Does Late Maturity Alpha-Amylase Impact Wheat Baking Quality?

Abstract

Late maturity α-amylase (LMA) and pre-harvest sprouting (PHS) are both recognized as environmentally induced grain quality defects resulting from abnormally high levels of α-amylase. LMA is a more recently identified quality issue that is now receiving increasing attention worldwide and whose prevalence is now seen as impeding the development of superior quality wheat varieties. LMA is a genetic defect present in specific wheat genotypes and is characterized by elevated levels of the high pI TaAMY1 α-amylase, triggered by environmental stress during wheat grain development. TaAMY1 remains present in the aleurone through the harvest, lowering Falling Number (FN) at receival, causing a down-grading of the grain, often to feed grade, thus reducing the farmers’ income. This downgrading is based on the assumption within the grain industry that, as for PHS, a low FN represents poor quality grain. Consequently any wheat line possessing low FN or high α-amylase levels is automatically considered a poor bread wheat despite there being no published evidence to date, to show that LMA is detrimental to end product quality. To evaluate the validity of this assumption a comprehensive evaluation of baking properties was performed from LMA prone lines using a subset of tall non-Rht lines from a multi-parent advanced generation inter-cross (MAGIC) wheat population grown at three different sites. LMA levels were determined along with quality parameters including end product functionality such as oven spring, bread loaf volume and weight, slice area and brightness, gas cell number and crumb firmness. No consistent or significant phenotypic correlation was found between LMA related FN and any of the quality traits. This manuscript provides for the first time, compelling evidence that LMA has limited impact on bread baking end product functionality.

How Foliar Fungal Diseases Affect Nitrogen Dynamics, Milling, and End-Use Quality of Wheat

“…The greater the amount of alphaamylase, the faster the stirrer will fall, determining low values of HFN. An additional cause for high alpha-amylase activity is late maturity alpha-amylase, which is a genetic defect existing in some genotypes related to rapid temperature change after flowering (Newberry et al, 2018).…”

Impacts of Starch and the Interactions Between Starch and Other Macromolecules on Wheat Falling Number

“…Marti, Cardone, Nicolodi, Quaglia, and Pagani () also reported that adding a small amount of sprouting wheat (less than 2%), which provided α‐amylase, improved bread volume and softness because starch hydrolysates are beneficial to yeast fermentation, which leads to enhanced bread baking quality (Marti et al., ). LMA‐affected wheat, with an increase of two to three times the hydrolytic activity compared with unaffected wheat, did not have a significantly negative impact on bread quality; although that wheat has reduced FNs (for example, 210 to 240 seconds) (Newberry et al., ).…”

Effects of cold temperature on starch molecular structure and gelatinization of late-maturity alpha-amylase affected wheat

“…At this time, no study has reported on any detrimental effects of LMA on end-product quality. The first comprehensive evaluation of LMA on bread quality (Newberry et al, 2018) reported a lack of correlation between bread baking traits, FN and LMA affected grain. These authors demonstrated that an elevated level of α-amylase in grains reduced the FN values of flour; however, no significant correlation was found between low LMA-FN and poor end-product quality, in terms of oven spring, loaf weight, loaf volume or any other quality parameters of breads processed using low and high FN wheat flours (ranging from 157 to 234 s, and from 250 to 300 s respectively).…”