Dairy Yield Loss: Where Is the Value Lost?

In dairy deep processing projects, yield differences are often only a few percentage points, but the final impact can be significant in terms of protein output, raw material costs, and annual profitability.

With the same batch of raw milk, some companies are able to efficiently recover high-value components such as whey protein and casein, while others continuously lose valuable ingredients during filtration, cleaning, and concentration processes. The equipment keeps running, but the valuable components are not fully recovered.

The first calculation in dairy deep processing should begin with one fundamental question: Where do the valuable components actually go?

1. Without Proper Separation, High-Value Components Are Easily Lost Together

Dairy products contain various components, including casein, whey protein, lactose, inorganic salts, and water. These components have different particle sizes and molecular weights, requiring different separation approaches.

If the membrane separation process is not properly selected, two major problems may occur:

One is that target proteins are not sufficiently retained and are lost with the permeate stream. The other is that components that should be removed, such as lactose, salts, and water, are not effectively separated in time, increasing the load on subsequent concentration and purification processes.

Jiuwu has developed a multi-stage membrane separation product portfolio for dairy deep processing:

●  1.4 μm ceramic membranes can be used for physical sterilization of dairy products;

●  0.1 μm ceramic membranes can be used for the separation of casein and whey protein;

●  10 kDa membranes can be used for protein retention as well as lactose and salt removal;

●  Polymeric ultrafiltration, nanofiltration, and reverse osmosis membranes perform functions including fine separation, desalination, and dehydration/concentration.

Each membrane technology addresses a specific process requirement. The ultimate goal is to retain valuable components while efficiently separating components that need to be removed.

2. The Higher the Fouling Load, the Shorter the Effective Production Time

Dairy streams typically contain high levels of proteins and fats, which can easily lead to flux decline, frequent cleaning, and poor recovery performance during membrane operation.

The losses caused by frequent cleaning involve not only cleaning chemicals and labor costs, but also:

●  Production losses caused by equipment downtime;

●  Product losses during cleaning and displacement processes;

●  Changes in separation performance caused by membrane element degradation;

●  Inconsistent product quality between batches;

●  Increased membrane replacement frequency and spare parts costs.

Therefore, improving yield cannot be achieved by focusing only on the retention rate of a single membrane element. It also requires comprehensive consideration of membrane materials, flow channel design, operating parameters, cleaning methods, and the compatibility of upstream and downstream processes.

A key point mentioned during the livestream was:

Yield is the result of combining product requirements with technology, supported by practical application experience.

Even with the same membrane pore size or molecular weight cut-off, the actual performance can vary significantly when applied to feed streams with different protein contents, fat contents, viscosities, and temperatures.

3. Define the Target Product First, Then Design the Separation Process

Dairy processors have different product objectives.

Some customers aim to produce whey protein, while others focus on casein production. Some are developing low-lactose dairy products, Greek yogurt, or concentrated milk, while others only need to improve protein composition and texture in products such as ice cream.

Different target products require different process configurations.

For example, whey protein production requires first considering the separation of casein and whey protein, followed by whey protein concentration, lactose removal, and desalination. For low-lactose and high-protein products, the key challenge is balancing protein retention, lactose permeation, and subsequent concentration processes.

Jiuwu is the pioneer of ceramic membrane technology in China and has established a complete business chain covering ceramic and polymeric membrane materials, process design, complete equipment manufacturing, and integrated solutions. Based on customer feed characteristics and target products, Jiuwu can combine different membrane technologies rather than applying a single standardized process to every project.

4. Improving Yield Ultimately Comes Down to Operational Benefits

The value of a dairy membrane system should ultimately be measured by four key outcomes:

●  How much high-value protein can be recovered;

●  How much target product can be produced from a given amount of raw material;

●  Whether cleaning frequency and downtime can be reduced;

●  Whether product quality and batch-to-batch consistency can be improved.

Before consulting on a project, it is recommended to first prepare information including feed composition, daily processing capacity, target products, and current yield performance. Only by clearly defining “what needs to be retained and what can be allowed to pass through” can the appropriate membrane specifications and process configuration be accurately determined.