Improvement of sensory quality of lowfat kefalograviera-type cheese by using commercial special starter cultures

Two commercially available special starter culture systems, Alp DIP and a mixture of Alp DIP D and Joghurt V1, were compared with one commercial regular starter culture, CH-1, for their effects on the compositional, sensory and textural characteristics of lowfat (9.5%) high moisture (49.6%) Kefalograviera-type cheese during aging. A full-fat control Kefalograviera cheese (30.8% fat, 37.8% moisture) was also made with the regular starter culture. The results indicated that the type of starter did not affect the composition (moisture, fat, protein, salt and pH) of the lowfat cheese. Sensory analysis showed that the lowfat cheeses made with the special cultures received greater body and texture scores and significantly higher flavor scores than the lowfat control cheese after aging for 90 and 180 d. Moreover, the former cheeses received body and texture and flavor scores not significantly different from those of the full-fat cheese. Texture profile analysis by Instron showed that there were no significant differences in the textural characteristics (force and compression to fracture, cohesiveness, springiness, gumminess and chewiness) between lowfat cheeses made with the special cultures and that made with the regular starter, except for hardness which was significantly lower in the former cheeses.     

适于大豆干酪加工的乳酸菌发酵剂研究

以豆浆为发酵底物,对8株乳酸菌的凝乳性能进行了研究,检测了凝乳的黏度、酸度、双乙酰、胞外多糖和pH值为4.6可溶性氮含量,采用混合权重法对结果进行统计分析,得出凝乳性能的排序结果为Lb2→La→St1→Lb1→Sl→St2→Sc→Lc。此外,对8株乳酸菌的α-低聚半乳糖代谢能力进行了研究,乳杆菌代谢能力显著高于乳球菌。最后,优选出适于大豆干酪加工的乳酸菌发酵剂为St1和La。     

发酵乳制品中苯甲酸的来源及水平

论述了发酵乳制品酸牛乳、干酪中苯甲酸的来源及水平,对分析、预测发酵乳制品中苯甲酸自然形成量,并有效控制产品的安全质量提供参考。     

脱脂乳的不同热处理对其酸奶凝胶流变学性质的影响

研究了复原脱脂乳经不同加热处理后其酸奶凝胶形成过程中流变学特性的变化,复原脱脂乳经７０～９０℃处理１０～２５ｍｉｎ,用Ｄ－葡萄糖－δ－内酯酸化成胶,用流变学方法动态监测凝胶性能。并监测酸化过程和成胶时间,结果显示,不同条件下自理后的脱脂乳在酸化过程中,ｐＨ值并未改变,但产储存模量（Ｇ′）和损失模量（Ｇ″）随受质变程度的增加而增加,只是当加热温度为９０℃时反而随加热时间的延长而降低,在８５℃加热２５     

Effect of starter cultures on properties of soft white cheese made from camel (Camelus dromedarius) milk

This experiment was conducted to investigate the effect of starter cultures on the physicochemical properties, texture, and consumer preferences of soft white cheese (SWC) made from camel (Camelus dromedarius) milk. The experiment was laid out in a completely randomized design with 5 treatments [starter cultures; i.e., 1 thermophilic (STI-12), 2 blended (RST-743 and XPL-2), and 2 mesophilic (R-707 and CHN-22) cultures]. Starter cultures STI-12 and RST-743 were inoculated at 37°C, whereas XPL-2, R-707, and CHN-22 were inoculated at 30°C. Camel milk inoculated using STI-12 and RST-743 cultures resulted in faster acidification than XPL-2, R-707, and CHN-22 cultures. Camel milk SWC made using STI-12 and CHN-22 cultures gave lower pH (4.54) and titratable acidity (0.59), respectively, whereas R-707 culture resulted in high cheese yield (13.44 g/100 g). In addition, high fat (20.91 g/100 g), protein (17.49 g/100 g), total solids (43.44 g/100 g), and ash (2.40 g/100 g) contents were recorded for SWC made from camel milk made using RST-743 culture. Instrumental analysis of cheese texture revealed differences in resistance to deformation in which camel milk SWC made using RST-743 culture gave higher firmness (3.20 N) and brittleness (3.12 N). However, no significant difference was observed among camel milk SWC adhesiveness made using different starter cultures. Consumer preference for appearance, aroma, taste, and overall acceptances of SWC were affected by inoculation of starter cultures. Considering curd firmness, cheese yield, compositional quality, and textures using STI-12, RST-743, and R-707, these cultures were found to be better for the manufacture of camel milk SWC.     

