The accumulation of phytic acid with relation to the deposition of the protein component in grain during maturation of three maize varieties grown under the same topographical and agrotechnical conditions over 2 crop years was investigated. Phytic acid was determined by the spectrophotometric method of Mohamed et al. (1986). Phytic acid content increased significantly (P = 0.05) up until the late stage of dough grain maturity. Afterwards, until full grain maturity, no significant changes of phytic acid content have been obtained. At the same time, changes of phytic acid content expressed on a dry matter basis correlate highly significantly (P = 0.001) and negatively with total nitrogen in both vegetation years (r = ‐0.848 and r = ‐0.845) and alpha‐aminonitrogen content (r=‐0.799 and r = ‐0.792), but highly significantly (P = 0.001) and positively with prolamine content (r = 0.823 and 0.654). Grain maturation under conditions of increased moisture and lower temperature resulted in lower phytic acid level.

A comparative investigation of the changes in available lysine content during industrial production of two dietetic hard biscuits based on whole grain wheat flour/grits and a standard hard biscuit based on white wheat flour was performed. Dough preparation did not significantly affect the available lysine content. However, after baking, a significant loss (27-47%) of available lysine was found in all three types of biscuit. The average relative decrease in available lysine in proteins of each type of biscuit correlated highly significantly with technological parameters, mainly with the interaction between baking temperature and baking time (r = 0.980, p = 0.001). Physical characteristics of the biscuits, such as thickness, surface area, weight and density, also contributed considerably to the extent of damage to available lysine. The two dietetic biscuits were characterised by a higher available lysine content than the standard biscuit, and accordingly by a higher protein nutritive quality, with average chemical scores (calculated for adults) of 97 and 105 as against 60 for the standard biscuit. Storage for a long time (1 year) had no significant influence on the chemical scores.

New criteria for the evaluation of wheat qualitative properties are worked out on the basis of the study of the shape and size of the extensographic curves. Approximating the experimental curvesextensogramsto the theoretical curves which are the closest to them in their shape and equal to them in their area, it also was possible to determine their shape parameters. The theoretical curve is an ellipse inscribed over the shape of the experimental curve. It changes its shape to the case when the ellipse eccentricity becomes equal to zero and further when x-axis and y-axis exchange their places in the coordinate system. It has been determined that the extensogram area can be the best means of measuring the wheat flour quality if it has been evaluated with reference to the curve circumference which circumscribes it. The ratio of the parameters of the theoretical curve maximum (mt) and the maximum of the theoretical curve of the ideal shape (r) is the basis for the extensogram evaluation and their classification into the qualitative range. The quantitative data of the ratio mdr indicate the shape, and the values for r indicate the extensogram size. On the basis of the expression (m&-l)lOO, it is possible to evaluate accurately the extensographic curves for the first time as well as to classify wheat into the qualitative range.

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