Dairy Products 101:
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Frequently Asked Questions

In March of 1992, the FDA Division of Regulatory Guidance issued an opinion letter after 18 months of study, that a product “made by the removal of non-protein components such as lactose, water, and minerals from skim milk by the ultrafiltration procedure, thereby concentrating the protein components to higher levels” could be called a milk protein concentrate. In the same writing, the FDA supplied a further description by stating that the milk protein concentrate should contain protein representative “of all the fractions of milk proteins in the same ratio as they are found naturally occurring in milk.” Although there is no official, legal identity for a milk protein concentrate in the Code of Federal Regulations, the above definition is the FDA’s intention for an identity of MPC.

There are some MPC’s being offered in the USA today that do not fit within the identity stated above. There are MPC’s being offered today that are mixtures of caseinates and whey protein concentrates. There are also mixtures of caseinates and skim milk that are being offered as MPC. Be very careful to ensure that your ingredient is true, filtered MPC within the spirit of the FDA opinion.

Cow’s milk contains a balance of the casein proteins and the soluble serum proteins, more commonly known as whey proteins. Typically, milk from Idaho Milk Products' cows will contain approximately 82% casein and 18% whey proteins along with a small amount of Non-Protein Nitrogen compounds. A well manufactured MPC/MPI will contain a ratio of casein to whey proteins of about 82% casein and 18% whey proteins. Much of the non-protein nitrogen compounds (e.g., urea, creatinine, ammonia compounds, and uric acid) are separated away from the casein and whey proteins during ultrafiltration and can be found in the milk permeate.

The casein proteins derive their name from the Latin word for cheese, “caseus”. It’s easy to surmise that caseins are the group of milk proteins that precipitate out as a curd during cheese manufacture. Whey proteins are so named because they are the group of proteins that remain soluble during cheese manufacture and are found in the cheese whey. In a well manufactured MPC/MPI, the caseins will be present in their natural, native milk structure, known as a micelle. A well manufactured MPC/MPI will also contain a high quantity of whey proteins that have not been damaged (denatured) by heat or chemicals.

The word “micelle” is a chemical term. It is used to describe the structure that certain very large molecules will form when dispersed in a solvent. Believe it or not, water is considered to be a solvent (chemicals are made soluble in water). Very large molecules are considered to be too large to be truly soluble in water. Instead, these large molecules will form structures that allow them to remain suspended in water as if they are soluble. The dispersion of these large structures in water is known as a colloidal suspension. The structures that allow large molecules to remain colloidally suspended in water are termed micelles. Under an electron microscope, micelles often look like little spheres. In the case of casein, the parts of the casein molecules that have an affinity for water form the outside of the casein micelle. Conversely, the parts of the casein molecule that are repelled by water form the inner core of the micelle spheres.

When casein molecules are manufactured by a mammal, they are manufactured in water (cow’s milk is 88% water). As the casein molecules are formed, they begin folding up into a spherical micelle structure so that the casein proteins can remain suspended indefinitely in the milk water. Along with the casein proteins in the micelle, important milk minerals, such as calcium and phosphorous also become bound inside the micelle. The micelle structure of casein is its natural structure. The micelle structure can be easily disrupted or changed – by addition of acid or alkali to milk – or by extreme heat exposure. Products such as acid casein, rennet casein and any and all caseinates no longer contain casein in its micelle form. These products are all manufactured in such a way that the micelle colloidal suspension in milk has been destroyed. Once a casein micelle is destroyed, it will not re-form. Over the years many attempts have been made to rebuild casein micelles after they have been destroyed. To date, nobody has been successful.

