Bakery properties of spelt wheat grain depending on fertilization and storage period

Abstract

The article presents the study results of spelt wheat grain baking properties depending on fertilization and storage period. Europe (huskless) winter spelt wheat variety obtained by hybridization of Triticum aestivum L./Triticum spelta L. was studied. For fertilization, ammonium nitrate, ammonium sulfate, granular superphosphate, potassium chloride were used. Spelt wheat grain was stored for a year without air access at an unregulated temperature regime dry (moisture content during storage – 13.0–13.5 %) in airtight polyethylene sleeves in the conditions of usual storage. It was found that spelt wheat has a high response to the application of nitrogen fertilizers. The protein content increased from 18.6 to 22.8 % in P60K60 + N120 variant. The spelt wheat grain quality varied depending on the storage period. Thus, before storage, the gluten content was 41.1–50.4 % depending on the fertilizer variant. The lowest indicator was in the control variant and for P60K60 introduction – 41.1–41.2 %. In other fertilizer variants, the gluten content was at the level of 49.1–49.9 %. The largest was in P60K60 + N60S70 + N60 –50.4 % variant or 9 % compared to the control. Storage had a positive effect on the gluten content in spelt wheat grain as its content increased signifcantly. It can be explained by the post-harvest grain ripening, in the process of which the protein-proteinase complex changes due to the oxidizing action, oxygen, in particular. Thus, after storage for 30 days, this indicator was 41.8–52.1 % depending on the experiment variant. It was the largest when N60S70 + N60 was applied – 52.1 %, and the smallest in the variant with no fertilizers and with phosphorus-potassium (P60K60) fertilizer – 41.8–42.3 %. These indicators exceeded the gluten content before storage by an average of 1.2 abs. %. The content of protein and gluten-forming fractions is the highest after storage for 90 days. These indicators almost did not change after 180–270 days of storage. After 360 days they decreased to the grain quality indicators before storage. The gluten deformation index increased to 105–108 units of GSI instrument or by 4–8 % depending on the fertilization compared to fresh grain. Gluten moisture content decreased after 30 days of grain storage, and then increased to 68.0–69.8 % after 360 days, depending on the experiment variant. The grain acidity also increased from 3.0 to 4.0–4.1 degrees. Key words: spelt wheat, fertilization, storage, protein, gluten, dynamics, moisture content, acidity.