Lesson 5 - Malting Process SAQ
This lesson provides the opportunity for you to test yourself on the material covered in Lesson 4 (Malting Process) and determine the level to which you have attained the expected outcomes.
Suggested Response - Q7
SAQ:
**Name one parameter that needs to be analysed to ensure food safety, and which can be caused by air pollution during malting. Explain its formation, and why this parameter is part of the due diligence analysis.
Response:
Nitrosodimethylamine (NDMA)
NDMA is formed by a reaction between amines (amino acids) and nitrogen oxides at high temperatures. The main precursor is hordenine, which is mostly found in the rootlets and this reacts with the nitrogen oxide rich (NOx) air. The change from direct to indirect kiln heating eliminates the hot nitrogen oxide-rich gas passing through the grain bed. This factor is thus now well within the control of the maltster.
Fuels that are low in sulphur oxidise nitrogen in the air. Although the kilns are heated through radiators, there is still a risk of NDMA in the malt due to air pollution.
NDMA will be part of the wort after mashing. Nitrosoamines are labelled as carcinogenic and are thus dangerous for human consumption.
To combat this dangerous molecule, malt must be analysed; a very low level of NDMA is permitted within the malt. In some textbooks, this is reported as 2.5 parts per billion, however an industry standard agreement is to keep it below 1 μg/kg.