Changes in the physical properties,solubility, and heat stability of milk protein concentrates prepared from partially acidified milk

A limiting factor in using milk protein concentrates (MPC) as a high-quality protein source for different food applications is their poor reconstitutability. Solubilization of colloidal calcium phosphate (CCP) from casein micelles during membrane filtration (e.g., through acidification) may affect the structural organization of these protein particles and consequently the rehydration and functional properties of the resulting MPC powder. The main objective of this study was to investigate the effects of acidification of milk by glucono-δ-lactone (GDL) before ultrafiltration (UF) on the composition, physical properties, solubility, and thermal stability (after reconstitution) of MPC powders. The MPC samples were manufactured in duplicate, either by UF (65% protein, MPC65) or by UF followed by diafiltration (80% protein, MPC80), using pasteurized skim milk, at either the native milk pH (~pH 6.6) or at pH 6.0 after addition of GDL, followed by spray drying. Samples of different treatments were reconstituted at 5% (wt/wt) protein to compare their solubility and thermal stability. Powders were tested in duplicate for basic composition, calcium content, reconstitutability, particle size, particle density, and microstructure. Acidification of milk did not have any significant effect on the proximate composition, particle size, particle density, or surface morphology of the MPC powders; however, the total calcium content of MPC80 decreased significantly with acidification (from 1.84 ± 0.03 to 1.59 ± 0.03 g/100 g of powder). Calcium-depleted MPC80 powders were also more soluble than the control powders. Diafiltered dispersions were significantly less heat stable (at 120°C) than UF samples when dissolved at 5% solids. The present work contributes to a better understanding of the differences in MPC commonly observed during processing.     

Production,nutritional and biological value of bambara groundnut (<Emphasis Type="Italic">Vigna subterranea</Emphasis>) milk and yoghurt

The purpose of this study was to assess the nutritional properties of Bambara milk and yoghurt. The milk was produced by aqueous extraction of flour obtained by dehulling the seeds followed by parboiling. It was then fermented using a mix culture of L. Bulgaricus, S. thermophilus and L. plantarum, followed by the evaluation of the protein biological value on rats. During the process of flour production, from the whole seeds to the flour, a significant drop in total polyphenol content (1.00?±?0.10–0.41?±?0.01 mg/100 g) and phytates (1.18?±?0.03–0.32?±?0.01 mg/100 g) was observed while the protein content increased (19.7?±?1.2–25.47?±?2.28 g/100 g). During the fermentation of the milk into yogurt, a significant decrease in phytate content (0.29?±?0.01–0.03?±?0.01 g/100 g), an increase in the protein content (1.8?±?0.1–2.6?±?0.1 g/100 g) and the protein digestibility (91.5–96%) were equally observed. Red blood cell, glycaemia, the ASAT and ALAT contents of rat bloods fed Bambara milk or yoghurt were not significantly different to rats fed casein as protein reference. In conclusion Bambara groundnut is a source of protein which the quality may be enhanced through processing of high value yogurt.     

Why semicarbazide (SEM) is not an appropriate marker for the usage of nitrofurazone on agricultural animals

A comprehensive global database on semicarbazide (SEM) in foodstuffs and food ingredients is presented, with over 4000 data collected in foods such as seafood (crustaceans, fish powders), meat (beef, chicken powders), dairy products (e.g. raw milk, milk powders, whey, sweet buttermilk powder, caseinate, yoghurt, cheese), honey and other ingredients. The results provide evidence that the presence of SEM in certain dairy ingredients (whey, milk protein concentrates) is a by-product of chemical reactions taking place during the manufacturing process. Of the dairy ingredients tested (c. 2000 samples), 5.3% showed traces of SEM > 0.5 µg/kg. The highest incidence of SEM-positive samples in the dairy category were whey (powders, liquid) and milk protein concentrates (35% positive), with up to 13 µg/kg measured in a whey powder. Sweet buttermilk powder and caseinate followed, with 27% and 9.3% positives, respectively. SEM was not detected in raw milk, or in yoghurt or cheese. Of the crustacean products (shrimp and prawn powders) tested, 44% were positive for SEM, the highest value measured at 284 µg/kg. Fish powders revealed an unexpectedly high incidence of positive samples (25%); in this case, fraudulent addition of shellfish shells or carry-over during processing cannot be excluded. Overall, the data provide new insights into the occurrence of SEM (for dairy products and fish powders), substantially strengthening the arguments that SEM in certain food categories is not a conclusive marker of the use of the illegal antibiotic nitrofurazone.     

