Analytical methods
Sweet sorghum stalks contained sugars primarily in the form of
sucrose, glucose and fructose. Glucose was determined enzymatically with a glucose oxidase-chromogen reagent (ShandongUniversity). Sorghum sucrose was hydrolysed in 1.2 N HCl for
7 min at 60 °C and neutralized with 1 N NaOH prior to its
determination by the method of reducing sugars. Reducing
sugar was determined using the 3,5-dinitrosalicylic acid (DNS)
method [14,15]. The moisture content of sweet sorghum stalks
was determined after drying and measuring the weight before
and after the drying procedure. The ethanol content was
measured by using Shimadzu GC-2050 gas chromatography
with cbp-20 capillary column and a flame ionization detector.
The chromatogram was run at 180 °C oven temperature and
90 °C injection temperature using N2 as a carrier gas and H2 as a
flaming gas.