Solubility and Suspension Stability

It is possible to have a protein powder that is highly soluble but displays poor suspension stability. Conversely, it is also possible to encounter a protein powder with good suspension stability and relatively low solubility. Suspension stability is really a measure of how well the powder stays suspended in water after it is dispersed into…

What are key factors that dictate stability?

The number one key factor is compatibility of the protein with the other ingredients in the system. For instance, excess free calcium is well known to cause a decrease in milk protein suspension stability and solubility. Sodium phosphate salts are well known to increase milk protein suspension stability and solubility. Probably the second most important…

What is suspension stability and how is it measured?

The response to this question is dependent upon the context in which you are asking the question. In a laboratory situation, suspension stability is measured by dispersing a protein powder in ambient temperature water (10% w/w) and pouring the aqueous protein dispersion into a 100 ml graduated cylinder. One then observes how long it takes…

Is solubility a reflection of quality?

Solubility of MPC/MPI is an important quality characteristic that determines how successful the product will be in various applications. This important product attribute can be affected by several process parameters including freshness of the raw milk prior to processing, processing conditions, and length/conditions of storage. In order to maximize MPC solubility it’s important to minimize…

What are typical NSI and WPNI results for MPC powders?

In analyses by outside laboratories, NSI results for MPC powders were found to range from a low of 35 to a high of 72. NSI results for three separate lots of Idaho Milk Products’ IdaPro® MPC powders ranged from 67 to 72. An outside laboratory also analyzed MPC powders for WPNI. Typically, most MPC powders…

What is NSI and WPNI?

These two terms are usually used in conjunction with discussions of protein solubility. NSI stands for Nitrogen Solubility Index and is expressed as a percentage of the protein nitrogen that is water soluble relative to the total protein nitrogen present. For example, if 75% of the total nitrogen contained in a protein is found by…

How is solubility of Dairy Proteins measured?

Solubility of dairy proteins is measured by determining the quantity of protein nitrogen that is water soluble versus the quantity of protein nitrogen that is water insoluble. Proteins are long chains of amino acids. Nitrogen is part of the backbone of every amino acid. Therefore, to measure protein solubility, one needs only to measure the…

Sensory properties of MPCs and MPIs

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…

What does highly-functional protein mean?

Usually, when one talks about protein function, it is in reference to the metabolic fate of the protein once in the bloodstream and/or the protein’s functional properties as a food ingredient/stabilizer. So, when we say that the protein remains highly functional, we are referring to the protein’s ability to affect metabolic pathways in the body…