Spray-Drying of Antioxidant-Rich Blueberry Waste Extracts; Interplay Between Waste Pretreatments and Spray-Drying Process

This study aimed to establish an efficient route for converting blueberry waste material (BWM) into antioxidant-rich powders. Extracts were produced from BWM by an aqueous method using water acidified with citric acid, in the absence or presence of Pectinex Ultra SP-L and Cellubrix. All BWM extracts contained antioxidants including phenolic acids, anthocyanins, and flavonoids (total phenolic content (TPC) 3655–4369 mg gallic acid equivalent (GAE) and total anthocyanin content (TAC) 219–296 mg cyanidin-3-glucoside equivalents (CyGE) per 100 g dry extract). Extractions at 50 °C yielded higher TPC and TAC but lower vitamin C and pectin contents than extractions at 20 °C. Spray-drying BWM extracts produced at 50 °C (no enzymatic treatments) and an encapsulant (alginate or inulin) at an inlet temperature 150 °C and feed temperature 50 °C yielded powders with desired dark purplish blue color, water activity (0.25–0.33), flowability, reconstitution time (23–46 s in water or milk), TPC (25–30 mg GAE/g), TAC (17–20 mg CyGE/g), storage stability, and Bifidobacterium-boosting properties. Enzymatic pretreatments of BWM did not confer any advantages in preserving antioxidants in powder products, suggesting that some intrinsic BWM components (e.g., pectins) may play an important role in the encapsulating process. The use of alginate as the encapsulant/drying aid afforded higher powder yields, superior protection of antioxidants, better stability over a prolonged storage or elevated temperature storage, greater retention of TPC/TAC under simulated gastrointestinal conditions, and greater Bifidobacterium-boosting effects, compared to powders prepared using inulin. Thus, simple aqueous extraction methods and spray-drying technology hold enormous promise for producing antioxidant-rich powders from blueberry processing by-products or waste.     

Carnitine in milk: a survey of content,distribution and temporal variation

Acid-soluble free carnitine and short-chain acylcarnitines were released following a selective alkaline hydrolysis scheme and estimated with use of a coupled carnitine acetyl transferase–Ellman reaction. Liquid skim milk contained elevated total carnitine levels compared to whole milk, due both to the minor contribution of liposoluble long-chain acylcarnitines in milkfat and the higher solids-not-fat content. Data are also reported for a range of dried protein products derived from milk (1–64 mg/100 g), and the stability characteristics of endogenous carnitine are described. A study of a single lactating cow exhibited decreasing concentrations of total carnitine with time postpartum during transition from colostrum to mature milk (>9 mg/100 g to ca. 3 mg/100 g). Regional influences on bovine milk carnitine levels within Australasia were shown to be insignificant, while carnitine content in milk powders and pooled herd milk were relatively constant across a production season. Bovine milk was compared against samples of caprine, ovine, equine, human, canine and feline milks. A survey of anhydrous infant formulas indicated diverse carnitine contents (6.9–30.1 mg/100 g) as a consequence of their complex and varied compositions and the common practice of supplementation.     

Physicochemical,Phytochemical and Mycological Characteristics of Italia Muscat Raisins Obtained Using Different Pre-treatments and Drying Techniques

Raisins represent an economically important grapevine by-product. However, their quality is largely dependent on drying techniques and processing conditions. In this context, two drying processes were monitored: hot air drying in a convective oven and greenhouse drying. Grape berries were previously subjected to two chemical pre-treatments (olive oil and K₂CO₃ emulsion dipping (I) and NaOH solution bleaching (II)). Pre-treated grapes processed using both methods were compared with sun-dried samples. The results show that oven drying was more efficient and rapid (5 days) as compared with greenhouse drying (13 days). The end moisture content of grapes varied from 16.12% to 22.25% on a wet basis in dried samples, respectively. Significant differences in the pH value (3.85–4), acidity (1172.5–2730 mg TA/100 g DW) and total sugars (31.5–49.7%) were also observed, between raisin samples subjected to both treatments and drying methods, whereas protein levels (1–1.25%) were not affected. The analysis of minerals indicates that greenhouse-dried raisins had high amounts of calcium (Ca), magnesium (Mg) and sodium (Na). The highest polyphenol (417.70 mg GAE/100 g DW), flavonoid (115.87 mg CE/100 g DW) and tannin (368.13 mg CE/100 g DW) contents were recorded in sun-dried samples, respectively. The distribution of fungal flora shows a noteworthy variability among raisin samples, with a marked abundance of ochratoxinogenic species such as Aspergillus ochraceus and Aspergillus carbonarius (15.56% and 10.41%, respectively). Italia Muscat raisins processed using oven drying could be an economically interesting alternative to manage the excessive grapes production and consequently solve related marketing issues.     