Production and properties of a semi-hard cheese made from soya milk

Summary A semi-hard soya cheese, with mean moisture content 61.5%, crude protein 21.8% and fat 2.6%, was produced from reconstituted soya-milk powder using a starter culture of Streptococcus thermophilus and Lactobacillus fermentum . The physical properties of the cheese, as determined with a Texture Profile Analyser , were similar to a cheese made to the same compositional standards from bovine milk. A taste panel of Far Eastern subjects did not find the flavour of the fresh soya cheese acceptable but, when cubes of the cheese (1 cm³) were deep-fried in corn oil, the hedonic rating improved significantly. It is suggested that the cheese could be used as a protein-rich component of a meal, e.g. to replace meat in a stew, or as a 'snack food'.     

Kinetics of available lysine in stored commercial skim milk powder at moderate temperatures

Kinetics of lysine blockage, as an early step of the Maillard reaction, was investigated in commercial skim milk powder to understand the extent of the reaction, specifically after packages are opened and during the subsequent storage. Samples were stored at six conditions including three temperatures (30, 32.5 and 35 °C) and two relative humidities (43% and 52%) for 30 days, the period in which the product is recommended to be consumed after opening. The reaction rate was determined using a dye‐binding method. Based on our findings, decrease in available lysine follows first‐order reaction kinetics model. Small changes in temperature (2.5 °C) caused significant increase in the reaction rate constants. Relative humidity affected temperature dependency of the reaction, and activation energies were estimated to be 142.5–170.8 kJ mol^?1. This study aims to increase the awareness of the significance of storage quality in relation to the nutritional status of the products.     

Comparison of casein micelles in raw and reconstituted skim milk

During the manufacture of skim milk powder, many important alterations to the casein micelles occur. This study investigates the nature and cause of these alterations and their reversibility upon reconstitution of the powders in water. Samples of skim milk and powder were taken at different stages of commercial production of low-, medium-, and high-heat powders. The nature and composition of the casein micelles were analyzed using a variety of analytical techniques including photon correlation spectroscopy, transmission electron microscopy, turbidity, and protein electrophoresis. It was found that during heat treatment, whey proteins are denatured and become attached to the casein micelles, resulting in larger micelles and more turbid milk. The extent of whey protein attachment to the micelles is directly related to the severity of the heat treatment. It also appeared that whey proteins denatured during heat treatment may continue to attach to casein micelles during water removal (evaporation and spray-drying). The process of water removal causes casein and Ca in the serum to become increasingly associated with the micelles. This results in much larger, denser micelles, increasing the turbidity while decreasing the viscosity of the milk. During reconstitution, the native equilibrium between colloidal Ca and serum Ca is slowly reestablished. The reequilibration of the caseins and detachment of the whey proteins occur even more slowly. The rate of reequilibration does not appear to be influenced by shear or temperature in the range of 4 to 40°C.     

Seasonal variation in conjugated linoleic acid and vaccenic acid in milk fat of sheep and its transfer to cheese and ricotta

The seasonal variation in conjugated linoleic acid (CLA) and vaccenic acid (VA) concentrations in sheep dairy products and the extent of their transfer from milk fat to cheese and ricotta fat were investigated. Samples were collected from 2 sheep milk processing plants in North Sardinia (Italy) every 2 wk from March through June. Concentrations of fatty acids (FA) in fresh cheese and ricotta fat were primarily dependent on the fatty acid content of the unprocessed raw milk. The content of c9,t11-CLA averaged 1.73, 1.69, and 1.75 mg/100 mg of FA methyl esters (FAME), respectively, for milk, cheese, and ricotta, and differed significantly between cheese and ricotta. The content of VA averaged 3.40, 3.33, and 3.43 mg/100 mg of FAME, respectively for milk, cheese, and ricotta. The FA composition of dairy products was markedly affected by period of sampling: the mean c9,t11-CLA and VA concentration decreased from March (2.20 and 4.52 mg/100 mg of FAME) to June (1.14 and 1.76 mg/100 mg of FAME) in all dairy products. No differences in c9,t11-CLA and VA concentration of dairy products were observed between the 2 dairy companies obtaining milk from the same geographical origin. The seasonal changes in CLA and VA in milk fat were probably related to changes in pasture quality.     