Casein in its micellar form is a unique molecular structure. When we consume micellar form casein, a “bolus” (a large curd) is formed in our stomach as the micellar casein reacts with gastric juices in the stomach. The bolus takes on a unique structure also. Our stomachs and upper intestines produce enzymes to help speed up digestion of food. Some of these enzymes are “site specific” … meaning that they will only act on specific sites of a molecule when that molecule is in a specific structure. These specific enzymes fit into molecular structures much as a specific key fits into a specific lock. Specific digestive enzymes will act on casein micelles to produce bioactive peptides from micellar casein. Some of these peptides will have immunomodulatory properties. Others will have antibacterial properties. Examples of peptides produced from consumption of micellar casein are:

  • Glycomacropeptide (GMP) – produced when kappa-casein is hydrolyzed at one specific peptide bond, between amino acids 105 and 106. The smaller peptide that is formed from amino acids 106 through 169 is GMP. When the stomach detects the formation of GMP, a hormonal cascade begins. The body produces cholecystokinin (CKK) a chemical that signals the brain of satiety and suppresses appetite. GMP has also been shown to enhance the absorption of calcium and zinc. GMP has been shown to inhibit platelet aggregation in our veins and arteries, thereby helping to prevent arteriosclerosis.
  • Casomorphins – These are peptides cleaved from micellar casein during digestion that elicit an opioid effect in the body. They have been shown to travel to the brain and can have a calming, tranquilizing effect. They have also been shown to be antihypertensive and, as such, are under investigation as a natural blood pressure control agent. Casomorphins can also act to slow motility of the small intestine, thereby allowing food to linger longer for maximum absorption of nutrients in the food.
  • Casein-Phospho-Peptide (CPP) – These peptides contain high levels of calcium and phosphorous. They are easily absorbed into the bloodstream and, therefore, carry large quantities of calcium and phosphorous into the bloodstream. Since calcium (of the form as found in milk) and phosphorous are the building blocks of our skeletal system, it can be said that CPP helps to build strong bones. In Asia, CPP is used as a preventative against osteoporosis.

Along with the bioactive peptides that form when micellar casein is consumed, there are other study proven benefits. Micellar casein is the only protein that has ever been shown to be anticatabolic (Boire et. al. 1997) – meaning that micellar form casein will help prevent oxidative breakdown of muscle tissue during and after intense exercise. Consumption of micellar casein results in prolonged periods (up to 7 hours) of elevated amino acids in the bloodstream, thereby allowing the body to repair and build muscle tissue after exercise for prolonged periods of time.

No. The metabolic benefits attributed to micellar casein consumption will not automatically transfer over to casein/caseinate consumption. As stated in the response above, many of the digestive enzymes are site specific and require a certain structure to perform. Acid casein and/or rennet casein have already been precipitated as a curd from milk as part of their manufacture. The casein micelle structure has already been destroyed in acid casein, rennet casein, and caseinates before you consume them. Therefore, when casein or caseinates hit the gastric juices in the stomach, they may or may not form a “bolus” structure that is compatible with the site specific enzymes. There is no guarantee that the array of bioactive peptides and anticatabolic activity of micellar casein will be exhibited after consumption of casein and/or caseinates.

Milk Protein Concentrate (MPC) and Milk Protein Isolate (MPI) is usually sold as a fine, white powder. In water, MPC/MPI forms a white, opaque dispersion of low viscosity – looking very similar to milk. MPC/MPI will remain suspended for prolonged periods of time in water. A well manufactured MPC/MPI will have no odor and a bland flavor profile. In water, a 10% dispersion of MPC/MPI has a smooth, creamy mouthfeel.

If you’re confused, you’re not alone! When speaking of protein contents, the only protein content (powder or liquid) that should concern a food processor is the “as is” protein content. Many protein manufacturers try to make their protein powder compositions look better by providing a “dry basis” protein content – the percent of protein based on total solids present, excluding water. All spray dried powders, however, contain some water content – usually about 4% to 5%. Therefore, a stated “dry basis” protein content of 90% in the average powder means that 90% of the 95% solids in that powder is protein (90% x 95%) which equals values anywhere from 85.5% to about 86.5% protein that is in the powder as you will be using it (otherwise known as the “as is” protein content). You want to know the “as is” protein content of the powder that you will be using because that is the protein content “as you will be using” the powder. When you compare protein contents of powders, be sure to compare the “as is” values. Do not compare a 90% “dry basis” value with an 85% “as is” value and think that you’re getting a much better buy with the 90%. Chances are that powder really only has an “as is” protein content of about 86%.

In many cases, yes. You will probably find that IdaPro MPC/MPI delivers a better flavor and more soluble mouthfeel than other MPC/MPI powders. For example,  manufacturers of high protein Ready to Drink products have found that they can decrease added flavoring levels and decrease stabilizing salt levels when they use IdaPro MPC/MPI powders compared to other MPC/MPI sources.

