The effect of dehulling and thermal treatment on the protein fractions in soryz (Sorghum oryzoidum) grains

Abstract

Cereals have a major importance in maintaining a healthy and balanced diet, they are tasty, easily assimilated and cannot miss the daily diet. Diversifying the assortment of cereal products is very topical in the context of increasing food security. Sorghum Oryzoidum or soryz is a relatively new cereal of hybrid origin obtained at the Research Institute for Maize and Sorghum, Republic of Moldova with great possibilities for valorification in human alimentation. In the present paper are presented and analyzed theresults of the study of the content of fractional composition of proteins in whole grains and hulled soryz grains and the influence of hydrothermal treatment on soryz grains. The majority of protein fractions (determined by differential solubility in various solvents) of whole grains and hulled sorize is prolamins, followed by gluteline, globulins and albumins. Technological processes such as peeling, hydration and boiling did not significantlychange the prolamins content, unlike the rest of the fractions. Morepronounced changes following technological processes are observed inhydrosoluble fractions - albumins, some of which were removed withdecortication and hidration and boiling significantly diminished their solubility. Whole grains preliminary hidration and later boiling have more pronunced negative effects on albumins and glutelins content compared to boiled whole grains wihout hidration. When boiling the loss of albumins and glutelins was bigger at hulled soriz than at whole grains. This can be explained by a more intensive diffusion of soluble substances of hulled beans relation to soryz beans in as a result of removing the protective outer covering to obtain hulled soryz. The results have scientific value and may be useful for a deeper understanding of soryz technological properties.

Keywords

• soryz grains
• hulled soryz grains
• protein fractions
• hydrothermal treatment