Utilizing the flour mill laboratory

by Teresa Acklin
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The flour mill laboratory has many uses. The main purpose is to check wheat quality, to make sure that the wheat and products of the plant are consistently suitable for their designed purposes by means of measurement. This article illustrates several further practices.

A reasonably comprehensive laboratory could include equipment for measuring a range of samples, such as bulk density, dockage, single kernel analysis, Hagberg Falling Number, hardness, moisture, protein, gluten ash, color, particle size, dough rheology, laboratory mill, NIR (near infrared) and baking. Other tests could cover gas production, gas retention, pigmentation and starch damage.

So, while quality measurement is the normal use of a mill laboratory, there are many connected or affiliated tests to support the business of flour milling.

ARCHIVES. Historic data, particularly in graphic or statistically analyzed form, will indicate trends that can be, and often will be, a pointer to the future. New crop data comparisons to previous years are beneficial.

Past complaints, properly detailed by their nature and solution, are helpful. Unfortunately, some genuine complaints come and go without explanation. This is a problem of the relative inexactitude of cereal chemistry, which is not as all embracing as physics or mathematics.

CORRECTION. Faults in raw materials and products picked up in the laboratory can be corrected during milling. One example is blending a substandard flour or wheat with better ones. The laboratory can only highlight the difficulty; the head miller and his team has to take action. There is no other way.

PRE-EMPTIVE ACTION. The laboratory can warn the milling crew of an impending difficulty — usually a potential customer complaint — before it occurs. One such possibility is prior detection of a rogue part truckload of grain identified after intake. The production system needs the capability to trace trouble through each step of the process.

DIAGNOSIS. Interpreting the resultant measurements is not only sometimes difficult but is a particular skill. It is common in the awkward cases for there to be different views among colleagues. These can be settled by internal debate.

PROGNOSIS. Forecasting the likelihood of performance of products from a particular combination of wheat varieties or sources is a desirable function of the mill laboratory. The same goes for treatments.

For instance, a newly available wheat sample may be assessed before purchase to determine its characteristics, and therefore suitability, either by itself or in conjunction with other wheat varieties. In addition, treatment levels can be balanced with the knowledge of not only the end user's process but also with the other ingredients that will be used at the final destination, such as the bakery.

TRIALS. Trials are especially necessary with the introduction of new crop wheat in order to ensure a smooth transition from old to new, with the customer in mind. This is more necessary for high-throughput facilities because changes are magnified.

Put another way, high capacity customer processes are more sensitive due to their greater reliance on machinery rather than manpower. Therefore, trials at harvest are important.

Additionally, a good exercise post-harvest is to measure individual flours from each machine to show new crop wheat differences. This could indicate possible diagram alterations.

NEW PRODUCT DEVELOPMENT. The competitive miller must review potential new products, including specialty products of unusual character when compared to regular trade. Reviewing new products provides millers opportunities to form different meals and flours of various particle sizes, incorporate germ, semolinas, test agglomeration, and so on.

LEAST COST FORMULATION (LCF). LCF is a powerful commercial tool when the choice of wheat types, varieties and availability is relatively wide. It is a fascinating subject widely practiced in some countries but hardly at all in others.

The mill laboratory measures the properties of wheats and flours, and it is evident that the relationship in performance in the widest sense be known between the laboratory and full-scale commercial mill.

The laboratory uses spreadsheets to assess the full range of parameters against cost to find the best solution. Reviews of the results, in addition to feedback, help the in-house grain buyers make optimum decisions.

In a large group of companies, it is surprising how individual mill locations indicate different freight rates. Certainly LCF produces surprisingly interesting ideas — some not always practical — but it is possible to save up to 1% of the cost of wheat.

CUSTOMER SUPPORT. Both diagnostics and prognostics via data logging support the disciplines of Good Manufacturing Practice, Total Quality Management and certification for ISO 9000. The flour laboratory is an excellent department to show visiting customers to create confidence and to point out care and attention to detail.

CAPITAL EXPENDITURE SUPPORT. The full range of facilities can be brought together to assist with projects for capital expenditure. For example, if updated blending (wheat, flour or both) equipment is desired, statistical information provided by the mill laboratory can be used to demonstrate greater consistency and less variation, which can lead to savings in wheat costs. Statistical information also can be used to check the financial consequences of increasing or decreasing quality.

HYGIENE. In these days of increasing demands from government or customers, the mill laboratory is often engaged in monitoring and advising hygiene, as well as auditing hygiene throughout the plant. It is a helpful part of satisfying due diligence, especially when properly recorded.

APPLIED RESEARCH. The practice of applied research can be employed in the mill laboratory to determine or compare, for example, the correct treatment levels for a particular product. This is normally judged against a control flour of known properties and performance. A number of other flours are then demonstrated alongside to highlight differences from which an appropriate one is selected.

GENERAL. There are some factors that must be in place at all times to protect integrity and reliability of output when running a mill laboratory. Keeping equipment areas clean makes for efficiency and orderliness.

Calibration and maintenance of instruments is vital, and the calibration recommendation should be made by the supplier. Some instruments need calibration more frequently than others, and NIR equipment needs calibrating daily. Should some instruments temporarily be incapable of calibration for one reason or another, then a sample of previously known value can be measured and an offset allowance can be made.

Furthermore, collaborative "ring" tests should be carried out, probably monthly. These tests consist of the same flour (or wheat) divided into as many samples as there are laboratories and measured by each lab in the "ring." Results are collated by one and distributed to all. Particular differences to the principal laboratory are then investigated and corrected.

It is always interesting and useful to have one independent, outside laboratory, perhaps as the principal laboratory.

Finally, we are probably years away from the single on-line "black box," which will measure everything needed (although NIR is not there yet). This "black box" would be non-invasive and non-destructive to materials or processes and would verify, not just identify, results

David Sugden, independent consultant to the grain industries, may be reached at The Coach House, Killigrews, Margaretting, Ingatestone, Essex CM4 0EZ, U.K. Tel: 44-1245-352048. Fax: 44-1245-251162.