Estimation of Protein in Anhydrous Milk Fat

A method for the estimation of protein in anhydrous milk fat is described. The protein concentration is estimated by quantifying the arginine and aspartic acid (ASX) released upon acid hydrolysis of the anhydrous milk fat. Arginine and aspartic acid are derivatized with the fluorescent tag 9-fluorenylmethoxycarbonyl (FMOC), the derivatives are quantified by reversed phase HPLC, and the protein concentration in the anhydrous milk fat is estimated as 8.77?×?(Arg?+?ASX). Method suitability was defined by experimental assessments of FMOC-arginine and FMOC-aspartic acid linearity (R ² averages?>?0.999), protein estimate precision [day-to-day RSD values (n?=?8 days) ranged from 7.3 to 14 % for protein concentrations of 9.42 to 40.0 mg/kg of anhydrous milk fat], protein estimate accuracy [spike recovery average?=?95.6 % (9.3 %), n?=?8, spiking level?=?20 mg/kg and agreement of the experimental protein estimate for butter, 0.611 (0.044)?g/100 g, n?=?3 lots, with a published value 0.6/100 g], and analyte selectivity (baseline resolution of FMOC-arginine and FMOC-aspartic acid from the FMOC derivatives of other common amino acids). The method provides for a reliable estimation of the protein content of anhydrous milk fat, when present at concentrations >2 mg/kg.     

Lupinus mutabilis: Composition,Uses, Toxicology,and Debittering

Lupinus mutabilis has protein (32.0–52.6 g/100 g dry weight) and lipid (13.0–24.6 g/100 g dry weight) contents similar to soya bean (Glycine max). The Ω3, Ω6, and Ω9 contents are 1.9–3.0, 26.5–39.6, and 41.2–56.2 g/100 g lipid, respectively. Lupins can be used to fortify the protein content of pasta, bread, biscuits, salads, hamburgers, sausages, and can substitute milk and soya bean. Specific lupin protein concentrates or isolates display protein solubility (>90%), water-absorption capacity (4.5 g/g dry weight), oil-absorption capacity (3.98 g/g), emulsifying capacity (2000 mL of oil/g), emulsifying stability (100%, 60 hours), foaming capacity (2083%), foaming stability (78.8%, 36 hours), and least gelation concentration (6%), which are of industrial interest. Lupins contain bitter alkaloids. Preliminary studies on their toxicity suggest as lethal acute dose for infants and children 10 mg/kg bw and for adults 25 mg/kg bw. However, alkaloids can also have medical use for their hypocholesterolemic, antiarrhythmic, and immunosuppressive activity. Bitter lupins can be detoxified by biological, chemical, or aqueous processes. The shortest debittering process requires one hour. This review presents the nutritional composition of lupins, their uses (as food, medicine, and functional protein isolates), toxicology, and debittering process scenarios. It critically evaluates the data, infers conclusions, and makes suggestions for future research.     

Fatty acid composition and CLA content in goat milk and cheese samples from Umbrian market

Goat dairy products are considered as a suitable alternative to cow milk products for some special categories of consumers (infants, old, and convalescent people). In the present research, a study on the lipid fraction of commercial goat milk and cheese samples purchased from Umbrian market was carried out. Particular attention has been paid to evaluating conjugated linoleic acid (CLA) content and determining some interesting nutritional indexes. The results of goat milk samples showed that saturated, monounsaturated and polyunsaturated fatty acid contents were on average 71.2, 23.4, and 3.8 %, respectively. CLA content (cis-9, trans-11 isomer) was on average 11.5 mg/100 g in milk. Considerable variability was observed for n6/n3 ratio that varied from 2.7 to 10.6 in the considered goat milk samples. With regard to goat cheese samples CLA concentration was on average 118.8 mg/100 g in fresh cheese and 217.7 mg/100 g in semi-hard cheese, and the difference was not significant. Interestingly, α-linolenic acid content was higher and n6/n3 ratio was lower in semi-hard with respect to fresh cheese samples (p < 0.05).     

