Quality improvement of wholegrain wheat flours (QUALIFLOUR)

• Forschungsstelle: BLW
• Projektnummer: 14.11
• Projekttitel Englisch: Quality improvement of wholegrain wheat flours (QUALIFLOUR)

Schlüsselwörter (Deutsch)

Weizen, Weizenmehl, Qualitätsverbesserung, Weizensorten

Schlüsselwörter (Englisch)

wheat flours, quality improvement, wheat varieties

Schlüsselwörter (Französisch)

farine de blé, amélioration de la qualité, variétés de blé

Kurzbeschreibung (Englisch)

Commonly cultivated wheat varieties and their suitability for milling, baking and other food processes have been evaluated from the perspective of standard wheat flour production. Currently, however, the use of wholegrain wheat is very much supported through the health benefits associated to higher intake of dietary fibre and associated phytochemicals. Wholegrain wheat products encounter serious stability challenges leading to rancidity and thereby decreased nutritional, technological and sensory quality. This project will offer the first steps for evaluation of wheat varieties from the perspective of wholegrain end use. We will evaluate approximately 200 wheat varieties from two growth years for the two main factors that are counteracting during storage of wholegrain flours, namely activity of lipase enzyme that hydrolyses lipids, and the content of endogenous antioxidants that may inhibit lipid autoxidation reactions. These phenotypic data will be further evaluated using a genetic association approach, utilizing the already existing genomic data of the same varieties. Furthermore, we will evaluate the relative importance of the two reaction pathways leading to rancidity, thereby offering tools for variety selection for cultivation and improved and more efficient use of wheat grains as food raw materials.

Projektziele (Englisch)

The overall goal of the project is to improve the quality of wholegrain wheat products by addressing
the challenges caused by storage instability and resulting decreases in technological, nutritional and sensory quality parameters. The projects centers on evaluating wheat varieties with the emphasis on factors that affect lipid instability, namely lipase activity and levels of endogenous antioxidants as pushing and pulling factors, respectively.

The study has three main aims:

1) Study the heritability of lipase in wheat varieties. We hypothesize that lipase activity in grains is to a part genetically controlled, and therefore could be decreased in grains by cultivating low-lipase varieties.

2) Examine the milling behaviour of wheat grains and the shelf life stability of resulting wholegrain wheat flour, differentiating the hydrolytic rancidity from oxidative instability. The goal of this aim is to assess the differences in milling behaviour of various wheat varieties and to demonstrate the negative correlation between lipase activity and shelf life of wholegrain wheat flours (the higher the activity, the lower the stability).

3) Establish dependencies between shelf life stability, endogenous antioxidants, and enzymatic vs. oxidative rancidity. The working hypothesis is that the role of oxidative instability can differentiated from enzymatic instability by studying the formation of radicals during storage, thus allowing the differentiation and proportional input of these two reactions in wholegrain instability. This will further allow to decide to what extent controlling lipase activity can be compensated by using varieties with high antioxidant contents.

Abstract (Deutsch)

Wholegrain wheat products encounter serious stability challenges, due to lipid rancidity caused by endogenous lipase. This study evaluated more than 300 European winter wheat varieties grown over 3 years from the perspective of wholegrain wheat flour production. Hydrolytic enzyme activities, lipid content, endogenous antioxidant profiles, lipid stability, milling performance, dough properties and gluten content were analyzed. Significant variance was observed among different varieties, indicating large genetic diversity. Heritability of esterase and lipase activities were calculated. Several lipase genes candidates were identified by genetic association. The results are the first steps for evaluation of wheat varieties for wholegrain end use. The study offers tools for cultivation selection and will improve the efficiency of wheat grain as food raw materials.

Publikationen / Ergebnisse (Englisch)

Wholegrain wheat products encounter serious stability challenges, due to lipid rancidity caused by endogenous lipase. This study evaluated more than 300 European winter wheat varieties grown over 3 years from the perspective of wholegrain wheat flour production. Hydrolytic enzyme activities, lipid content, endogenous antioxidant profiles, lipid stability, milling performance, dough properties and gluten content were analyzed. Significant variance was observed among different varieties, indicating large genetic diversity. Heritability of esterase and lipase activities were calculated. Several lipase genes candidates were identified by genetic association. The results are the first steps for evaluation of wheat varieties for wholegrain end use. The study offers tools for cultivation selection and will improve the efficiency of wheat grain as food raw materials.