A detailed study of the moisture-vapour dynamics occurring in the hydration, mixing, extrusion and drying phases of the manufacture of pasta/noodle products is used as a basis to identify new quality traits which are likely to have a high probability of a genotype connection and explanation. The importance of specifying the end-use, as part of phenotype identification, is stressed, and illustrated by examining the cooking quality of pasta. Considerable genetic variation exists among Australian wheat and durum lines in breeding programs with regards to their suitability for noodle and pasta production. A key challenge is to accurately describe the drying process mathematically and provide the basis for investigating the molecular nature of flour component/singredients that control and moderate the movement of water within the product during drying.
In the construction of genetic markers, using, for example, QTL’s, the first step is the identification of a phenotype trait (property) that is central and important to the process under investigation. The next step is an assessment of the extent to which the identified trait is controlled genetically and environmentally. Among other things, this involves the design and implementation of suitable experiments that allow a sensitivity analysis to be performed with respect to a range of appropriate genetic and environmental stimuli.
However, because of the cost of such experiments, the identification of phenotypes, which are likely to have a strong genotype connection to the process being examined, needs to be more than a simple trial-and-error process. An easily observable or visible phenotype trait, such as the hardness and vitreousness of wheat grains or the colour of dried pasta, is a simple summary (indirect measurement) of the complex collage of the underlying genetic, biological, chemical and environmental interactions. This leads naturally to the idea that phenotype identification, which has a high probability of having a strong genotype connection, must, where possible, be based on the underlying processes rather than their easily observable or visual ramifications. For example, some of the underlying chemical and biological interactions contributing to the hardness-vitreousness of wheat grains and the colour of dried pasta are more likely to have a genotype connection than the vitreousness or colour alone.