of activated carbon adsorption to remove food colorants, which reduce recycling possibilities. The effects of initial pH (2.5-9), food colorant concentration (10-110 g fruit leather/L) and adsorbent dosage (1-12 g/L) on the adsorption process were investigated. Maximum adsorption was obtained at the original pH value of dissolved fruit candy waste in water. Maximum adsorbent capacities for red, yellow and blue food colorants were 4.4; 11.7 and 2 mg/g at pH 3.5 respectively. Regeneration of food colorant loaded activated carbon can be effected at 400 °C. Cost estimates indicate that red color removal would seem to be an economical proposition, costing about $19/ton fruit candy waste, yellow marginal at $70/ton waste, and blue uneconomical at $245/ton waste.     

Colorants in cheese manufacture: Production,chemistry, interactions,and regulation

Colored Cheddar cheeses are prepared by adding an aqueous annatto extract (norbixin) to cheese milk; however, a considerable proportion (～20%) of such colorant is transferred to whey, which can limit the end use applications of whey products. Different geographical regions have adopted various strategies for handling whey derived from colored cheeses production. For example, in the United States, whey products are treated with oxidizing agents such as hydrogen peroxide and benzoyl peroxide to obtain white and colorless spray‐dried products; however, chemical bleaching of whey is prohibited in Europe and China. Fundamental studies have focused on understanding the interactions between colorants molecules and various components of cheese. In addition, the selective delivery of colorants to the cheese curd through approaches such as encapsulated norbixin and microcapsules of bixin or use of alternative colorants, including fat‐soluble/emulsified versions of annatto or beta‐carotene, has been studied. This review provides a critical analysis of pertinent scientific and patent literature pertaining to colorant delivery in cheese and various types of colorant products on the market for cheese manufacture, and also considers interactions between colorant molecules and cheese components; various strategies for elimination of color transfer to whey during cheese manufacture are also discussed.     

Preconditioning of the stainless steel surface affects the adhesion of Bacillus cereus spores

The adhesion of Bacillus cereus on stainless steel, with and without prior conditioning of the surface (water, skimmed milk, and whole milk) was evaluated. Inocula consisting of a pool of spores of four different B. cereus strains isolated from the dairy industry, and spores of B. cereus ATCC 14579 were used. The pool of B. cereus spores adhered in all conditions evaluated. Higher adhesion of B. cereus spores (4.93 log cfu cm⁻²) was observed when using whole milk as conditioning matrix. However, without prior conditioning, lower adhesion was observed (3.01 log cfu cm⁻²) when the pool of B. cereus spores was inoculated on whole milk, suggesting the interaction between milk fat and microorganism on the stainless steel. The pool of B. cereus spores showed higher adhesion to the surface, possibly due to its greater hydrophobicity (66%) when compared with the B. cereus ATCC 14579 spores (47%).     

The combined effects of fat content,calcium chloride,and coagulant concentration on the development of cheese curd structure

The effects of differing content levels of calcium chloride (approximately 200 and 400 μg Ca per 100 g milk protein) and of a microbial coagulant (3200 and 6400 μL per 100 L of milk; 950 IMCU (international milk coagulating units) mL⁻¹) on the coagulation of cows' milk with various fat levels (0.02–3.77%, w/w) was studied. Non-linear regression analysis was used to evaluate dynamic factors (lag time, t_lag; maximum coagulation rate, C_max; time for the maximum coagulation rate, t_max). Increasing fat content in the milk at constant calcium chloride and coagulant contents had no significant and clear effects on the t_lag, C_max, and t_max values. Increased levels of calcium chloride or microbial coagulant led to a significant decrease in t_lag and t_max, and conversely increased C_max. Therefore, milk fat content had no significant effect on gel development; however, levels of calcium chloride and coagulant significantly influenced gel structure.     