Efficient removal of spores from skim milk using cold microfiltration: Spore size and surface property considerations

Bacterial spores present in milk can cause quality and shelf-life issues for dairy products. The objectives of this study were to evaluate the effectiveness of microfiltration (MF) in removing Bacillus licheniformis and Geobacillus sp. spores from skim milk using membranes with pore sizes of 1.4 and 1.2 µm, and to investigate the role of spore surface properties in MF removal. Cell sizes were determined by scanning electron microscopy, surface charge by zeta potential analysis, and surface hydrophobicity by contact angle measurements. Commercially pasteurized skim milk was inoculated with a spore suspension at about 10⁶ cfu/mL, and then processed by MF using ceramic membranes at 6°C, a cross-flow velocity of 4.1 m/s, and transmembrane pressure of 69 to 74 kPa. Total aerobic plate and spore counts in the milk were determined before and after MF. All processing runs and surface and product analyses were conducted in triplicate, and data were analyzed statistically. For the same strain, spores were shorter and wider than vegetative cells, averaging 1.37 to 1.59 µm in length and 0.64 to 0.81 µm in width. Reduction of B. licheniformis spores significantly increased with a reduction in MF pore size, from 2.17 log for 1.4-µm pore size, to 4.57 log for 1.2-µm pore size. Both pore sizes resulted in almost complete removal of Geobacillus sp. spores. All spores and the ceramic membrane had a negative surface charge at milk pH, indicating an electrostatic repulsion between them. Bacillus licheniformis spores were hydrophilic, whereas Geobacillus sp. spores were hydrophobic. Consequently, Geobacillus sp. spores had a tendency to cluster in skim milk, preventing their passage even through the 1.4-µm MF membrane, whereas some B. licheniformis spores could still pass through a 1.2-µm membrane. This study demonstrates that efficient removal of spores from skim milk by cold MF may require a smaller membrane pore size than required for removal of vegetative cells of the same species, and that cell surface properties may interfere with the outcome of filtration as would be anticipated based on size alone.     

南瓜胡萝卜发酵乳饮料的工艺研究

以南瓜、胡萝卜为主要原料,经预处理、软化、打浆等工序,添加各种辅料,采用单因素试验和响应面设计,确定南瓜胡萝卜发酵乳饮料生产的最佳配方和工艺条件.结果表明,饮料的最佳配方为南瓜汁70％,胡萝卜汁30％,脱脂乳粉2.5％,安赛蜜0.025％,复合稳定剂0.18％.饮料的最佳工艺条件为接种量3％,发酵温度42℃,发酵时间4h.     

Thermocalcic aggregation of milk fat globule membrane fragments from acid buttermilk cheese whey

Fragments originating from the milk fat globule membrane (MFGM), which is rich in polar lipids and membrane-specific proteins, are gaining interest for their functional and nutritional properties. Acid buttermilk cheese whey was used as a source for MFGM purification, because its MFGM content is more than 5 times higher than that of standard rennet whey. Because polar lipids are the main constituent of the MFGM and only occur in membranous structures, the polar lipid content was taken as a parameter for the total MFGM fragment content. The process of thermocalcic aggregation was evaluated on its recovery of MFGM fragments in the pellet. This method, originally intended for whey clarification and defatting, is a combination of calcium addition, a pH increase, and a thermal treatment. The influence of pH (6.5 to 8), temperature (40 to 70°C), and calcium concentration (0.1 to 0.24 g/100 g) on the pellet mass and dry matter (DM) content and on recovery of protein and polar lipids (and thus indirectly on MFGM fragments) was investigated by means of a response surface Box-Behnken orthogonal design. Reduced quadratic models were fit to the experimental data and were found to be highly significant. No outliers were observed. The recovery of MFGM fragments was found to be highly dependent on the pH, and less dependent on temperature and calcium addition. Next to MFGM proteins, whey proteins were also found to be involved in the formation of aggregates. Optimal conditions were found at 55°C, pH 7.7, and 0.205 g of calcium/L of whey. Under these conditions, 91.0% of the whey polar lipids were recovered in a firm and compact pellet of only 7.86% of the original whey mass, with a polar lipid concentration of 8.34% on pellet DM. Washing with water and centrifugation of the pellet was successful because after one washing step, virtually all sugars were removed, whereas 75.9% of the whey polar lipids could still be recovered. As such, the polar lipid content of the washed pellet increased to 10.70% on a DM basis. However, a second washing step resulted in serious losses of MFGM material.     

