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Commonalities in quality requirements of wheat products.

R.L. Cracknell, G.B. Crosbie, A.B. Blakeney, D.M. Miskelly, L. O’Brien, K.J. Quail, C.T. Westcott and R.M. Williams.

Wheat Quality Objectives Group, C/- Westcott Consultants, P.O. Box 334 Greenacre NSW 2190.


Australian wheat is segregated into a series of grades on the basis of variety, protein content and receival standards. These grades are sold to end-users who require them to produce a wide range of products. The grain properties necessary to meet the quality specifications of these products vary considerably.

Grading in Australia began with the development of the Standard Sample system, later known as the FAQ system, in South Australia in 1888. The FAQ, or Fair Average Quality. System spread to Victoria in 1891, New South Wales in 1899 and Western Australia in 1905. (Callagan and Millington, 1956). Many Wheat industry leaders considered the FAQ to be a very poor system and worked for the adoption of objective grades but it was not until the late 1950’s that objective grades began to be established led initially by the Prime Wheat Associations efforts.

Wheat quality requirments

Individual cereal chemists from Guthrie recognised the need to provide Wheat Breeders with guidelines for quality. In 1992 the GRDC agreed to form a “Wheat Quality Objectives group” to provide guidelines to Australian Breeders and aimed at identifying the quality requirements of each of the major end products made from Australian wheat. The group identified major end use groups and specified the generalised quality requirements for each of the end uses. This market based approach, while providing a large amount of information for wheat breeding and grading discussions, did not highlight the commodities that exist for various end uses.

Hierarchial cluster analysis

In Hierarchical Cluster Analysis (HCA), Mahalanobis distances between the samples (in this case, “end use quality groups”) in a data set are calculated and compared. When the distance between end use quality groups are relatively small, this implies that they are likely similar, at least in respect to the measurements taken. Dissimilar end use quality groups will have larger relative distances. Known in biological sciences as numerical taxonomy, HCA allows the groupings of data into clusters showing similar attributes.

The primary purpose of HCA is to present data in a manner that emphasises the natural groupings in that data set. In contrast with analytical techniques that attempt to group new samples into pre-existing categories, HCA seeks to define those categories in the first place. Although it is not a necessary part of the algorithm, the presentation of HCA results in the form of a dendrogram makes it possible to visualise clustering such that relationships can be more readily seen.

Commonality of quality requirements

The Wheat Quality Objectives Group presented a HCA analysis to the 1995 Australian Cereal Chemistry conference based on the findings of their first confidential report. ( Blakeney et al 1995). We now present an updated analysis based on the third confidential report of 2003.

The end uses that are for human food and that require hexaploid wheat share many commonalities in their quality requirements. For instance, most of the products require hard grain, high milling quality, medium dough strength and high extensibility. We have used a hierarchical cluster analysis program {Pirouette, Infometrix Ltd, Seattle. WA, USA} to illustrate these broad quality commonalties. Quality requirements were digitised and a dendrogram developed using the autoscale and nearest neighbour maths option of the program. The analysis, which should be used for any sample in association with the preferred hardness and protein ranges given in the “Moss” diagram (Figure 1, Moss 1978), is shown in Figure 2.

Figure 1. Grain hardness and % protein values of wheat used for different end products.

Use of the dendrogram (Fig 2.) should assist cereal chemists, breeders, marketers and bulk handling companies to visualise the end use quality requirements of Australian wheat and to plan for varieties and grades that will best suit market requirements.

Figure 2. Hierarchical cluster analysis dendrogram of the broad quality requirements of major end-uses of Australian wheat


We thank the GRDC for funding the group’s activities and our numerous colleagues who have contributed to the group’s discussions.


Blakeney A.B. Cracknell R.L. and Crosbie G.B. (1995) Hierarchal Cluster Analysis of Wheat End-use Qualities. In. Williams and Wrigley Cereals 95, Proceedings of the 45th Australian Cereal Chemistry Conference Adelaide. RACI Melbourne. Pp 534-537.

Callaghan A. R. and Millington A. J. (1956) “The Wheat Industry in Australia” , Angus and Robertson Ltd. Sydney.

Moss H.J. (1978) Factors determining the optimum hardness of Wheat. AJAR 29, 1117-26.

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