Study on the behavior of the trace metal and macro minerals in Mytilus galloprovincialis as a bioindicator species: the case of Marmara Sea, Turkey

Sea food is a major source of animal protein. Marine foods are very rich sources of mineral components. The total content of minerals in the raw flesh of marine fish and invertebrates is in the range of 0.6–1.5% wet weight. The contents of Na, K, Ca, Mg and P are up to 1 mg/100 g, whereas those of Fe, Zn, I are less than 1 mg/100 g. Mussels (Mytilus galloprovincialis) were investigated for macro and trace element composition throughout the year. Ranges of moisture, ash, protein and fat contents were 79.76–87.46 g/100 g, 1.06–2.06 g/100 g, 7.28–12.65 g/100 g and 0.33–3.49 g/100 g, respectively. While the highest protein and fat values were found in the summer (July–August), the highest moisture and ash contents were found in the winter (December–January). The contents of highest Na, K, Ca were found in the summer. Cadmium, lead and copper were found to be below the legislative limits throughout year. High levels of mercury were found in January and October. It should be discussed whether mussel may provide an alternative source of mineral for healthy nutrition.     

Comparative study on physicochemical and functional properties of egg powders from Japanese quail and white Leghorn chicken

Physicochemical and functional properties of freeze-dried egg powders (egg white, egg yolk, and whole egg) from Japanese quail and white Leghorn chicken were studied comparatively. All egg powders had protein content in the range of 91.13–97.03 g/100 g powder. The quail egg powder had higher mineral and essential amino acid contents, but lower fat content as compared to chicken egg powders (P < 0.05). Moreover, egg white powder from both quail and chicken presented higher total amino acids content than corresponding whole egg and egg yolk powders, respectively. Fourier transform infrared spectroscopic study revealed that β-sheet is the major secondary structure of all egg powders. Based on differential scanning calorimetry analysis, quail egg powders showed slightly lower denaturation temperatures than corresponding chicken egg powders (P < 0.05). Sodium dodecyl sulfate–polyacrylamide gel electrophoresis study showed the slight difference in protein patterns of corresponding quail and chicken egg powders. The quail egg powders presented higher protein solubility than corresponding chicken egg powders at all pH tested. Furthermore, quail egg powders exhibited higher emulsion activity index and emulsion stability index with higher foam expansion and stability than the corresponding chicken egg powders. Therefore, Japanese quail egg powders could be used as an alternative to white Leghorn chicken egg in the preparation of foods and diets that require high protein content with positive health benefits.     

Lipolysis, proteolysis and physico-chemical modifications during ripening of dry-cured duck breast

Chemical traits related to dry-curing process (pH, moisture, water activity total and chlorides), color and textural properties and changes of free fatty acid and amino acid compositions during the processing of dry-cured duck breast were quantified. For this purpose, 25 male ducks from crossbred mule were used in this study and samples at 0 days (raw breast) and after 7, 14, 21 and 28 days of ripening were taken. The results showed that all physico-chemical parameters suffered significant differences during the manufacture of dry-cured duck breast. A decrease in all variables was observed with the exception of chlorides and textural properties due to dehydration process. Concerning free fatty acids, a significant increase (P < 0.05) from 299.57 mg/g of fat in the raw breast to 380.43 mg/g of fat at the end of the drying–ripening stage was recorded. Finally, a significant increase (P < 0.001) in the total free amino acids was observed from raw breast (1,059.17 mg/100 g of DM) to the end of dry-ripening (2,792.48 mg/100 g of DM).     

Aflatoxin M1 and B1 in Colombian milk powder and estimated risk exposure

ABSTRACT

Aflatoxin M₁ (AFM₁) and aflatoxin B₁ (AFB₁) were determined in 51 milk powder samples purchased from different grocery stores located in the Caribbean region of Colombia. Analysis was conducted using QuEChERS extraction and high-performance liquid chromatography with fluorescence detection. Results from the analytical method showed recovery ranges from 65% to 110% and relative standard deviations lower than 20%. AFM₁ was detected in 100% of the milk samples (0.20–1.19 µg/kg) and 55% exceeded the maximum level in milk (0.5 µg/kg) set by the Colombian and European regulations. AFB₁ was not detected in any of the analysed samples. Considering the measured contamination the maximum AFM₁ level that can be ingested by consumption of milk powder is 0.007–0.013 µg/person/day. These values are above the average dietary intake estimated in Latin America according to the Joint FAO/WHO Expert Committee, which is 0.0035 µg/person/day.     

