NIR; food quality control; soybeans

Chapter 20

The detectives yield the power of NIR for soybean quality control

📁 Case overview: The detectives continue their vegetarian streak by getting another taste of soybeans used to make tofu. But their client demands a fast method that can be used directly at the raw material intake point and still provide reliable soybean quality control. Can the detectives find a fitting solution, or will they be left behind in the dust? Read on to find out.

The detectives are sitting down poking at their breakfast, waiting for Shallot Holmes to assign them their next case. Nancy Beef and Eggcule Poirot are unusually quiet. Shallot Holmes is quick to notice and inquires if there is something wrong with his two colleagues. Nancy Beef admits she is still thinking about their last case on plant-based foods and how close the protein content of tofu was to a beef steak.

Shallot Holmes strokes his chin and nods as he listens to her. He rummages through the pile of cases on their desk and pulls one out with a satisfied grunt. He asks if they would be interested in exploring soybean quality control, as soybeans are actually what tofu is made of.

Nancy Beef and Shallot Holmes visibly perk up at the idea. The others also curiously look over the client case. Lieutenant Cornlumbo volunteers to be the principal investigator, as he excitedly announces that he sees potential for NIR to be used here. As he is one of the NIR experts of the team, Shallot Holmes gladly assigns him the case.

Lieutenant Cornlumbo takes some time to go over the case in more detail. He also digs into a brand new food analytics guide to explore the suitability of NIR for food quality control. It is not the first time that they are analyzing soybeans, but it is the first time that soybean quality control must be performed directly at the production line. So Lieutenant Cornlumbo summarizes the needs of the client for his colleagues. She requires soybean quality control during raw material intake with a process that can be documented quickly, simply and reliably.

Lieutenant Cornlumbo lists several reasons why whole soybean quality control at the raw material intake is important:

  • Prevention of entry of out-of-specification material
  • Quality segregation
  • Authentication of raw material
  • Payment decisions for farmers based on exact oil levels
  • Decisions on how to store and process the raw material based on whole soybeans composition

The detective clarifies the last point. Based on accurate measurements of moisture, protein and oil content, soybeans can be stored at different silos and subjected to drying treatment or optimally pretreated for subsequent production steps.

Knowing the correct values of key control parameters enables the producer to optimize their process and maximize quality and profit.

One concern of the producer is that traditional laboratory methods for soybean analysis require considerable time and require large quantities of solvent. To sidestep these issues, Lieutenant Cornlumbo would like to use NIR. He suggests implementing an NIR-Online Process Analyzer at the raw material intake step for full characterization of soybeans quality. With this instrument, several parameters can be accurately measured in parallel. The detective draws out exactly where he would like to install the instrument for soybean quality control:

quality control; soybeans; NIR

The others like his plan and they drive over to the client to test out the set-up.
Lieutenant Cornlumbo installs the NIR system with the following parameters:

  • Wavelength range: 900 to 1700 nm
  • Measurement principle: Reflection
  • Interface to process: Flange

After set-up is complete, they test out their NIR unit for soybean quality control.

Parameter (%)RangeSEC
Protein32.0 - 39.20.30
Oil content18.0 - 21.80.25
Moisture8.0 - 18.00.15

They happily note that they can accurately measure relevant parameters in whole soybeans.

The client is also satisfied with the results and the convenience of the technique. As she thanks the detectives, she mentions she is also pleasantly surprised that she can also monitor fiber, ash and acidity. Obtaining real-time data on critical-to-quality attributes will certainly enable her to optimize crushing conditions and maximize yield and quality of the final product.

As a parting gift, the client gives them some tofu made from downstream processes in her factory. Nancy Beef, by now convinced of the beauty of soybeans, makes the giant sacrifice of inviting the detectives over for a tofu-inspired meal. And this evening, everyone receives their protein intake from one very yummy, plant-based dish! Even Nancy Beef and Eggcule Poirot.