%0 Journal Article
%T Influencia del estr¨¦s t¨¦rmico en la calidad panadera del trigo: progenies con diferentes niveles de sensibilidad Effects of heat stress on breadmaking quality of wheat: progenies with different levels of sensitivity
%A Z. A. Gaido
%A M. E. Dubois
%J Agriscientia
%D 2008
%I 
%X Picos de altas temperaturas durante el llenado del grano de trigo est¨¢n relacionados con modificaciones de la calidad panadera, especialmente con disminuciones en la fuerza de la masa. Se evalu¨® la influencia del estr¨¦s t¨¦rmico en la calidad de progenies de trigo pan clasific¨¢ndolas en grupos seg¨²n su sensibilidad. Se analizaron 60 progenies de trigo durante 3 a os consecutivos. Se tomaron fechas de siembra, espigaz¨®n, cosecha y temperaturas m¨¢ximas diarias. Se determin¨®, para cada muestra, la variable estr¨¦s t¨¦rmico total (ETT), definida como la sumatoria de grados de los episodios de estr¨¦s t¨¦rmico (al menos 2 d¨ªas consecutivos con temperaturas > 30 oC) durante el periodo del llenado efectivo del grano, estableci¨¦ndose 3 niveles: bajo, medio y alto. Se midieron prote¨ªna en grano (PTG), gluten h¨²medo (GH) y variables mixogr¨¢ficas. Se realizaron an¨¢lisis de la varianza y coeficientes de correlaci¨®n de Pearson. Para niveles de ETT medio y alto disminuyeron PTG, GH y altura mixogr¨¢fica (Amix), mientras que la fuerza de la masa medida en tiempo de desarrollo mixogr¨¢fico (TDmix) disminuy¨® s¨®lo en 62% de las muestras. En este sentido, se identificaron genotipos que poseen tolerancia al estr¨¦s t¨¦rmico y una mayor estabilidad de la masa. Periods of heat stress during the grain filling have been observed to influence the baking quality of wheat with a decline in dough strength. The objective of this study was to evaluate the effects of heat stress on bread-making quality of wheat and to identify progenies with different levels of sensitivity. Sixty wheat progenies were analyzed for three consecutive years. The dates of sowing, heading, harvests and the daily maximum temperatures were taken. For each sample, the total heat stress (ETT), defined as the cumulative number of degrees of the episodes of heat stress (at least two consecutive days with temperatures > 30 oC) happened during the grain filling period, was determined. Three levels of ETT were determined: low, medium and high. The grain protein (PTG), humid gluten (GH) and mixograph variables were measured. The analysis of variance and the Pearson correlation coefficient were performed. For medium and high levels of ETT, PTG, GH and mixograph peak height in all the samples decreased, while the mixograph dough development time (TDmix), to related with dough strength, diminished in 62% of the samples. This way, genotypes that possess tolerance to heat stress and the greater stability of dough quality were identified.
%K Trigo pan
%K Calidad panadera
%K Periodo de llenado del grano
%K Estr¨¦s t¨¦rmico
%K Sensibilidad al estr¨¦s t¨¦rmico
%K Bread wheat
%K Bread-making quality
%K Grain filling period
%K Heat stress
%K Heat sensibilit
%U http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1668-298X2008000200005