Analysis of grains and flour

Producers and distributors of cereals and flour face numerous challenges that affect the safety and quality of their products.

• The necessary use of pesticides to combat pest infestations can leave residues in the end product that need to be analyzed in detail.
• Improper storage can lead to the formation of mycotoxins, which can endanger consumers' health.
• In addition, the use of genetically modified organisms (GMOs) is a controversial issue that requires clear consumer information to ensure trust and transparency.
• Another problem is possible product adulteration. This concerns durum wheat in particular. If inferior wheat varieties are added without permission, this constitutes food fraud, which reduces the authenticity and quality of the product.

These factors influencing the quality of flour and cereal products require detailed and precise analyses to guarantee compliance with safety standards and product quality.

Pesticides/residue analysis

Cereals can easily become contaminated with pesticides and other contaminants, especially during cultivation, harvesting, or processing. Residue analysis is therefore essential to ensure that cereal products are safe for the consumer and comply with legal limits.

Gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) are among the methods used to carry out these analyses. These methods make it possible to precisely identify and quantify even the smallest amounts of chemical residues.

The most common contaminants found in cereals include pyrethroids (PYRs) such as cyfluthrin, deltamethrin, phenothrin, cypermethrin, and fenvalerate, as well as organophosphates (OPs) such as chlorpyrifos and pirimiphos-methyl. These substances are known for their effectiveness in pest control but pose significant health risks. Therefore, their close monitoring is essential.

Microbiological contamination

Microbiological contamination poses a significant risk in cereals and flour, as pathogenic germs such as bacteria, viruses, and fungi can enter the products throughout the entire process chain - from harvesting to storage and processing. Comprehensive microbiological analyses are therefore essential to ensure the safety of cereal products. In our specialized laboratories, samples of wheat, barley, and other cereals are examined for microorganisms and their excretory products.

These analyses include the isolation and identification of microorganisms using cultivation methods. Biochemical tests or molecular biological techniques such as the polymerase chain reaction (PCR) follow to detect specific DNA sequences of pathogenic microorganisms. These methods allow a quick and accurate determination of the microbial load.

Mycotoxins can develop through mold growth if stored improperly. Particularly critical are aflatoxins and ochratoxin A, which can form in grain under damp storage conditions. Zearalenone, an oestrogenic mycotoxin that occurs mainly in cooler climate zones, can have considerable health effects. The Tentamus Group laboratories use sensitive analytical methods such as high-performance liquid chromatography (HPLC) coupled with tandem mass spectrometry (MS/MS) to detect these toxins. These tests ensure that the ingredients of grain and flour are free of harmful contaminants and that the products meet the legal standards for food safety.

Frequently analyzed microorganisms in flour and cereals include:

• Salmonella spp.
• E. coli
• Listeria monocytogenes
• Staphylococcus aureus
• Bacillus cereus
• Clostridium perfringens
• Aspergillus spp.
• Penicillium spp.
• Fusarium spp.

Testing for food fraud

Food fraud testing plays an essential role in the grain industry, especially in verifying the purity of durum wheat and detecting unlabeled genetically modified organisms (GMOs).

Authenticity testing of durum wheat helps to detect adulteration with other types of wheat. Spectroscopic methods such as near-infrared spectroscopy (NIRS) are used here, which enable the composition of the flour to be determined quickly and precisely. This is particularly important to ensure that the end product meets the expected quality standards and does not contain any unauthorized additives.

At the same time, analysis of GMOs is essential to ensure compliance with legal requirements and labeling obligations. PCR (polymerase chain reaction) methods are used to amplify and analyze specific DNA sequences that indicate genetic modifications. These tests are of the utmost importance to ensure the integrity of cereal products and provide transparency to consumers.

Further analyses of cereals and flour

• Crude protein content

The crude protein content measures how much protein is contained in a food. It is given as a percentage of the total mass of the product. For cereals and flour, the determination of the crude protein content is important both for nutritional labeling and for assessing the quality of the cereal for various uses, such as baking or brewing.

The Kjeldahl method or the Dumas method are usually used to analyze the crude protein content. Both methods determine the total nitrogen content, which is then converted into protein content.

Kjeldahl method: This method measures the total nitrogen content by acid digestion of the sample and subsequent quantification of the ammonium released. It is considered to be particularly precise and is often used as a reference method.

Dumas method: This fast and automated method burns the sample in pure oxygen to determine the nitrogen content from the resulting gases. It offers the advantage of fast turnaround times and requires fewer chemicals.

• Acrylamide

Acrylamide is a chemical compound that is mainly produced when baking, frying, or roasting starchy foods at high temperatures. This substance is of particular relevance to food safety as it is potentially carcinogenic and is therefore the subject of intensive investigations and regulation. In cereals and flour, acrylamide can be formed by the Maillard reaction, in which sugar and amino acids react when exposed to heat.

• Checking gluten-free products

Correct gluten labeling is crucial for consumers suffering from celiac disease or gluten intolerance. Gluten, a protein that occurs naturally in many grains such as wheat, barley, and rye, can cause severe health reactions in some people. Products containing gluten must indicate this on the label following legal requirements to protect consumers and enable them to make an informed choice. The Tentamus Group laboratories test products labeled as gluten-free, ensuring the accuracy of product labeling and consumer safety.

In addition to the analysis method, the sampling and shipping process is also crucial for the analysis of grain and flour. The laboratories of the Tentamus Group offer you a convenient service for taking and collecting samples. These carefully coordinated steps ensure that the samples of wheat, barley and other cereals are taken in optimal condition for precise analysis and thus provide reliable results.