Wheat Quality

The research described here is from a three-year project (2001-2003) sponsored mainly by HGCA with contributions from ADM Milling, Allied Mills and Weston Research Laboratories, Alvan Blanch, Yara, RAGT Seeds, Rank Hovis and Syngenta.

Background

Research at Harper Adams has discovered that a large-scale climatic phenomenon over the North Atlantic Ocean strongly influences wheat quality.

The problem of pre-harvest sprouting of wheat grain and low Hagberg falling number has been studied at Harper Adams for many years, and by chance it was noticed that the national average Hagberg falling number appeared to follow a pattern similar to that of a standard winter air pressure index over the Atlantic ocean - the North Atlantic Oscillation (NAO). There was a good relationship between the NAO in the winter and Hagberg the following summer. The NAO was also found to affect wheat specific weight. Some of our work on this topic has been presented in the following papers:

• Atkinson, M.D., Kettlewell, P.S., Poulton, P.R. & Hollins, P.D.
  Grain quality in the Broadbalk Wheat Experiment and the winter North Atlantic Oscillation.
  Journal of Agricultural Science 146: 541-549. (2008)
• Hollins, P.D., Kettlewell, P.S., Parsons, S.T., & Atkinson, M.D.
  The impact of supply, demand and grain quality on the bread and feed wheat price differential in the UK.
  Journal of Agricultural Science, Cambridge 144, 411-419. (2006)
• Atkinson, M.D., Kettlewell, P.S., Hollins, P.D., Stephenson, D.B. & Hardwick, N.V.
  Summer climate mediates UK wheat quality response to winter North Atlantic Oscillation.
  Agricultural and Forest Meteorology 130, 27-37. (2005)
• Hollins, P.D., Kettlewell, P.S., Peltonen-Sainio, P. & Atkinson, M.D.
  Relationships between climate and winter cereal grain quality in Finland and their potential for forecasting.
  Agricultural and Food Science 13, 295-308. (2004b)
• Hollins, P.D., Kettlewell, P.S., Atkinson, M.D., Stephenson, D.B., Corden, J.M., Millington, W.M. & Mullins, J.
  Relationships between airborne fungal spore concentration of Cladosporium and the summer climate at two sites in Britain.
  International Journal of Biometeorology 48, 137-141. (2004a)
• Kettlewell, P.S., Stephenson, D.B., Atkinson, M.D. & Hollins, P.D.
  Summer rainfall and wheat grain quality: relationships with the North Atlantic Oscillation.
  Weather 58, 155-163. (2003)
• Atkinson, M.D., Kettlewell, P.S., Hollins, P.D., Stephenson, D.B. & Parsons, S.T.
  Forecasting wheat quality and the breadmaking premium from the North Atlantic Oscillation.
  Project Report No. 308. Home-Grown Cereals Authority, London 20 pp. (2003)
• Atkinson, M.D., Kettlewell, P.S., Hollins, P.D. & Stephenson, D.B.
  Regression forecast of UK harvest wheat quality from the preceding winter North Atlantic Oscillation.
  Experimental Long-Lead Forecast Bulletin, 11(2). (2002)
• Kettlewell, P.S., Atkinson, M.D., Stephenson, D.B. & Hollins, P.D.
  Climatic factors mediating the effect of the winter North Atlantic Oscillation on wheat quality.
  Aspects of Applied Biology 64, Wheat quality, 129-130. (2001)
• Atkinson, M.D., Kettlewell, P.S., Hollins, P.D., Stephenson, D.B. & Parsons, S.T.
  Forecasting quality and breadmaking premium of wheat from the winter North Atlantic Oscillation.
  Aspects of Applied Biology 64, Wheat quality, 127-128. (2001)
• Kettlewell, P.S., Sothern, R.B. & Koukkari, W.L.
  UK wheat quality and economic value are dependent on the North Atlantic Oscillation.
  Journal of Cereal Science 29, 205-209. (1999)

Some background on wheat quality

Specific weight

Specific weight is the bulk density of the grain, i.e. it is the weight of a particular volume of grain. In the UK and Europe it is expressed as kg/hl, and is measured in a chondrometer.

The usual commercial minimum for breadmaking is 76 kg/hl for specific weight.

Hagberg falling number

Hagberg falling number (HFN) is an indicator of the alpha-amylase activity in the flour. A high HFN means a low alpha-amylase activity, and means that the flour is less degraded by the enzyme. It is measured by heating the flour in water and measuring the rate of fall of a plunger.

The usual commercial minimum for breadmaking is 250 for Hagberg falling number.