Composition, yield, and functionality of reduced-fat Oaxaca cheese: effects of using skim milk or a dry milk protein concentrate

The effect of adding either skim milk or a commercial dry milk protein concentrate (MPC) to whole milk on the composition, yield, and functional properties of Mexican Oaxaca cheese were investigated. Five batches of Oaxaca cheeses were produced. One batch (the control) was produced from whole milk containing 3.5% fat and 9% nonfat solids (SNF). Two batches were produced from milk standardized with skim milk to 2.7 and 1.8% fat, maintaining the SNF content at 9%. In the other 2 batches, an MPC (40% protein content) was used to standardize the milk to a SNF content of 10 and 11%, maintaining the milk fat content at 3.5%. The use of either skim milk or MPC caused a significant decrease in the fat percentage in cheese. The use of skim milk or MPC showed a nonsignificant tendency to lower total solids and fat recoveries in cheese. Actual, dry matter, and moisture-adjusted cheese yields significantly decreased with skim milk addition, but increased with MPC addition. However, normalized yields adjusted to milk fat and protein reference levels did not show significant differences between treatments. Considering skim milk-added and control cheeses, actual yield increased with cheese milk fat content at a rate of 1.34 kg/kg of fat (R = 0.88). In addition, cheese milk fat and SNF:fat ratio proved to be strong individual predictors of cheese moisture-adjusted yield (r² ≈ 0.90). Taking into account the results obtained from control and MPC-added cheeses, a 2.0-kg cheese yield increase rate per kg of milk MPC protein was observed (R = 0.89), with TS and SNF being the strongest predictors for moisture adjusted yield (r² ≈ 0.77). Reduced-fat Oaxaca cheese functionality differed from that of controls. In unmelted reduced-fat cheeses, hardness and springiness increased. In melted reduced-fat cheeses, meltability and free oil increased, but stretchability decreased. These changes were related to differences in cheese composition, mainly fat in dry matter and calcium in SNF.     

干酪风味物质的生成

干酪发酵中物质的生成来自于糖酵解(牛奶中的乳糖)、脂解以及蛋白质水解和肽水解过程中所涉及到的一系列生化化学反应，尤其是由发酵荆引起蛋白质(酪蛋白)发生酶降解导致重要风味成分的形成，这有助于干酪制品的感官特性。酪蛋白继续降解成肽和氨基酸，而氨基酸是挥发性风味化合物的前体，本文就从氨基酸产生风味物质的主要途径尤其是蛋氨酸、芳香族氨基酸和枝链氨基酸的代谢过程进行了综述。转氨酶启动的反应在风味形成方面有重要的作用，而α—酮戊二酸是LAB氨基酸代谢的关键中间媒介。     

Genotypic identification of some lactic acid bacteria by amplified fragment length polymorphism analysis and investigation of their potential usage as starter culture combinations in Beyaz cheese manufacture

In this study, 2 different starter culture combinations were prepared for cheesemaking. Starter culture combinations were formed from 8 strains of lactic acid bacteria. They were identified as Lactococcus lactis ssp. lactis (2 strains), Lactobacillus plantarum (5 strains), and Lactobacillus paraplantarum (1 strain) by amplified fragment length polymorphism analysis. The effects of these combinations on the physicochemical and microbiological properties of Beyaz cheeses were investigated. These cheeses were compared with Beyaz cheeses that were produced with a commercial starter culture containing Lc. lactis ssp. lactis and Lc. lactis ssp. cremoris as control. All cheeses were ripened in brine at 4°C for 90 d. Dry matter, fat in dry matter, titratable acidity, pH, salt in dry matter, total N, water-soluble N, and ripening index were determined. Sodium dodecyl sulfate-PAGE patterns of cheeses showed that α_S-casein and β-casein degraded slightly during the ripening period. Lactic acid bacteria, total mesophilic aerobic bacteria, yeast, molds, and coliforms were also counted. All analyses were repeated twice during d 7, 30, 60, and 90. The starter culture combinations were found to be significantly different from the control group in pH, salt content, and lactobacilli, lactococci, and total mesophilic aerobic bacteria counts, whereas the cheeses were similar in fat, dry matter content, and coliform, yeast, and mold counts. The sensory analysis of cheeses indicated that textural properties of control cheeses presented somewhat lower scores than those of the test groups. The panelists preferred the tastes of treatment cheeses, whereas cheeses with starter culture combinations and control cheeses had similar scores for appearance and flavor. These results indicated that both starter culture combinations are suitable for Beyaz cheese production.     

