Maltitol COA Essentials: Purity, Reducing Sugars and Heavy Metals

A certificate of analysis does more than satisfy a purchasing file. For maltitol, the COA is the document that tells a formulator whether the lot in front of them will temper, flow and taste like the sample that was approved. When a shipment is rejected at goods-in, the argument is almost never about the headline purity figure alone; it is about reducing sugars, moisture, crystal form and the trace contaminants that quietly change processing behaviour. Reading the certificate properly is therefore a technical skill, not an administrative one.

Why purity alone is not enough

Maltitol is produced by hydrogenating maltose, and the economics of that process mean purity is usually high. A powder grade will commonly assay at or above 98 percent maltitol on a dry basis, while a syrup is quoted in solids, often 75 percent or more. These headline numbers are reassuring, but two suppliers quoting the same assay can still deliver materials that behave very differently. The difference usually sits in the parameters that surround the purity figure: residual reducing sugars, water content, pH and the physical form of the crystals.

The parameters that decide acceptance

A working specification should state a target, an acceptable range and the test method. The table below reflects the limits that most often separate a smooth run from a problem batch.

Reducing sugars: the quiet indicator

Reducing sugars deserve more attention than they usually receive. A maltitol syrup that has not been fully hydrogenated retains a small fraction of maltose and other reducing sugars. That residue can participate in Maillard browning during candy boiling or baking, darkening a product that should stay pale, and it can influence colour drift over shelf life. A limit at or below about 0.1 percent is common for confectionery grades. If a lot arrives above the agreed ceiling, the safest response is to raise it with the supplier before the material reaches the line, because the defect will only become visible after heat has been applied.

Heavy metals and contaminant limits

Heavy metal testing covers the elements that regulatory frameworks monitor in food ingredients, principally lead, arsenic, cadmium and mercury. Limits are set in milligrams per kilogram and vary by destination market and by intended use. The COA should report each element against a stated method, and the method matters: results produced by different techniques are not always directly comparable. A supplier who reports only a single combined figure, or who cannot name the test method, is giving a buyer less to work with than one who lists element-by-element results.

What a credible certificate looks like

A trustworthy COA is batch-specific and traceable. It should carry the lot or batch number, the production or release date, the customer or specification reference, and a clear layout showing specification, result and pass or fail for every parameter. It should also state the sampling basis and, ideally, identify the laboratory or method used. Certificates that are undated, that repeat the specification in the result column without variation, or that never record a value close to a limit, are worth questioning.

Retention samples and dispute handling

No analytical programme replaces physical evidence. Retain a sealed counter-sample from every delivery, stored under the conditions the material is meant to tolerate, so that a later disagreement can be settled by testing the actual lot rather than a memory of it. Retain the incoming COA alongside the sample and the receiving inspection record. When the three agree, quality claims become a short conversation instead of a prolonged negotiation.

Frequently Asked Questions