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Powdered dairy ingredients are added in various food products to impart desired technofunctional properties, improve nutritional values, and sensory characteristics. These ingredients undergo various changes during storage, the extent of these changes is a function of powder composition, processing parameters, and storage conditions. Most of the changes in powder characteristics are associated with the change in free moisture content that occurs due to change in headspace relative humidity and temperature. Uptake of moisture results into various undesirable changes including decrease in Tg, crystallization of lactose, alteration in color (Maillard browning), oxidation of lipids, modifications of protein conformation, changes in surface composition, and particle morphology. These changes adversely affect the physicochemical characteristics, functional properties, and sensory attributes of these ingredients. Crystallization of lactose alters the microstructure and surface chemical composition of powders, induces caking and compromises flowability and solubility. Maillard reactions increase protein-sugar and protein-protein interactions which compromises color and solubility. The composition of powdered dairy ingredients and products, if they are rich in lipids and lactose, are particularly sensitive to changes in headspace RH and temperature. Longer Storage times consolidate the underlying mechanisms driving the undesirable changes mentioned above. This review shows that to preserve the quality of these ingredients during storage, it is essential to design storage parameters (relative humidity, temperature, vapor, and gas barrier of primary packaging) of powdered dairy ingredients and products such a way that crystallization of lactose, lactose-protein interaction, and melting of lipid and migration of lipid to the surface is minimized. [ABSTRACT FROM AUTHOR]

Abstract Milk protein, in particular native whey protein, is of interest to dairy manufacturers as a measure of functional and nutritional quality. However, quantification of soluble whey protein (SP) is time consuming; giving rise to the need to develop rapid, accurate, and portable at-line process analytical technology. In this study, the performance of a fluorescence-based analyser(F) (Amaltheys II, Spectralys Innovations, France) was evaluated for quantification of SP F and whey protein nitrogen index (WPNI) F in skim milk, whey protein concentrate and infant formula powders. Rehydration of powders prior to analysis was a key factor for ensuring repeatability and reproducibility. A comparison of the analyser with reference methods for SP F and WPNI F resulted in coefficient of determination (R2) > 0.993 for both SP Kjeldahl method and WPNI GEA. The results show the fluorescence-based analyser to be rapid, compact, and accurate device, suited for providing reliable support to dairy ingredient and infant formula manufacturers. Industrial relevance The fluorescence based analysis investigated in this article is suitable for application in the dairy industry where it can be used as a rapid, at-line PAT tool for both liquid and powder samples. The technology has the potential to replace well-established methods for measurement of soluble protein. The main benefit to industry is the ability to respond more rapidly to variations in soluble protein without compromising on the accuracy associated with more time consuming methods. Highlights • Rapid and accurate at-line process analytical technology for dairy industry • Fluorescence-based analyser for replacement of standard analytical methods • Quantitative measurement of soluble whey protein and whey protein nitrogen index [ABSTRACT FROM AUTHOR]

The influence of emulsifiers and dairy solids on churning and physical attributes of butter was investigated. Commercial dairy cream was blended with each of the ingredients (0.5%, w/w) separately, aged overnight (10 °C), and churned (10 °C) into butter. The employed additives showed a distinctive impact on the macroscopic properties of butter without largely affecting the melting behavior. In fresh butter, polyglycerol polyricinoleate (PGPR) emulsifier having dominated hydrophobic moieties significantly (p < 0.05) enhanced the softness. Among dairy solids, sodium caseinate (SC) was the most effective in reducing the solid fat fraction, hardness, and elastic modulus (G’), while whey protein isolate (WPI) and whole milk powder (WMP) produced significantly harder, stiffer, and more adhesive butter texture. As per tribological analysis, PGPR, Tween 80, and SC lowered the friction-coefficient of butter, indicating an improved lubrication property of the microstructure. The extent of butter-setting during 28 days of storage (5 °C) varied among the samples, and in specific, appeared to be delayed in presence of WPI, WMP, and buttermilk solids. The findings of the study highlighted the potential of using applied emulsifiers and dairy-derived ingredients in modifying the physical functionality of butter and butter-like churned emulsions in addition to a conventional cream-ageing process.