They still maintain excellent product flavor and prolonged shelf life stability while decreasing ingredient costs. Just as with RTD products, in many other  applications IdaPro MPC/MPI powders will significantly improve sensory properties while decreasing cost.

Casein is manufactured by adding acid to warm skim milk. As the pH of the skim milk lowers to the range of 4.2 to 4.6, the casein precipitates out of the skim milk as a curd. The casein curd is then washed repeatedly with acidified fresh water to “purify” the casein (wash away unwanted, occluded milk solids such as fat and lactose). Because the casein curd is kept at an acid pH, the milk minerals are leached out of the protein. The result is a relatively pure protein curd (96% protein on a dry basis).

This casein curd, however, is not very useful in food products. Acid casein (as the curd is known) is insoluble in water, behaving much like sand. In order to make the casein curd more useful in food products, the acid casein curd is reacted with a strong alkali to result in an almost neutral protein product termed a caseinate. The type of alkali used to neutralize the acid casein curd will determine what type of caseinate is produced. For example, reacting acid casein curd with sodium hydroxide (to a pH of about 6.8) results in the formation of sodium caseinate. Reacting acid casein curd with calcium oxide or calcium hydroxide (to pH 6.8 to 7.6) results in the formation of calcium caseinate. Sodium caseinate is the most water soluble form of caseinate. Sodium caseinate typically forms high viscosity water dispersions, has an amber color in water, and imparts a “glue-like sodium” flavor. Sodium caseinate is the basis of simple glues. Calcium caseinate forms a low viscosity, opaque, off white dispersion in water. Calcium caseinate is usually the least water soluble of the caseinates and tends to sediment out of suspension within hours of being mixed into water. Whereas sodium caseinate will exhibit a smooth mouthfeel when dispersed in water, calcium caseinate will exhibit a slightly gritty or grainy mouthfeel. There are also sodium calcium caseinates, calcium sodium caseinates, and even calcium ammonium caseinates. The levels of each mineral are determined by the ratios of alkali used in the caseinate manufacture. The higher the sodium content, the higher the viscosity and water solubility. The higher the calcium content, the lower the water viscosity and solubility. Potassium caseinate possesses properties similar to sodium caseinate and magnesium caseinate possesses properties similar to calcium caseinate.

The process of manufacturing acid casein and/or caseinates does extensive damage to the proteins. Some of the “damage” causes off flavors to develop. Dried acid casein, for example has a very strong, objectionable odor and flavor that is difficult to cover up. Although much work is performed to decrease or eliminate these objectionable casein flavors when manufacturing caseinates, most people would agree that caseinates still possess strong objectionable, flavors – usually these flavors are described as “cow-ey”, “barny”, “gluey”, and “livestock”.

Milk Protein Concentrate and Isolate, on the other hand, is manufactured by a gentle process. At Idaho Milk Products, our MPC/MPI is manufactured at cold temperatures. We do not add chemicals* to the milk and the milk does not undergo pH changes. The milk protein is separated out of skim milk using filtration techniques. MPC/MPI typically contains high levels of milk calcium, phosphorous, potassium, and magnesium. These minerals are bound to the protein. Milk protein concentrate and isolate typically have no odor and a very bland flavor profile. Milk protein concentrate and isolate typically contain about 82% casein and 18% whey proteins. These proteins are present in MPC/MPI in the natural (Native), undamaged (undenatured) state.

*see FAQ titled "Are any additives used during the filtration process when producing MPI-85 Low Lactose?"

In most cases, yes, you can use IdaPro MPC/MPI to replace casein and/or caseinates in food formulations.