The nutritional ingredients and antioxidant activity of donkey milk and donkey milk powder

The aim of this work was to shed light on the nutritional ingredients and antioxidant activity of donkey milk and powder. It indicated that basic components of donkey milk were closed to human milk, especially lactose. The fat content of donkey milk was lower than that of cow milk and human milk. The essential amino acids, fatty acids and taurine in donkey milk and powder were richer. The whey protein content of donkey milk was 49.08 g/100 g. The ratio of casein to whey protein in donkey milk and powder was 70.3:100. The cholesterol of donkey milk was 8.6 mg/100 g. Therefore, donkey milk and powder are typical low-fat and low-cholesterol foods. The precious values of donkey milk and powder are suitable calcium and phosphorus proportion, and strongly resistant to oxidation. In conclusion, donkey milk and powder are good supplementary of cow milk and powder, would be better for infant dietary.     

Evaluation of the yield,molar mass of exopolysaccharides,and rheological properties of gels formed during fermentation of milk by Streptococcus thermophilus strains St-143 and ST-10255y

The yield and chemical structures of exopolysaccharides (EPS) produced by many strains of Streptococcus thermophilus have been characterized. However, the kinetics (or production profile) for EPS during milk fermentation is not clear. In this study, we investigated whether any differences existed in the yield and molar mass of EPS when milk was fermented at the same acidification rate by 2 strains of S. thermophilus (St-143 and ST-10255y). The type of EPS produced by these 2 strains is different. Milk samples were analyzed for EPS concentration every 30 min during a fermentation period of 270 min (final pH 4.5) by using a modified quantification method, which was faster and validated for its recovery of added EPS. Rheological properties of milks during fermentation were also analyzed using small-strain dynamic oscillatory rheology. For the determination of molar mass, EPS extracts were isolated by ultrafiltration of whey obtained during fermentation of milk to pH values 5.2, 4.9, 4.7, and 4.5, and molar mass was analyzed using size-exclusion chromatography–multi-angle laser light scattering. During fermentation, both strains appeared to start producing significant amounts of EPS after about ～150 min, which corresponded to pH ～5.3, which was close to the point of gelation. During the remainder of the fermentation process (150–270 min), the EPS concentration from strains St-143 and ST-10255y significantly increased from 30 to 72 mg/L and from 26 to 56 mg/L, respectively. The quantity of EPS recovered by our modified method was estimated to represent ～60% of the total EPS added to milk. The molar mass of EPS produced by both strains appeared to slightly decrease during fermentation. At pH 5.2, EPS from St-143 and ST-10255y had molar masses of 2.9 × 10⁶ and 1.4 × 10⁶ g/mol, respectively, which decreased to 1.6 × 10⁶ and 0.8 × 10⁶ g/mol, respectively, when the pH of milk was 4.5. Distinct differences were apparent in the rheological properties of gels fermented by the 2 strains. At the end of fermentation, St-143 fermented milk had weaker gels with storage modulus (G′) value at pH 4.6 of 26 Pa, whereas gels made with ST-10255y were stiffer with a G′ value at pH 4.6 of 82 Pa. For St-143 gels, maximum loss tangent (LT_max) values were higher (0.50) and occurred earlier (at a higher pH value) than the LT_max values (0.46) for gels from ST-10255y strain. Because the fermentation conditions were identical for both strains, the observed changes in rheological properties could be due to the differences in chemical structures and molar mass of the EPS produced by these 2 S. thermophilus strains.     