Filtration of milk fat globule membrane fragments from acid buttermilk cheese whey

The proteins and polar lipids present in milk fat globule membrane (MFGM) fragments are gaining attention for their technological and nutritional properties. These MFGM fragments are preferentially enriched in side streams of the dairy industry, like butter serum, buttermilk, and whey. The objective of this study was to recover MFGM fragments from whey by tangential filtration techniques. Acid buttermilk cheese whey was chosen as a source for purification by tangential membrane filtration because it is relatively rich in MFGM-fragments and because casein micelles are absent. Polyethersulfone and cellulose acetate membranes of different pore sizes were evaluated on polar lipid and MFGM-protein retention upon filtration at 40°C. All fractions were analyzed for dry matter, ash, lipids, proteins, reducing sugars, polar lipid content by HPLC, and for the presence of MFGM proteins by sodium dodecyl sulfate-PAGE. A fouling coefficient was calculated. It was found that a thermocalcic aggregation whey pretreatment was very effective in the clarification of the whey, but resulted in low permeate fluxes and high retention of ash and whey proteins. By means of an experimental design, the influence of pH and temperature on the fouling and the retention of polar lipids (and thus MFGM fragments), proteins, and total lipids upon microfiltration with 0.15 μM cellulose acetate membrane was investigated. All models were highly significant, and no outliers were observed. By increasing the pH from 4.6 to 7.5, polar lipid retention at 50°C increased from 64 to 98%, whereas fouling of the filtration membrane was minimized. A 3-step diafiltration of acid whey under these conditions resulted in a polar lipid concentration of 6.79 g/100 g of dry matter. As such, this study shows that tangential filtration techniques are suited for the purification of MFGM fragments.     

Classification of Swiss cheese starter and adjunct cultures using Fourier transform infrared microspectroscopy

The acceptability of Swiss cheese largely depends on the flavor profile, and strain variations of cheese cultures will affect the final quality. Conventional biochemical methods to identify the cultures at the strain level are time-consuming and expensive, and require skilled labor. Our objective was to develop rapid classification methods of starter cultures at the strain level by using a combination of hydrophobic grid membrane filters and Fourier transform infrared (FTIR) spectroscopy. Forty-four pulsed-field gel electrophoresis-verified strains of starter and nonstarter cultures including Streptococcus thermophilus, Propionibacterium freudenreichii, and Lactobacillus spp. were analyzed. The strains were grown on their respective agar media, transferred to broth media, and incubated. Then, cultures were centrifuged and the pellets were resuspended in saline solution (10 μL). Aliquots (2 μL) of the suspended bacterial solution were placed onto a grid of the hydrophobic grid membrane filters, having 6 grids per each strain analyzed. The dried filters were read by FTIR microspectroscopy fitted with an attenuated total reflectance probe. Collected spectra were statistically analyzed by a soft independent modeling of class analogy (SIMCA) for pattern recognition. Classification models were developed for Streptococcus thermophilus, Propionibacterium freudenreichii, and Lactobacillus spp. strains. The models showed major discrimination in the spectral region from 1,200 to 900 cm⁻¹ associated with signals from phosphate-containing compounds and various polysaccharides in the cell wall. The developed method allowed for rapid classification of several Swiss cheese starter and nonstarter cultures at the strain level. This information provides a detailed overview of microbiological status, which would enable corrective measures to be taken early in the cheese making process, limiting production of inferior quality cheese and minimizing defects. This method could be an effective tool to identify and monitor activity of cheese and other dairy starter cultures.     