Obviously, since MPC/MPI forms water dispersions that are most similar in appearance to calcium caseinate, one can easily substitute MPC/MPI into any calcium caseinate application. Usually, substituting MPC/MPI for calcium caseinate will result in an improvement in food product quality as MPC/MPI is more water soluble/suspendable than calcium caseinate, imparts a creamier mouth feel, and has a more preferable flavor profile compared to calcium caseinate. Many people use calcium sodium caseinates to gain a better mouth feel and better water solubility (compared to calcium caseinate). MPC/MPI is very comparable to the best calcium sodium caseinates and even many sodium calcium caseinates in solution appearance, suspension stability, mouth feel, and viscosity. MPC/MPI also has a cleaner, blander flavor than calcium sodium caseinate or sodium calcium caseinate. Even though sodium caseinate is the least similar to MPC/MPI, one can still replace sodium caseinate with MPC/MPI in many applications. MPC/MPI has been used to replace or extend sodium caseinate in coffee whiteners, whipped toppings, and cheese analog products.

The amount of rennet casein that can be replaced with MPC/MPI depends on the type of processed cheese application and the expertise of the manufacturer. In general, almost every manufacturer should be able to replace one-third of their rennet casein requirement with MPC/MPI without any noticeable changes in product quality.

If one replaces too much rennet casein, the most noticeable effect would be a softening of product texture or a significant change in melt rate and spread of the cheese product. MPI-85 would be the most logical product to use when replacing rennet casein. The protein content of MPI-85 is almost identical to the protein content of rennet casein and, therefore, would be a direct substitute for rennet casein without the need of adjusting the formula to meet required protein/fat ratios.

IdaPro MPC/MPI is best used in processed cheese or analog cheese applications to replace caseinates. As stated in the answer to the question above, MPC/MPI can only be used to replace a percentage of rennet casein in those applications before changes in product texture or melt properties become significant. In those non-specific processed cheeses and cheese analog products that use caseinate, however, MPC/MPI can completely replace the caseinate as the protein base of the product without loss of product properties.

The term, Milk Protein Concentrate, was modeled after the already existing name for protein that had been concentrated from cheese whey by ultrafiltration, Whey Protein Concentrate (WPC). In spite of the fact that MPC (and MPI) is significantly different from WPC, many people today continue to confuse the two. As per the FDA opinion, a Milk Protein Concentrate should contain all of the proteins that are naturally found in milk and these proteins should be found in an MPC in the same ratios as they are naturally found in milk. Since cow’s milk contains approximately 80% to 82% casein and only 18% to 20% whey proteins, it’s easy to understand that MPC (and MPI) contains only a small amount of whey protein.

WPC (and also WPI), on the other hand, contains 100% whey proteins … by definition, there is no casein present in WPC. MPC forms a milk white suspension when dispersed in water. WPC (and WPI) form somewhat clear, brownish tinted dispersions in water. Aqueous dispersions of MPC/MPI have a bland or creamy flavor. Aqueous dispersions of WPC tend to have a slightly astringent flavor due to the high levels of sodium, potassium, and chlorine. Do not confuse MPC or MPI with WPC or WPI. They are significantly different in all respects – nutritionally, compositionally, and functionally. Yet, IdaPro MPC/MPI powders can be used to replace whey proteins in nutritional applications without issue.

Yes. Flavor, texture, and functional properties of MPC/MPI powders can vary between manufacturers. Factors such as milk freshness, aggregate exposure to heat, and processing temperatures will all play an important role in sensory quality, water solubility, and functional properties of powders. IdaPro MPC/MPIs are manufactured from the freshest milk and are exposed to a minimum of heat during processing. As a result, IdaPro MPC/MPI powders display superior properties compared to other powders.

 

Even at refrigerated temperatures, as milk sits around, reactions occur. Calcium and phosphorous will react with each other to form insoluble calcium phosphate salts and they will also react with the casein and whey proteins to decrease protein solubility. Fat in the milk will hydrolyze and oxidize, modifying the flavor characteristics of all of the milk ingredients. While these reactions may not be visible at the time of processing, they will affect shelf life and the functional properties of MPC powder.

At Idaho Milk Products our IdaPro MPC and MPI powders are made from the freshest milk in the world.

To begin the manufacturing process, milk is collected at dairy farms that belong to and are completely under the control of our farmer-owners. These farms are all within a 45 minute transport drive from our processing facility. The milk is immediately cooled to refrigeration temperatures at the dairy farms and stored under refrigeration until it is soon collected for transport to the facility. From the milking parlor forward, the milk is maintained in a hygienic, closed loop system (i.e., is not exposed to air) until the finished product is packaged at the facility.