Chocolate is considered as both caloric and functional food. Its nutritional properties may be improved by addition of fiber; however, this may reduce polyphenols content. The aim of this research was to determine the influence of cocoa shell addition (as a source of fiber) and its combination with different ingredients (cocoa butter equivalents (CBE), emulsifiers, dairy ingredients) on polyphenols of dark and milk chocolates. Total polyphenol (TPC) and total flavonoid (TFC) contents were determined spectrophotometrically, identification and quantification of individual compounds by high pressure liquid chromatography and antioxidant capacity by ferric reducing antioxidant power (FRAP) assay. Results showed that even though addition of cocoa shell to chocolate results in reduced contents of TPC, TFC, and individual compounds, it is not significant compared to ones reported by other authors for commercial chocolates. Other ingredients influence determined values for all investigated parameters; however, additional research is needed to reveal exact mechanisms and implications.

This study investigated the feasibility of mid-infrared (MIR) and Raman spectroscopy for (i) discrimination of three dried dairy ingredients, namely skim milk powder (SMP), whey protein concentrate (WPC) and demineralised whey protein (DWP) powder, and (ii) discrimination of preheat treatments of dried dairy ingredients using partial least squares discriminant analysis (PLS-DA). PLS1-DA models developed using MIR ranges of 800-1800 and 1200-1800 cm−1 yielded the best discrimination (correct identification of 97.2% for SMP discrimination and 100% for WPC and DWP discrimination). The best PLS2-DA model using MIR spectroscopy was developed over the spectral range of 800-1800 cm−1 and produced correct identification of 100% for dairy ingredient discrimination. Models developed using Raman 800-1800 and 1200-1800 cm−1 spectral ranges correctly discriminated (100% correctly identified) each dairy ingredient. Although all PLS1-DA and PLS2-DA models developed using both spectral technologies for preheat treatment discrimination had good discrimination accuracy (86-100%), they employed a high number of factors (8-9 for the best model). The use of the Martens uncertainty test successfully reduced the number of factors employed (3-4 for the best models) and improved the performance of PLS1-DA models for preheat treatment discrimination (all 100% correctly identified). This feasibility study demonstrates the potential of both MIR and Raman spectroscopy for rapid characterisation of dried dairy ingredients. [ABSTRACT FROM AUTHOR]

An LC-MS/MS method for screening 14 aminoglycosides in foodstuffs of animal origin is presented. Its scope includes raw materials and processed ingredients but also finished products composed of milk, meat, fish, egg or fat. Aminoglycosides are extracted in an acidic aqueous solution, which is first recovered after centrifugation, then diluted with a basic buffer and finally purified by molecularly imprinted polymer-solid phase extraction (MIP-SPE). Analytes are detected within 8 min by ion-pair reversed phase LC-MS/MS. Due to the large range of foodstuffs involved, the variability of matrix effects led to significant MS signal variations. This was circumvented by systematically extracting each sample twice, i.e. ‘unspiked’ and ‘spiked’ at the screening target concentration of 50 µg kg−1. The method was validated according to the European Community Reference Laboratories Residues Guidelines giving false-negative and false-positive rates ≤3% for all compounds. Ruggedness of the method was further demonstrated in quality control operations by a second laboratory. The 14 aminoglycosides in water-based standard solutions were stable for up to 6 months when stored at either −80°C, −20°C or at 4°C storage temperatures. [ABSTRACT FROM AUTHOR]

A procedure for screening 105 veterinary drugs in foods by liquid chromatography tandem mass-spectrometry (LC-MS/MS) is presented. Its scope encompasses raw materials of animal origin (milk, meat, fish, egg and fat) but also related processed ingredients and finished products commonly used and manufactured by food business operators. Due to the complexity of the matrices considered and to efficiently deal with losses during extraction and matrix effects during MS source ionisation, each sample was analysed twice, that is ‘unspiked’ and ‘spiked at the screening target concentration’ using a QuEChERS-like extraction. The entire procedure was validated according to the European Community Reference Laboratories Residues Guidelines. False-negative and false-positive rates were below 5% for all veterinary drugs whatever the food matrix. Effectiveness of the procedure was further demonstrated through participation to five proficiency tests and its ruggedness demonstrated in quality control operations by a second laboratory. [ABSTRACT FROM AUTHOR]

A fast and robust high performance LC-MS/MS screening method was developed for the analysis of β-lactam antibiotics in foods of animal origin: eggs, raw milk, processed dairy ingredients, infant formula, and meat- and fish-based products including baby foods. QuEChERS extraction with some adaptations enabled 23 drugs to be simultaneously monitored. Screening target concentrations were set at levels adequate to ensure compliance with current European, Chinese, US and Canadian regulations. The method was fully validated according to the European Community Reference Laboratories Residues Guidelines using 93 food samples of different composition. False-negative and false-positive rates were below 5% for all analytes. The method is adequate for use in high-routine laboratories. A 1-year study was additionally conducted to assess the stability of the 23 analytes in the working standard solution. [ABSTRACT FROM AUTHOR]

