Characterization of Sorghum and Millet with Special Reference to Fatty Acid and Volatile Profile.

Abstract

Sorghum and millet are important food staples in semi-arid tropics of Asia and Africa. Sorghum and millet are cereal grains that have prospective to be used as substitute to wheat flour for celiac patients. These are considered as the good source of many important and essential fatty acids. The volatile profiling of these two important crops is comparable to other cereals as well. The present study was an effort to explore biochemical composition of commercially available sorghum and millet varieties with special reference to their fatty acid and volatile profiling. Chemical composition of sorghum and millet was determined according to respective methods. Fatty acid methyl esters were prepared and then subjected to GC-FID for fatty acids analysis. The results indicated that both sorghum and millet oils are rich in essential fatty acids comprising mono and polyunsaturated fatty acids. Main fatty acids that are identified in current study includes palmitic acid, oleic acid, palmitoleic acid, behenic acid, linoleic acid, linoleic acid, stearic acid, myristic acid, etc. On the other hand volatile compounds from sorghum and millet were determined by preparing their respective volatile samples by using calvenger apparatus with suitable volatile extracting solvent. Volatile samples were then subjected to GC-MS analysis and respected results were compared with NIST library. About 30 different volatiles were identified in millet varieties while 35 different compounds were discovered in sorghum varieties belonging to aldehydes, ketones, benzene derivatives, esters, alcohols, sulphur compounds.

Comparison of the phenolic contents, antioxidant activity and volatile compounds of different sorghum varieties during tea processing

“…Alcohols including 1‐octanol ( 13 ), 1‐nonanol ( 25 ), phenylethyl alcohol ( 19 ), 3,7‐dimethyl‐1,6‐octadien‐3‐ol ( 17 ) and 1‐hexanol ( 1 ) were found in all sorghum varieties. In previous studies 1‐octanol ( 13 ), 1‐nonanol ( 25 ) and 1‐hexanol ( 1 ) were reported in seven commercial sorghum; and 1‐octanol ( 13 ) was also found in both fragrant (E228) and non‐fragrant (M35‐1) sorghum …”

“…Esters usually have high odour threshold values, and they do not make a significant contribution to the overall aroma in some foods but they are important volatile compounds found in fermented foods such as soy source . However, none of these ester compounds was reported in previous studies of sorghum volatile compounds …”

“…Alkanes are responsible for unpleasant waxy and gasoline‐like odour, but often have low odour intensity and high odour threshold values; and they have less sensory significance than alcohols . Dodecane ( 28 ) and tridecane ( 46 ) were previously reported in Chengari, F‐114, JS‐263, JS‐2002, MR‐Sorghum, PC‐1 and Sandal Bar sorghum varieties; while tridecane ( 46 ) was only found in fragrant (E228) sorghum, and tetradecane ( 54 ) and pentadecane ( 59 ) were reported in both fragrant (E228) and non‐fragrant (M35‐1) sorghum …”

“…The aldehyde nonanal ( 18 ) was found in all sorghum. Nonanal ( 18 ) has been widely found in many sorghums including Serena cultivar; both fragrant (E228) and non‐fragrant (M35‐1) sorghum; and Chengari, F‐114, JS‐263, JS‐2002, MR‐Sorghum, PC‐1 and Sandal Bar sorghum varieties . These compounds are products of lipid oxidation, and responsible for the off‐flavour and deterioration .…”

Effects of different distillation patterns on main compounds of ChineseLuzhou-flavour raw liquors

“…Meanwhile, the concentration of hexyl acetate decreased significantly in the AG pattern in contrast with NG. These results suggested that esterifying and extraction were more effective in the AG pattern since some ester constituents such as propyl benzoate, ethyl acetate and propyl acetate were identified in sorghum (13).…”