Under our normal operating procedures, less than 24 hours will elapse between milking of the cows and final packaging of the finished MPC/MPI/MPP powders. In other factories around the world, the milk used is at least 24 hours old before the factories begin the manufacturing process. That is why independent lab testing has shown that IdaPro MPC/MPI powders have superior solubility and sensory properties compared to the competition.

Yes. Different manufacturers follow their own, unique processing methods. Just as milk powders can vary in heat exposure and heat damage from one manufacturer to another, MPC can vary from one manufacturer to another. Milk powders are graded according to their heat exposure/damage by assaying the powders for undenatured whey protein nitrogen. The powders are usually classified into low heat (treatment), medium heat (treatment), or high heat (treatment) classifications.

A low heat powder would have the least damage from heat while a high heat powder would contain very little or no undenatured whey protein. The same testing methods can be used to compare heat exposure/damage of MPC powders. The Hungarian Dairy Research Institute, pioneers of MPC manufacture, compared Idaho Milk Products MPC-80 to competitive international brands. They used the American Dairy Products Institute (ADPI) Method for Determination of Undenatured Whey Protein Nitrogen in Nonfat Dry Milk (modified to reflect the higher protein content of MPC) to compare heat exposure of the varying MPC powders.

By the ADPI testing method, a low heat milk powder is considered to contain a minimum of 6.0 mg undenatured whey protein nitrogen per gram of powder. A medium heat milk powder will contain from 1.51 to 5.99 mg undenatured whey protein nitrogen per gram of powder and a high heat milk powder contains 1.50 mg undenatured whey protein nitrogen or less per gram of milk powder. The results showed that Idaho Milk Products MPC-80 had been exposed to significantly less heat than the competitive powders, yielding undenatured whey protein nitrogen values (15 mg per gram of powder) that were almost double that of the next nearest competitor (8 mg per gram of powder). Idaho Milk Products’ MPC-80 had 2.5 times the undenatured whey protein of the average competitor MPC (6 mg per gram of powder). At least half of the competitive MPC powders tested assayed as medium heat powders.  The same proprietary low heat process is used in the production of IdaPro Milk Protein Concentrates and Isolates resulting in higher quality, undenatured proteins.

Yes. The degree of heat exposure will determine the solubility of the whey proteins in MPC/MPI and the stability of casein micelles over time. High heat exposure denatures almost all of the whey proteins in MP/MPI and initiates casein micelle aggregation, eventually resulting in a loss of solubility. A low heat MPC/MPI will contain higher amounts of undenatured, biologically active whey proteins and should have a longer shelf storage life. In general, one can say that a low heat powder will be more water soluble (the proteins are not heat denatured and aggregated) and have better sensory properties (whiter in color and lower levels of off flavors). High heat powder, in contrast, will be the least soluble.

High heat powders are used in the baking industry, where use of casein is desired for providing extra volume to baked goods, while whey proteins, if undenatured when included in the recipe, will decrease baked goods volume as they heat denature during baking. Medium heat powder, the most common type of powder because it is the easiest to manufacture, can be used in reconstituted milk beverages and as protein fortification of most food products. Wherever medium heat powder is used, low heat powder will do a better job. In high protein, UHT processed Ready to Drink beverages, for example, shelf life can be extended when starting with low heat MPC/MPI because of a complex formed between undenatured beta-lactoglobulin and kappa-casein during UHT treatment that has been shown to make the casein micelles more resistant to storage gelation.

Low heat powder also has a huge advantage over medium and high heat powders in nutritional applications. Whey proteins are renowned for their health providing benefits. Not many people, however, are aware that all of these health benefits apply only to native, undenatured whey proteins. High heat powders, therefore, would possess little or no whey protein health benefits.
By the same logic, medium heat powders possess less whey protein health benefits than low heat powders. The fact that IdaPro MPC-80 and MPI-85 have a significantly higher quantity of undenatured whey protein than any other MPC/MPIs tested make our products ideal for use in Nutritional applications.

