How to sample grain
Grain is an important product to sample and analyse for faults and infestations. The loose structure of grain makes it an environment in which problems can easily hide and spread undetected, making diligent testing a matter of necessity.
Grain sampling equipment can take some of the arduous manual processes out of testing, but it’s still vital that farmers and food producers understand why it’s necessary to sample grain in the first place, and the kind of things that can be uncovered by sampling.
What is grain sampling?
Grain sampling is the overarching process of testing a grain crop by taking small amounts – ideally at various points throughout the chain of production – to act as representative samples. By doing this, the quality of the crop as a whole can be ascertained and certain requirements can be met to satisfy regulations and concerns from buyers.
Grain sampling should occur at several points for best practice, including various stages of harvest and processing:
- At harvest, when it is first collected to assess for moisture content before any other processes can affect it.
- During storage, taking samples as the grain store is being filled and not simply afterwards. This prevents instances of a single column inaccurately representing the entire store.
- Once stored as a means of monitoring the quality for any emerging issues like moisture and pests.
- At outloading, taking samples from each lorry load before it undergoes transportation from farm to client.
Buyers are also likely to sample the product themselves at intake. This helps them ensure that agreements and due diligence by the farmer have been observed, and that proper storage was undertaken. It also helps to eliminate any fault being taken by the buyer if quality issues were to arise after transport.
Grain is particularly necessary to sample as its behaviour as a living crop means it is susceptible to infection even after harvest, and improper drying presents opportunity for mycotoxins to develop.
ISO 24333 (previously 13690) suggests a minimum of five incremental samples of 500g each for grain sampling. This should represent up to 50t of grain to be used for human consumption, and up to 100t of grain intended for animal feed.
These incremental samples must be thoroughly mixed to create a composite sample, which will then serve as representative of the bulk.
Why do we sample grain?
Living grain respires during storage, meaning it takes in oxygen and uses it to create food via its endosperm. This process produces heat, water vapour, and carbon dioxide, increasing the risk of spoilage and other risks like mould and insects.
Grain is best stored cool and dry, which reduces the output of respiration and therefore the risks of spoilage. Sampling helps to ascertain whether storage of a particular crop is being undertaken as it should. A reading of moisture and temperature can be taken from these samples and analysed for signs of common problems.
Sampling grain allows a specific bulk to be better understood. This is essential not only for knowing of any problems with the grain, but also for being able to better market the product and ensure it’s going to the right buyers, maximising the return on the time and cost sunk into growing the crop. Growers who are more educated about their crop can make better decisions and more accurate assessments on matters of storage and quality.
This can also elucidate any problems between different bulks, for instance between grain harvested from two different fields. Bodies like the Agriculture and Horticulture Development Board (AHDB) advise to keep yields from different fields separate wherever possible for this reason.
Knowing the stages from harvest to outloading at which certain issues are arising gives farmers and buyers the knowledge they need to home in on problems and rectify them faster and more confidently.
Perhaps most significantly, sampling of grain is required to satisfy certain standards and regulations, not least of all to ensure the health and wellbeing of the humans and animals that will be consuming it. Food growers need to ensure their own due diligence through competent sampling, as food businesses who are found to be in violation of the General Food Regulations 2004 can face fines and imprisonment.
Best equipment for grain sampling
To simplify the process of gathering and testing, much modern grain sampling equipment is convenient and easy to use.
Perten IM9500 Plus Wholegrain NIR Analyser
The Perten IM9500 utilises near-infrared spectroscopy, a fast and non-invasive method of analysing material with repeatable results. Among other content, the machine can measure moisture content, a useful indicator of grain storage conditions and possible respiration issues. The IM9500 can test flour as well as wholegrain, to help judge the product of grains in addition to the grains themselves.
GrainSense
The GrainSense is a handheld protein and moisture meter, allowing measurement of moisture, protein, and nitrogen levels in a portable piece of equipment. This facilitates on-the-spot measurements that gives farmers a handheld laboratory for fast answers and fast decisions.
Perten Shakematic Sample Mixer
The Perten Shakematic makes sample preparation fast and easy, taking merely three seconds to mix. Combining samples into an aggregate can be done without human error or bias, reducing differences between laboratories. Repeatable results with automatic precision means more trustworthy outcomes every time.
CGrain
CGrain analyses individual kernels to assess overall grain quality in a sample. At least 90% of a kernel’s surface is imaged, allowing CGrain to measure for broken kernels, foreign material, green kernels, ergot, and more signs of potential issues in the sample. Data and images can be saved for future reference or proof of testing outcomes, making grain testing a breeze.
Calibre Control for grain sampling equipment
We make grain sampling simple by providing the very best equipment to keep you in control. Our extensive experience in food safety and hygiene means that we can listen to your needs and suggest only the exact solutions you need.
To hear more about testing and the equipment we can recommend, please don’t hesitate to contact us today.