Fate of pyrrolizidine alkaloids during processing of milk of cows treated with ragwort

ABSTRACT

To investigate the fate of pyrrolizidine alkaloids (PAs) during milk processing, milk of cows treated via rumen fistula with a mixture of 84% (w/w) ragwort (Jacobaea vulgaris, syn. Senecio jacobaea) and 16% narrow-leaved ragwort (Senecio inaequidens) was processed using laboratory scale heating systems with industrial settings. Pasteurised and sterilised (UHT) milk were produced, as well as set-type yoghurt and cheese. Samples were analysed for 29 PAs using LC-MS/MS, of which 11 PAs were detected above LOQ in the samples (0.1 µg l^?1). Alterations in the PA concentration and composition between the standardised milk and the corresponding end-product(s) were evaluated. The heat treatments applied for pasteurisation and UHT sterilisation to prepare semi-skimmed consumption milk did not affect the PA levels in the end-products. In yoghurt, after fermentation of standardised milk (6 h, pH 4.4), 73% of total PAs were recovered. The PA concentration, specifically dehydrojacoline, was decreased, although not quantifiable, during cheese production. A further decrease of 38% during 6 weeks of ripening was observed. The results show that the PA concentration of natural contaminated cow’s milk is not affected by heat treatment applied for pasteurised and sterilised milk, but that microbial fermentation of the milk leads to a lowered PA concentration in yoghurt and cheese. This is probably due to microbiological degradation, since PAs are fairly stable under acidic conditions.     

Molecularly Imprinted Polymer as Sorbent for Solid-Phase Extraction Coupling to Gas Chromatography for the Simultaneous Determination of Trichlorfon and Monocrotophos Residues in Vegetables

In this study, a molecularly imprinted polymer (MIP) was prepared using the mixture of trichlorfon and monocrotophos as the mixed template. The imprinted polymer was characterized and exhibited good recognition ability and fast adsorption–desorption dynamic toward the trichlorfon and monocrotophos. Using this imprinted polymer as sorbent, a new method of molecularly imprinted solid-phase extraction coupled to gas chromatography for the simultaneous determination of two organophosphate pesticides residues was developed. Under optimal condition, the linear range was 0.005–10.0 mg/l. At a loading flow rate of 2.0 ml/min for loading 100 ml, the detection limits were 0.28 μg/l for trichlorfon and 0.090 μg/l for monocrotophos, the peak area precision (RSD) for five replicates was 4.23–4.50 %. The blank rape samples spiked with two organophosphate pesticides at 0.05 and 0.1 mg/l levels were determined by this method with recoveries ranging from 89.41 % to 95.12 %. Moreover, this method was successfully applied to the quantitative detection of the trichlorfon and monocrotophos residues in leek samples.     

Electrophoretic Analysis of Natural Antioxidants in Plant and Beverage Samples Using Dynamically Coated Capillaries with Chitosan and Multiwall Carbon Nanotubes

Statically, chitosan-coated capillaries were simply dynamically coated with multiwall carbon nanotubes (MWNTs) coaggregated with sodium dodecyl sulfate (SDS). The capillary electrophoresis method was used to separate natural antioxidants in plant and beverage samples. In this way, a great improvement in the electrophoretic resolution was achieved when the running buffer was composed of 50 mM SDS and 10 mM sodium borate with 6.0 μg/mL of SDS-coated MWNTs, at pH 8.0, with an applied voltage of 30 kV. Under the optimal conditions, the limits of detection and quantitation for the target analytes were in the range of 0.14–0.82 μg/mL and of 0.47–2.75 μg/mL, respectively. The mean recovery values of 83.9–106.2 % were obtained for the spiked chrysanthemum samples. This proposed method was successfully applied for determining 12 phenolic compounds in complex chrysanthemum samples.     

Role of calcium content in antibacterial activity of donkeys’ milk toward E. coli

The objective of this study was to investigate the effect of calcium content in raw donkeys’ milk (DM) on its antibacterial activity against Escherichia coli. Antibacterial assay was performed in artificially contaminated milk samples (without and with added CaCl₂ and EDTA) incubated at 38 °C (donkeys’ body temperature). The EDTA was added to DM to bind its calcium ions, while CaCl₂ was used as the donor of calcium ions. The content of calcium, lysozyme (LYZ) and lactoferrin (LF) as well as pH value were determined in all of the tested milk samples. DM samples showed varying degrees of antibacterial activity against the tested E. coli strains. The milk samples with higher calcium content possessed stronger antibacterial potential toward the tested bacteria. The determinated calcium-dependant antibacterial activity of DM was proved thorough addition of CaCl₂ and EDTA to DM. Calcium content in tested samples was in the range from 377.1 to 1,231 mg/l. The LYZ and LF in tested DM were present at concentrations between 0.98–3.74 g/l and 2.2–54.3 mg/l, respectively. LF was not detected in five of the tested samples, and pH values of the samples were in range from 7.11 to 7.25.