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The implications of frequently encountered grading factors on the processing quality of durum wheat



5. Concluding remarks

Common grading factors in durum wheat have different degrees of importance than for common wheat. The necessity for bright speck-free semolina that produces pasta with excellent aesthetic appearance makes grading factors that cause surface discoloration of far more importance for durum wheat. As a result the top Canadian and American durum wheat grades tolerate very low levels of grading factors such as smudge, black-point, severe midge, etc. Protein content is more important than gluten strength in determining pasta cooking quality, so factors detrimental to durum wheat gluten strength have less impact on end-product texture than for bread wheats.

Grade standards are strictly maintained to ensure durum wheat millers of quality required to give desired semolina milling performance. However, ongoing evolution of durum wheat processing requires continual review of tolerances for individual grading factors. A trend to finer semolina granulation may reduce the importance of HVK on durum wheat marketability. Increasing popularity of debranning of durum wheat before milling could reduce the importance of surface discoloration (Dexter and Wood 1996).

High temperature (HT) and ultra-high temperature drying have become universally accepted in pasta processing. HT yields firmer, less sticky pasta than traditional low temperature (LT) drying cycles (Dexter et al. 1981). As a result raw material quality, particularly protein content, can be compromized when using HT technology without sacrificing pasta textural properties