First, it is necessary to understand that high heat NFDM is only required for use in some baking applications … not all baking applications. In certain baking applications, high heat treated milk powder is required because whey proteins, in low heat treated powders, that denature during the baking process will interfere with desired final properties of the baked goods. This is not the case, however, for all baked goods … only some baked goods. In many baking applications, medium heat and low heat milk powders can be used as the milk powder ingredient. It is in those applications where our MPC powder can be used as a substitute ingredient for skim milk powder. Also, MPC may be used as a substitute for high heat skim milk powder in some baking applications.

Yes. All high protein powders experience degrading chemical reactions as they age. When MPC/MPI powder ages, reactions such as residual fat hydrolysis, loss of solubility, and Maillard browning will continually progress. These chemical reactions are fueled by the concentration of the milk proteins in close proximity with milk minerals and remaining sugar as well as residual lypolytic and proteolytic activity. Such reactions have a negative effect on protein powder properties. For example, the Maillard Reaction, or sometimes it is more commonly known as the Maillard Browning Reaction, is a chemical reaction between an amino acid (or hydrolyzed protein peptides) and a reducing sugar (in the case of milk, lactose). The two molecules form a new compound that is significantly altered from a simple amino acid and a simple sugar. The new compound may exhibit lower water solubility than either of the two chemicals separately.

The new compound may also impart a new flavor and in many cases, the new flavor can be overpowering.

There are also numerous studies that show that MPC/MPI powders lose solubility on storage. The leading theory is that calcium and phosphorous in the MPC/MPI powder will react with the proteins and cause a loss of protein solubility. In addition, dairy powders contain residual levels of native milk enzymes. These enzymes will, over time, hydrolyze fat and protein in powders and can cause formation of bitter fatty acids and/or bitter protein peptides. The newly formed fatty acids and peptides will detract from the fresh, bland flavor of the powder and could even affect overall protein solubility.

It is important to utilize the freshest MPC/MPI powders available to ensure that your products will have maximum shelf life. Most MPC powders sold in the US are manufactured overseas. By the time these powders clear US ports, they are months old. Idaho Milk Products manufactures IdaPro MPC/MPI powders domestically and on a make to order basis. IdaPro MPC/MPI powders can be delivered anywhere within North America within weeks of manufacture, thus ensuring that your food products will exhibit the best sensory, solubility, and maximum shelf life properties. These properties are very important in ingredient sensitive applications such as Ready to Drink protein beverages. In such applications, the solubility of the protein will affect shelf stability (beverage gelling or clotting) and the MPC/MPI flavor will affect how much flavor and what type of flavor needs to be added to manufacture a pleasant tasting consumer product. Fresh MPC/MPI powders are essential ingredients for manufacturing the best Ready to Drink clinical, adult, and sports nutrition protein beverages. IdaPro MPC/MPI powders are the freshest available in North America.

To understand seasonal variation of cow’s milk, one first needs to understand that all cow’s milk is produced by a cow as part of the mammalian lactation cycle for feeing of infant mammals.

Once a cow begins the pregnancy cycle, the lactation cycle begins. When a calf is birthed (as with all mammal births) the mother cow begins to produce milk. For the first 48 hours, the milk is not what most people would think of as “milk” … it is a somewhat clear liquid that is called colostrum. Colostrum contains mostly whey protein fractions to support the baby’s immune system such as lactoferrin, immunoglobulins, and even growth factors (because most mammals are born with a low functioning immune and hormonal system). The colostrum gives mammal newborns a “jumpstart”. Over the first 48 hours, the mother’s milk changes rapidly in composition. The casein levels increase and whey protein levels decrease. After 48 to 72 hours, cow’s milk becomes much closer to the appearance and definition of what we consumers think of as cow’s milk. What people don’t realize, however, is that cow’s milk continues to change in composition throughout the entire lactation cycle of the mother cow. Because the composition of milk does not remain constant throughout the milking season, manufacturers who use milk proteins as ingredients in their applications notice these changes. It is these changes in the milk composition that can cause numerous formulation headaches for end users. See the graph below for a general overview of the changes in milk production through a season.