This work aimed to provide a comprehensive characterisation of several physicochemical properties of different milk protein powders frequently used as ingredients in dairy-based food formulations, in particular flowability and wettability. The flow and wetting properties were influenced mainly by the powder composition, less than by other physicochemical properties, such as particle size and microstructure. Powders with high fat content had poor flow and wetting properties. The wetting properties were also influenced by the protein content (mainly by the casein content) of the powders and were poor for powders having poor release of ionic calcium. [ABSTRACT FROM AUTHOR]

Camel milk produces watery texture when it is processed to yogurt. Despite the extensive studies on microbial transglutaminase (MTGase) in dairy research, the effect of this enzyme on the properties of yogurt made from camel milk has not been studied. This study aims to investigate the impact of MTGase with and without bovine skimmed milk powder (SMP), whey protein concentrate (WPC),or β-lactoglobulin (β-lg) on physico-chemical, rheological, microstructural, and sensory properties of camel-milk yogurt during 15 days of storage period. MTGase treatment markedly reduced the fermentation time of unfortified and SMP-fortified camel milk. The fortification of camel milk without MTGase failed to give set-type yogurt. The treatment of unfortified milk with MTGase enormously improved the viscosity and the body of yogurt samples. Fortification of MTGase-treated milk impacted positively on the viscosity, the water holding capacity, and the density of the protein matrix in the gel microstructure, which were influenced by the type of dairy ingredients. All MTGase-treated yogurts differed from each other in hardness and adhesiveness values. Electrophoresis results showed that the susceptibility of the individual milk proteins to MTGase varied, and there were differences among the treatments toward the enzyme. SMP-fortified yogurt was the most accepted product. Generally, the addition of MTGase preparation at a concentration of 0.4%, simultaneously with starter culture, to fortified camel milk was considered an effective tool to solve the challenges of producing set-type yogurt from this milk. [ABSTRACT FROM AUTHOR]

The protein content of skim milk was increased from 3.3 to 4.1% (wt/wt) by the addition of a blend of skim milk powder and sodium caseinate (NaCas), in which the weight ratio of skim milk powder to NaCas was varied from 0.8:0.0 to 0.0:0.8. Addition of NaCas increased the levels of nonsedimentable casein (from ~6 to 18% of total casein) and calcium (from ~36 to 43% of total calcium) and reduced the turbidity of the fortified milk, to a degree depending on level of NaCas added. Rennet gelation was adversely affected by the addition of NaCas at 0.2% (wt/wt) and completely inhibited at NaCas ≥0.4% (wt/wt). Rennet-induced hydrolysis was not affected by added NaCas. The proportion of total casein that was nonsedimentable on centrifugation (3,000 × g, 1 h, 25°C) of the rennet-treated milk after incubation for 1 h at 31°C increased significantly on addition of NaCas at ≥0.4% (wt/wt). Heat stability in the pH range 6.7 to 7.2 and ethanol stability at pH 6.4 were enhanced by the addition of NaCas. It is suggested that the negative effect of NaCas on rennet gelation is due to the increase in nonsedimentable casein, which upon hydrolysis by chymosin forms into small nonsedimentable particles that physically come between, and impede the aggregation of, rennet-altered para-casein micelles, and thereby inhibit the development of a gel network. [ABSTRACT FROM AUTHOR]

Recently, reports have been published on the occurrence of chlorate mainly in fruits and vegetables. Chlorate is a by-product of chlorinating agents used to disinfect water, and can be expected to be found in varying concentrations in drinking water. Data on potable water taken at 39 sampling points across Europe showed chlorate to range from < 0.003 to 0.803 mg l–1with a mean of 0.145 mg l–1. Chlorate, however, can also be used as a pesticide, but authorisation was withdrawn in the European Union (EU), resulting in a default maximum residue limit (MRL) for foods of 0.01 mg kg–1. This default MRL has now led to significant problems in the EU, where routinely disinfected water, used in the preparation of food products such as vegetables or fruits, leaves chlorate residues in excess of the default MRL, and in strict legal terms renders the food unmarketable. Due to the paucity of data on the chlorate content of prepared foods in general, we collated chlorate data on more than 3400 samples of mainly prepared foods, including dairy products, meats, fruits, vegetables and different food ingredients/additives. In total, 50.5% of the food samples contained chlorate above 0.01 mg kg–1, albeit not due to the use of chlorate as a pesticide but mainly due to the occurrence of chlorate as an unavoidable disinfectant by-product. A further entry point of chlorate into foods may be via additives/ingredients that may contain chlorate as a by-product of the manufacturing process (e.g. electrolysis). Of the positive samples in this study, 22.4% revealed chlorate above 0.1 mg kg–1. In the absence of EU levels for chlorate in water, any future EU regulations must consider the already available WHO guideline value of 0.7 mg l–1in potable water, and the continued importance of the usage of oxyhalides for disinfection purposes. [ABSTRACT FROM AUTHOR]