Influence of calcium salt supplementation on calcium equilibrium in skim milk during pH cycle

Calcium is a mineral essential for humans, especially for bone constitution. Yet most of the worldwide population does not satisfy their Ca needs. Hence, Ca supplementation is of major importance, even in western countries where some specific populations at risk do not satisfy the recommended daily intake of Ca. More than 70% of dietary Ca comes from dairy products. Calcium supplementation of naturally Ca-rich sources such as skim milk is then of special interest. To our knowledge, few data are available concerning milk Ca (MC) supplementation of milk, particularly when followed by pH cycle. In this paper, MC supplementation is studied and compared with Ca chloride (CC) supplementation as a well-known source of Ca. The effect of Ca salt supplementation followed by pH cycle was studied in reconstituted skim milk. Calcium supplementation was carried out with CC and MC at 25 mmol of Ca/kg of skim milk. Ionized Ca concentration and turbidity variations were followed in situ by Ca ion selective electrode and turbidimetry using light reflection. From normalized data on ionized Ca concentration and turbidity vs. pH, it appeared that hysteresis areas were smaller for CC-supplemented milk, whereas unsupplemented milk and MC-supplemented milk behaved similarly. For these 3 dairy systems, pH cycles to pH 5.0 led to a larger hysteresis area than pH cycles to pH 5.5. The shrinkage of the hysteresis area could be interpreted as a reinforcement of casein micelles with Ca ions over the pH cycle.     

Diversity and dynamic of lactic acid bacteria strains during aging of a long ripened hard cheese produced from raw milk and undefined natural starter

The aim of this study was to explore diversity and dynamic of indigenous LAB strains associated with a long ripened hard cheese produced from raw milk and undefined natural starter such as PDO Grana Padano cheese. Samples of milk, curd, natural whey culture and cheeses (2nd, 6th, 9th and 13th months of ripening) were collected from 6 cheese factories in northern Italy. DNA was extracted from each sample and from 194 LAB isolates. tRNA^Ala-23S rDNA-RFLP was applied to identify isolates. Strain diversity was assessed by (GTG)5 rep-PCR and RAPD(P1)-PCR. Finally, culture-independent LH-PCR (V1–V2 16S-rDNA), was considered to explore structure and dynamic of the microbiota. Grana Padano LAB were represented mainly by Lactobacillus rhamnosus, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus delbrueckii, Lactobacillus helveticus and Pediococcus acidilactici, while the structure and dynamic of microbiota at different localities was specific. The strength of this work is to have focused the study on isolates coming from more than one cheese factories rather than a high number of isolates from one unique production. We provided a valuable insight into inter and intraspecies diversity of typical LAB strains during ripening of traditional PDO Grana Padano, contributing to the understanding of specific microbial ecosystem of this cheese.     

Transfer of melamine from feed to milk and from milk to cheese and whey in lactating dairy cows fed single oral doses

A study was conducted to evaluate the excretion pattern, after a single oral dose, of melamine from feed into milk, and the subsequent transfer to cheese and whey. The transfer of cyanuric acid was also investigated. Twenty-four lactating Holstein cows were randomly allocated to 4 treatments and received single doses of melamine as follows: 0.05, 0.50, 5.00, and 50.00 g/cow for groups D1, D2, D3, and D4, respectively. Individual milk samples were collected for melamine and cyanuric acid analyses on d 1, 2, 3, 4, 5, and 7. Milk collected individually from the second milking after melamine ingestion was used to make cheese on a laboratory scale. Melamine and cyanuric acid were extracted using a solid-phase extraction cartridge, and analyses were carried out by liquid chromatography-mass spectrometry/mass spectrometry. Maximal melamine concentrations occurred between 6 and 18 h after treatment and increased with log dose (linear and quadratic), ranging from 0.019 to 35.105 mg/kg. More than 60% of the melamine that was transferred to the milk was observed within 30 h after melamine ingestion. Melamine was not detected (limit of detection was 0.002 mg/kg) in milk 5 d after treatment in group D1, and 7 d after treatment in groups D2, D3, and D4. Blood urea nitrogen was not influenced by melamine ingestion. During cheese making, melamine was transferred mainly to the whey fraction. Cyanuric acid was not detected in any of the samples (milk, cheese, or whey). The excretion pattern of melamine in milk and whey may represent a health concern when cows ingest more than 0.50 g of melamine/d. However, only at intake levels of 5 and 50 g/d did cheese exceed the limits as set forth by the European Union. The results confirmed that melamine contamination of milk and milk products may be related not only to direct contamination, but also to adulteration of animal feeds.