Potential use of new Colombian sources of betalains. Colorimetric study of red prickly pear (Opuntia dillenii) extracts under different technological conditions

A new source of betalains to be used as natural colorant (Opuntia dillenii) has been studied. The stability of O. dillenii extracts in different pHs and temperatures over time has been scrutinized. Our attention was focused on differential tristimulus colorimetry and betalain content related to the color, not previously conducted in conjunction in that raw material. On the basis of the results, cold storage conditions (4 °C) were optimal to maintain as possible the initial red color (h_ab), lightness (L*) and betalain content of the O. dillenii extracts, regardless of pH. Highly-acidic extracts (pH 4) manifested a significantly (p < 0.05) lower colorant intensity (C*_ab) and betalain concentration (around 25% and 35%, respectively), with a clearer tendency toward yellowish tonalities (values of h_ab from 45° to 90°) over time. Furthermore, visually perceptible color changes (ΔE*_ab > 3) were induced among very acid (pH 4) and low-acidic (pH 5 and 6) extracts at each temperature.     

Examination of the persistency of milk fatty acid composition responses to fish oil and sunflower oil in the diet of dairy cows

Based on the potential benefits of cis-9, trans-11 conjugated linoleic acid (CLA) for human health, there is a need to develop effective strategies for enhancing milk fat CLA concentrations. Levels of cis-9, trans-11 CLA in milk can be increased by supplements of fish oil (FO) and sunflower oil (SO), but there is considerable variation in the response. Part of this variance may reflect time-dependent ruminal adaptations to high levels of lipid in the diet, which lead to alterations in the formation of specific biohydrogenation intermediates. To test this hypothesis, 16 late lactation Holstein-British Friesian cows were used in a repeated measures randomized block design to examine milk fatty acid composition responses to FO and SO in the diet over a 28-d period. Cows were allocated at random to corn silage-based rations (8 per treatment) containing 0 (control) or 45 g of oil supplement/kg of dry matter consisting (1:2; wt/wt) of FO and SO (FSO), and milk composition was determined on alternate days from d 1. Compared with the control, the FSO diet decreased mean dry matter intake (21.1 vs. 17.9 kg/d), milk fat (47.7 vs. 32.6 g/kg), and protein content (36.1 vs. 33.3 g/kg), but had no effect on milk yield (27.1 vs. 26.4 kg/d). Reductions in milk fat content relative to the FSO diet were associated with increases in milk trans-10 18:1, trans-10, cis-12 CLA, and trans-9, cis-11 CLA concentrations (r² = 0.74, 0.57, and 0.80, respectively). Compared with the control, the FSO diet reduced milk 4:0 to 18:0 and cis 18:1 content and increased trans 18:1, trans 18:2, cis-9, trans-11 CLA, 20:5 n-3, and 22:6 n-3 concentrations. The FSO diet caused a rapid elevation in milk cis-9, trans-11 CLA content, reaching a maximum of 5.37 g/100 g of fatty acids on d 5, but these increases were transient, declining to 2.35 g/100 g of fatty acids by d 15. They remained relatively constant thereafter. Even though concentrations of trans-11 18:1 followed the same pattern of temporal changes as cis-9, trans-11 CLA, the total trans 18:1 content of FSO milk was unchanged because of the concomitant increases in the concentration of other isomers (Δ^4-10 and Δ^12-15), predominantely trans-10 18:1. In conclusion, supplementing diets with FSO enhances milk fat cis-9, trans-11 CLA content, but the high level of enrichment declines because of changes in ruminal biohydrogenation that result in trans-10 replacing trans-11 as the major 18:1 biohydrogenation intermediate formed in the rumen.     

Effects of oil and natural or synthetic vitamin E on ruminal and milk fatty acid profiles in cows receiving a high-starch diet