This article describes current research on the development of alternative ready-to-use therapeutic foods (RUTFs) in the treatment of severe acute malnutrition. An innovative and versatile linear programming tool has been developed to facilitate the creation of therapeutic formulas that are determined acceptable on multiple levels: costs, ingredient acceptability, availability and stability, nutrient requirements, and personal preferences. The formulas are analyzed for ease of production by Washington University team members and for organoleptic properties acceptability to target populations. In the future, RUTF products that are cost-effective, acceptable, sustainable, and widely available will become a reality. [ABSTRACT FROM AUTHOR]

Background: Nutritional interventions to help prevent stunting, particularly in the first 1000 days from conception to 2 years of a child's life, are a major focus of numerous food aid organizations worldwide. Dairy ingredients can play an important role in enhancing the nutritional value and effectiveness of food products used in food aid.Objective: This article addresses gaps in research on malnutrition from both a broad perspective and specific to dairy ingredients.Methodology: Narrative review.Results and Conclusions: From a broad perspective, there is a need for gaining a consensus by the research community and funders of research on best practices for protocol development, outcomes measured, and reporting of study outcomes. Identification of biomarkers and rapid screening methods and consistent application of their use would expedite future research. A better understanding of nutritional requirements for malnourished populations, including the effects of energy deficits and disease on those requirements, is needed. More specific to dairy ingredients, a key research question is: Does dairy protein or the package of nutrients provided by dairy ingredients have a unique impact on growth, and if so, how? Also, data on the optimal levels of dairy ingredients based on the effective cost of treatment are needed, particularly in the treatment and prevention of moderate acute malnutrition and during pregnancy. [ABSTRACT FROM AUTHOR]

This review examines the global market for dairy ingredients by assessing the global demand for dairy products in relation to major dairy ingredient categories. Each broad category of dairy ingredients is reviewed including its definition, production and trade status, key applications, and future trends. Ingredient categories examined include whole and skim milk powders (WMPs, SMPs), whey protein concentrates (WPCs) and whey protein isolates (WPIs), milk protein concentrates (MPCs) and milk protein isolates (MPIs), caseins, and caseinates. Increases in world population and improvements in socioeconomic conditions will continue to drive the demand for dairy products and ingredients in the future. Dairy proteins are increasingly recognized to have nutritional and functional advantages compared to many protein sources, and the variety of ingredients with different protein concentrations, functionality, and flavor can meet the needs of the increasingly global dairy consumption. A thorough understanding of the variety of ingredients, how the ingredients are derived from milk, and how the demand from particular markets affects the supply situation are critical elements in understanding the current ingredient marketplace. [ABSTRACT FROM AUTHOR]

Abstract: High intensity low frequency ultrasound was used to process dairy ingredients to improve functional properties. Based on a number of lab-scale experiments, several experimental parameters were optimised for processing large volumes of whey and casein-based dairy systems in pilot scale ultrasonic reactors. A continuous sonication process at 20kHz capable of delivering up to 4kW of power with a flow-through reactor design was used to treat dairy ingredients at flow rates ranging from 200 to 6000mL/min. Dairy ingredients treated by ultrasound included reconstituted whey protein concentrate (WPC), whey protein and milk protein retentates and calcium caseinate. The sonication of solutions with a contact time of less than 1min and up to 2.4min led to a significant reduction in the viscosity of materials containing 18% to 54% (w/w) solids. The viscosity of aqueous dairy ingredients treated with ultrasound was reduced by between 6% and 50% depending greatly on the composition, processing history, acoustic power and contact time. A notable improvement in the gel strength of sonicated and heat coagulated dairy systems was also observed. When sonication was combined with a pre-heat treatment of 80°C for 1min or 85°C for 30s, the heat stability of the dairy ingredients containing whey proteins was significantly improved. The effect of sonication was attributed mainly to physical forces generated through acoustic cavitation as supported by particle size reduction in response to sonication. As a result, the gelling properties and heat stability aspects of sonicated dairy ingredients were maintained after spray drying and reconstitution. Overall, the sonication procedure for processing dairy systems may be used to improve process efficiency, improve throughput and develop value added ingredients with the potential to deliver economical benefits to the dairy industry. [Copyright &y& Elsevier]

