Chemical characteristics and nutritive value of various rye hybrids

Rye (Secale cereale L.) belongs like wheat to basic bread-stuffs, and it participates in total production of cereals with 3% only. We evaluate in this contribution nutritive value of 3 German rye hybrids grown in 4 different localities of Slovakia (OSIVO, joint-stock company Zvolen). Results of analyses of the tested hybrids Fernando, Picaso and Esprit show significant differences in chemical composition among hybrids as well as among localities (P less than 0.05). Their variability results from influences of environment and more marked effect have agro-ecological conditions during the vegetation than the variety. Fernando from the locality Dobra Niva has markedly the highest amount crude protein and lowest content of starch (P less than 0.001). Content of energy and content and quality of a protein, which is higher, compared with wheat, are decisive for the nutritional value. Corn of rye contains in general less starch and proteins than wheat but more fibre and sugars. Rye is the richest cereal in sugar (73g/kg d.m.). Average content of ME was 13.6 MJ ME. Rye shows the lowest content of proteins out of all cereals but their fractional analysis confirms higher content of fractions of good nutritional quality. Content of protoplasmic proteins reaches up to 40% out of total amount of proteins, and it conditions also higher concentration of lysine. Higher content of crude protein is not always attended by higher content of proteins; it is supported by results of the hybrid Fernando (64% proteins only). Higher content of crude protein had negative impact on fraction of albumins and globulins (decrease by 3.5%). Prolamin proteins in rye are called secalins and they belong together with gluteinic ones to typical storage proteins and accumulate in endosperm. Endosperm creates approximately 80% portion of dry matter of corn and its composition is decisive for resulting quality of corn. Lower portion of the mentioned fractions in hybrid Picaso becomes evident also in lower content of amino acids that characterize this fraction. Mainly the glutamic acid and proline are involved. On the contrtary, the highest content was in hybrid Fernando from the locality Dobra Niva with higher portion of prolamins and gluteins, and the portion of albumins and globulins lower. Biological test with rats showed that the quality of proteins in rye is higher than in wheat; it is confirmed also by higher values of BVP, NPU and UP.