Responses of breadmaking quality to sulphur in three wheat varieties
✍ Scribed by Zhao, Fang-Jie; Salmon, Sue E; Withers, Paul J?A; Evans, Eric J; Monaghan, Jim M; Shewry, Peter R; McGrath, Steve P
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 148 KB
- Volume
- 79
- Category
- Article
- ISSN
- 0022-5142
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✦ Synopsis
Field experiments were carried out at three sites in England to investigate the effects of S fertilisation on breadmaking quality of three winter wheat varieties (Hereward, Rialto and Spark) in the 1996±1997 season. The soils at the three sites differed in extractable S contents. Depending on site, either 180 and 230 kg ha À1 N or 230 and 280 kg ha À1 N treatments were factorially combined with three S treatments (0, 20 and 100 kg ha À1 S). Addition of S increased loaf volume signi®cantly at two sites where grain S concentration was also signi®cantly increased and grain N:S ratio decreased. Application of the extra 50 kg ha À1 N increased grain protein concentration but did not increase loaf volume at any of the sites. Loaf volume was found to correlate more closely with grain S than with grain protein concentration. Addition of S generally decreased the elastic modulus of gel protein and dough resistance but increased dough extensibility. Despite considerable differences in their dough rheology, the responses in rheology and loaf volume to S were similar in all three varieties. Selected ¯our samples of Rialto from the Bridgets site were also analysed for the glutenin subunit distribution, showing that S addition increased the relative proportion of low-molecular-weight subunits at the expense of highmolecular-weight subunits of glutenin. This study therefore shows that the bene®cial effects of S on breadmaking quality are associated with decreased dough elasticity and increased extensibility resulting from effects on the amount and composition of the glutenin polymers. The results also indicate that S fertilisation is required in some areas of England to maintain breadmaking quality.