Different low lactose dairy ingredients including sodium caseinate (SC), milk protein isolate (MPI), whey protein isolates (WPIS and WPIM) and whey protein concentrate (WPC) were tested in a gluten-free bread formulation and compared to controls with the addition of no dairy ingredient (C) and one dairy ingredient containing lactose, skim milk powder. Rheological characterisation (frequency sweep and creep-recovery) of the batters at 90% water level (WL) suggested that the addition of WPIS, WPIM and WPC significantly decreased G′ and G″ values. SC and MPI had the opposite effect with a significant increase in both these parameters being found ( p < 0.05). The WL of the batters was adjusted in order to obtain the same consistency of the batter C at 90% WL. A Power Law model was used to predict the new WL based on single frequency measurements of G* for each sample. The baking analysis demonstrated that the correction of the WL did not show a strong impact in the quality of the breads. Nevertheless, whey proteins demonstrated the ability to increase significantly the specific volume of the breads and decrease the hardness over time ( p < 0.05). SC had a negative impact on the specific volume, which led to an increase in crumb hardness ( p < 0.05). [ABSTRACT FROM AUTHOR]

Abstract: The effects of varying time/temperature-conditions of pre-heating and cross-linking with transglutaminase (TG) on the functional properties of reconstituted products from skim milk, WPC and sodium caseinate was analyzed. The degree of cross-linking (DC) of skim milk proteins could be increased from 54.4% to 70.5% by varying process conditions. Thereby the water-holding capacity (WHC) increased from 10% to 20%, while the heat stability decreased. The burning-on was lower than that of the non-treated products at optimum pre-heating conditions (90°C/30s). Using sodium caseinate as substrate for TG the DC increased from 39.2% to 100% due to the improvement of the process. As a result the WHC increased by 30% and the heat stability up to 380%. However, the burning-on of casein increased as well. TG-treated sodium caseinate started to gel at 10% protein, whereas untreated sodium caseinate gelled not before 15% protein. The WHC of enzyme-treated whey proteins was lowered. The heat stability of WPC could be doubled by TG-treatment, and the burning-on of the products was, especially at optimum pre-heating conditions, less pronounced. The degree of denaturation of TG-treated whey proteins was 2–5% higher than that of untreated samples. [Copyright &y& Elsevier]

The influence of emulsifiers and dairy solids on churning and physical attributes of butter was investigated. Commercial dairy cream was blended with each of the ingredients (0.5%, w/w) separately, aged overnight (10 °C), and churned (10 °C) into butter. The employed additives showed a distinctive impact on the macroscopic properties of butter without largely affecting the melting behavior. In fresh butter, polyglycerol polyricinoleate (PGPR) emulsifier having dominated hydrophobic moieties significantly (p < 0.05) enhanced the softness. Among dairy solids, sodium caseinate (SC) was the most effective in reducing the solid fat fraction, hardness, and elastic modulus (G'), while whey protein isolate (WPI) and whole milk powder (WMP) produced significantly harder, stiffer, and more adhesive butter texture. As per tribological analysis, PGPR, Tween 80, and SC lowered the friction-coefficient of butter, indicating an improved lubrication property of the microstructure. The extent of butter-setting during 28 days of storage (5 °C) varied among the samples, and in specific, appeared to be delayed in presence of WPI, WMP, and buttermilk solids. The findings of the study highlighted the potential of using applied emulsifiers and dairy-derived ingredients in modifying the physical functionality of butter and butter-like churned emulsions in addition to a conventional cream-ageing process. [ABSTRACT FROM AUTHOR]

Chocolate is considered as both caloric and functional food. Its nutritional properties may be improved by addition of fiber; however, this may reduce polyphenols content. The aim of this research was to determine the influence of cocoa shell addition (as a source of fiber) and its combination with different ingredients (cocoa butter equivalents (CBE), emulsifiers, dairy ingredients) on polyphenols of dark and milk chocolates. Total polyphenol (TPC) and total flavonoid (TFC) contents were determined spectrophotometrically, identification and quantification of individual compounds by high pressure liquid chromatography and antioxidant capacity by ferric reducing antioxidant power (FRAP) assay. Results showed that even though addition of cocoa shell to chocolate results in reduced contents of TPC, TFC, and individual compounds, it is not significant compared to ones reported by other authors for commercial chocolates. Other ingredients influence determined values for all investigated parameters; however, additional research is needed to reveal exact mechanisms and implications. [ABSTRACT FROM AUTHOR]