Among trans fatty acids, trans-10,cis-12 CLA has negative effects on cow milk fat production and can affect human health. In high-yielding dairy cows, a shift from the trans-11 to the trans-10 pathway of biohydrogenation (BH) can occur in the rumen of cows receiving high-concentrate diets, especially when the diet is supplemented with unsaturated fat sources. In some but not all experiments, vitamin E has been shown to control this shift. To ascertain the effects of vitamin E on this shift of BH pathway, 2 studies were conducted. The first study explored in vitro the effects of addition of natural (RRR-α-tocopherol acetate) and synthetic (dl-α-tocopherol acetate) vitamin E. Compared with control and synthetic vitamin E, the natural form resulted in a greater trans-10/trans-11 ratio; however, the effect was very low, suggesting that vitamin E was neither a limiting factor for rumen BH nor a modulator of the BH pathway. An in vivo study investigated the effect of natural vitamin E (RRR-α-tocopherol) on this shift and subsequent milk fat depression. Six rumen-fistulated lactating Holstein cows were assigned to a 2 × 2 crossover design. Cows received 20-kg DM of a control diet based on corn silage with 22% of wheat, and after 2 wk of adaptation, the diet was supplemented with 600 g of sunflower oil for 2 more weeks. During the last week of this 4-wk experimental period, cows were divided into 2 groups: an unsupplemented control group and a group receiving 11 g of RRR-α-tocopherol acetate per day. A trans-10 shift of ruminal BH associated with milk fat depression due to oil supplementation of a high-wheat diet was observed, but vitamin E supplementation of dairy cows did not result in a reversal toward a trans-11 BH pathway, and did not restore milk fat content.     

Detection of alkaline phosphatase by competitive indirect ELISA using immunoglobulin in yolk (IgY) specific against bovine milk alkaline phosphatase

Immunoglobulin in yolk (IgY) (with a titer of 1.3 × 10⁶) specific against bovine milk (BM) alkaline phosphatase (ALP) was obtained by intramuscularly immunizing hens on the thigh and was used as the primary antibody to conduct competitive indirect enzyme-linked immunosorbent assay (CI-ELISA) to determine BMALP in ALPs from BM and Escherichia coli sources. A relationship between the ELISA value and the BMALP level (0.01–10 μg/mL) in whole milk (R² = 0.9019) or in skimmed milk (R² = 0.9402) was observed. The maximal inhibition (%) of BMALP on the microtiter plate by free BMALP at 10 μg/mL whole milk (3.89 mU/μg BMALP) was about 50%, while no inhibition (%) of BMALP by free E. coli ALP at concentrations between 0.01 to 10 μg/mL (60 mU/μg E. coli ALP) was determined. At BMALP levels higher than 0.1 μg/mL, CI-ELISA was proved to be effective in differentiating between BMALP and E. coli ALP and quantifying BMALP in whole milk or skimmed milk in the presence of E. coli ALP with an activity of 0.6 U/mL. Higher inhibition (about 70%) of BMALP on the microtiter plate by free BMALP in diluted (10¹–10⁴ fold) milk samples was observed. The optimal conditions for CI-ELISA in determining BMALP (0.1–10 μg/mL) from ALPs in milk samples were using 10³-fold diluted crude IgY specific against BMALP as primary antibody and 10³-fold diluted goat anti-chicken IgG–ALP conjugate as the secondary antibody.     

Influence of skimmed milk concentrate replacement by dry dairy products in a low‐fat set‐type yoghurt model system. Use of caseinates,co‐precipitate and blended dairy powders

Yoghurt fortification with caseinates, co‐precipitate and blended dairy powders in a low‐fat yoghurt model system was studied. These dairy products were characterised for pH, moisture, lactose, mineral and protein fractions. Milk proteins were characterised by polyacrylamide gel electrophoresis (SDS‐PAGE) and isoelectric focusing (IEF). Minerals such as Na, Ca, K and Mg were analysed by atomic absorption spectroscopy. Yoghurts were formulated using a skimmed milk concentrate as a milk base enriched with different dry dairy products up to 43 g kg⁻¹ protein content. The percentage of skimmed milk concentrate replaced with dry dairy products in the mix was between 1.37 and 6.35%. Yoghurts enriched with caseinates had higher viscosity and syneresis index (56.81 Pa s and 548.8 g kg⁻¹ respectively) than yoghurts based on concentrated skimmed milk fortified with co‐precipitate (39.00 Pa s and 392.9 g kg⁻¹) or blended dairy products (33.25 Pa s and 431.8 g kg⁻¹). One blended dairy product was tested to manufacture low‐fat yoghurt on an industrial scale, yielding good rheological properties (high viscosity‐consistence, 37.77 Pa s, and low syneresis index, 450 g kg⁻¹) and lower cost than traditional enrichment with skimmed milk powder. © 2000 Society of Chemical Industry