Effect of durum wheat (Triticum turgidum L. var. durum) semolina extraction rate on semolina refinement, strength indicators and pasta properties

Abstract

. 2004. Effect of durum wheat (Triticum turgidum L. var. durum) semolina extraction rate on semolina refinement, strength indicators and pasta properties. Can. J. Plant Sci. 84: 1001-1013. Since the 1980s, there have been general trends in the durum wheat milling industry to higher semolina extraction rate, and in the pasta processing industry to the use of higher drying temperatures. During this time, specification of gluten strength by gluten index, mixograph mixing properties and alveograph parameters has also become widespread. These trends prompted this study of the appropriateness of protocols for quality testing of Canadian durum wheat breeding lines. Four cultivars with intrinsic differences in yellow pigment levels and gluten strength were grown in field plots in Swift Current, Saskatchewan for three consecutive years. A laboratory-scale milling procedure was modified to produce semolina at extraction rates from about 65% to about 80%. Milling to extraction rates above 65%, the extraction rate used routinely in quality testing of Canadian durum wheat breeding lines, had a major impact on semolina ash content and colour, but did not offer any advantage in ranking cultivars for either semolina yield or semolina refinement. Gluten strength, as measured by gluten index, was independent of semolina extraction rate. Dough strength, as measured by mixograph properties and alveograph properties, showed a tendency to weakening at high extraction, particularly for strong cultivars. Semolina was processed into spaghetti using low-temperature (LT), high-temperature (HT) and ultra-high-temperature (UHT) drying cycles. The firmness of cooked spaghetti was predominantly influenced by protein content. As a result, cultivars generally ranked in spaghetti firmness according to protein content. Regardless of drying cycle or cultivar, spaghetti firmness increased as drying temperature increased. Spaghetti dried at LT was less yellow than spaghetti dried at HT or UHT, probably due to thermal inactivation of the bleaching enzyme lipoxygenase at HT and UHT. Regardless of drying cycle, spaghetti became duller, more red and less yellow as extraction rate increased. For each spaghetti trait, cultivar ranking remained relatively constant regardless of extraction rate or drying temperature. On the basis of these results, there appears to be no advantage to increasing semolina extraction rate beyond 65% for evaluation of durum wheat milling performance, gluten strength or pasta properties. In addition, it appears that one drying cycle is adequate to reliably evaluate durum wheat lines for spaghetti colour and firmness. Depuis les années 80, la tendance générale dans l'industrie meunière consiste à extraire de plus en plus de semoule du blé dur alors que l'industrie des pâtes alimentaires recourt à des températures de séchage de plus en plus élevées. Durant le même laps de temps, la détermination de la fermeté du gluten d'après l'indice de gluten, les propriétés de pétrissage révélées au mixographe et les paramètres de l'alvéographe...

Characterization of Old And Recent Durum Wheat [Triticum turgidum (L.) Tell. convar. Durum (Desf.) Mackey] Varieties Assessed under South Mediterranean Conditions

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Gluten index compared with SDS-sedimentation volume for early generation selection for gluten strength in durum wheat

“…Pasta manufacturers in Europe tend to use the gluten index and alveograph to measure gluten strength of semolina, whereas the mixograph is widely used in North America (Dexter et al 2004). Evaluation of the efficacy of a particular gluten strength predictor depends on the relationship with the industrial standard test, cost of determination, and repeatability over years and environments.…”

The Genetic Potential of Spring Durum Wheat Grain Quality in the North of Kazakhstan

“…The quality of wheat is focused on increasing the level of yellow pigment and the brightness of pasta. The variation in the most common Canadian commercial varieties AC Avonlea, AC Navigator, Strong field, and Commander, ranged from 13.7 to 14.6% in protein content, with a gluten index of 34-94 (Dexter, 2008;Dexter et al, 2004).…”