Within the first 4 to 8 weeks of a cow’s lactation cycle, the volume of milk builds up rapidly, leading to a peak volume. Then, after approximately 10 weeks, the milk volume per cow starts to decrease. Throughout the remainder of the season, milk volume continues to decrease. At the beginning of the season, during the build up and peak volumes, the milk is higher than normal in whey protein content. Higher whey protein levels can cause discoloration of the MPC
powder, decreases in MPC viscosity, decreases in MPC heat stability, gellation during heat processing or lower solubility after heat processing, and poor quality cheese curd or yogurt gels manufactured from the MPC. In the middle of the milking season, the composition is much as would be expected from textbook descriptions of milk. As the season winds down however, the whey protein content continues to decrease and the casein portion increases. At the same time the mineral content of the milk begins to increase, especially those minerals that are known to “interfere” with the desirable functional properties of milk proteins. As the milk minerals increase, MPC functional properties will again change. Viscosities will modify (either higher or lower depending on your formula), the mouth feel of the MPC will become less smooth (more grainy), the MPC will exhibit decreased solution stability in the presence of added minerals, stability after high heat pasteurization could become more pronounced, and MPC used in cheese or yogurt will again exhibit different curding characteristics. Anyone who has ever made Ready to Drink UHT milk based beverages knows that such changes in milk composition pose tremendous challenges for production crews – higher than expected whey protein contents can lead to heat gellation and/or lower solubility of the protein, while higher than expected mineral levels can result in diminished solubility/suspendability of the protein.

 

Yes, through proper herd management. It is possible to maintain a consistent balance in a dairy herd of the numbers of cows at all stages of the lactation cycle by practicing what is known as “herd rotation” – at any time during the 12 month calendar year, the same number of cows are at all stages of lactation, resulting in a consistent composition of milk coming from that herd.

The farmer/owners of Idaho Milk Products are not seasonal dairy farmers. Our owners “rotate” their herds so that roughly the same number of cows are calving and lactating throughout the year and milk production remains relatively constant. The resultant milk used in our factory therefore remains relatively constant in composition. The advantage for you, the end user, is that you will receive an IdaPro MPC/MPI with the same functional properties in January, June and November. Your production will proceed with fewer problems and your product quality will be consistent at the levels you desire throughout the year.

True rotation of herds is only possible, however, when the cows are fed the same feed supply throughout the year. Of all of the dairy regions of the world, the only region that practices wide scale formula feeding of the dairy herds is the Western USA. Throughout the North Central and Eastern USA as well as in Europe and in Oceania, cows are pasture grazed. The pastures are not always ideal for grazing during certain times of the year. This is when farmers in these regions usually let their cows “dry up”. Have you heard other milk protein vendors talk about the “new season” or “next season”? They are actually talking about the seasonality of their milk supply. In every country other than the US, manufacture of milk proteins has a definite season. In Europe the season begins in March and extends to November. In Oceania, the season begins in October and extends to April/ May, depending on how fast the cows start drying up. Throughout the 8 or so months that these regions milk their cows for the manufacture of proteins, the composition of their milk changes. As we have seen above, changes in milk composition result in production problems for manufacturers.
 

Yes, feed composition is a large determinant factor of cow’s milk quality/ consistency. Have you heard the old saying … “You are what you eat”? Well, this saying holds especially true for cows.

The quality of milk produced by a cow is determined by what the cow eats. A cow produces milk from the components of the food that it consumes. In most parts of North America, in Europe, and in Oceania, cows are pasture fed. Throughout the year, with varying intensities of sunlight and temperature, pasture grasses change in composition. In spring, the grasses are a dark green, filled with chlorophyll and carotene. In fall, field grasses start to dry up. The nutrients in those grasses changes constantly throughout the milking cycle. If the feed composition is constantly changing, the resultant milk composition also changes. The diet of pasture fed cows is strictly up to the whims of nature.

The herds of the farmer/owners of Idaho Milk Products do not feed on field grasses. They are fed a scientifically formulated diet consisting of a mix of grains, corn, and grasses. Staff veterinarians carefully plan the diets. Dietary composition is carefully monitored to ensure the same levels of required nutrients every day of the year. The result is milk that is compositionally the same throughout the year. IdaPro MPC/MPI manufactured from this milk can be expected to be consistent in quality all year.

