Influence of variety and year of wheat cultivation on the chemical composition of starch and properties of glucose hydrolysates

The effect of chemical composition of starch samples derived from selected wheat cultivars harvested in different years (lipid content, amylose–lipid complex (AML) content, amylose concentration and the degree of starch damage) on physicochemical properties of glucose syrups produced from these starches was determined. It was found that glucose syrups obtained from the same wheat cultivar but harvested in different years displayed different physicochemical attributes such as concentration of reducing compounds, rate of filtration and coefficients of colour and transparency. Besides, the analyses showed that AML changed their form from amorphous to crystalline during enzymatic starch liquefaction by α-amylase. This in turn rendered starch less susceptible to enzymatic digestion and affected physicochemical features of glucose syrups. Presented results provide evidence that not only the total concentration of lipids and AML but also the AML polymorph present in starch hydrolysates (on completion of starch liquefaction) have an impact on quality of glucose syrups.

► Environmental conditions during growth of wheat influence the content of lipids and AML complexes in starch.
► The presence of AML complexes decrease filtration rate and DE of glucose hydrolysates.
► During starch liquefaction with α-amylase change of polymorphic form of AML complexes occur.
► AML complexes present in a crystalline form decrease susceptibility of starch to enzymatic degradation.