# Characterization of Sorghum Processed through Dry Heat Treatment and Milling
###### Abstract  
Sorghum grain nutritional quality can be enhanced by applying dry heat treatments. The purpose of this study was to investigate the effects of dry heat treatment at two temperatures (121 and 140 \({}^{\circ}\)C) with three fractionation factors (S fraction < 200 \(\upmu\)m, M fraction 200-250 \(\upmu\)m and, L fraction > 300 \(\upmu\)m) on sorghum flour chemical and functional properties, to optimize processes by means of a desirability function, and to characterize the optimal products. Treatment temperature negatively affected oil- and water-absorption capacity, protein and moisture contents, while the opposite trend was obtained for hydration capacity, swelling power, emulsifying properties, fat, ash, and carbohydrate content. Sorghum flour fractions positively influenced the hydration and water-retention capacities, emulsifying properties, and protein and carbohydrate content, while oil absorption, swelling power, fat, ash, and moisture were negatively affected. The optimal processing determined for each fraction was heat treatment at 121.00 \({}^{\circ}\)C for S fraction, 132.11 \({}^{\circ}\)C for M, and 139.47 \({}^{\circ}\)C for L. Optimal product characterization revealed that the color, bioactive properties, and protein and starch structures of the optimal samples had changed after heat treatment, depending on the fraction. These findings could be helpful for the cereal industry, since sorghum flour could be an alternative for conventional crops for the development of new products, such as snacks, baked goods, and pasta. s +
Footnote †: journal: Applied sciences  
1 Faculty of Food Engineering, \"Stefan cel Mare\" University of Suceava, 13 Universitatti Street, 720229 Suceava, Romania; [EMAIL_ADDRESS]  
1 Faculty of Food Engineering, \"Stefan cel Mare\" University of Suceava, 13 Universitatti Street, 720229 Suceava, Romania; ana. Sorghum grain chemical composition (Table 1) is influenced by genetic and environmental factors. A significant and inverse correlation has been observed for protein with grain weight and starch content, while the ash content was positively correlated with protein content [9]. The main carbohydrates found in sorghum grains are starch, soluble sugar, and fiber. Sorghum is a rich source of slowly digestible starch (SDS), which is beneficial for the digestion and intestinal absorption of carbohydrates in intestine, while the raised amount of dietary fiber (9.7-14.3 g) contributes to digestion enhancement and carbohydrate and cholesterol metabolization [9; 10]. Sorghum grain contains low amounts of fat, which is mainly found in the scutellar zone of the germ [9]. [PERSON] et al. [10] reported that sorghum grain contains compounds that could be introduced in foods or dietary supplements to regulate cholesterol levels. Sorghum is rich in minerals and vitamins, which are mainly found in the aleurone coating and germ, being an important fount of B vitamins, except for vitamin B\({}_{12}\)[11]. The main structural components of sorghum grain are the pericarp, germ, and endosperm (Figure 2). Sorghum grains are of the caryopsis type, with the pericarp fully merged with the endosperm. Component weights are pericarp 6%, endosperm 84%, and germ 10% [9]. Sorghum grain processing implies the partial removal and/or change of the three most important components (germ, endosperm, and pericarp), some of the techniques applied being decoritation, malting, fermentation, roasting, flaking, and grinding [9].