This study investigated the effect of growth conditions on proteolytic activity of six Pseudomonas strains, (Pseudomonas fragi DZ1, Pseudomonas koreensis DZ138, Pseudomonas rhodesiae DZ351, Pseudomonas fluorescens DZ390, Pseudomonas synxantha DZ832 and Pseudomonas lundensis DZ845), isolated from raw milk. The proteolytic activity of all Pseudomonas strains in dairy media (skim milk and whole milk) was significantly higher (p < 0.05) than in non-dairy media (TSB), with most activity from Pseudomonas grown in whole milk. The proteolytic activity from P. lundensis DZ845 grown in TSB with the addition of 5% (w/v) butter was higher than other dairy ingredients added to TSB and the amount of proteolytic activity increased with increasing concentrations of butter (from 5 to 15%). P. rhodesiae DZ351 showed little proteolytic activity in all TSB supplemented with dairy ingredients. Only four of the six strains produced one protease of 47 kDa when grown in TSB. However, all six strains were able to produce at least one type of proteases in milk medium. For P. lundensis DZ845, a 12% casein zymography gel revealed that the presence of butter could induce proteolytic activity. This is the first study showing the effect of milk fat (butter) on the proteolytic activity of Pseudomonas. This highlights the greater vulnerability of whole milk compared to skim milk to proteolytic activity. • The proteolytic activity of all six dairy isolates of Pseudomonas strains varies with the strongest being P. lundensis DZ845. • Pseudomonas showed more proteolytic activity in milk medium than TSB. • Milk fat induces the activity or production of protease from Pseudomonas. [ABSTRACT FROM AUTHOR]

The addition of dairy ingredients (buttermilk powder and/or sodium caseinate) to the cheese feed before spray drying, as well as the age of the cheese used as raw material on reconstitution behavior of cheese powder without emulsifying salt were studied. Cheese powders made with addition of 2% sodium caseinate plus 2% buttermilk powder showed increased wettability and the lowest amount of fat on the surface, but a delayed dispersibility. Powders made using only buttermilk powder (4%) and powders produced with 45 weeks old cheese exhibited faster dispersibility, but reduced total rehydration. Reconstituted powders produced with 16 weeks old cheese showed the best total rehydration. The amount of surface fat, lactose, and protein interactions with water in the cheese casein network are pointed to be the main reasons for the differences observed, as they affect particle size distribution or ability of the powder components to interact with the water. • Adding both buttermilk powder and sodium caseinate improved wettability. • Wettability was correlated with the N/C ratio on the powder surface. • Cheese powders produced with 45 weeks old cheeses had faster dispersibility. • Dispersibility decreased when buttermilk powder and sodium caseinate were added. • Powders produced with 16 weeks old cheeses showed better total rehydration. [ABSTRACT FROM AUTHOR]

The objective of this study was to characterize physical and microbiological properties of powders prepared by mixing Lactobacillus salivarius NRRL B-30514 suspensions with skim milk powder (SMP), spray-dried lactose (SDL), milk protein concentrate (MPC), or MPC/SDL at a mass ratio of 1:2, 1:1 or 2:1 to understand the relative significance of proteins and lactose in bacterial survival. The probiotic viability and storage stability were significantly improved with the increase of dairy protein content. Based on water sorption isotherms and X-ray diffraction spectroscopy, MPC was suggested to preferentially absorb water in cell suspensions, which inhibited the hydration of SDL and therefore lowered the hypertonic pressure to the adhered cells. The LIVE/DEAD® Bac Light™ and CTC reduction assays detected higher membrane integrity and respiratory activity of bacteria for treatments with more proteins. Findings from the current study indicated the more significant role of milk proteins than lactose protecting bacteria during dehydration. • Lactobacillus salivarius powders were produced by mixing cell suspensions with dairy powder. • Bacterial viability after mixing and subsequent storage was affected by powder composition. • Milk protein concentrate (MPC) was more effective than spray-dried lactose (SDL) on protecting probiotics. • MPC delayed the hydration of SDL to lower hypertonic stress on adhered cells. • Cells treated with a greater amount of MPC had higher membrane integrity and respiratory activity. [ABSTRACT FROM AUTHOR]