Milk Permeate contains primarily crystals of α-lactose monohydrate and have a characteristic tomahawk-like shape. These crystals are very hard and brittle. Milk permeate also contains all of the mother liquor which is typically separated out of refined lactose. This mother liquor is made up of denatured casein and smaller whey proteins, vitamins and minerals. Milk Permeate produced at Idaho Milk Products is primarily comprised of α-lactose Monohydrate. In its crystalline form, each lactose molecule is associated with one molecule of water. The water is incorporated in the crystal and forms an integral part of it. It is not removed by normal drying processes. When working with formulators, it is important to understand the free and bound moisture content of any lactose crystal as it will lend to degradation by Maillard browning which in turn shortens shelf life. Free moisture is on the “surface” of the lactose crystal and is measured by drying at 100 °C for 5 hours in a convection Oven. Milk permeate typically has a free moisture content of <3.00%. Total moisture is the molecule of water picked up by the molecule of lactose during the crystallization process and is perfectly stable under suitable conditions. This is measured at 100 °C for 15 hours in a convection oven. Milk permeate typically has a bound moisture content of approximately 9.00%.

Since MPC and MPI are made up of Casein and Whey Proteins, we can look at the glutamine content of each protein to get an idea of the glutamine content of the respective product. Whey protein is reputed to contain roughly 7% to 8% glutamine (per 100 grams of amino acids). Casein has a slightly higher glutamine content that usually ranges from 8% to 10% (per 100 grams of amino acids). MPC and MPI will usually contain 7% to 9% glutamine, based on the total amino acids present. That means that our MPC-80 powder will have an “as is” glutamine content of roughly 6.5% to 7.5% and our MPI-85 powder will have an “as is” glutamine content of 7% to 8%.

Maillard browning is a chemical reaction that usually occurs between amino acids (the building blocks of protein) and those carbohydrates known as reducing sugars – although the reaction has been known to occur between reducing sugars and whole proteins. In a Maillard reaction, the reactive carbonyl group of a reducing sugar molecule reacts with the nucleophilic group of an amino acid, causing a change in color (usually darkening of color) and flavor of a food product. Heat (energy) is usually required for a Maillard reaction to proceed. Reactions between reducing sugars and free amino acids occur easily and with very little heat required. Reducing sugars will also easily react with the reactive terminal end amino acids of hydrolyzed proteins and, again, very little heat is required.

Reactions between reducing sugars and amino acids that are part of a whole protein are less common and require more heat (energy) to proceed. In the food industry, the troublesome Maillard reactions that occur over shelf life time are usually those reactions between reducing sugars and free amino acids or small peptides (fragments of proteins) that result from protein hydrolysis that occurred during food processing. The visible result of a Maillard reaction is development of a darker color … called browning. A flavor change usually accompanies the development of the darker color.

It is well known that Whey Permeate Powder (WPP) will undergo Maillard Browning over storage time. This is because WPP contains the milk sugar, lactose, which is a well known reducing sugar along with free amino acids and short length, hydrolyzed protein peptides.
In the manufacture of cheese, protein hydrolysis occurs, leaving a remnant of free amino acids and small peptides that end up in the permeate (WPP) that results after filtration of the cheese whey to concentrate intact proteins. Because there are so many reactive nucleophilic amino acid groups in WPP, very little energy is required for the Maillard reaction to proceed.
Therefore, the Maillard reaction can occur at ambient temperatures over time in Whey Permeate Powders.

MPP is not as likely to undergo a Maillard reaction as is WPP. Milk Permeate Powder (MPP) also contains lactose but it does not contain as many free amino acids or hydrolyzed protein peptides as WPP because the process of filtering skim milk to make MPC does not cause protein hydrolysis a will occur in cheese manufacture. Therefore, the Maillard reaction does not proceed as easily with MPP. MPP will undergo Maillard reactions in applications where sufficient heat is introduced and sufficient time is allowed for the reaction to proceed. In general, however, it can be said that the Maillard reaction is less likely to occur when using MPP as an ingredient when compared to WPP.

Yes.  Cold filtration manufacture of IdaPro MPI-85% results in a product with approximately 3.6% lactose. To deliver a product with less than 1% lactose, we utilize a very small amount of lactase enzyme which reduces the disaccharide lactose to its component sugars of glucose and galactose, resulting in a product with a typical analysis of 0.85% lactose, 1.4% glucose and 1.4% galactose.